From 82e9697250977f3f87cd42e71e8daa8810e64520 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Fri, 4 May 2018 14:49:50 -0700 Subject: bpf: btf: Avoid WARN_ON when CONFIG_REFCOUNT_FULL=y If CONFIG_REFCOUNT_FULL=y, refcount_inc() WARN when refcount is 0. When creating a new btf, the initial btf->refcnt is 0 and triggered the following: [ 34.855452] refcount_t: increment on 0; use-after-free. [ 34.856252] WARNING: CPU: 6 PID: 1857 at lib/refcount.c:153 refcount_inc+0x26/0x30 .... [ 34.868809] Call Trace: [ 34.869168] btf_new_fd+0x1af6/0x24d0 [ 34.869645] ? btf_type_seq_show+0x200/0x200 [ 34.870212] ? lock_acquire+0x3b0/0x3b0 [ 34.870726] ? security_capable+0x54/0x90 [ 34.871247] __x64_sys_bpf+0x1b2/0x310 [ 34.871761] ? __ia32_sys_bpf+0x310/0x310 [ 34.872285] ? bad_area_access_error+0x310/0x310 [ 34.872894] do_syscall_64+0x95/0x3f0 This patch uses refcount_set() instead. Reported-by: Yonghong Song Tested-by: Yonghong Song Signed-off-by: Martin KaFai Lau Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- kernel/bpf/btf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 22e1046a1a86..fa0dce0452e7 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -1977,7 +1977,7 @@ static struct btf *btf_parse(void __user *btf_data, u32 btf_data_size, if (!err) { btf_verifier_env_free(env); - btf_get(btf); + refcount_set(&btf->refcnt, 1); return btf; } -- cgit v1.2.3 From 78958fca7ead2f81b60a6827881c4866d1ed0c52 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Fri, 4 May 2018 14:49:51 -0700 Subject: bpf: btf: Introduce BTF ID This patch gives an ID to each loaded BTF. The ID is allocated by the idr like the existing prog-id and map-id. The bpf_put(map->btf) is moved to __bpf_map_put() so that the userspace can stop seeing the BTF ID ASAP when the last BTF refcnt is gone. It also makes BTF accessible from userspace through the 1. new BPF_BTF_GET_FD_BY_ID command. It is limited to CAP_SYS_ADMIN which is inline with the BPF_BTF_LOAD cmd and the existing BPF_[MAP|PROG]_GET_FD_BY_ID cmd. 2. new btf_id (and btf_key_id + btf_value_id) in "struct bpf_map_info" Once the BTF ID handler is accessible from userspace, freeing a BTF object has to go through a rcu period. The BPF_BTF_GET_FD_BY_ID cmd can then be done under a rcu_read_lock() instead of taking spin_lock. [Note: A similar rcu usage can be done to the existing bpf_prog_get_fd_by_id() in a follow up patch] When processing the BPF_BTF_GET_FD_BY_ID cmd, refcount_inc_not_zero() is needed because the BTF object could be already in the rcu dead row . btf_get() is removed since its usage is currently limited to btf.c alone. refcount_inc() is used directly instead. Signed-off-by: Martin KaFai Lau Acked-by: Alexei Starovoitov Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- include/linux/btf.h | 2 + include/uapi/linux/bpf.h | 5 +++ kernel/bpf/btf.c | 108 ++++++++++++++++++++++++++++++++++++++++++----- kernel/bpf/syscall.c | 24 ++++++++++- 4 files changed, 128 insertions(+), 11 deletions(-) diff --git a/include/linux/btf.h b/include/linux/btf.h index a966dc6d61ee..e076c4697049 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -44,5 +44,7 @@ const struct btf_type *btf_type_id_size(const struct btf *btf, u32 *ret_size); void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj, struct seq_file *m); +int btf_get_fd_by_id(u32 id); +u32 btf_id(const struct btf *btf); #endif diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 93d5a4eeec2a..6106f23a9a8a 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -96,6 +96,7 @@ enum bpf_cmd { BPF_PROG_QUERY, BPF_RAW_TRACEPOINT_OPEN, BPF_BTF_LOAD, + BPF_BTF_GET_FD_BY_ID, }; enum bpf_map_type { @@ -344,6 +345,7 @@ union bpf_attr { __u32 start_id; __u32 prog_id; __u32 map_id; + __u32 btf_id; }; __u32 next_id; __u32 open_flags; @@ -2130,6 +2132,9 @@ struct bpf_map_info { __u32 ifindex; __u64 netns_dev; __u64 netns_ino; + __u32 btf_id; + __u32 btf_key_id; + __u32 btf_value_id; } __attribute__((aligned(8))); /* User bpf_sock_addr struct to access socket fields and sockaddr struct passed diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index fa0dce0452e7..40950b6bf395 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include @@ -179,6 +180,9 @@ i < btf_type_vlen(struct_type); \ i++, member++) +static DEFINE_IDR(btf_idr); +static DEFINE_SPINLOCK(btf_idr_lock); + struct btf { union { struct btf_header *hdr; @@ -193,6 +197,8 @@ struct btf { u32 types_size; u32 data_size; refcount_t refcnt; + u32 id; + struct rcu_head rcu; }; enum verifier_phase { @@ -598,6 +604,42 @@ static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t) return 0; } +static int btf_alloc_id(struct btf *btf) +{ + int id; + + idr_preload(GFP_KERNEL); + spin_lock_bh(&btf_idr_lock); + id = idr_alloc_cyclic(&btf_idr, btf, 1, INT_MAX, GFP_ATOMIC); + if (id > 0) + btf->id = id; + spin_unlock_bh(&btf_idr_lock); + idr_preload_end(); + + if (WARN_ON_ONCE(!id)) + return -ENOSPC; + + return id > 0 ? 0 : id; +} + +static void btf_free_id(struct btf *btf) +{ + unsigned long flags; + + /* + * In map-in-map, calling map_delete_elem() on outer + * map will call bpf_map_put on the inner map. + * It will then eventually call btf_free_id() + * on the inner map. Some of the map_delete_elem() + * implementation may have irq disabled, so + * we need to use the _irqsave() version instead + * of the _bh() version. + */ + spin_lock_irqsave(&btf_idr_lock, flags); + idr_remove(&btf_idr, btf->id); + spin_unlock_irqrestore(&btf_idr_lock, flags); +} + static void btf_free(struct btf *btf) { kvfree(btf->types); @@ -607,15 +649,19 @@ static void btf_free(struct btf *btf) kfree(btf); } -static void btf_get(struct btf *btf) +static void btf_free_rcu(struct rcu_head *rcu) { - refcount_inc(&btf->refcnt); + struct btf *btf = container_of(rcu, struct btf, rcu); + + btf_free(btf); } void btf_put(struct btf *btf) { - if (btf && refcount_dec_and_test(&btf->refcnt)) - btf_free(btf); + if (btf && refcount_dec_and_test(&btf->refcnt)) { + btf_free_id(btf); + call_rcu(&btf->rcu, btf_free_rcu); + } } static int env_resolve_init(struct btf_verifier_env *env) @@ -2006,10 +2052,15 @@ const struct file_operations btf_fops = { .release = btf_release, }; +static int __btf_new_fd(struct btf *btf) +{ + return anon_inode_getfd("btf", &btf_fops, btf, O_RDONLY | O_CLOEXEC); +} + int btf_new_fd(const union bpf_attr *attr) { struct btf *btf; - int fd; + int ret; btf = btf_parse(u64_to_user_ptr(attr->btf), attr->btf_size, attr->btf_log_level, @@ -2018,12 +2069,23 @@ int btf_new_fd(const union bpf_attr *attr) if (IS_ERR(btf)) return PTR_ERR(btf); - fd = anon_inode_getfd("btf", &btf_fops, btf, - O_RDONLY | O_CLOEXEC); - if (fd < 0) + ret = btf_alloc_id(btf); + if (ret) { + btf_free(btf); + return ret; + } + + /* + * The BTF ID is published to the userspace. + * All BTF free must go through call_rcu() from + * now on (i.e. free by calling btf_put()). + */ + + ret = __btf_new_fd(btf); + if (ret < 0) btf_put(btf); - return fd; + return ret; } struct btf *btf_get_by_fd(int fd) @@ -2042,7 +2104,7 @@ struct btf *btf_get_by_fd(int fd) } btf = f.file->private_data; - btf_get(btf); + refcount_inc(&btf->refcnt); fdput(f); return btf; @@ -2062,3 +2124,29 @@ int btf_get_info_by_fd(const struct btf *btf, return 0; } + +int btf_get_fd_by_id(u32 id) +{ + struct btf *btf; + int fd; + + rcu_read_lock(); + btf = idr_find(&btf_idr, id); + if (!btf || !refcount_inc_not_zero(&btf->refcnt)) + btf = ERR_PTR(-ENOENT); + rcu_read_unlock(); + + if (IS_ERR(btf)) + return PTR_ERR(btf); + + fd = __btf_new_fd(btf); + if (fd < 0) + btf_put(btf); + + return fd; +} + +u32 btf_id(const struct btf *btf) +{ + return btf->id; +} diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 9b87198deea2..31c4092da277 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -252,7 +252,6 @@ static void bpf_map_free_deferred(struct work_struct *work) bpf_map_uncharge_memlock(map); security_bpf_map_free(map); - btf_put(map->btf); /* implementation dependent freeing */ map->ops->map_free(map); } @@ -273,6 +272,7 @@ static void __bpf_map_put(struct bpf_map *map, bool do_idr_lock) if (atomic_dec_and_test(&map->refcnt)) { /* bpf_map_free_id() must be called first */ bpf_map_free_id(map, do_idr_lock); + btf_put(map->btf); INIT_WORK(&map->work, bpf_map_free_deferred); schedule_work(&map->work); } @@ -2002,6 +2002,12 @@ static int bpf_map_get_info_by_fd(struct bpf_map *map, info.map_flags = map->map_flags; memcpy(info.name, map->name, sizeof(map->name)); + if (map->btf) { + info.btf_id = btf_id(map->btf); + info.btf_key_id = map->btf_key_id; + info.btf_value_id = map->btf_value_id; + } + if (bpf_map_is_dev_bound(map)) { err = bpf_map_offload_info_fill(&info, map); if (err) @@ -2059,6 +2065,19 @@ static int bpf_btf_load(const union bpf_attr *attr) return btf_new_fd(attr); } +#define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id + +static int bpf_btf_get_fd_by_id(const union bpf_attr *attr) +{ + if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID)) + return -EINVAL; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + return btf_get_fd_by_id(attr->btf_id); +} + SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size) { union bpf_attr attr = {}; @@ -2142,6 +2161,9 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz case BPF_BTF_LOAD: err = bpf_btf_load(&attr); break; + case BPF_BTF_GET_FD_BY_ID: + err = bpf_btf_get_fd_by_id(&attr); + break; default: err = -EINVAL; break; -- cgit v1.2.3 From 62dab84c81a487d946a5fc37c6df541dd95cca38 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Fri, 4 May 2018 14:49:52 -0700 Subject: bpf: btf: Add struct bpf_btf_info During BPF_OBJ_GET_INFO_BY_FD on a btf_fd, the current bpf_attr's info.info is directly filled with the BTF binary data. It is not extensible. In this case, we want to add BTF ID. This patch adds "struct bpf_btf_info" which has the BTF ID as one of its member. The BTF binary data itself is exposed through the "btf" and "btf_size" members. Signed-off-by: Martin KaFai Lau Acked-by: Alexei Starovoitov Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- include/uapi/linux/bpf.h | 6 ++++++ kernel/bpf/btf.c | 26 +++++++++++++++++++++----- kernel/bpf/syscall.c | 17 ++++++++++++++++- 3 files changed, 43 insertions(+), 6 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 6106f23a9a8a..d615c777b573 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -2137,6 +2137,12 @@ struct bpf_map_info { __u32 btf_value_id; } __attribute__((aligned(8))); +struct bpf_btf_info { + __aligned_u64 btf; + __u32 btf_size; + __u32 id; +} __attribute__((aligned(8))); + /* User bpf_sock_addr struct to access socket fields and sockaddr struct passed * by user and intended to be used by socket (e.g. to bind to, depends on * attach attach type). diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 40950b6bf395..ded10ab47b8a 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -2114,12 +2114,28 @@ int btf_get_info_by_fd(const struct btf *btf, const union bpf_attr *attr, union bpf_attr __user *uattr) { - void __user *udata = u64_to_user_ptr(attr->info.info); - u32 copy_len = min_t(u32, btf->data_size, - attr->info.info_len); + struct bpf_btf_info __user *uinfo; + struct bpf_btf_info info = {}; + u32 info_copy, btf_copy; + void __user *ubtf; + u32 uinfo_len; - if (copy_to_user(udata, btf->data, copy_len) || - put_user(btf->data_size, &uattr->info.info_len)) + uinfo = u64_to_user_ptr(attr->info.info); + uinfo_len = attr->info.info_len; + + info_copy = min_t(u32, uinfo_len, sizeof(info)); + if (copy_from_user(&info, uinfo, info_copy)) + return -EFAULT; + + info.id = btf->id; + ubtf = u64_to_user_ptr(info.btf); + btf_copy = min_t(u32, btf->data_size, info.btf_size); + if (copy_to_user(ubtf, btf->data, btf_copy)) + return -EFAULT; + info.btf_size = btf->data_size; + + if (copy_to_user(uinfo, &info, info_copy) || + put_user(info_copy, &uattr->info.info_len)) return -EFAULT; return 0; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 31c4092da277..e2aeb5e89f44 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2021,6 +2021,21 @@ static int bpf_map_get_info_by_fd(struct bpf_map *map, return 0; } +static int bpf_btf_get_info_by_fd(struct btf *btf, + const union bpf_attr *attr, + union bpf_attr __user *uattr) +{ + struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info); + u32 info_len = attr->info.info_len; + int err; + + err = check_uarg_tail_zero(uinfo, sizeof(*uinfo), info_len); + if (err) + return err; + + return btf_get_info_by_fd(btf, attr, uattr); +} + #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info static int bpf_obj_get_info_by_fd(const union bpf_attr *attr, @@ -2044,7 +2059,7 @@ static int bpf_obj_get_info_by_fd(const union bpf_attr *attr, err = bpf_map_get_info_by_fd(f.file->private_data, attr, uattr); else if (f.file->f_op == &btf_fops) - err = btf_get_info_by_fd(f.file->private_data, attr, uattr); + err = bpf_btf_get_info_by_fd(f.file->private_data, attr, uattr); else err = -EINVAL; -- cgit v1.2.3 From e34d98d3b4e2e3edcaebb68b1fad564af68f2b73 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Fri, 4 May 2018 14:49:53 -0700 Subject: bpf: btf: Some test_btf clean up This patch adds a CHECK() macro for condition checking and error report purpose. Something similar to test_progs.c It also counts the number of tests passed/skipped/failed and print them at the end of the test run. Signed-off-by: Martin KaFai Lau Acked-by: Alexei Starovoitov Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/test_btf.c | 201 ++++++++++++++++----------------- 1 file changed, 99 insertions(+), 102 deletions(-) diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c index 7b39b1f712a1..b7880a20fad1 100644 --- a/tools/testing/selftests/bpf/test_btf.c +++ b/tools/testing/selftests/bpf/test_btf.c @@ -20,6 +20,30 @@ #include "bpf_rlimit.h" +static uint32_t pass_cnt; +static uint32_t error_cnt; +static uint32_t skip_cnt; + +#define CHECK(condition, format...) ({ \ + int __ret = !!(condition); \ + if (__ret) { \ + fprintf(stderr, "%s:%d:FAIL ", __func__, __LINE__); \ + fprintf(stderr, format); \ + } \ + __ret; \ +}) + +static int count_result(int err) +{ + if (err) + error_cnt++; + else + pass_cnt++; + + fprintf(stderr, "\n"); + return err; +} + #define min(a, b) ((a) < (b) ? (a) : (b)) #define __printf(a, b) __attribute__((format(printf, a, b))) @@ -894,17 +918,13 @@ static void *btf_raw_create(const struct btf_header *hdr, void *raw_btf; type_sec_size = get_type_sec_size(raw_types); - if (type_sec_size < 0) { - fprintf(stderr, "Cannot get nr_raw_types\n"); + if (CHECK(type_sec_size < 0, "Cannot get nr_raw_types")) return NULL; - } size_needed = sizeof(*hdr) + type_sec_size + str_sec_size; raw_btf = malloc(size_needed); - if (!raw_btf) { - fprintf(stderr, "Cannot allocate memory for raw_btf\n"); + if (CHECK(!raw_btf, "Cannot allocate memory for raw_btf")) return NULL; - } /* Copy header */ memcpy(raw_btf, hdr, sizeof(*hdr)); @@ -915,8 +935,7 @@ static void *btf_raw_create(const struct btf_header *hdr, for (i = 0; i < type_sec_size / sizeof(raw_types[0]); i++) { if (raw_types[i] == NAME_TBD) { next_str = get_next_str(next_str, end_str); - if (!next_str) { - fprintf(stderr, "Error in getting next_str\n"); + if (CHECK(!next_str, "Error in getting next_str")) { free(raw_btf); return NULL; } @@ -973,9 +992,8 @@ static int do_test_raw(unsigned int test_num) free(raw_btf); err = ((btf_fd == -1) != test->btf_load_err); - if (err) - fprintf(stderr, "btf_load_err:%d btf_fd:%d\n", - test->btf_load_err, btf_fd); + CHECK(err, "btf_fd:%d test->btf_load_err:%u", + btf_fd, test->btf_load_err); if (err || btf_fd == -1) goto done; @@ -992,16 +1010,15 @@ static int do_test_raw(unsigned int test_num) map_fd = bpf_create_map_xattr(&create_attr); err = ((map_fd == -1) != test->map_create_err); - if (err) - fprintf(stderr, "map_create_err:%d map_fd:%d\n", - test->map_create_err, map_fd); + CHECK(err, "map_fd:%d test->map_create_err:%u", + map_fd, test->map_create_err); done: if (!err) - fprintf(stderr, "OK\n"); + fprintf(stderr, "OK"); if (*btf_log_buf && (err || args.always_log)) - fprintf(stderr, "%s\n", btf_log_buf); + fprintf(stderr, "\n%s", btf_log_buf); if (btf_fd != -1) close(btf_fd); @@ -1017,10 +1034,10 @@ static int test_raw(void) int err = 0; if (args.raw_test_num) - return do_test_raw(args.raw_test_num); + return count_result(do_test_raw(args.raw_test_num)); for (i = 1; i <= ARRAY_SIZE(raw_tests); i++) - err |= do_test_raw(i); + err |= count_result(do_test_raw(i)); return err; } @@ -1080,8 +1097,7 @@ static int do_test_get_info(unsigned int test_num) *btf_log_buf = '\0'; user_btf = malloc(raw_btf_size); - if (!user_btf) { - fprintf(stderr, "Cannot allocate memory for user_btf\n"); + if (CHECK(!user_btf, "!user_btf")) { err = -1; goto done; } @@ -1089,9 +1105,7 @@ static int do_test_get_info(unsigned int test_num) btf_fd = bpf_load_btf(raw_btf, raw_btf_size, btf_log_buf, BTF_LOG_BUF_SIZE, args.always_log); - if (btf_fd == -1) { - fprintf(stderr, "bpf_load_btf:%s(%d)\n", - strerror(errno), errno); + if (CHECK(btf_fd == -1, "errno:%d", errno)) { err = -1; goto done; } @@ -1103,31 +1117,31 @@ static int do_test_get_info(unsigned int test_num) raw_btf_size - expected_nbytes); err = bpf_obj_get_info_by_fd(btf_fd, user_btf, &user_btf_size); - if (err || user_btf_size != raw_btf_size || - memcmp(raw_btf, user_btf, expected_nbytes)) { - fprintf(stderr, - "err:%d(errno:%d) raw_btf_size:%u user_btf_size:%u expected_nbytes:%u memcmp:%d\n", - err, errno, - raw_btf_size, user_btf_size, expected_nbytes, - memcmp(raw_btf, user_btf, expected_nbytes)); + if (CHECK(err || user_btf_size != raw_btf_size || + memcmp(raw_btf, user_btf, expected_nbytes), + "err:%d(errno:%d) raw_btf_size:%u user_btf_size:%u expected_nbytes:%u memcmp:%d", + err, errno, + raw_btf_size, user_btf_size, expected_nbytes, + memcmp(raw_btf, user_btf, expected_nbytes))) { err = -1; goto done; } while (expected_nbytes < raw_btf_size) { fprintf(stderr, "%u...", expected_nbytes); - if (user_btf[expected_nbytes++] != 0xff) { - fprintf(stderr, "!= 0xff\n"); + if (CHECK(user_btf[expected_nbytes++] != 0xff, + "user_btf[%u]:%x != 0xff", expected_nbytes - 1, + user_btf[expected_nbytes - 1])) { err = -1; goto done; } } - fprintf(stderr, "OK\n"); + fprintf(stderr, "OK"); done: if (*btf_log_buf && (err || args.always_log)) - fprintf(stderr, "%s\n", btf_log_buf); + fprintf(stderr, "\n%s", btf_log_buf); free(raw_btf); free(user_btf); @@ -1144,10 +1158,10 @@ static int test_get_info(void) int err = 0; if (args.get_info_test_num) - return do_test_get_info(args.get_info_test_num); + return count_result(do_test_get_info(args.get_info_test_num)); for (i = 1; i <= ARRAY_SIZE(get_info_tests); i++) - err |= do_test_get_info(i); + err |= count_result(do_test_get_info(i)); return err; } @@ -1175,28 +1189,21 @@ static int file_has_btf_elf(const char *fn) Elf *elf; int ret; - if (elf_version(EV_CURRENT) == EV_NONE) { - fprintf(stderr, "Failed to init libelf\n"); + if (CHECK(elf_version(EV_CURRENT) == EV_NONE, + "elf_version(EV_CURRENT) == EV_NONE")) return -1; - } elf_fd = open(fn, O_RDONLY); - if (elf_fd == -1) { - fprintf(stderr, "Cannot open file %s: %s(%d)\n", - fn, strerror(errno), errno); + if (CHECK(elf_fd == -1, "open(%s): errno:%d", fn, errno)) return -1; - } elf = elf_begin(elf_fd, ELF_C_READ, NULL); - if (!elf) { - fprintf(stderr, "Failed to read ELF from %s. %s\n", fn, - elf_errmsg(elf_errno())); + if (CHECK(!elf, "elf_begin(%s): %s", fn, elf_errmsg(elf_errno()))) { ret = -1; goto done; } - if (!gelf_getehdr(elf, &ehdr)) { - fprintf(stderr, "Failed to get EHDR from %s\n", fn); + if (CHECK(!gelf_getehdr(elf, &ehdr), "!gelf_getehdr(%s)", fn)) { ret = -1; goto done; } @@ -1205,9 +1212,8 @@ static int file_has_btf_elf(const char *fn) const char *sh_name; GElf_Shdr sh; - if (gelf_getshdr(scn, &sh) != &sh) { - fprintf(stderr, - "Failed to get section header from %s\n", fn); + if (CHECK(gelf_getshdr(scn, &sh) != &sh, + "file:%s gelf_getshdr != &sh", fn)) { ret = -1; goto done; } @@ -1243,53 +1249,44 @@ static int do_test_file(unsigned int test_num) return err; if (err == 0) { - fprintf(stderr, "SKIP. No ELF %s found\n", BTF_ELF_SEC); + fprintf(stderr, "SKIP. No ELF %s found", BTF_ELF_SEC); + skip_cnt++; return 0; } obj = bpf_object__open(test->file); - if (IS_ERR(obj)) + if (CHECK(IS_ERR(obj), "obj: %ld", PTR_ERR(obj))) return PTR_ERR(obj); err = bpf_object__btf_fd(obj); - if (err == -1) { - fprintf(stderr, "bpf_object__btf_fd: -1\n"); + if (CHECK(err == -1, "bpf_object__btf_fd: -1")) goto done; - } prog = bpf_program__next(NULL, obj); - if (!prog) { - fprintf(stderr, "Cannot find bpf_prog\n"); + if (CHECK(!prog, "Cannot find bpf_prog")) { err = -1; goto done; } bpf_program__set_type(prog, BPF_PROG_TYPE_TRACEPOINT); err = bpf_object__load(obj); - if (err < 0) { - fprintf(stderr, "bpf_object__load: %d\n", err); + if (CHECK(err < 0, "bpf_object__load: %d", err)) goto done; - } map = bpf_object__find_map_by_name(obj, "btf_map"); - if (!map) { - fprintf(stderr, "btf_map not found\n"); + if (CHECK(!map, "btf_map not found")) { err = -1; goto done; } err = (bpf_map__btf_key_id(map) == 0 || bpf_map__btf_value_id(map) == 0) != test->btf_kv_notfound; - if (err) { - fprintf(stderr, - "btf_kv_notfound:%u btf_key_id:%u btf_value_id:%u\n", - test->btf_kv_notfound, - bpf_map__btf_key_id(map), - bpf_map__btf_value_id(map)); + if (CHECK(err, "btf_key_id:%u btf_value_id:%u test->btf_kv_notfound:%u", + bpf_map__btf_key_id(map), bpf_map__btf_value_id(map), + test->btf_kv_notfound)) goto done; - } - fprintf(stderr, "OK\n"); + fprintf(stderr, "OK"); done: bpf_object__close(obj); @@ -1302,10 +1299,10 @@ static int test_file(void) int err = 0; if (args.file_test_num) - return do_test_file(args.file_test_num); + return count_result(do_test_file(args.file_test_num)); for (i = 1; i <= ARRAY_SIZE(file_tests); i++) - err |= do_test_file(i); + err |= count_result(do_test_file(i)); return err; } @@ -1425,7 +1422,7 @@ static int test_pprint(void) unsigned int key; uint8_t *raw_btf; ssize_t nread; - int err; + int err, ret; fprintf(stderr, "%s......", test->descr); raw_btf = btf_raw_create(&hdr_tmpl, test->raw_types, @@ -1441,10 +1438,8 @@ static int test_pprint(void) args.always_log); free(raw_btf); - if (btf_fd == -1) { + if (CHECK(btf_fd == -1, "errno:%d", errno)) { err = -1; - fprintf(stderr, "bpf_load_btf: %s(%d)\n", - strerror(errno), errno); goto done; } @@ -1458,26 +1453,23 @@ static int test_pprint(void) create_attr.btf_value_id = test->value_id; map_fd = bpf_create_map_xattr(&create_attr); - if (map_fd == -1) { + if (CHECK(map_fd == -1, "errno:%d", errno)) { err = -1; - fprintf(stderr, "bpf_creat_map_btf: %s(%d)\n", - strerror(errno), errno); goto done; } - if (snprintf(pin_path, sizeof(pin_path), "%s/%s", - "/sys/fs/bpf", test->map_name) == sizeof(pin_path)) { + ret = snprintf(pin_path, sizeof(pin_path), "%s/%s", + "/sys/fs/bpf", test->map_name); + + if (CHECK(ret == sizeof(pin_path), "pin_path %s/%s is too long", + "/sys/fs/bpf", test->map_name)) { err = -1; - fprintf(stderr, "pin_path is too long\n"); goto done; } err = bpf_obj_pin(map_fd, pin_path); - if (err) { - fprintf(stderr, "Cannot pin to %s. %s(%d).\n", pin_path, - strerror(errno), errno); + if (CHECK(err, "bpf_obj_pin(%s): errno:%d.", pin_path, errno)) goto done; - } for (key = 0; key < test->max_entries; key++) { set_pprint_mapv(&mapv, key); @@ -1485,10 +1477,8 @@ static int test_pprint(void) } pin_file = fopen(pin_path, "r"); - if (!pin_file) { + if (CHECK(!pin_file, "fopen(%s): errno:%d", pin_path, errno)) { err = -1; - fprintf(stderr, "fopen(%s): %s(%d)\n", pin_path, - strerror(errno), errno); goto done; } @@ -1497,9 +1487,8 @@ static int test_pprint(void) *line == '#') ; - if (nread <= 0) { + if (CHECK(nread <= 0, "Unexpected EOF")) { err = -1; - fprintf(stderr, "Unexpected EOF\n"); goto done; } @@ -1518,9 +1507,9 @@ static int test_pprint(void) mapv.ui8a[4], mapv.ui8a[5], mapv.ui8a[6], mapv.ui8a[7], pprint_enum_str[mapv.aenum]); - if (nexpected_line == sizeof(expected_line)) { + if (CHECK(nexpected_line == sizeof(expected_line), + "expected_line is too long")) { err = -1; - fprintf(stderr, "expected_line is too long\n"); goto done; } @@ -1535,15 +1524,15 @@ static int test_pprint(void) nread = getline(&line, &line_len, pin_file); } while (++key < test->max_entries && nread > 0); - if (key < test->max_entries) { + if (CHECK(key < test->max_entries, + "Unexpected EOF. key:%u test->max_entries:%u", + key, test->max_entries)) { err = -1; - fprintf(stderr, "Unexpected EOF\n"); goto done; } - if (nread > 0) { + if (CHECK(nread > 0, "Unexpected extra pprint output: %s", line)) { err = -1; - fprintf(stderr, "Unexpected extra pprint output: %s\n", line); goto done; } @@ -1551,9 +1540,9 @@ static int test_pprint(void) done: if (!err) - fprintf(stderr, "OK\n"); + fprintf(stderr, "OK"); if (*btf_log_buf && (err || args.always_log)) - fprintf(stderr, "%s\n", btf_log_buf); + fprintf(stderr, "\n%s", btf_log_buf); if (btf_fd != -1) close(btf_fd); if (map_fd != -1) @@ -1634,6 +1623,12 @@ static int parse_args(int argc, char **argv) return 0; } +static void print_summary(void) +{ + fprintf(stderr, "PASS:%u SKIP:%u FAIL:%u\n", + pass_cnt - skip_cnt, skip_cnt, error_cnt); +} + int main(int argc, char **argv) { int err = 0; @@ -1655,15 +1650,17 @@ int main(int argc, char **argv) err |= test_file(); if (args.pprint_test) - err |= test_pprint(); + err |= count_result(test_pprint()); if (args.raw_test || args.get_info_test || args.file_test || args.pprint_test) - return err; + goto done; err |= test_raw(); err |= test_get_info(); err |= test_file(); +done: + print_summary(); return err; } -- cgit v1.2.3 From 7a01f6a3bd695d6d0f993a6df242a73a8b7c28c8 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Fri, 4 May 2018 14:49:54 -0700 Subject: bpf: btf: Update tools/include/uapi/linux/btf.h with BTF ID This patch sync the tools/include/uapi/linux/btf.h with the newly introduced BTF ID support. Signed-off-by: Martin KaFai Lau Acked-by: Alexei Starovoitov Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- tools/include/uapi/linux/bpf.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 83a95ae388dd..fff51c187d1e 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -96,6 +96,7 @@ enum bpf_cmd { BPF_PROG_QUERY, BPF_RAW_TRACEPOINT_OPEN, BPF_BTF_LOAD, + BPF_BTF_GET_FD_BY_ID, }; enum bpf_map_type { @@ -343,6 +344,7 @@ union bpf_attr { __u32 start_id; __u32 prog_id; __u32 map_id; + __u32 btf_id; }; __u32 next_id; __u32 open_flags; @@ -2129,6 +2131,15 @@ struct bpf_map_info { __u32 ifindex; __u64 netns_dev; __u64 netns_ino; + __u32 btf_id; + __u32 btf_key_id; + __u32 btf_value_id; +} __attribute__((aligned(8))); + +struct bpf_btf_info { + __aligned_u64 btf; + __u32 btf_size; + __u32 id; } __attribute__((aligned(8))); /* User bpf_sock_addr struct to access socket fields and sockaddr struct passed -- cgit v1.2.3 From cd8b89280c1c843756a2c95ed50a1a6446b42b52 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Fri, 4 May 2018 14:49:55 -0700 Subject: bpf: btf: Tests for BPF_OBJ_GET_INFO_BY_FD and BPF_BTF_GET_FD_BY_ID This patch adds test for BPF_BTF_GET_FD_BY_ID and the new btf_id/btf_key_id/btf_value_id in the "struct bpf_map_info". It also modifies the existing BPF_OBJ_GET_INFO_BY_FD test to reflect the new "struct bpf_btf_info". Signed-off-by: Martin KaFai Lau Acked-by: Alexei Starovoitov Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- tools/lib/bpf/bpf.c | 10 ++ tools/lib/bpf/bpf.h | 1 + tools/testing/selftests/bpf/test_btf.c | 289 +++++++++++++++++++++++++++++++-- 3 files changed, 287 insertions(+), 13 deletions(-) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 76b36cc16e7f..a3a8fb2ac697 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -458,6 +458,16 @@ int bpf_map_get_fd_by_id(__u32 id) return sys_bpf(BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr)); } +int bpf_btf_get_fd_by_id(__u32 id) +{ + union bpf_attr attr; + + bzero(&attr, sizeof(attr)); + attr.btf_id = id; + + return sys_bpf(BPF_BTF_GET_FD_BY_ID, &attr, sizeof(attr)); +} + int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len) { union bpf_attr attr; diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index 553b11ad52b3..fb3a146d92ff 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -98,6 +98,7 @@ int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id); int bpf_map_get_next_id(__u32 start_id, __u32 *next_id); int bpf_prog_get_fd_by_id(__u32 id); int bpf_map_get_fd_by_id(__u32 id); +int bpf_btf_get_fd_by_id(__u32 id); int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len); int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags, __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt); diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c index b7880a20fad1..c8bceae7ec02 100644 --- a/tools/testing/selftests/bpf/test_btf.c +++ b/tools/testing/selftests/bpf/test_btf.c @@ -1047,9 +1047,13 @@ struct btf_get_info_test { const char *str_sec; __u32 raw_types[MAX_NR_RAW_TYPES]; __u32 str_sec_size; - int info_size_delta; + int btf_size_delta; + int (*special_test)(unsigned int test_num); }; +static int test_big_btf_info(unsigned int test_num); +static int test_btf_id(unsigned int test_num); + const struct btf_get_info_test get_info_tests[] = { { .descr = "== raw_btf_size+1", @@ -1060,7 +1064,7 @@ const struct btf_get_info_test get_info_tests[] = { }, .str_sec = "", .str_sec_size = sizeof(""), - .info_size_delta = 1, + .btf_size_delta = 1, }, { .descr = "== raw_btf_size-3", @@ -1071,20 +1075,274 @@ const struct btf_get_info_test get_info_tests[] = { }, .str_sec = "", .str_sec_size = sizeof(""), - .info_size_delta = -3, + .btf_size_delta = -3, +}, +{ + .descr = "Large bpf_btf_info", + .raw_types = { + /* int */ /* [1] */ + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), + BTF_END_RAW, + }, + .str_sec = "", + .str_sec_size = sizeof(""), + .special_test = test_big_btf_info, +}, +{ + .descr = "BTF ID", + .raw_types = { + /* int */ /* [1] */ + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), + /* unsigned int */ /* [2] */ + BTF_TYPE_INT_ENC(0, 0, 0, 32, 4), + BTF_END_RAW, + }, + .str_sec = "", + .str_sec_size = sizeof(""), + .special_test = test_btf_id, }, }; +static inline __u64 ptr_to_u64(const void *ptr) +{ + return (__u64)(unsigned long)ptr; +} + +static int test_big_btf_info(unsigned int test_num) +{ + const struct btf_get_info_test *test = &get_info_tests[test_num - 1]; + uint8_t *raw_btf = NULL, *user_btf = NULL; + unsigned int raw_btf_size; + struct { + struct bpf_btf_info info; + uint64_t garbage; + } info_garbage; + struct bpf_btf_info *info; + int btf_fd = -1, err; + uint32_t info_len; + + raw_btf = btf_raw_create(&hdr_tmpl, + test->raw_types, + test->str_sec, + test->str_sec_size, + &raw_btf_size); + + if (!raw_btf) + return -1; + + *btf_log_buf = '\0'; + + user_btf = malloc(raw_btf_size); + if (CHECK(!user_btf, "!user_btf")) { + err = -1; + goto done; + } + + btf_fd = bpf_load_btf(raw_btf, raw_btf_size, + btf_log_buf, BTF_LOG_BUF_SIZE, + args.always_log); + if (CHECK(btf_fd == -1, "errno:%d", errno)) { + err = -1; + goto done; + } + + /* + * GET_INFO should error out if the userspace info + * has non zero tailing bytes. + */ + info = &info_garbage.info; + memset(info, 0, sizeof(*info)); + info_garbage.garbage = 0xdeadbeef; + info_len = sizeof(info_garbage); + info->btf = ptr_to_u64(user_btf); + info->btf_size = raw_btf_size; + + err = bpf_obj_get_info_by_fd(btf_fd, info, &info_len); + if (CHECK(!err, "!err")) { + err = -1; + goto done; + } + + /* + * GET_INFO should succeed even info_len is larger than + * the kernel supported as long as tailing bytes are zero. + * The kernel supported info len should also be returned + * to userspace. + */ + info_garbage.garbage = 0; + err = bpf_obj_get_info_by_fd(btf_fd, info, &info_len); + if (CHECK(err || info_len != sizeof(*info), + "err:%d errno:%d info_len:%u sizeof(*info):%lu", + err, errno, info_len, sizeof(*info))) { + err = -1; + goto done; + } + + fprintf(stderr, "OK"); + +done: + if (*btf_log_buf && (err || args.always_log)) + fprintf(stderr, "\n%s", btf_log_buf); + + free(raw_btf); + free(user_btf); + + if (btf_fd != -1) + close(btf_fd); + + return err; +} + +static int test_btf_id(unsigned int test_num) +{ + const struct btf_get_info_test *test = &get_info_tests[test_num - 1]; + struct bpf_create_map_attr create_attr = {}; + uint8_t *raw_btf = NULL, *user_btf[2] = {}; + int btf_fd[2] = {-1, -1}, map_fd = -1; + struct bpf_map_info map_info = {}; + struct bpf_btf_info info[2] = {}; + unsigned int raw_btf_size; + uint32_t info_len; + int err, i, ret; + + raw_btf = btf_raw_create(&hdr_tmpl, + test->raw_types, + test->str_sec, + test->str_sec_size, + &raw_btf_size); + + if (!raw_btf) + return -1; + + *btf_log_buf = '\0'; + + for (i = 0; i < 2; i++) { + user_btf[i] = malloc(raw_btf_size); + if (CHECK(!user_btf[i], "!user_btf[%d]", i)) { + err = -1; + goto done; + } + info[i].btf = ptr_to_u64(user_btf[i]); + info[i].btf_size = raw_btf_size; + } + + btf_fd[0] = bpf_load_btf(raw_btf, raw_btf_size, + btf_log_buf, BTF_LOG_BUF_SIZE, + args.always_log); + if (CHECK(btf_fd[0] == -1, "errno:%d", errno)) { + err = -1; + goto done; + } + + /* Test BPF_OBJ_GET_INFO_BY_ID on btf_id */ + info_len = sizeof(info[0]); + err = bpf_obj_get_info_by_fd(btf_fd[0], &info[0], &info_len); + if (CHECK(err, "errno:%d", errno)) { + err = -1; + goto done; + } + + btf_fd[1] = bpf_btf_get_fd_by_id(info[0].id); + if (CHECK(btf_fd[1] == -1, "errno:%d", errno)) { + err = -1; + goto done; + } + + ret = 0; + err = bpf_obj_get_info_by_fd(btf_fd[1], &info[1], &info_len); + if (CHECK(err || info[0].id != info[1].id || + info[0].btf_size != info[1].btf_size || + (ret = memcmp(user_btf[0], user_btf[1], info[0].btf_size)), + "err:%d errno:%d id0:%u id1:%u btf_size0:%u btf_size1:%u memcmp:%d", + err, errno, info[0].id, info[1].id, + info[0].btf_size, info[1].btf_size, ret)) { + err = -1; + goto done; + } + + /* Test btf members in struct bpf_map_info */ + create_attr.name = "test_btf_id"; + create_attr.map_type = BPF_MAP_TYPE_ARRAY; + create_attr.key_size = sizeof(int); + create_attr.value_size = sizeof(unsigned int); + create_attr.max_entries = 4; + create_attr.btf_fd = btf_fd[0]; + create_attr.btf_key_id = 1; + create_attr.btf_value_id = 2; + + map_fd = bpf_create_map_xattr(&create_attr); + if (CHECK(map_fd == -1, "errno:%d", errno)) { + err = -1; + goto done; + } + + info_len = sizeof(map_info); + err = bpf_obj_get_info_by_fd(map_fd, &map_info, &info_len); + if (CHECK(err || map_info.btf_id != info[0].id || + map_info.btf_key_id != 1 || map_info.btf_value_id != 2, + "err:%d errno:%d info.id:%u btf_id:%u btf_key_id:%u btf_value_id:%u", + err, errno, info[0].id, map_info.btf_id, map_info.btf_key_id, + map_info.btf_value_id)) { + err = -1; + goto done; + } + + for (i = 0; i < 2; i++) { + close(btf_fd[i]); + btf_fd[i] = -1; + } + + /* Test BTF ID is removed from the kernel */ + btf_fd[0] = bpf_btf_get_fd_by_id(map_info.btf_id); + if (CHECK(btf_fd[0] == -1, "errno:%d", errno)) { + err = -1; + goto done; + } + close(btf_fd[0]); + btf_fd[0] = -1; + + /* The map holds the last ref to BTF and its btf_id */ + close(map_fd); + map_fd = -1; + btf_fd[0] = bpf_btf_get_fd_by_id(map_info.btf_id); + if (CHECK(btf_fd[0] != -1, "BTF lingers")) { + err = -1; + goto done; + } + + fprintf(stderr, "OK"); + +done: + if (*btf_log_buf && (err || args.always_log)) + fprintf(stderr, "\n%s", btf_log_buf); + + free(raw_btf); + if (map_fd != -1) + close(map_fd); + for (i = 0; i < 2; i++) { + free(user_btf[i]); + if (btf_fd[i] != -1) + close(btf_fd[i]); + } + + return err; +} + static int do_test_get_info(unsigned int test_num) { const struct btf_get_info_test *test = &get_info_tests[test_num - 1]; unsigned int raw_btf_size, user_btf_size, expected_nbytes; uint8_t *raw_btf = NULL, *user_btf = NULL; - int btf_fd = -1, err; + struct bpf_btf_info info = {}; + int btf_fd = -1, err, ret; + uint32_t info_len; - fprintf(stderr, "BTF GET_INFO_BY_ID test[%u] (%s): ", + fprintf(stderr, "BTF GET_INFO test[%u] (%s): ", test_num, test->descr); + if (test->special_test) + return test->special_test(test_num); + raw_btf = btf_raw_create(&hdr_tmpl, test->raw_types, test->str_sec, @@ -1110,19 +1368,24 @@ static int do_test_get_info(unsigned int test_num) goto done; } - user_btf_size = (int)raw_btf_size + test->info_size_delta; + user_btf_size = (int)raw_btf_size + test->btf_size_delta; expected_nbytes = min(raw_btf_size, user_btf_size); if (raw_btf_size > expected_nbytes) memset(user_btf + expected_nbytes, 0xff, raw_btf_size - expected_nbytes); - err = bpf_obj_get_info_by_fd(btf_fd, user_btf, &user_btf_size); - if (CHECK(err || user_btf_size != raw_btf_size || - memcmp(raw_btf, user_btf, expected_nbytes), - "err:%d(errno:%d) raw_btf_size:%u user_btf_size:%u expected_nbytes:%u memcmp:%d", - err, errno, - raw_btf_size, user_btf_size, expected_nbytes, - memcmp(raw_btf, user_btf, expected_nbytes))) { + info_len = sizeof(info); + info.btf = ptr_to_u64(user_btf); + info.btf_size = user_btf_size; + + ret = 0; + err = bpf_obj_get_info_by_fd(btf_fd, &info, &info_len); + if (CHECK(err || !info.id || info_len != sizeof(info) || + info.btf_size != raw_btf_size || + (ret = memcmp(raw_btf, user_btf, expected_nbytes)), + "err:%d errno:%d info.id:%u info_len:%u sizeof(info):%lu raw_btf_size:%u info.btf_size:%u expected_nbytes:%u memcmp:%d", + err, errno, info.id, info_len, sizeof(info), + raw_btf_size, info.btf_size, expected_nbytes, ret)) { err = -1; goto done; } -- cgit v1.2.3 From 0d8300325660f81787892a1c58dc1f9428a67143 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Tue, 8 May 2018 19:37:06 -0700 Subject: bpf: xdp: allow offloads to store into rx_queue_index It's fairly easy for offloaded XDP programs to select the RX queue packets go to. We need a way of expressing this in the software. Allow write to the rx_queue_index field of struct xdp_md for device-bound programs. Skip convert_ctx_access callback entirely for offloads. Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann --- include/linux/bpf.h | 2 +- kernel/bpf/verifier.c | 2 +- net/core/filter.c | 9 ++++++++- 3 files changed, 10 insertions(+), 3 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 321969da67b7..a38e474bf7ee 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -627,7 +627,7 @@ bool bpf_offload_dev_match(struct bpf_prog *prog, struct bpf_map *map); #if defined(CONFIG_NET) && defined(CONFIG_BPF_SYSCALL) int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr); -static inline bool bpf_prog_is_dev_bound(struct bpf_prog_aux *aux) +static inline bool bpf_prog_is_dev_bound(const struct bpf_prog_aux *aux) { return aux->offload_requested; } diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index d5e1a6c4165d..d92d9c37affd 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5215,7 +5215,7 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) } } - if (!ops->convert_ctx_access) + if (!ops->convert_ctx_access || bpf_prog_is_dev_bound(env->prog->aux)) return 0; insn = env->prog->insnsi + delta; diff --git a/net/core/filter.c b/net/core/filter.c index 6877426c23a6..0baa715e4699 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4645,8 +4645,15 @@ static bool xdp_is_valid_access(int off, int size, const struct bpf_prog *prog, struct bpf_insn_access_aux *info) { - if (type == BPF_WRITE) + if (type == BPF_WRITE) { + if (bpf_prog_is_dev_bound(prog->aux)) { + switch (off) { + case offsetof(struct xdp_md, rx_queue_index): + return __is_valid_xdp_access(off, size); + } + } return false; + } switch (off) { case offsetof(struct xdp_md, data): -- cgit v1.2.3 From d985888faae6588c8ce9e45ad1e4a3ab5f0376b4 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Tue, 8 May 2018 19:37:07 -0700 Subject: nfp: bpf: support setting the RX queue index BPF has access to all internal FW datapath structures. Including the structure containing RX queue selection. With little coordination with the datapath we can let the offloaded BPF select the RX queue. We just need a way to tell the datapath that queue selection has already been done and it shouldn't overwrite it. Define a bit to tell datapath BPF already selected a queue (QSEL_SET), if the selected queue is not enabled (>= number of enabled queues) datapath will perform normal RSS. BPF queue selection on the NIC can be used to replace standard datapath RSS with fully programmable BPF/XDP RSS. Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann --- drivers/net/ethernet/netronome/nfp/bpf/fw.h | 1 + drivers/net/ethernet/netronome/nfp/bpf/jit.c | 47 +++++++++++++++++++++++ drivers/net/ethernet/netronome/nfp/bpf/main.c | 11 ++++++ drivers/net/ethernet/netronome/nfp/bpf/main.h | 8 ++++ drivers/net/ethernet/netronome/nfp/bpf/verifier.c | 28 +++++++++++++- drivers/net/ethernet/netronome/nfp/nfp_asm.h | 22 ++++++----- 6 files changed, 105 insertions(+), 12 deletions(-) diff --git a/drivers/net/ethernet/netronome/nfp/bpf/fw.h b/drivers/net/ethernet/netronome/nfp/bpf/fw.h index 3dbc21653ce5..4c7972e3db63 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/fw.h +++ b/drivers/net/ethernet/netronome/nfp/bpf/fw.h @@ -50,6 +50,7 @@ enum bpf_cap_tlv_type { NFP_BPF_CAP_TYPE_ADJUST_HEAD = 2, NFP_BPF_CAP_TYPE_MAPS = 3, NFP_BPF_CAP_TYPE_RANDOM = 4, + NFP_BPF_CAP_TYPE_QUEUE_SELECT = 5, }; struct nfp_bpf_cap_tlv_func { diff --git a/drivers/net/ethernet/netronome/nfp/bpf/jit.c b/drivers/net/ethernet/netronome/nfp/bpf/jit.c index 326a2085d650..a4d3da215863 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c @@ -42,6 +42,7 @@ #include "main.h" #include "../nfp_asm.h" +#include "../nfp_net_ctrl.h" /* --- NFP prog --- */ /* Foreach "multiple" entries macros provide pos and next pointers. @@ -1470,6 +1471,38 @@ nfp_perf_event_output(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) return 0; } +static int +nfp_queue_select(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) +{ + u32 jmp_tgt; + + jmp_tgt = nfp_prog_current_offset(nfp_prog) + 5; + + /* Make sure the queue id fits into FW field */ + emit_alu(nfp_prog, reg_none(), reg_a(meta->insn.src_reg * 2), + ALU_OP_AND_NOT_B, reg_imm(0xff)); + emit_br(nfp_prog, BR_BEQ, jmp_tgt, 2); + + /* Set the 'queue selected' bit and the queue value */ + emit_shf(nfp_prog, pv_qsel_set(nfp_prog), + pv_qsel_set(nfp_prog), SHF_OP_OR, reg_imm(1), + SHF_SC_L_SHF, PKT_VEL_QSEL_SET_BIT); + emit_ld_field(nfp_prog, + pv_qsel_val(nfp_prog), 0x1, reg_b(meta->insn.src_reg * 2), + SHF_SC_NONE, 0); + /* Delay slots end here, we will jump over next instruction if queue + * value fits into the field. + */ + emit_ld_field(nfp_prog, + pv_qsel_val(nfp_prog), 0x1, reg_imm(NFP_NET_RXR_MAX), + SHF_SC_NONE, 0); + + if (!nfp_prog_confirm_current_offset(nfp_prog, jmp_tgt)) + return -EINVAL; + + return 0; +} + /* --- Callbacks --- */ static int mov_reg64(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) { @@ -2160,6 +2193,17 @@ mem_stx_stack(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, false, wrp_lmem_store); } +static int mem_stx_xdp(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) +{ + switch (meta->insn.off) { + case offsetof(struct xdp_md, rx_queue_index): + return nfp_queue_select(nfp_prog, meta); + } + + WARN_ON_ONCE(1); /* verifier should have rejected bad accesses */ + return -EOPNOTSUPP; +} + static int mem_stx(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, unsigned int size) @@ -2186,6 +2230,9 @@ static int mem_stx2(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) static int mem_stx4(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) { + if (meta->ptr.type == PTR_TO_CTX) + if (nfp_prog->type == BPF_PROG_TYPE_XDP) + return mem_stx_xdp(nfp_prog, meta); return mem_stx(nfp_prog, meta, 4); } diff --git a/drivers/net/ethernet/netronome/nfp/bpf/main.c b/drivers/net/ethernet/netronome/nfp/bpf/main.c index d72f9e7f42da..f1846d8f59cc 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/main.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/main.c @@ -334,6 +334,13 @@ nfp_bpf_parse_cap_random(struct nfp_app_bpf *bpf, void __iomem *value, return 0; } +static int +nfp_bpf_parse_cap_qsel(struct nfp_app_bpf *bpf, void __iomem *value, u32 length) +{ + bpf->queue_select = true; + return 0; +} + static int nfp_bpf_parse_capabilities(struct nfp_app *app) { struct nfp_cpp *cpp = app->pf->cpp; @@ -376,6 +383,10 @@ static int nfp_bpf_parse_capabilities(struct nfp_app *app) if (nfp_bpf_parse_cap_random(app->priv, value, length)) goto err_release_free; break; + case NFP_BPF_CAP_TYPE_QUEUE_SELECT: + if (nfp_bpf_parse_cap_qsel(app->priv, value, length)) + goto err_release_free; + break; default: nfp_dbg(cpp, "unknown BPF capability: %d\n", type); break; diff --git a/drivers/net/ethernet/netronome/nfp/bpf/main.h b/drivers/net/ethernet/netronome/nfp/bpf/main.h index 82682378d57f..8b143546ae85 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/main.h +++ b/drivers/net/ethernet/netronome/nfp/bpf/main.h @@ -82,10 +82,16 @@ enum static_regs { enum pkt_vec { PKT_VEC_PKT_LEN = 0, PKT_VEC_PKT_PTR = 2, + PKT_VEC_QSEL_SET = 4, + PKT_VEC_QSEL_VAL = 6, }; +#define PKT_VEL_QSEL_SET_BIT 4 + #define pv_len(np) reg_lm(1, PKT_VEC_PKT_LEN) #define pv_ctm_ptr(np) reg_lm(1, PKT_VEC_PKT_PTR) +#define pv_qsel_set(np) reg_lm(1, PKT_VEC_QSEL_SET) +#define pv_qsel_val(np) reg_lm(1, PKT_VEC_QSEL_VAL) #define stack_reg(np) reg_a(STATIC_REG_STACK) #define stack_imm(np) imm_b(np) @@ -139,6 +145,7 @@ enum pkt_vec { * @helpers.perf_event_output: output perf event to a ring buffer * * @pseudo_random: FW initialized the pseudo-random machinery (CSRs) + * @queue_select: BPF can set the RX queue ID in packet vector */ struct nfp_app_bpf { struct nfp_app *app; @@ -181,6 +188,7 @@ struct nfp_app_bpf { } helpers; bool pseudo_random; + bool queue_select; }; enum nfp_bpf_map_use { diff --git a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c index e163f3cfa47d..844a9be6e55a 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c @@ -467,6 +467,30 @@ nfp_bpf_check_ptr(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, return 0; } +static int +nfp_bpf_check_store(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, + struct bpf_verifier_env *env) +{ + const struct bpf_reg_state *reg = cur_regs(env) + meta->insn.dst_reg; + + if (reg->type == PTR_TO_CTX) { + if (nfp_prog->type == BPF_PROG_TYPE_XDP) { + /* XDP ctx accesses must be 4B in size */ + switch (meta->insn.off) { + case offsetof(struct xdp_md, rx_queue_index): + if (nfp_prog->bpf->queue_select) + goto exit_check_ptr; + pr_vlog(env, "queue selection not supported by FW\n"); + return -EOPNOTSUPP; + } + } + pr_vlog(env, "unsupported store to context field\n"); + return -EOPNOTSUPP; + } +exit_check_ptr: + return nfp_bpf_check_ptr(nfp_prog, meta, env, meta->insn.dst_reg); +} + static int nfp_bpf_check_xadd(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, struct bpf_verifier_env *env) @@ -522,8 +546,8 @@ nfp_verify_insn(struct bpf_verifier_env *env, int insn_idx, int prev_insn_idx) return nfp_bpf_check_ptr(nfp_prog, meta, env, meta->insn.src_reg); if (is_mbpf_store(meta)) - return nfp_bpf_check_ptr(nfp_prog, meta, env, - meta->insn.dst_reg); + return nfp_bpf_check_store(nfp_prog, meta, env); + if (is_mbpf_xadd(meta)) return nfp_bpf_check_xadd(nfp_prog, meta, env); diff --git a/drivers/net/ethernet/netronome/nfp/nfp_asm.h b/drivers/net/ethernet/netronome/nfp/nfp_asm.h index 5f2b2f24f4fa..faa4e131c136 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_asm.h +++ b/drivers/net/ethernet/netronome/nfp/nfp_asm.h @@ -183,16 +183,18 @@ enum shf_sc { #define OP_ALU_DST_LMEXTN 0x80000000000ULL enum alu_op { - ALU_OP_NONE = 0x00, - ALU_OP_ADD = 0x01, - ALU_OP_NOT = 0x04, - ALU_OP_ADD_2B = 0x05, - ALU_OP_AND = 0x08, - ALU_OP_SUB_C = 0x0d, - ALU_OP_ADD_C = 0x11, - ALU_OP_OR = 0x14, - ALU_OP_SUB = 0x15, - ALU_OP_XOR = 0x18, + ALU_OP_NONE = 0x00, + ALU_OP_ADD = 0x01, + ALU_OP_NOT = 0x04, + ALU_OP_ADD_2B = 0x05, + ALU_OP_AND = 0x08, + ALU_OP_AND_NOT_A = 0x0c, + ALU_OP_SUB_C = 0x0d, + ALU_OP_AND_NOT_B = 0x10, + ALU_OP_ADD_C = 0x11, + ALU_OP_OR = 0x14, + ALU_OP_SUB = 0x15, + ALU_OP_XOR = 0x18, }; enum alu_dst_ab { -- cgit v1.2.3 From ea7e3435297c6ba3c8ae51db6ea48f1ed657dc5c Mon Sep 17 00:00:00 2001 From: Björn Töpel Date: Mon, 7 May 2018 19:43:50 +0200 Subject: xsk: fix 64-bit division MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit i386 builds report: net/xdp/xdp_umem.o: In function `xdp_umem_reg': xdp_umem.c:(.text+0x47e): undefined reference to `__udivdi3' This fix uses div_u64 instead of the GCC built-in. Fixes: c0c77d8fb787 ("xsk: add user memory registration support sockopt") Signed-off-by: Björn Töpel Reported-by: Randy Dunlap Tested-by: Randy Dunlap Signed-off-by: Daniel Borkmann --- net/xdp/xdp_umem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c index 881dfdefe235..2b47a1dd7c6c 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -209,7 +209,7 @@ int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr) if ((addr + size) < addr) return -EINVAL; - nframes = size / frame_size; + nframes = (unsigned int)div_u64(size, frame_size); if (nframes == 0 || nframes > UINT_MAX) return -EINVAL; -- cgit v1.2.3 From cd65cd95128781ca59d06611270fcbd9b4a7cf8d Mon Sep 17 00:00:00 2001 From: Sirio Balmelli Date: Tue, 8 May 2018 15:36:12 +0200 Subject: selftests/bpf: add architecture-agnostic headers The BPF selftests fail to build with missing headers 'asm/bitsperlong.h' and 'asm/errno.h'. These already exist in 'tools/arch/[arch]/include'; add architecture-agnostic header files in 'tools/include/uapi' to reference them. Signed-off-by: Sirio Balmelli Signed-off-by: Daniel Borkmann --- tools/include/uapi/asm/bitsperlong.h | 18 ++++++++++++++++++ tools/include/uapi/asm/errno.h | 18 ++++++++++++++++++ 2 files changed, 36 insertions(+) create mode 100644 tools/include/uapi/asm/bitsperlong.h create mode 100644 tools/include/uapi/asm/errno.h diff --git a/tools/include/uapi/asm/bitsperlong.h b/tools/include/uapi/asm/bitsperlong.h new file mode 100644 index 000000000000..8dd6aefdafa4 --- /dev/null +++ b/tools/include/uapi/asm/bitsperlong.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#if defined(__i386__) || defined(__x86_64__) +#include "../../arch/x86/include/uapi/asm/bitsperlong.h" +#elif defined(__aarch64__) +#include "../../arch/arm64/include/uapi/asm/bitsperlong.h" +#elif defined(__powerpc__) +#include "../../arch/powerpc/include/uapi/asm/bitsperlong.h" +#elif defined(__s390__) +#include "../../arch/s390/include/uapi/asm/bitsperlong.h" +#elif defined(__sparc__) +#include "../../arch/sparc/include/uapi/asm/bitsperlong.h" +#elif defined(__mips__) +#include "../../arch/mips/include/uapi/asm/bitsperlong.h" +#elif defined(__ia64__) +#include "../../arch/ia64/include/uapi/asm/bitsperlong.h" +#else +#include +#endif diff --git a/tools/include/uapi/asm/errno.h b/tools/include/uapi/asm/errno.h new file mode 100644 index 000000000000..ce3c5945a1c4 --- /dev/null +++ b/tools/include/uapi/asm/errno.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#if defined(__i386__) || defined(__x86_64__) +#include "../../arch/x86/include/uapi/asm/errno.h" +#elif defined(__powerpc__) +#include "../../arch/powerpc/include/uapi/asm/errno.h" +#elif defined(__sparc__) +#include "../../arch/sparc/include/uapi/asm/errno.h" +#elif defined(__alpha__) +#include "../../arch/alpha/include/uapi/asm/errno.h" +#elif defined(__mips__) +#include "../../arch/mips/include/uapi/asm/errno.h" +#elif defined(__ia64__) +#include "../../arch/ia64/include/uapi/asm/errno.h" +#elif defined(__xtensa__) +#include "../../arch/xtensa/include/uapi/asm/errno.h" +#else +#include +#endif -- cgit v1.2.3 From 96112e936350ae14454cb53be8d8c0b2c6f239f4 Mon Sep 17 00:00:00 2001 From: Sirio Balmelli Date: Tue, 8 May 2018 15:36:37 +0200 Subject: selftests/bpf: ignore build products Update .gitignore files. Signed-off-by: Sirio Balmelli Signed-off-by: Daniel Borkmann --- tools/bpf/bpftool/.gitignore | 3 +++ tools/testing/selftests/bpf/.gitignore | 1 + 2 files changed, 4 insertions(+) create mode 100644 tools/bpf/bpftool/.gitignore diff --git a/tools/bpf/bpftool/.gitignore b/tools/bpf/bpftool/.gitignore new file mode 100644 index 000000000000..d7e678c2d396 --- /dev/null +++ b/tools/bpf/bpftool/.gitignore @@ -0,0 +1,3 @@ +*.d +bpftool +FEATURE-DUMP.bpftool diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore index 3e3b3ced3f7c..adc8e5474b66 100644 --- a/tools/testing/selftests/bpf/.gitignore +++ b/tools/testing/selftests/bpf/.gitignore @@ -16,3 +16,4 @@ test_sock test_sock_addr urandom_read test_btf +test_sockmap -- cgit v1.2.3 From 68625b7631e040707b24197451a475a3e9197e2a Mon Sep 17 00:00:00 2001 From: Wang YanQing Date: Thu, 10 May 2018 11:09:21 +0800 Subject: bpf, doc: clarification for the meaning of 'id' For me, as a reader whose mother language isn't English, the old words bring a little difficulty to catch the meaning, this patch rewords the subsection in a more clarificatory way. This patch also add blank lines as separator at two places to improve readability. Signed-off-by: Wang YanQing Signed-off-by: Daniel Borkmann --- Documentation/networking/filter.txt | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/Documentation/networking/filter.txt b/Documentation/networking/filter.txt index 5032e1263bc9..e6b4ebb2b243 100644 --- a/Documentation/networking/filter.txt +++ b/Documentation/networking/filter.txt @@ -1142,6 +1142,7 @@ into a register from memory, the register's top 56 bits are known zero, while the low 8 are unknown - which is represented as the tnum (0x0; 0xff). If we then OR this with 0x40, we get (0x40; 0xbf), then if we add 1 we get (0x0; 0x1ff), because of potential carries. + Besides arithmetic, the register state can also be updated by conditional branches. For instance, if a SCALAR_VALUE is compared > 8, in the 'true' branch it will have a umin_value (unsigned minimum value) of 9, whereas in the 'false' @@ -1150,14 +1151,16 @@ BPF_JSGE) would instead update the signed minimum/maximum values. Information from the signed and unsigned bounds can be combined; for instance if a value is first tested < 8 and then tested s> 4, the verifier will conclude that the value is also > 4 and s< 8, since the bounds prevent crossing the sign boundary. + PTR_TO_PACKETs with a variable offset part have an 'id', which is common to all pointers sharing that same variable offset. This is important for packet range -checks: after adding some variable to a packet pointer, if you then copy it to -another register and (say) add a constant 4, both registers will share the same -'id' but one will have a fixed offset of +4. Then if it is bounds-checked and -found to be less than a PTR_TO_PACKET_END, the other register is now known to -have a safe range of at least 4 bytes. See 'Direct packet access', below, for -more on PTR_TO_PACKET ranges. +checks: after adding a variable to a packet pointer register A, if you then copy +it to another register B and then add a constant 4 to A, both registers will +share the same 'id' but the A will have a fixed offset of +4. Then if A is +bounds-checked and found to be less than a PTR_TO_PACKET_END, the register B is +now known to have a safe range of at least 4 bytes. See 'Direct packet access', +below, for more on PTR_TO_PACKET ranges. + The 'id' field is also used on PTR_TO_MAP_VALUE_OR_NULL, common to all copies of the pointer returned from a map lookup. This means that when one copy is checked and found to be non-NULL, all copies can become PTR_TO_MAP_VALUEs. -- cgit v1.2.3 From 6454743bc13e7dfd4f2720758ca3fcdea76b82a4 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Wed, 9 May 2018 20:34:19 -0700 Subject: net/ipv6: Rename fib6_lookup to fib6_node_lookup Rename fib6_lookup to fib6_node_lookup to better reflect what it returns. The fib6_lookup name will be used in a later patch for an IPv6 equivalent to IPv4's fib_lookup. Signed-off-by: David Ahern Acked-by: David S. Miller Signed-off-by: Daniel Borkmann --- include/net/ip6_fib.h | 6 +++--- net/ipv6/ip6_fib.c | 14 ++++++++------ net/ipv6/route.c | 8 ++++---- 3 files changed, 15 insertions(+), 13 deletions(-) diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h index a3ec08d05756..43ab545e64ea 100644 --- a/include/net/ip6_fib.h +++ b/include/net/ip6_fib.h @@ -376,9 +376,9 @@ struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, const struct sk_buff *skb, int flags, pol_lookup_t lookup); -struct fib6_node *fib6_lookup(struct fib6_node *root, - const struct in6_addr *daddr, - const struct in6_addr *saddr); +struct fib6_node *fib6_node_lookup(struct fib6_node *root, + const struct in6_addr *daddr, + const struct in6_addr *saddr); struct fib6_node *fib6_locate(struct fib6_node *root, const struct in6_addr *daddr, int dst_len, diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index f0a4262a4789..487faffeae28 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -1354,8 +1354,8 @@ struct lookup_args { const struct in6_addr *addr; /* search key */ }; -static struct fib6_node *fib6_lookup_1(struct fib6_node *root, - struct lookup_args *args) +static struct fib6_node *fib6_node_lookup_1(struct fib6_node *root, + struct lookup_args *args) { struct fib6_node *fn; __be32 dir; @@ -1400,7 +1400,8 @@ static struct fib6_node *fib6_lookup_1(struct fib6_node *root, #ifdef CONFIG_IPV6_SUBTREES if (subtree) { struct fib6_node *sfn; - sfn = fib6_lookup_1(subtree, args + 1); + sfn = fib6_node_lookup_1(subtree, + args + 1); if (!sfn) goto backtrack; fn = sfn; @@ -1422,8 +1423,9 @@ backtrack: /* called with rcu_read_lock() held */ -struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr, - const struct in6_addr *saddr) +struct fib6_node *fib6_node_lookup(struct fib6_node *root, + const struct in6_addr *daddr, + const struct in6_addr *saddr) { struct fib6_node *fn; struct lookup_args args[] = { @@ -1442,7 +1444,7 @@ struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *dad } }; - fn = fib6_lookup_1(root, daddr ? args : args + 1); + fn = fib6_node_lookup_1(root, daddr ? args : args + 1); if (!fn || fn->fn_flags & RTN_TL_ROOT) fn = root; diff --git a/net/ipv6/route.c b/net/ipv6/route.c index daa3662da0ee..443d2a0bc150 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1006,7 +1006,7 @@ static struct fib6_node* fib6_backtrack(struct fib6_node *fn, pn = rcu_dereference(fn->parent); sn = FIB6_SUBTREE(pn); if (sn && sn != fn) - fn = fib6_lookup(sn, NULL, saddr); + fn = fib6_node_lookup(sn, NULL, saddr); else fn = pn; if (fn->fn_flags & RTN_RTINFO) @@ -1059,7 +1059,7 @@ static struct rt6_info *ip6_pol_route_lookup(struct net *net, flags &= ~RT6_LOOKUP_F_IFACE; rcu_read_lock(); - fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); + fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); restart: f6i = rcu_dereference(fn->leaf); if (!f6i) { @@ -1815,7 +1815,7 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, rcu_read_lock(); - fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); + fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); saved_fn = fn; if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF) @@ -2425,7 +2425,7 @@ static struct rt6_info *__ip6_route_redirect(struct net *net, */ rcu_read_lock(); - fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); + fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); restart: for_each_fib6_node_rt_rcu(fn) { if (rt->fib6_nh.nh_flags & RTNH_F_DEAD) -- cgit v1.2.3 From 3b290a31bbc5969f9193f73d547a6dc8a25c6f9e Mon Sep 17 00:00:00 2001 From: David Ahern Date: Wed, 9 May 2018 20:34:20 -0700 Subject: net/ipv6: Rename rt6_multipath_select Rename rt6_multipath_select to fib6_multipath_select and export it. A later patch wants access to it similar to IPv4's fib_select_path. Signed-off-by: David Ahern Acked-by: David S. Miller Signed-off-by: Daniel Borkmann --- include/net/ip6_fib.h | 5 +++++ net/ipv6/route.c | 17 +++++++++-------- 2 files changed, 14 insertions(+), 8 deletions(-) diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h index 43ab545e64ea..2597d8fdd92f 100644 --- a/include/net/ip6_fib.h +++ b/include/net/ip6_fib.h @@ -376,6 +376,11 @@ struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, const struct sk_buff *skb, int flags, pol_lookup_t lookup); +struct fib6_info *fib6_multipath_select(const struct net *net, + struct fib6_info *match, + struct flowi6 *fl6, int oif, + const struct sk_buff *skb, int strict); + struct fib6_node *fib6_node_lookup(struct fib6_node *root, const struct in6_addr *daddr, const struct in6_addr *saddr); diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 443d2a0bc150..6a10608d9025 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -419,11 +419,11 @@ static bool rt6_check_expired(const struct rt6_info *rt) return false; } -static struct fib6_info *rt6_multipath_select(const struct net *net, - struct fib6_info *match, - struct flowi6 *fl6, int oif, - const struct sk_buff *skb, - int strict) +struct fib6_info *fib6_multipath_select(const struct net *net, + struct fib6_info *match, + struct flowi6 *fl6, int oif, + const struct sk_buff *skb, + int strict) { struct fib6_info *sibling, *next_sibling; @@ -1068,8 +1068,9 @@ restart: f6i = rt6_device_match(net, f6i, &fl6->saddr, fl6->flowi6_oif, flags); if (f6i->fib6_nsiblings && fl6->flowi6_oif == 0) - f6i = rt6_multipath_select(net, f6i, fl6, - fl6->flowi6_oif, skb, flags); + f6i = fib6_multipath_select(net, f6i, fl6, + fl6->flowi6_oif, skb, + flags); } if (f6i == net->ipv6.fib6_null_entry) { fn = fib6_backtrack(fn, &fl6->saddr); @@ -1824,7 +1825,7 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, redo_rt6_select: f6i = rt6_select(net, fn, oif, strict); if (f6i->fib6_nsiblings) - f6i = rt6_multipath_select(net, f6i, fl6, oif, skb, strict); + f6i = fib6_multipath_select(net, f6i, fl6, oif, skb, strict); if (f6i == net->ipv6.fib6_null_entry) { fn = fib6_backtrack(fn, &fl6->saddr); if (fn) -- cgit v1.2.3 From 1d053da910947afccec96d90892c0f5488c7a9cf Mon Sep 17 00:00:00 2001 From: David Ahern Date: Wed, 9 May 2018 20:34:21 -0700 Subject: net/ipv6: Extract table lookup from ip6_pol_route ip6_pol_route is used for ingress and egress FIB lookups. Refactor it moving the table lookup into a separate fib6_table_lookup that can be invoked separately and export the new function. ip6_pol_route now calls fib6_table_lookup and uses the result to generate a dst based rt6_info. Signed-off-by: David Ahern Acked-by: David S. Miller Signed-off-by: Daniel Borkmann --- include/net/ip6_fib.h | 4 ++++ net/ipv6/route.c | 39 +++++++++++++++++++++++++-------------- 2 files changed, 29 insertions(+), 14 deletions(-) diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h index 2597d8fdd92f..c70705f2647a 100644 --- a/include/net/ip6_fib.h +++ b/include/net/ip6_fib.h @@ -376,6 +376,10 @@ struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, const struct sk_buff *skb, int flags, pol_lookup_t lookup); +/* called with rcu lock held; caller needs to select path */ +struct fib6_info *fib6_table_lookup(struct net *net, struct fib6_table *table, + int oif, struct flowi6 *fl6, int strict); + struct fib6_info *fib6_multipath_select(const struct net *net, struct fib6_info *match, struct flowi6 *fl6, int oif, diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 6a10608d9025..019d8ba9021e 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1800,21 +1800,12 @@ void rt6_age_exceptions(struct fib6_info *rt, rcu_read_unlock_bh(); } -struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, - int oif, struct flowi6 *fl6, - const struct sk_buff *skb, int flags) +/* must be called with rcu lock held */ +struct fib6_info *fib6_table_lookup(struct net *net, struct fib6_table *table, + int oif, struct flowi6 *fl6, int strict) { struct fib6_node *fn, *saved_fn; struct fib6_info *f6i; - struct rt6_info *rt; - int strict = 0; - - strict |= flags & RT6_LOOKUP_F_IFACE; - strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE; - if (net->ipv6.devconf_all->forwarding == 0) - strict |= RT6_LOOKUP_F_REACHABLE; - - rcu_read_lock(); fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); saved_fn = fn; @@ -1824,8 +1815,6 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, redo_rt6_select: f6i = rt6_select(net, fn, oif, strict); - if (f6i->fib6_nsiblings) - f6i = fib6_multipath_select(net, f6i, fl6, oif, skb, strict); if (f6i == net->ipv6.fib6_null_entry) { fn = fib6_backtrack(fn, &fl6->saddr); if (fn) @@ -1838,6 +1827,28 @@ redo_rt6_select: } } + return f6i; +} + +struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, + int oif, struct flowi6 *fl6, + const struct sk_buff *skb, int flags) +{ + struct fib6_info *f6i; + struct rt6_info *rt; + int strict = 0; + + strict |= flags & RT6_LOOKUP_F_IFACE; + strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE; + if (net->ipv6.devconf_all->forwarding == 0) + strict |= RT6_LOOKUP_F_REACHABLE; + + rcu_read_lock(); + + f6i = fib6_table_lookup(net, table, oif, fl6, strict); + if (f6i->fib6_nsiblings) + f6i = fib6_multipath_select(net, f6i, fl6, oif, skb, strict); + if (f6i == net->ipv6.fib6_null_entry) { rt = net->ipv6.ip6_null_entry; rcu_read_unlock(); -- cgit v1.2.3 From cc065a9eb96f7f2a29a04ca49331a9ccb1cfcfa2 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Wed, 9 May 2018 20:34:22 -0700 Subject: net/ipv6: Refactor fib6_rule_action Move source address lookup from fib6_rule_action to a helper. It will be used in a later patch by a second variant for fib6_rule_action. Signed-off-by: David Ahern Acked-by: David S. Miller Signed-off-by: Daniel Borkmann --- net/ipv6/fib6_rules.c | 52 ++++++++++++++++++++++++++++++--------------------- 1 file changed, 31 insertions(+), 21 deletions(-) diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c index 6547fc6491a6..d040c4bff3a0 100644 --- a/net/ipv6/fib6_rules.c +++ b/net/ipv6/fib6_rules.c @@ -96,6 +96,31 @@ struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, return &net->ipv6.ip6_null_entry->dst; } +static int fib6_rule_saddr(struct net *net, struct fib_rule *rule, int flags, + struct flowi6 *flp6, const struct net_device *dev) +{ + struct fib6_rule *r = (struct fib6_rule *)rule; + + /* If we need to find a source address for this traffic, + * we check the result if it meets requirement of the rule. + */ + if ((rule->flags & FIB_RULE_FIND_SADDR) && + r->src.plen && !(flags & RT6_LOOKUP_F_HAS_SADDR)) { + struct in6_addr saddr; + + if (ipv6_dev_get_saddr(net, dev, &flp6->daddr, + rt6_flags2srcprefs(flags), &saddr)) + return -EAGAIN; + + if (!ipv6_prefix_equal(&saddr, &r->src.addr, r->src.plen)) + return -EAGAIN; + + flp6->saddr = saddr; + } + + return 0; +} + static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp, int flags, struct fib_lookup_arg *arg) { @@ -134,27 +159,12 @@ static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp, rt = lookup(net, table, flp6, arg->lookup_data, flags); if (rt != net->ipv6.ip6_null_entry) { - struct fib6_rule *r = (struct fib6_rule *)rule; - - /* - * If we need to find a source address for this traffic, - * we check the result if it meets requirement of the rule. - */ - if ((rule->flags & FIB_RULE_FIND_SADDR) && - r->src.plen && !(flags & RT6_LOOKUP_F_HAS_SADDR)) { - struct in6_addr saddr; - - if (ipv6_dev_get_saddr(net, - ip6_dst_idev(&rt->dst)->dev, - &flp6->daddr, - rt6_flags2srcprefs(flags), - &saddr)) - goto again; - if (!ipv6_prefix_equal(&saddr, &r->src.addr, - r->src.plen)) - goto again; - flp6->saddr = saddr; - } + err = fib6_rule_saddr(net, rule, flags, flp6, + ip6_dst_idev(&rt->dst)->dev); + + if (err == -EAGAIN) + goto again; + err = rt->dst.error; if (err != -EAGAIN) goto out; -- cgit v1.2.3 From 138118ec96cbfc303c1d7cc05fbb2caf8382c95b Mon Sep 17 00:00:00 2001 From: David Ahern Date: Wed, 9 May 2018 20:34:23 -0700 Subject: net/ipv6: Add fib6_lookup Add IPv6 equivalent to fib_lookup. Does a fib lookup, including rules, but returns a FIB entry, fib6_info, rather than a dst based rt6_info. fib6_lookup is any where from 140% (MULTIPLE_TABLES config disabled) to 60% faster than any of the dst based lookup methods (without custom rules) and 25% faster with custom rules (e.g., l3mdev rule). Since the lookup function has a completely different signature, fib6_rule_action is split into 2 paths: the existing one is renamed __fib6_rule_action and a new one for the fib6_info path is added. fib6_rule_action decides which to call based on the lookup_ptr. If it is fib6_table_lookup then the new path is taken. Caller must hold rcu lock as no reference is taken on the returned fib entry. Signed-off-by: David Ahern Acked-by: David S. Miller Signed-off-by: Daniel Borkmann --- include/net/ip6_fib.h | 6 ++++ net/ipv6/fib6_rules.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++-- net/ipv6/ip6_fib.c | 7 +++++ 3 files changed, 97 insertions(+), 2 deletions(-) diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h index c70705f2647a..cc70f6da8462 100644 --- a/include/net/ip6_fib.h +++ b/include/net/ip6_fib.h @@ -376,6 +376,12 @@ struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, const struct sk_buff *skb, int flags, pol_lookup_t lookup); +/* called with rcu lock held; can return error pointer + * caller needs to select path + */ +struct fib6_info *fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, + int flags); + /* called with rcu lock held; caller needs to select path */ struct fib6_info *fib6_table_lookup(struct net *net, struct fib6_table *table, int oif, struct flowi6 *fl6, int strict); diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c index d040c4bff3a0..f590446595d8 100644 --- a/net/ipv6/fib6_rules.c +++ b/net/ipv6/fib6_rules.c @@ -60,6 +60,39 @@ unsigned int fib6_rules_seq_read(struct net *net) return fib_rules_seq_read(net, AF_INET6); } +/* called with rcu lock held; no reference taken on fib6_info */ +struct fib6_info *fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, + int flags) +{ + struct fib6_info *f6i; + int err; + + if (net->ipv6.fib6_has_custom_rules) { + struct fib_lookup_arg arg = { + .lookup_ptr = fib6_table_lookup, + .lookup_data = &oif, + .flags = FIB_LOOKUP_NOREF, + }; + + l3mdev_update_flow(net, flowi6_to_flowi(fl6)); + + err = fib_rules_lookup(net->ipv6.fib6_rules_ops, + flowi6_to_flowi(fl6), flags, &arg); + if (err) + return ERR_PTR(err); + + f6i = arg.result ? : net->ipv6.fib6_null_entry; + } else { + f6i = fib6_table_lookup(net, net->ipv6.fib6_local_tbl, + oif, fl6, flags); + if (!f6i || f6i == net->ipv6.fib6_null_entry) + f6i = fib6_table_lookup(net, net->ipv6.fib6_main_tbl, + oif, fl6, flags); + } + + return f6i; +} + struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, const struct sk_buff *skb, int flags, pol_lookup_t lookup) @@ -121,8 +154,48 @@ static int fib6_rule_saddr(struct net *net, struct fib_rule *rule, int flags, return 0; } -static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp, - int flags, struct fib_lookup_arg *arg) +static int fib6_rule_action_alt(struct fib_rule *rule, struct flowi *flp, + int flags, struct fib_lookup_arg *arg) +{ + struct flowi6 *flp6 = &flp->u.ip6; + struct net *net = rule->fr_net; + struct fib6_table *table; + struct fib6_info *f6i; + int err = -EAGAIN, *oif; + u32 tb_id; + + switch (rule->action) { + case FR_ACT_TO_TBL: + break; + case FR_ACT_UNREACHABLE: + return -ENETUNREACH; + case FR_ACT_PROHIBIT: + return -EACCES; + case FR_ACT_BLACKHOLE: + default: + return -EINVAL; + } + + tb_id = fib_rule_get_table(rule, arg); + table = fib6_get_table(net, tb_id); + if (!table) + return -EAGAIN; + + oif = (int *)arg->lookup_data; + f6i = fib6_table_lookup(net, table, *oif, flp6, flags); + if (f6i != net->ipv6.fib6_null_entry) { + err = fib6_rule_saddr(net, rule, flags, flp6, + fib6_info_nh_dev(f6i)); + + if (likely(!err)) + arg->result = f6i; + } + + return err; +} + +static int __fib6_rule_action(struct fib_rule *rule, struct flowi *flp, + int flags, struct fib_lookup_arg *arg) { struct flowi6 *flp6 = &flp->u.ip6; struct rt6_info *rt = NULL; @@ -182,6 +255,15 @@ out: return err; } +static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp, + int flags, struct fib_lookup_arg *arg) +{ + if (arg->lookup_ptr == fib6_table_lookup) + return fib6_rule_action_alt(rule, flp, flags, arg); + + return __fib6_rule_action(rule, flp, flags, arg); +} + static bool fib6_rule_suppress(struct fib_rule *rule, struct fib_lookup_arg *arg) { struct rt6_info *rt = (struct rt6_info *) arg->result; diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index 487faffeae28..d1dc6017f5a6 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -354,6 +354,13 @@ struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, return &rt->dst; } +/* called with rcu lock held; no reference taken on fib6_info */ +struct fib6_info *fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, + int flags) +{ + return fib6_table_lookup(net, net->ipv6.fib6_main_tbl, oif, fl6, flags); +} + static void __net_init fib6_tables_init(struct net *net) { fib6_link_table(net, net->ipv6.fib6_main_tbl); -- cgit v1.2.3 From d4bea421f7322400d804c2284739e42e61f78349 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Wed, 9 May 2018 20:34:24 -0700 Subject: net/ipv6: Update fib6 tracepoint to take fib6_info Similar to IPv4, IPv6 should use the FIB lookup result in the tracepoint. Signed-off-by: David Ahern Acked-by: David S. Miller Signed-off-by: Daniel Borkmann --- include/trace/events/fib6.h | 14 +++++++------- net/ipv6/route.c | 14 ++++++-------- 2 files changed, 13 insertions(+), 15 deletions(-) diff --git a/include/trace/events/fib6.h b/include/trace/events/fib6.h index 7e8d48a81b91..1b8d951e3c12 100644 --- a/include/trace/events/fib6.h +++ b/include/trace/events/fib6.h @@ -12,10 +12,10 @@ TRACE_EVENT(fib6_table_lookup, - TP_PROTO(const struct net *net, const struct rt6_info *rt, + TP_PROTO(const struct net *net, const struct fib6_info *f6i, struct fib6_table *table, const struct flowi6 *flp), - TP_ARGS(net, rt, table, flp), + TP_ARGS(net, f6i, table, flp), TP_STRUCT__entry( __field( u32, tb_id ) @@ -48,20 +48,20 @@ TRACE_EVENT(fib6_table_lookup, in6 = (struct in6_addr *)__entry->dst; *in6 = flp->daddr; - if (rt->rt6i_idev) { - __assign_str(name, rt->rt6i_idev->dev->name); + if (f6i->fib6_nh.nh_dev) { + __assign_str(name, f6i->fib6_nh.nh_dev); } else { __assign_str(name, ""); } - if (rt == net->ipv6.ip6_null_entry) { + if (f6i == net->ipv6.fib6_null_entry) { struct in6_addr in6_zero = {}; in6 = (struct in6_addr *)__entry->gw; *in6 = in6_zero; - } else if (rt) { + } else if (f6i) { in6 = (struct in6_addr *)__entry->gw; - *in6 = rt->rt6i_gateway; + *in6 = f6i->fib6_nh.nh_gw; } ), diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 019d8ba9021e..73f9c29a5878 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1078,6 +1078,8 @@ restart: goto restart; } + trace_fib6_table_lookup(net, f6i, table, fl6); + /* Search through exception table */ rt = rt6_find_cached_rt(f6i, &fl6->daddr, &fl6->saddr); if (rt) { @@ -1096,8 +1098,6 @@ restart: rcu_read_unlock(); - trace_fib6_table_lookup(net, rt, table, fl6); - return rt; } @@ -1827,6 +1827,8 @@ redo_rt6_select: } } + trace_fib6_table_lookup(net, f6i, table, fl6); + return f6i; } @@ -1853,7 +1855,6 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, rt = net->ipv6.ip6_null_entry; rcu_read_unlock(); dst_hold(&rt->dst); - trace_fib6_table_lookup(net, rt, table, fl6); return rt; } @@ -1864,7 +1865,6 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, dst_use_noref(&rt->dst, jiffies); rcu_read_unlock(); - trace_fib6_table_lookup(net, rt, table, fl6); return rt; } else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) && !(f6i->fib6_flags & RTF_GATEWAY))) { @@ -1890,9 +1890,7 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, dst_hold(&uncached_rt->dst); } - trace_fib6_table_lookup(net, uncached_rt, table, fl6); return uncached_rt; - } else { /* Get a percpu copy */ @@ -1906,7 +1904,7 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, local_bh_enable(); rcu_read_unlock(); - trace_fib6_table_lookup(net, pcpu_rt, table, fl6); + return pcpu_rt; } } @@ -2491,7 +2489,7 @@ out: rcu_read_unlock(); - trace_fib6_table_lookup(net, ret, table, fl6); + trace_fib6_table_lookup(net, rt, table, fl6); return ret; }; -- cgit v1.2.3 From 65a2022e89a4760f9702837e2d9d15a39a9c68a3 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Wed, 9 May 2018 20:34:25 -0700 Subject: net/ipv6: Add fib lookup stubs for use in bpf helper Add stubs to retrieve a handle to an IPv6 FIB table, fib6_get_table, a stub to do a lookup in a specific table, fib6_table_lookup, and a stub for a full route lookup. The stubs are needed for core bpf code to handle the case when the IPv6 module is not builtin. Signed-off-by: David Ahern Acked-by: David S. Miller Signed-off-by: Daniel Borkmann --- include/net/addrconf.h | 14 ++++++++++++++ net/ipv6/addrconf_core.c | 33 ++++++++++++++++++++++++++++++++- net/ipv6/af_inet6.c | 6 +++++- 3 files changed, 51 insertions(+), 2 deletions(-) diff --git a/include/net/addrconf.h b/include/net/addrconf.h index 8312cc25a3af..ff766ab207e0 100644 --- a/include/net/addrconf.h +++ b/include/net/addrconf.h @@ -223,6 +223,20 @@ struct ipv6_stub { const struct in6_addr *addr); int (*ipv6_dst_lookup)(struct net *net, struct sock *sk, struct dst_entry **dst, struct flowi6 *fl6); + + struct fib6_table *(*fib6_get_table)(struct net *net, u32 id); + struct fib6_info *(*fib6_lookup)(struct net *net, int oif, + struct flowi6 *fl6, int flags); + struct fib6_info *(*fib6_table_lookup)(struct net *net, + struct fib6_table *table, + int oif, struct flowi6 *fl6, + int flags); + struct fib6_info *(*fib6_multipath_select)(const struct net *net, + struct fib6_info *f6i, + struct flowi6 *fl6, int oif, + const struct sk_buff *skb, + int strict); + void (*udpv6_encap_enable)(void); void (*ndisc_send_na)(struct net_device *dev, const struct in6_addr *daddr, const struct in6_addr *solicited_addr, diff --git a/net/ipv6/addrconf_core.c b/net/ipv6/addrconf_core.c index 32b564dfd02a..2fe754fd4f5e 100644 --- a/net/ipv6/addrconf_core.c +++ b/net/ipv6/addrconf_core.c @@ -134,8 +134,39 @@ static int eafnosupport_ipv6_dst_lookup(struct net *net, struct sock *u1, return -EAFNOSUPPORT; } +static struct fib6_table *eafnosupport_fib6_get_table(struct net *net, u32 id) +{ + return NULL; +} + +static struct fib6_info * +eafnosupport_fib6_table_lookup(struct net *net, struct fib6_table *table, + int oif, struct flowi6 *fl6, int flags) +{ + return NULL; +} + +static struct fib6_info * +eafnosupport_fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, + int flags) +{ + return NULL; +} + +static struct fib6_info * +eafnosupport_fib6_multipath_select(const struct net *net, struct fib6_info *f6i, + struct flowi6 *fl6, int oif, + const struct sk_buff *skb, int strict) +{ + return f6i; +} + const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) { - .ipv6_dst_lookup = eafnosupport_ipv6_dst_lookup, + .ipv6_dst_lookup = eafnosupport_ipv6_dst_lookup, + .fib6_get_table = eafnosupport_fib6_get_table, + .fib6_table_lookup = eafnosupport_fib6_table_lookup, + .fib6_lookup = eafnosupport_fib6_lookup, + .fib6_multipath_select = eafnosupport_fib6_multipath_select, }; EXPORT_SYMBOL_GPL(ipv6_stub); diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index d0af96e0d109..50de8b0d4f70 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -889,7 +889,11 @@ static struct pernet_operations inet6_net_ops = { static const struct ipv6_stub ipv6_stub_impl = { .ipv6_sock_mc_join = ipv6_sock_mc_join, .ipv6_sock_mc_drop = ipv6_sock_mc_drop, - .ipv6_dst_lookup = ip6_dst_lookup, + .ipv6_dst_lookup = ip6_dst_lookup, + .fib6_get_table = fib6_get_table, + .fib6_table_lookup = fib6_table_lookup, + .fib6_lookup = fib6_lookup, + .fib6_multipath_select = fib6_multipath_select, .udpv6_encap_enable = udpv6_encap_enable, .ndisc_send_na = ndisc_send_na, .nd_tbl = &nd_tbl, -- cgit v1.2.3 From 87f5fc7e48dd3175b30dd03b41564e1a8e136323 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Wed, 9 May 2018 20:34:26 -0700 Subject: bpf: Provide helper to do forwarding lookups in kernel FIB table Provide a helper for doing a FIB and neighbor lookup in the kernel tables from an XDP program. The helper provides a fastpath for forwarding packets. If the packet is a local delivery or for any reason is not a simple lookup and forward, the packet continues up the stack. If it is to be forwarded, the forwarding can be done directly if the neighbor is already known. If the neighbor does not exist, the first few packets go up the stack for neighbor resolution. Once resolved, the xdp program provides the fast path. On successful lookup the nexthop dmac, current device smac and egress device index are returned. The API supports IPv4, IPv6 and MPLS protocols, but only IPv4 and IPv6 are implemented in this patch. The API includes layer 4 parameters if the XDP program chooses to do deep packet inspection to allow compare against ACLs implemented as FIB rules. Header rewrite is left to the XDP program. The lookup takes 2 flags: - BPF_FIB_LOOKUP_DIRECT to do a lookup that bypasses FIB rules and goes straight to the table associated with the device (expert setting for those looking to maximize throughput) - BPF_FIB_LOOKUP_OUTPUT to do a lookup from the egress perspective. Default is an ingress lookup. Initial performance numbers collected by Jesper, forwarded packets/sec: Full stack XDP FIB lookup XDP Direct lookup IPv4 1,947,969 7,074,156 7,415,333 IPv6 1,728,000 6,165,504 7,262,720 These number are single CPU core forwarding on a Broadwell E5-1650 v4 @ 3.60GHz. Signed-off-by: David Ahern Acked-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann --- include/uapi/linux/bpf.h | 81 +++++++++++++- net/core/filter.c | 267 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 347 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index d615c777b573..02e4112510f8 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1828,6 +1828,33 @@ union bpf_attr { * Return * 0 on success, or a negative error in case of failure. * + * + * int bpf_fib_lookup(void *ctx, struct bpf_fib_lookup *params, int plen, u32 flags) + * Description + * Do FIB lookup in kernel tables using parameters in *params*. + * If lookup is successful and result shows packet is to be + * forwarded, the neighbor tables are searched for the nexthop. + * If successful (ie., FIB lookup shows forwarding and nexthop + * is resolved), the nexthop address is returned in ipv4_dst, + * ipv6_dst or mpls_out based on family, smac is set to mac + * address of egress device, dmac is set to nexthop mac address, + * rt_metric is set to metric from route. + * + * *plen* argument is the size of the passed in struct. + * *flags* argument can be one or more BPF_FIB_LOOKUP_ flags: + * + * **BPF_FIB_LOOKUP_DIRECT** means do a direct table lookup vs + * full lookup using FIB rules + * **BPF_FIB_LOOKUP_OUTPUT** means do lookup from an egress + * perspective (default is ingress) + * + * *ctx* is either **struct xdp_md** for XDP programs or + * **struct sk_buff** tc cls_act programs. + * + * Return + * Egress device index on success, 0 if packet needs to continue + * up the stack for further processing or a negative error in case + * of failure. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -1898,7 +1925,8 @@ union bpf_attr { FN(xdp_adjust_tail), \ FN(skb_get_xfrm_state), \ FN(get_stack), \ - FN(skb_load_bytes_relative), + FN(skb_load_bytes_relative), \ + FN(fib_lookup), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call @@ -2321,4 +2349,55 @@ struct bpf_raw_tracepoint_args { __u64 args[0]; }; +/* DIRECT: Skip the FIB rules and go to FIB table associated with device + * OUTPUT: Do lookup from egress perspective; default is ingress + */ +#define BPF_FIB_LOOKUP_DIRECT BIT(0) +#define BPF_FIB_LOOKUP_OUTPUT BIT(1) + +struct bpf_fib_lookup { + /* input */ + __u8 family; /* network family, AF_INET, AF_INET6, AF_MPLS */ + + /* set if lookup is to consider L4 data - e.g., FIB rules */ + __u8 l4_protocol; + __be16 sport; + __be16 dport; + + /* total length of packet from network header - used for MTU check */ + __u16 tot_len; + __u32 ifindex; /* L3 device index for lookup */ + + union { + /* inputs to lookup */ + __u8 tos; /* AF_INET */ + __be32 flowlabel; /* AF_INET6 */ + + /* output: metric of fib result */ + __u32 rt_metric; + }; + + union { + __be32 mpls_in; + __be32 ipv4_src; + __u32 ipv6_src[4]; /* in6_addr; network order */ + }; + + /* input to bpf_fib_lookup, *dst is destination address. + * output: bpf_fib_lookup sets to gateway address + */ + union { + /* return for MPLS lookups */ + __be32 mpls_out[4]; /* support up to 4 labels */ + __be32 ipv4_dst; + __u32 ipv6_dst[4]; /* in6_addr; network order */ + }; + + /* output */ + __be16 h_vlan_proto; + __be16 h_vlan_TCI; + __u8 smac[6]; /* ETH_ALEN */ + __u8 dmac[6]; /* ETH_ALEN */ +}; + #endif /* _UAPI__LINUX_BPF_H__ */ diff --git a/net/core/filter.c b/net/core/filter.c index 0baa715e4699..ca60d2872da4 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -60,6 +60,10 @@ #include #include #include +#include +#include +#include +#include /** * sk_filter_trim_cap - run a packet through a socket filter @@ -4032,6 +4036,265 @@ static const struct bpf_func_proto bpf_skb_get_xfrm_state_proto = { }; #endif +#if IS_ENABLED(CONFIG_INET) || IS_ENABLED(CONFIG_IPV6) +static int bpf_fib_set_fwd_params(struct bpf_fib_lookup *params, + const struct neighbour *neigh, + const struct net_device *dev) +{ + memcpy(params->dmac, neigh->ha, ETH_ALEN); + memcpy(params->smac, dev->dev_addr, ETH_ALEN); + params->h_vlan_TCI = 0; + params->h_vlan_proto = 0; + + return dev->ifindex; +} +#endif + +#if IS_ENABLED(CONFIG_INET) +static int bpf_ipv4_fib_lookup(struct net *net, struct bpf_fib_lookup *params, + u32 flags) +{ + struct in_device *in_dev; + struct neighbour *neigh; + struct net_device *dev; + struct fib_result res; + struct fib_nh *nh; + struct flowi4 fl4; + int err; + + dev = dev_get_by_index_rcu(net, params->ifindex); + if (unlikely(!dev)) + return -ENODEV; + + /* verify forwarding is enabled on this interface */ + in_dev = __in_dev_get_rcu(dev); + if (unlikely(!in_dev || !IN_DEV_FORWARD(in_dev))) + return 0; + + if (flags & BPF_FIB_LOOKUP_OUTPUT) { + fl4.flowi4_iif = 1; + fl4.flowi4_oif = params->ifindex; + } else { + fl4.flowi4_iif = params->ifindex; + fl4.flowi4_oif = 0; + } + fl4.flowi4_tos = params->tos & IPTOS_RT_MASK; + fl4.flowi4_scope = RT_SCOPE_UNIVERSE; + fl4.flowi4_flags = 0; + + fl4.flowi4_proto = params->l4_protocol; + fl4.daddr = params->ipv4_dst; + fl4.saddr = params->ipv4_src; + fl4.fl4_sport = params->sport; + fl4.fl4_dport = params->dport; + + if (flags & BPF_FIB_LOOKUP_DIRECT) { + u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN; + struct fib_table *tb; + + tb = fib_get_table(net, tbid); + if (unlikely(!tb)) + return 0; + + err = fib_table_lookup(tb, &fl4, &res, FIB_LOOKUP_NOREF); + } else { + fl4.flowi4_mark = 0; + fl4.flowi4_secid = 0; + fl4.flowi4_tun_key.tun_id = 0; + fl4.flowi4_uid = sock_net_uid(net, NULL); + + err = fib_lookup(net, &fl4, &res, FIB_LOOKUP_NOREF); + } + + if (err || res.type != RTN_UNICAST) + return 0; + + if (res.fi->fib_nhs > 1) + fib_select_path(net, &res, &fl4, NULL); + + nh = &res.fi->fib_nh[res.nh_sel]; + + /* do not handle lwt encaps right now */ + if (nh->nh_lwtstate) + return 0; + + dev = nh->nh_dev; + if (unlikely(!dev)) + return 0; + + if (nh->nh_gw) + params->ipv4_dst = nh->nh_gw; + + params->rt_metric = res.fi->fib_priority; + + /* xdp and cls_bpf programs are run in RCU-bh so + * rcu_read_lock_bh is not needed here + */ + neigh = __ipv4_neigh_lookup_noref(dev, (__force u32)params->ipv4_dst); + if (neigh) + return bpf_fib_set_fwd_params(params, neigh, dev); + + return 0; +} +#endif + +#if IS_ENABLED(CONFIG_IPV6) +static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params, + u32 flags) +{ + struct in6_addr *src = (struct in6_addr *) params->ipv6_src; + struct in6_addr *dst = (struct in6_addr *) params->ipv6_dst; + struct neighbour *neigh; + struct net_device *dev; + struct inet6_dev *idev; + struct fib6_info *f6i; + struct flowi6 fl6; + int strict = 0; + int oif; + + /* link local addresses are never forwarded */ + if (rt6_need_strict(dst) || rt6_need_strict(src)) + return 0; + + dev = dev_get_by_index_rcu(net, params->ifindex); + if (unlikely(!dev)) + return -ENODEV; + + idev = __in6_dev_get_safely(dev); + if (unlikely(!idev || !net->ipv6.devconf_all->forwarding)) + return 0; + + if (flags & BPF_FIB_LOOKUP_OUTPUT) { + fl6.flowi6_iif = 1; + oif = fl6.flowi6_oif = params->ifindex; + } else { + oif = fl6.flowi6_iif = params->ifindex; + fl6.flowi6_oif = 0; + strict = RT6_LOOKUP_F_HAS_SADDR; + } + fl6.flowlabel = params->flowlabel; + fl6.flowi6_scope = 0; + fl6.flowi6_flags = 0; + fl6.mp_hash = 0; + + fl6.flowi6_proto = params->l4_protocol; + fl6.daddr = *dst; + fl6.saddr = *src; + fl6.fl6_sport = params->sport; + fl6.fl6_dport = params->dport; + + if (flags & BPF_FIB_LOOKUP_DIRECT) { + u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN; + struct fib6_table *tb; + + tb = ipv6_stub->fib6_get_table(net, tbid); + if (unlikely(!tb)) + return 0; + + f6i = ipv6_stub->fib6_table_lookup(net, tb, oif, &fl6, strict); + } else { + fl6.flowi6_mark = 0; + fl6.flowi6_secid = 0; + fl6.flowi6_tun_key.tun_id = 0; + fl6.flowi6_uid = sock_net_uid(net, NULL); + + f6i = ipv6_stub->fib6_lookup(net, oif, &fl6, strict); + } + + if (unlikely(IS_ERR_OR_NULL(f6i) || f6i == net->ipv6.fib6_null_entry)) + return 0; + + if (unlikely(f6i->fib6_flags & RTF_REJECT || + f6i->fib6_type != RTN_UNICAST)) + return 0; + + if (f6i->fib6_nsiblings && fl6.flowi6_oif == 0) + f6i = ipv6_stub->fib6_multipath_select(net, f6i, &fl6, + fl6.flowi6_oif, NULL, + strict); + + if (f6i->fib6_nh.nh_lwtstate) + return 0; + + if (f6i->fib6_flags & RTF_GATEWAY) + *dst = f6i->fib6_nh.nh_gw; + + dev = f6i->fib6_nh.nh_dev; + params->rt_metric = f6i->fib6_metric; + + /* xdp and cls_bpf programs are run in RCU-bh so rcu_read_lock_bh is + * not needed here. Can not use __ipv6_neigh_lookup_noref here + * because we need to get nd_tbl via the stub + */ + neigh = ___neigh_lookup_noref(ipv6_stub->nd_tbl, neigh_key_eq128, + ndisc_hashfn, dst, dev); + if (neigh) + return bpf_fib_set_fwd_params(params, neigh, dev); + + return 0; +} +#endif + +BPF_CALL_4(bpf_xdp_fib_lookup, struct xdp_buff *, ctx, + struct bpf_fib_lookup *, params, int, plen, u32, flags) +{ + if (plen < sizeof(*params)) + return -EINVAL; + + switch (params->family) { +#if IS_ENABLED(CONFIG_INET) + case AF_INET: + return bpf_ipv4_fib_lookup(dev_net(ctx->rxq->dev), params, + flags); +#endif +#if IS_ENABLED(CONFIG_IPV6) + case AF_INET6: + return bpf_ipv6_fib_lookup(dev_net(ctx->rxq->dev), params, + flags); +#endif + } + return 0; +} + +static const struct bpf_func_proto bpf_xdp_fib_lookup_proto = { + .func = bpf_xdp_fib_lookup, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_PTR_TO_MEM, + .arg3_type = ARG_CONST_SIZE, + .arg4_type = ARG_ANYTHING, +}; + +BPF_CALL_4(bpf_skb_fib_lookup, struct sk_buff *, skb, + struct bpf_fib_lookup *, params, int, plen, u32, flags) +{ + if (plen < sizeof(*params)) + return -EINVAL; + + switch (params->family) { +#if IS_ENABLED(CONFIG_INET) + case AF_INET: + return bpf_ipv4_fib_lookup(dev_net(skb->dev), params, flags); +#endif +#if IS_ENABLED(CONFIG_IPV6) + case AF_INET6: + return bpf_ipv6_fib_lookup(dev_net(skb->dev), params, flags); +#endif + } + return -ENOTSUPP; +} + +static const struct bpf_func_proto bpf_skb_fib_lookup_proto = { + .func = bpf_skb_fib_lookup, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_PTR_TO_MEM, + .arg3_type = ARG_CONST_SIZE, + .arg4_type = ARG_ANYTHING, +}; + static const struct bpf_func_proto * bpf_base_func_proto(enum bpf_func_id func_id) { @@ -4181,6 +4444,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_FUNC_skb_get_xfrm_state: return &bpf_skb_get_xfrm_state_proto; #endif + case BPF_FUNC_fib_lookup: + return &bpf_skb_fib_lookup_proto; default: return bpf_base_func_proto(func_id); } @@ -4206,6 +4471,8 @@ xdp_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_xdp_redirect_map_proto; case BPF_FUNC_xdp_adjust_tail: return &bpf_xdp_adjust_tail_proto; + case BPF_FUNC_fib_lookup: + return &bpf_xdp_fib_lookup_proto; default: return bpf_base_func_proto(func_id); } -- cgit v1.2.3 From fe616055f78457a0b78e0d3693d1ae26f2d7dab3 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Wed, 9 May 2018 20:34:27 -0700 Subject: samples/bpf: Add example of ipv4 and ipv6 forwarding in XDP Simple example of fast-path forwarding. It has a serious flaw in not verifying the egress device index supports XDP forwarding. If the egress device does not packets are dropped. Take this only as a simple example of fast-path forwarding. Signed-off-by: David Ahern Acked-by: David S. Miller Acked-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann --- samples/bpf/Makefile | 4 + samples/bpf/xdp_fwd_kern.c | 115 +++++++++++++++++++++++++ samples/bpf/xdp_fwd_user.c | 136 ++++++++++++++++++++++++++++++ tools/testing/selftests/bpf/bpf_helpers.h | 3 + 4 files changed, 258 insertions(+) create mode 100644 samples/bpf/xdp_fwd_kern.c create mode 100644 samples/bpf/xdp_fwd_user.c diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 8e0c7fb6d7cc..28513d6be1bf 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -46,6 +46,7 @@ hostprogs-y += syscall_tp hostprogs-y += cpustat hostprogs-y += xdp_adjust_tail hostprogs-y += xdpsock +hostprogs-y += xdp_fwd # Libbpf dependencies LIBBPF := ../../tools/lib/bpf/bpf.o ../../tools/lib/bpf/nlattr.o @@ -100,6 +101,7 @@ syscall_tp-objs := bpf_load.o $(LIBBPF) syscall_tp_user.o cpustat-objs := bpf_load.o $(LIBBPF) cpustat_user.o xdp_adjust_tail-objs := bpf_load.o $(LIBBPF) xdp_adjust_tail_user.o xdpsock-objs := bpf_load.o $(LIBBPF) xdpsock_user.o +xdp_fwd-objs := bpf_load.o $(LIBBPF) xdp_fwd_user.o # Tell kbuild to always build the programs always := $(hostprogs-y) @@ -154,6 +156,7 @@ always += syscall_tp_kern.o always += cpustat_kern.o always += xdp_adjust_tail_kern.o always += xdpsock_kern.o +always += xdp_fwd_kern.o HOSTCFLAGS += -I$(objtree)/usr/include HOSTCFLAGS += -I$(srctree)/tools/lib/ @@ -201,6 +204,7 @@ HOSTLOADLIBES_syscall_tp += -lelf HOSTLOADLIBES_cpustat += -lelf HOSTLOADLIBES_xdp_adjust_tail += -lelf HOSTLOADLIBES_xdpsock += -lelf -pthread +HOSTLOADLIBES_xdp_fwd += -lelf # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline: # make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang diff --git a/samples/bpf/xdp_fwd_kern.c b/samples/bpf/xdp_fwd_kern.c new file mode 100644 index 000000000000..cdf4fc383cc9 --- /dev/null +++ b/samples/bpf/xdp_fwd_kern.c @@ -0,0 +1,115 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2017-18 David Ahern + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ +#define KBUILD_MODNAME "foo" +#include +#include +#include +#include +#include +#include +#include + +#include "bpf_helpers.h" + +#define IPV6_FLOWINFO_MASK cpu_to_be32(0x0FFFFFFF) + +struct bpf_map_def SEC("maps") tx_port = { + .type = BPF_MAP_TYPE_DEVMAP, + .key_size = sizeof(int), + .value_size = sizeof(int), + .max_entries = 64, +}; + +static __always_inline int xdp_fwd_flags(struct xdp_md *ctx, u32 flags) +{ + void *data_end = (void *)(long)ctx->data_end; + void *data = (void *)(long)ctx->data; + struct bpf_fib_lookup fib_params; + struct ethhdr *eth = data; + int out_index; + u16 h_proto; + u64 nh_off; + + nh_off = sizeof(*eth); + if (data + nh_off > data_end) + return XDP_DROP; + + __builtin_memset(&fib_params, 0, sizeof(fib_params)); + + h_proto = eth->h_proto; + if (h_proto == htons(ETH_P_IP)) { + struct iphdr *iph = data + nh_off; + + if (iph + 1 > data_end) + return XDP_DROP; + + fib_params.family = AF_INET; + fib_params.tos = iph->tos; + fib_params.l4_protocol = iph->protocol; + fib_params.sport = 0; + fib_params.dport = 0; + fib_params.tot_len = ntohs(iph->tot_len); + fib_params.ipv4_src = iph->saddr; + fib_params.ipv4_dst = iph->daddr; + } else if (h_proto == htons(ETH_P_IPV6)) { + struct in6_addr *src = (struct in6_addr *) fib_params.ipv6_src; + struct in6_addr *dst = (struct in6_addr *) fib_params.ipv6_dst; + struct ipv6hdr *iph = data + nh_off; + + if (iph + 1 > data_end) + return XDP_DROP; + + fib_params.family = AF_INET6; + fib_params.flowlabel = *(__be32 *)iph & IPV6_FLOWINFO_MASK; + fib_params.l4_protocol = iph->nexthdr; + fib_params.sport = 0; + fib_params.dport = 0; + fib_params.tot_len = ntohs(iph->payload_len); + *src = iph->saddr; + *dst = iph->daddr; + } else { + return XDP_PASS; + } + + fib_params.ifindex = ctx->ingress_ifindex; + + out_index = bpf_fib_lookup(ctx, &fib_params, sizeof(fib_params), flags); + + /* verify egress index has xdp support + * TO-DO bpf_map_lookup_elem(&tx_port, &key) fails with + * cannot pass map_type 14 into func bpf_map_lookup_elem#1: + * NOTE: without verification that egress index supports XDP + * forwarding packets are dropped. + */ + if (out_index > 0) { + memcpy(eth->h_dest, fib_params.dmac, ETH_ALEN); + memcpy(eth->h_source, fib_params.smac, ETH_ALEN); + return bpf_redirect_map(&tx_port, out_index, 0); + } + + return XDP_PASS; +} + +SEC("xdp_fwd") +int xdp_fwd_prog(struct xdp_md *ctx) +{ + return xdp_fwd_flags(ctx, 0); +} + +SEC("xdp_fwd_direct") +int xdp_fwd_direct_prog(struct xdp_md *ctx) +{ + return xdp_fwd_flags(ctx, BPF_FIB_LOOKUP_DIRECT); +} + +char _license[] SEC("license") = "GPL"; diff --git a/samples/bpf/xdp_fwd_user.c b/samples/bpf/xdp_fwd_user.c new file mode 100644 index 000000000000..9c6606f57126 --- /dev/null +++ b/samples/bpf/xdp_fwd_user.c @@ -0,0 +1,136 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2017-18 David Ahern + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "bpf_load.h" +#include "bpf_util.h" +#include "libbpf.h" + + +static int do_attach(int idx, int fd, const char *name) +{ + int err; + + err = bpf_set_link_xdp_fd(idx, fd, 0); + if (err < 0) + printf("ERROR: failed to attach program to %s\n", name); + + return err; +} + +static int do_detach(int idx, const char *name) +{ + int err; + + err = bpf_set_link_xdp_fd(idx, -1, 0); + if (err < 0) + printf("ERROR: failed to detach program from %s\n", name); + + return err; +} + +static void usage(const char *prog) +{ + fprintf(stderr, + "usage: %s [OPTS] interface-list\n" + "\nOPTS:\n" + " -d detach program\n" + " -D direct table lookups (skip fib rules)\n", + prog); +} + +int main(int argc, char **argv) +{ + char filename[PATH_MAX]; + int opt, i, idx, err; + int prog_id = 0; + int attach = 1; + int ret = 0; + + while ((opt = getopt(argc, argv, ":dD")) != -1) { + switch (opt) { + case 'd': + attach = 0; + break; + case 'D': + prog_id = 1; + break; + default: + usage(basename(argv[0])); + return 1; + } + } + + if (optind == argc) { + usage(basename(argv[0])); + return 1; + } + + if (attach) { + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + + if (access(filename, O_RDONLY) < 0) { + printf("error accessing file %s: %s\n", + filename, strerror(errno)); + return 1; + } + + if (load_bpf_file(filename)) { + printf("%s", bpf_log_buf); + return 1; + } + + if (!prog_fd[prog_id]) { + printf("load_bpf_file: %s\n", strerror(errno)); + return 1; + } + } + if (attach) { + for (i = 1; i < 64; ++i) + bpf_map_update_elem(map_fd[0], &i, &i, 0); + } + + for (i = optind; i < argc; ++i) { + idx = if_nametoindex(argv[i]); + if (!idx) + idx = strtoul(argv[i], NULL, 0); + + if (!idx) { + fprintf(stderr, "Invalid arg\n"); + return 1; + } + if (!attach) { + err = do_detach(idx, argv[i]); + if (err) + ret = err; + } else { + err = do_attach(idx, prog_fd[prog_id], argv[i]); + if (err) + ret = err; + } + } + + return ret; +} diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h index 265f8e0e8ada..2375d06c706b 100644 --- a/tools/testing/selftests/bpf/bpf_helpers.h +++ b/tools/testing/selftests/bpf/bpf_helpers.h @@ -103,6 +103,9 @@ static int (*bpf_skb_get_xfrm_state)(void *ctx, int index, void *state, (void *) BPF_FUNC_skb_get_xfrm_state; static int (*bpf_get_stack)(void *ctx, void *buf, int size, int flags) = (void *) BPF_FUNC_get_stack; +static int (*bpf_fib_lookup)(void *ctx, struct bpf_fib_lookup *params, + int plen, __u32 flags) = + (void *) BPF_FUNC_fib_lookup; /* llvm builtin functions that eBPF C program may use to * emit BPF_LD_ABS and BPF_LD_IND instructions -- cgit v1.2.3 From 91bc07c9e8a0d553250275088fad337806f5a3cf Mon Sep 17 00:00:00 2001 From: Joe Stringer Date: Thu, 10 May 2018 15:26:51 -0700 Subject: selftests/bpf: Fix bash reference in Makefile '|& ...' is a bash 4.0+ construct which is not guaranteed to be available when using '$(shell ...)' in a Makefile. Fall back to the more portable '2>&1 | ...'. Fixes the following warning during compilation: /bin/sh: 1: Syntax error: "&" unexpected Signed-off-by: Joe Stringer Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/Makefile | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 9d762184b805..79d29d6cc719 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -90,9 +90,9 @@ CLANG_FLAGS = -I. -I./include/uapi -I../../../include/uapi \ $(OUTPUT)/test_l4lb_noinline.o: CLANG_FLAGS += -fno-inline $(OUTPUT)/test_xdp_noinline.o: CLANG_FLAGS += -fno-inline -BTF_LLC_PROBE := $(shell $(LLC) -march=bpf -mattr=help |& grep dwarfris) -BTF_PAHOLE_PROBE := $(shell $(BTF_PAHOLE) --help |& grep BTF) -BTF_OBJCOPY_PROBE := $(shell $(LLVM_OBJCOPY) --version |& grep LLVM) +BTF_LLC_PROBE := $(shell $(LLC) -march=bpf -mattr=help 2>&1 | grep dwarfris) +BTF_PAHOLE_PROBE := $(shell $(BTF_PAHOLE) --help 2>&1 | grep BTF) +BTF_OBJCOPY_PROBE := $(shell $(LLVM_OBJCOPY) --version 2>&1 | grep LLVM) ifneq ($(BTF_LLC_PROBE),) ifneq ($(BTF_PAHOLE_PROBE),) -- cgit v1.2.3 From cb9c28ef579debbc51e48b37f2534390f5da8467 Mon Sep 17 00:00:00 2001 From: Prashant Bhole Date: Wed, 9 May 2018 11:04:59 +0900 Subject: bpf: sync tools bpf.h uapi header Sync the header from include/uapi/linux/bpf.h which was updated to add fib lookup helper function. This fixes selftests/bpf build failure. Signed-off-by: Prashant Bhole Signed-off-by: Daniel Borkmann --- tools/include/uapi/linux/bpf.h | 82 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 81 insertions(+), 1 deletion(-) diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index fff51c187d1e..02e4112510f8 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -117,6 +117,7 @@ enum bpf_map_type { BPF_MAP_TYPE_DEVMAP, BPF_MAP_TYPE_SOCKMAP, BPF_MAP_TYPE_CPUMAP, + BPF_MAP_TYPE_XSKMAP, }; enum bpf_prog_type { @@ -1827,6 +1828,33 @@ union bpf_attr { * Return * 0 on success, or a negative error in case of failure. * + * + * int bpf_fib_lookup(void *ctx, struct bpf_fib_lookup *params, int plen, u32 flags) + * Description + * Do FIB lookup in kernel tables using parameters in *params*. + * If lookup is successful and result shows packet is to be + * forwarded, the neighbor tables are searched for the nexthop. + * If successful (ie., FIB lookup shows forwarding and nexthop + * is resolved), the nexthop address is returned in ipv4_dst, + * ipv6_dst or mpls_out based on family, smac is set to mac + * address of egress device, dmac is set to nexthop mac address, + * rt_metric is set to metric from route. + * + * *plen* argument is the size of the passed in struct. + * *flags* argument can be one or more BPF_FIB_LOOKUP_ flags: + * + * **BPF_FIB_LOOKUP_DIRECT** means do a direct table lookup vs + * full lookup using FIB rules + * **BPF_FIB_LOOKUP_OUTPUT** means do lookup from an egress + * perspective (default is ingress) + * + * *ctx* is either **struct xdp_md** for XDP programs or + * **struct sk_buff** tc cls_act programs. + * + * Return + * Egress device index on success, 0 if packet needs to continue + * up the stack for further processing or a negative error in case + * of failure. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -1897,7 +1925,8 @@ union bpf_attr { FN(xdp_adjust_tail), \ FN(skb_get_xfrm_state), \ FN(get_stack), \ - FN(skb_load_bytes_relative), + FN(skb_load_bytes_relative), \ + FN(fib_lookup), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call @@ -2320,4 +2349,55 @@ struct bpf_raw_tracepoint_args { __u64 args[0]; }; +/* DIRECT: Skip the FIB rules and go to FIB table associated with device + * OUTPUT: Do lookup from egress perspective; default is ingress + */ +#define BPF_FIB_LOOKUP_DIRECT BIT(0) +#define BPF_FIB_LOOKUP_OUTPUT BIT(1) + +struct bpf_fib_lookup { + /* input */ + __u8 family; /* network family, AF_INET, AF_INET6, AF_MPLS */ + + /* set if lookup is to consider L4 data - e.g., FIB rules */ + __u8 l4_protocol; + __be16 sport; + __be16 dport; + + /* total length of packet from network header - used for MTU check */ + __u16 tot_len; + __u32 ifindex; /* L3 device index for lookup */ + + union { + /* inputs to lookup */ + __u8 tos; /* AF_INET */ + __be32 flowlabel; /* AF_INET6 */ + + /* output: metric of fib result */ + __u32 rt_metric; + }; + + union { + __be32 mpls_in; + __be32 ipv4_src; + __u32 ipv6_src[4]; /* in6_addr; network order */ + }; + + /* input to bpf_fib_lookup, *dst is destination address. + * output: bpf_fib_lookup sets to gateway address + */ + union { + /* return for MPLS lookups */ + __be32 mpls_out[4]; /* support up to 4 labels */ + __be32 ipv4_dst; + __u32 ipv6_dst[4]; /* in6_addr; network order */ + }; + + /* output */ + __be16 h_vlan_proto; + __be16 h_vlan_TCI; + __u8 smac[6]; /* ETH_ALEN */ + __u8 dmac[6]; /* ETH_ALEN */ +}; + #endif /* _UAPI__LINUX_BPF_H__ */ -- cgit v1.2.3 From e3687510fce2a5b039133be8979b2c8e8cbffa67 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 10 May 2018 10:24:37 -0700 Subject: tools: bpftool: use PERF_SAMPLE_TIME instead of reading the clock Ask the kernel to include sample time in each even instead of reading the clock. This is also more accurate because our clock reading was done when user space would dump the buffer, not when sample was produced. Suggested-by: Daniel Borkmann Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann --- tools/bpf/bpftool/map_perf_ring.c | 17 ++++++----------- 1 file changed, 6 insertions(+), 11 deletions(-) diff --git a/tools/bpf/bpftool/map_perf_ring.c b/tools/bpf/bpftool/map_perf_ring.c index c5a2ced8552d..9ae4bb8a2cad 100644 --- a/tools/bpf/bpftool/map_perf_ring.c +++ b/tools/bpf/bpftool/map_perf_ring.c @@ -39,6 +39,7 @@ struct event_ring_info { struct perf_event_sample { struct perf_event_header header; + u64 time; __u32 size; unsigned char data[]; }; @@ -57,17 +58,9 @@ print_bpf_output(struct event_ring_info *ring, struct perf_event_sample *e) __u64 id; __u64 lost; } *lost = (void *)e; - struct timespec ts; - - if (clock_gettime(CLOCK_MONOTONIC, &ts)) { - perror("Can't read clock for timestamp"); - return; - } if (json_output) { jsonw_start_object(json_wtr); - jsonw_name(json_wtr, "timestamp"); - jsonw_uint(json_wtr, ts.tv_sec * 1000000000ull + ts.tv_nsec); jsonw_name(json_wtr, "type"); jsonw_uint(json_wtr, e->header.type); jsonw_name(json_wtr, "cpu"); @@ -75,6 +68,8 @@ print_bpf_output(struct event_ring_info *ring, struct perf_event_sample *e) jsonw_name(json_wtr, "index"); jsonw_uint(json_wtr, ring->key); if (e->header.type == PERF_RECORD_SAMPLE) { + jsonw_name(json_wtr, "timestamp"); + jsonw_uint(json_wtr, e->time); jsonw_name(json_wtr, "data"); print_data_json(e->data, e->size); } else if (e->header.type == PERF_RECORD_LOST) { @@ -89,8 +84,8 @@ print_bpf_output(struct event_ring_info *ring, struct perf_event_sample *e) jsonw_end_object(json_wtr); } else { if (e->header.type == PERF_RECORD_SAMPLE) { - printf("== @%ld.%ld CPU: %d index: %d =====\n", - (long)ts.tv_sec, ts.tv_nsec, + printf("== @%lld.%09lld CPU: %d index: %d =====\n", + e->time / 1000000000ULL, e->time % 1000000000ULL, ring->cpu, ring->key); fprint_hex(stdout, e->data, e->size, " "); printf("\n"); @@ -185,7 +180,7 @@ static void perf_event_unmap(void *mem) static int bpf_perf_event_open(int map_fd, int key, int cpu) { struct perf_event_attr attr = { - .sample_type = PERF_SAMPLE_RAW, + .sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_TIME, .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_BPF_OUTPUT, }; -- cgit v1.2.3 From 74662ea5d41683e7ff723c35649b0192a8e6ba8f Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 10 May 2018 10:24:38 -0700 Subject: samples: bpf: rename struct bpf_map_def to avoid conflict with libbpf Both tools/lib/bpf/libbpf.h and samples/bpf/bpf_load.h define their own version of struct bpf_map_def. The version in bpf_load.h has more fields. libbpf does not support inner maps and its definition of struct bpf_map_def lacks the related fields. Rename the definition in bpf_load.h (samples/bpf) to avoid conflicts. Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann --- samples/bpf/bpf_load.c | 10 +++++----- samples/bpf/bpf_load.h | 4 ++-- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c index da9bccfaf391..a6b290de5632 100644 --- a/samples/bpf/bpf_load.c +++ b/samples/bpf/bpf_load.c @@ -420,7 +420,7 @@ static int load_elf_maps_section(struct bpf_map_data *maps, int maps_shndx, /* Keeping compatible with ELF maps section changes * ------------------------------------------------ - * The program size of struct bpf_map_def is known by loader + * The program size of struct bpf_load_map_def is known by loader * code, but struct stored in ELF file can be different. * * Unfortunately sym[i].st_size is zero. To calculate the @@ -429,7 +429,7 @@ static int load_elf_maps_section(struct bpf_map_data *maps, int maps_shndx, * symbols. */ map_sz_elf = data_maps->d_size / nr_maps; - map_sz_copy = sizeof(struct bpf_map_def); + map_sz_copy = sizeof(struct bpf_load_map_def); if (map_sz_elf < map_sz_copy) { /* * Backward compat, loading older ELF file with @@ -448,8 +448,8 @@ static int load_elf_maps_section(struct bpf_map_data *maps, int maps_shndx, /* Memcpy relevant part of ELF maps data to loader maps */ for (i = 0; i < nr_maps; i++) { + struct bpf_load_map_def *def; unsigned char *addr, *end; - struct bpf_map_def *def; const char *map_name; size_t offset; @@ -464,9 +464,9 @@ static int load_elf_maps_section(struct bpf_map_data *maps, int maps_shndx, /* Symbol value is offset into ELF maps section data area */ offset = sym[i].st_value; - def = (struct bpf_map_def *)(data_maps->d_buf + offset); + def = (struct bpf_load_map_def *)(data_maps->d_buf + offset); maps[i].elf_offset = offset; - memset(&maps[i].def, 0, sizeof(struct bpf_map_def)); + memset(&maps[i].def, 0, sizeof(struct bpf_load_map_def)); memcpy(&maps[i].def, def, map_sz_copy); /* Verify no newer features were requested */ diff --git a/samples/bpf/bpf_load.h b/samples/bpf/bpf_load.h index 2c3d0b448632..f9da59bca0cc 100644 --- a/samples/bpf/bpf_load.h +++ b/samples/bpf/bpf_load.h @@ -7,7 +7,7 @@ #define MAX_MAPS 32 #define MAX_PROGS 32 -struct bpf_map_def { +struct bpf_load_map_def { unsigned int type; unsigned int key_size; unsigned int value_size; @@ -21,7 +21,7 @@ struct bpf_map_data { int fd; char *name; size_t elf_offset; - struct bpf_map_def def; + struct bpf_load_map_def def; }; typedef void (*fixup_map_cb)(struct bpf_map_data *map, int idx); -- cgit v1.2.3 From 5f9380572b4bb24f60cd492b17331db6ee34a516 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 10 May 2018 10:24:39 -0700 Subject: samples: bpf: compile and link against full libbpf samples/bpf currently cherry-picks object files from tools/lib/bpf to link against. Just compile the full library and link statically against it. Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann --- samples/bpf/Makefile | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 28513d6be1bf..79cdb66a5ea7 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -49,7 +49,7 @@ hostprogs-y += xdpsock hostprogs-y += xdp_fwd # Libbpf dependencies -LIBBPF := ../../tools/lib/bpf/bpf.o ../../tools/lib/bpf/nlattr.o +LIBBPF := ../../tools/lib/bpf/libbpf.a CGROUP_HELPERS := ../../tools/testing/selftests/bpf/cgroup_helpers.o TRACE_HELPERS := ../../tools/testing/selftests/bpf/trace_helpers.o @@ -74,10 +74,10 @@ offwaketime-objs := bpf_load.o $(LIBBPF) offwaketime_user.o $(TRACE_HELPERS) spintest-objs := bpf_load.o $(LIBBPF) spintest_user.o $(TRACE_HELPERS) map_perf_test-objs := bpf_load.o $(LIBBPF) map_perf_test_user.o test_overhead-objs := bpf_load.o $(LIBBPF) test_overhead_user.o -test_cgrp2_array_pin-objs := $(LIBBPF) test_cgrp2_array_pin.o -test_cgrp2_attach-objs := $(LIBBPF) test_cgrp2_attach.o -test_cgrp2_attach2-objs := $(LIBBPF) test_cgrp2_attach2.o $(CGROUP_HELPERS) -test_cgrp2_sock-objs := $(LIBBPF) test_cgrp2_sock.o +test_cgrp2_array_pin-objs := test_cgrp2_array_pin.o $(LIBBPF) +test_cgrp2_attach-objs := test_cgrp2_attach.o $(LIBBPF) +test_cgrp2_attach2-objs := test_cgrp2_attach2.o $(LIBBPF) $(CGROUP_HELPERS) +test_cgrp2_sock-objs := test_cgrp2_sock.o $(LIBBPF) test_cgrp2_sock2-objs := bpf_load.o $(LIBBPF) test_cgrp2_sock2.o xdp1-objs := bpf_load.o $(LIBBPF) xdp1_user.o # reuse xdp1 source intentionally @@ -91,7 +91,7 @@ tc_l2_redirect-objs := bpf_load.o $(LIBBPF) tc_l2_redirect_user.o lwt_len_hist-objs := bpf_load.o $(LIBBPF) lwt_len_hist_user.o xdp_tx_iptunnel-objs := bpf_load.o $(LIBBPF) xdp_tx_iptunnel_user.o test_map_in_map-objs := bpf_load.o $(LIBBPF) test_map_in_map_user.o -per_socket_stats_example-objs := $(LIBBPF) cookie_uid_helper_example.o +per_socket_stats_example-objs := cookie_uid_helper_example.o $(LIBBPF) xdp_redirect-objs := bpf_load.o $(LIBBPF) xdp_redirect_user.o xdp_redirect_map-objs := bpf_load.o $(LIBBPF) xdp_redirect_map_user.o xdp_redirect_cpu-objs := bpf_load.o $(LIBBPF) xdp_redirect_cpu_user.o @@ -165,6 +165,8 @@ HOSTCFLAGS += -I$(srctree)/tools/lib/ -I$(srctree)/tools/include HOSTCFLAGS += -I$(srctree)/tools/perf HOSTCFLAGS_bpf_load.o += -I$(objtree)/usr/include -Wno-unused-variable +HOSTLOADLIBES_test_lru_dist += -lelf +HOSTLOADLIBES_sock_example += -lelf HOSTLOADLIBES_fds_example += -lelf HOSTLOADLIBES_sockex1 += -lelf HOSTLOADLIBES_sockex2 += -lelf @@ -176,6 +178,10 @@ HOSTLOADLIBES_tracex4 += -lelf -lrt HOSTLOADLIBES_tracex5 += -lelf HOSTLOADLIBES_tracex6 += -lelf HOSTLOADLIBES_tracex7 += -lelf +HOSTLOADLIBES_test_cgrp2_array_pin += -lelf +HOSTLOADLIBES_test_cgrp2_attach += -lelf +HOSTLOADLIBES_test_cgrp2_attach2 += -lelf +HOSTLOADLIBES_test_cgrp2_sock += -lelf HOSTLOADLIBES_test_cgrp2_sock2 += -lelf HOSTLOADLIBES_load_sock_ops += -lelf HOSTLOADLIBES_test_probe_write_user += -lelf @@ -195,6 +201,7 @@ HOSTLOADLIBES_tc_l2_redirect += -l elf HOSTLOADLIBES_lwt_len_hist += -l elf HOSTLOADLIBES_xdp_tx_iptunnel += -lelf HOSTLOADLIBES_test_map_in_map += -lelf +HOSTLOADLIBES_per_socket_stats_example += -lelf HOSTLOADLIBES_xdp_redirect += -lelf HOSTLOADLIBES_xdp_redirect_map += -lelf HOSTLOADLIBES_xdp_redirect_cpu += -lelf @@ -226,7 +233,7 @@ clean: @rm -f *~ $(LIBBPF): FORCE - $(MAKE) -C $(dir $@) $(notdir $@) + $(MAKE) -C $(dir $@) $(obj)/syscall_nrs.s: $(src)/syscall_nrs.c $(call if_changed_dep,cc_s_c) -- cgit v1.2.3 From d0cabbb021bee5c4b831a0235af9534ad07f8d3d Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 10 May 2018 10:24:40 -0700 Subject: tools: bpf: move the event reading loop to libbpf There are two copies of event reading loop - in bpftool and trace_helpers "library". Consolidate them and move the code to libbpf. Return codes from trace_helpers are kept, but renamed to include LIBBPF prefix. Suggested-by: Alexei Starovoitov Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann --- samples/bpf/Makefile | 8 +++ samples/bpf/trace_output_user.c | 6 +- tools/bpf/bpftool/map_perf_ring.c | 66 +++++----------------- tools/lib/bpf/Makefile | 2 +- tools/lib/bpf/libbpf.c | 61 ++++++++++++++++++++ tools/lib/bpf/libbpf.h | 13 +++++ tools/testing/selftests/bpf/Makefile | 2 +- tools/testing/selftests/bpf/test_progs.c | 6 +- tools/testing/selftests/bpf/trace_helpers.c | 87 ++++++++++------------------- tools/testing/selftests/bpf/trace_helpers.h | 11 ++-- 10 files changed, 139 insertions(+), 123 deletions(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 79cdb66a5ea7..8ce72d211c3e 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -165,6 +165,14 @@ HOSTCFLAGS += -I$(srctree)/tools/lib/ -I$(srctree)/tools/include HOSTCFLAGS += -I$(srctree)/tools/perf HOSTCFLAGS_bpf_load.o += -I$(objtree)/usr/include -Wno-unused-variable +HOSTCFLAGS_trace_helpers.o += -I$(srctree)/tools/lib/bpf/ + +HOSTCFLAGS_trace_output_user.o += -I$(srctree)/tools/lib/bpf/ +HOSTCFLAGS_offwaketime_user.o += -I$(srctree)/tools/lib/bpf/ +HOSTCFLAGS_spintest_user.o += -I$(srctree)/tools/lib/bpf/ +HOSTCFLAGS_trace_event_user.o += -I$(srctree)/tools/lib/bpf/ +HOSTCFLAGS_sampleip_user.o += -I$(srctree)/tools/lib/bpf/ + HOSTLOADLIBES_test_lru_dist += -lelf HOSTLOADLIBES_sock_example += -lelf HOSTLOADLIBES_fds_example += -lelf diff --git a/samples/bpf/trace_output_user.c b/samples/bpf/trace_output_user.c index 5e78c2ecd08d..da98be721001 100644 --- a/samples/bpf/trace_output_user.c +++ b/samples/bpf/trace_output_user.c @@ -48,7 +48,7 @@ static int print_bpf_output(void *data, int size) if (e->cookie != 0x12345678) { printf("BUG pid %llx cookie %llx sized %d\n", e->pid, e->cookie, size); - return PERF_EVENT_ERROR; + return LIBBPF_PERF_EVENT_ERROR; } cnt++; @@ -56,10 +56,10 @@ static int print_bpf_output(void *data, int size) if (cnt == MAX_CNT) { printf("recv %lld events per sec\n", MAX_CNT * 1000000000ll / (time_get_ns() - start_time)); - return PERF_EVENT_DONE; + return LIBBPF_PERF_EVENT_DONE; } - return PERF_EVENT_CONT; + return LIBBPF_PERF_EVENT_CONT; } static void test_bpf_perf_event(void) diff --git a/tools/bpf/bpftool/map_perf_ring.c b/tools/bpf/bpftool/map_perf_ring.c index 9ae4bb8a2cad..1832100d1b27 100644 --- a/tools/bpf/bpftool/map_perf_ring.c +++ b/tools/bpf/bpftool/map_perf_ring.c @@ -50,14 +50,15 @@ static void int_exit(int signo) stop = true; } -static void -print_bpf_output(struct event_ring_info *ring, struct perf_event_sample *e) +static enum bpf_perf_event_ret print_bpf_output(void *event, void *priv) { + struct event_ring_info *ring = priv; + struct perf_event_sample *e = event; struct { struct perf_event_header header; __u64 id; __u64 lost; - } *lost = (void *)e; + } *lost = event; if (json_output) { jsonw_start_object(json_wtr); @@ -96,60 +97,23 @@ print_bpf_output(struct event_ring_info *ring, struct perf_event_sample *e) e->header.type, e->header.size); } } + + return LIBBPF_PERF_EVENT_CONT; } static void perf_event_read(struct event_ring_info *ring, void **buf, size_t *buf_len) { - volatile struct perf_event_mmap_page *header = ring->mem; - __u64 buffer_size = MMAP_PAGE_CNT * get_page_size(); - __u64 data_tail = header->data_tail; - __u64 data_head = header->data_head; - void *base, *begin, *end; - - asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */ - if (data_head == data_tail) - return; - - base = ((char *)header) + get_page_size(); - - begin = base + data_tail % buffer_size; - end = base + data_head % buffer_size; - - while (begin != end) { - struct perf_event_sample *e; - - e = begin; - if (begin + e->header.size > base + buffer_size) { - long len = base + buffer_size - begin; - - if (*buf_len < e->header.size) { - free(*buf); - *buf = malloc(e->header.size); - if (!*buf) { - fprintf(stderr, - "can't allocate memory"); - stop = true; - return; - } - *buf_len = e->header.size; - } - - memcpy(*buf, begin, len); - memcpy(*buf + len, base, e->header.size - len); - e = (void *)*buf; - begin = base + e->header.size - len; - } else if (begin + e->header.size == base + buffer_size) { - begin = base; - } else { - begin += e->header.size; - } - - print_bpf_output(ring, e); + enum bpf_perf_event_ret ret; + + ret = bpf_perf_event_read_simple(ring->mem, + MMAP_PAGE_CNT * get_page_size(), + get_page_size(), buf, buf_len, + print_bpf_output, ring); + if (ret != LIBBPF_PERF_EVENT_CONT) { + fprintf(stderr, "perf read loop failed with %d\n", ret); + stop = true; } - - __sync_synchronize(); /* smp_mb() */ - header->data_tail = data_head; } static int perf_mmap_size(void) diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index e6d5f8d1477f..f3fab4af4260 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -69,7 +69,7 @@ FEATURE_USER = .libbpf FEATURE_TESTS = libelf libelf-getphdrnum libelf-mmap bpf FEATURE_DISPLAY = libelf bpf -INCLUDES = -I. -I$(srctree)/tools/include -I$(srctree)/tools/arch/$(ARCH)/include/uapi -I$(srctree)/tools/include/uapi +INCLUDES = -I. -I$(srctree)/tools/include -I$(srctree)/tools/arch/$(ARCH)/include/uapi -I$(srctree)/tools/include/uapi -I$(srctree)/tools/perf FEATURE_CHECK_CFLAGS-bpf = $(INCLUDES) check_feat := 1 diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 7bcdca13083a..ce96f1fe3f37 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include #include @@ -2210,3 +2211,63 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, *prog_fd = bpf_program__fd(first_prog); return 0; } + +enum bpf_perf_event_ret +bpf_perf_event_read_simple(void *mem, unsigned long size, + unsigned long page_size, void **buf, size_t *buf_len, + bpf_perf_event_print_t fn, void *priv) +{ + volatile struct perf_event_mmap_page *header = mem; + __u64 data_tail = header->data_tail; + __u64 data_head = header->data_head; + void *base, *begin, *end; + int ret; + + asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */ + if (data_head == data_tail) + return LIBBPF_PERF_EVENT_CONT; + + base = ((char *)header) + page_size; + + begin = base + data_tail % size; + end = base + data_head % size; + + while (begin != end) { + struct perf_event_header *ehdr; + + ehdr = begin; + if (begin + ehdr->size > base + size) { + long len = base + size - begin; + + if (*buf_len < ehdr->size) { + free(*buf); + *buf = malloc(ehdr->size); + if (!*buf) { + ret = LIBBPF_PERF_EVENT_ERROR; + break; + } + *buf_len = ehdr->size; + } + + memcpy(*buf, begin, len); + memcpy(*buf + len, base, ehdr->size - len); + ehdr = (void *)*buf; + begin = base + ehdr->size - len; + } else if (begin + ehdr->size == base + size) { + begin = base; + } else { + begin += ehdr->size; + } + + ret = fn(ehdr, priv); + if (ret != LIBBPF_PERF_EVENT_CONT) + break; + + data_tail += ehdr->size; + } + + __sync_synchronize(); /* smp_mb() */ + header->data_tail = data_tail; + + return ret; +} diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 197f9ce2248c..ce681097584e 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -267,4 +267,17 @@ int bpf_prog_load(const char *file, enum bpf_prog_type type, struct bpf_object **pobj, int *prog_fd); int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags); + +enum bpf_perf_event_ret { + LIBBPF_PERF_EVENT_DONE = 0, + LIBBPF_PERF_EVENT_ERROR = -1, + LIBBPF_PERF_EVENT_CONT = -2, +}; + +typedef enum bpf_perf_event_ret (*bpf_perf_event_print_t)(void *event, + void *priv); +int bpf_perf_event_read_simple(void *mem, unsigned long size, + unsigned long page_size, + void **buf, size_t *buf_len, + bpf_perf_event_print_t fn, void *priv); #endif diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 79d29d6cc719..438d4f93875b 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -10,7 +10,7 @@ ifneq ($(wildcard $(GENHDR)),) GENFLAGS := -DHAVE_GENHDR endif -CFLAGS += -Wall -O2 -I$(APIDIR) -I$(LIBDIR) -I$(GENDIR) $(GENFLAGS) -I../../../include +CFLAGS += -Wall -O2 -I$(APIDIR) -I$(LIBDIR) -I$(BPFDIR) -I$(GENDIR) $(GENFLAGS) -I../../../include LDLIBS += -lcap -lelf -lrt -lpthread TEST_CUSTOM_PROGS = $(OUTPUT)/urandom_read diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c index ed197eef1cfc..f7731973ec68 100644 --- a/tools/testing/selftests/bpf/test_progs.c +++ b/tools/testing/selftests/bpf/test_progs.c @@ -1337,12 +1337,12 @@ static int get_stack_print_output(void *data, int size) good_user_stack = true; } if (!good_kern_stack || !good_user_stack) - return PERF_EVENT_ERROR; + return LIBBPF_PERF_EVENT_ERROR; if (cnt == MAX_CNT_RAWTP) - return PERF_EVENT_DONE; + return LIBBPF_PERF_EVENT_DONE; - return PERF_EVENT_CONT; + return LIBBPF_PERF_EVENT_CONT; } static void test_get_stack_raw_tp(void) diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c index ad025bd75f1c..8fb4fe8686e4 100644 --- a/tools/testing/selftests/bpf/trace_helpers.c +++ b/tools/testing/selftests/bpf/trace_helpers.c @@ -74,7 +74,7 @@ struct ksym *ksym_search(long key) static int page_size; static int page_cnt = 8; -static volatile struct perf_event_mmap_page *header; +static struct perf_event_mmap_page *header; int perf_event_mmap(int fd) { @@ -107,74 +107,47 @@ struct perf_event_sample { char data[]; }; -static int perf_event_read(perf_event_print_fn fn) +static enum bpf_perf_event_ret bpf_perf_event_print(void *event, void *priv) { - __u64 data_tail = header->data_tail; - __u64 data_head = header->data_head; - __u64 buffer_size = page_cnt * page_size; - void *base, *begin, *end; - char buf[256]; + struct perf_event_sample *e = event; + perf_event_print_fn fn = priv; int ret; - asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */ - if (data_head == data_tail) - return PERF_EVENT_CONT; - - base = ((char *)header) + page_size; - - begin = base + data_tail % buffer_size; - end = base + data_head % buffer_size; - - while (begin != end) { - struct perf_event_sample *e; - - e = begin; - if (begin + e->header.size > base + buffer_size) { - long len = base + buffer_size - begin; - - assert(len < e->header.size); - memcpy(buf, begin, len); - memcpy(buf + len, base, e->header.size - len); - e = (void *) buf; - begin = base + e->header.size - len; - } else if (begin + e->header.size == base + buffer_size) { - begin = base; - } else { - begin += e->header.size; - } - - if (e->header.type == PERF_RECORD_SAMPLE) { - ret = fn(e->data, e->size); - if (ret != PERF_EVENT_CONT) - return ret; - } else if (e->header.type == PERF_RECORD_LOST) { - struct { - struct perf_event_header header; - __u64 id; - __u64 lost; - } *lost = (void *) e; - printf("lost %lld events\n", lost->lost); - } else { - printf("unknown event type=%d size=%d\n", - e->header.type, e->header.size); - } + if (e->header.type == PERF_RECORD_SAMPLE) { + ret = fn(e->data, e->size); + if (ret != LIBBPF_PERF_EVENT_CONT) + return ret; + } else if (e->header.type == PERF_RECORD_LOST) { + struct { + struct perf_event_header header; + __u64 id; + __u64 lost; + } *lost = (void *) e; + printf("lost %lld events\n", lost->lost); + } else { + printf("unknown event type=%d size=%d\n", + e->header.type, e->header.size); } - __sync_synchronize(); /* smp_mb() */ - header->data_tail = data_head; - return PERF_EVENT_CONT; + return LIBBPF_PERF_EVENT_CONT; } int perf_event_poller(int fd, perf_event_print_fn output_fn) { - int ret; + enum bpf_perf_event_ret ret; + void *buf = NULL; + size_t len = 0; for (;;) { perf_event_poll(fd); - ret = perf_event_read(output_fn); - if (ret != PERF_EVENT_CONT) - return ret; + ret = bpf_perf_event_read_simple(header, page_cnt * page_size, + page_size, &buf, &len, + bpf_perf_event_print, + output_fn); + if (ret != LIBBPF_PERF_EVENT_CONT) + break; } + free(buf); - return PERF_EVENT_DONE; + return ret; } diff --git a/tools/testing/selftests/bpf/trace_helpers.h b/tools/testing/selftests/bpf/trace_helpers.h index fe3eefd21e86..36d90e3b1ea9 100644 --- a/tools/testing/selftests/bpf/trace_helpers.h +++ b/tools/testing/selftests/bpf/trace_helpers.h @@ -2,6 +2,8 @@ #ifndef __TRACE_HELPER_H #define __TRACE_HELPER_H +#include + struct ksym { long addr; char *name; @@ -10,14 +12,9 @@ struct ksym { int load_kallsyms(void); struct ksym *ksym_search(long key); -typedef int (*perf_event_print_fn)(void *data, int size); - -/* return code for perf_event_print_fn */ -#define PERF_EVENT_DONE 0 -#define PERF_EVENT_ERROR -1 -#define PERF_EVENT_CONT -2 +typedef enum bpf_perf_event_ret (*perf_event_print_fn)(void *data, int size); int perf_event_mmap(int fd); -/* return PERF_EVENT_DONE or PERF_EVENT_ERROR */ +/* return LIBBPF_PERF_EVENT_DONE or LIBBPF_PERF_EVENT_ERROR */ int perf_event_poller(int fd, perf_event_print_fn output_fn); #endif -- cgit v1.2.3 From 2eb57bb8f6769fe94f8f9865342ffa0f6c257e0a Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 10 May 2018 10:24:41 -0700 Subject: tools: bpf: improve comments in libbpf.h Fix spelling mistakes, improve and clarify the language of comments in libbpf.h. Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.h | 48 ++++++++++++++++++++++++------------------------ 1 file changed, 24 insertions(+), 24 deletions(-) diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index ce681097584e..4574b9563278 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -52,8 +52,8 @@ enum libbpf_errno { int libbpf_strerror(int err, char *buf, size_t size); /* - * In include/linux/compiler-gcc.h, __printf is defined. However - * it should be better if libbpf.h doesn't depend on Linux header file. + * __printf is defined in include/linux/compiler-gcc.h. However, + * it would be better if libbpf.h didn't depend on Linux header files. * So instead of __printf, here we use gcc attribute directly. */ typedef int (*libbpf_print_fn_t)(const char *, ...) @@ -92,7 +92,7 @@ int bpf_object__set_priv(struct bpf_object *obj, void *priv, bpf_object_clear_priv_t clear_priv); void *bpf_object__priv(struct bpf_object *prog); -/* Accessors of bpf_program. */ +/* Accessors of bpf_program */ struct bpf_program; struct bpf_program *bpf_program__next(struct bpf_program *prog, struct bpf_object *obj); @@ -121,28 +121,28 @@ struct bpf_insn; /* * Libbpf allows callers to adjust BPF programs before being loaded - * into kernel. One program in an object file can be transform into - * multiple variants to be attached to different code. + * into kernel. One program in an object file can be transformed into + * multiple variants to be attached to different hooks. * * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd - * are APIs for this propose. + * form an API for this purpose. * * - bpf_program_prep_t: - * It defines 'preprocessor', which is a caller defined function + * Defines a 'preprocessor', which is a caller defined function * passed to libbpf through bpf_program__set_prep(), and will be * called before program is loaded. The processor should adjust - * the program one time for each instances according to the number + * the program one time for each instance according to the instance id * passed to it. * * - bpf_program__set_prep: - * Attachs a preprocessor to a BPF program. The number of instances - * whould be created is also passed through this function. + * Attaches a preprocessor to a BPF program. The number of instances + * that should be created is also passed through this function. * * - bpf_program__nth_fd: - * After the program is loaded, get resuling fds from bpf program for - * each instances. + * After the program is loaded, get resulting FD of a given instance + * of the BPF program. * - * If bpf_program__set_prep() is not used, the program whould be loaded + * If bpf_program__set_prep() is not used, the program would be loaded * without adjustment during bpf_object__load(). The program has only * one instance. In this case bpf_program__fd(prog) is equal to * bpf_program__nth_fd(prog, 0). @@ -156,7 +156,7 @@ struct bpf_prog_prep_result { struct bpf_insn *new_insn_ptr; int new_insn_cnt; - /* If not NULL, result fd is set to it */ + /* If not NULL, result FD is written to it. */ int *pfd; }; @@ -169,8 +169,8 @@ struct bpf_prog_prep_result { * - res: Output parameter, result of transformation. * * Return value: - * - Zero: pre-processing success. - * - Non-zero: pre-processing, stop loading. + * - Zero: pre-processing success. + * - Non-zero: pre-processing error, stop loading. */ typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n, struct bpf_insn *insns, int insns_cnt, @@ -182,7 +182,7 @@ int bpf_program__set_prep(struct bpf_program *prog, int nr_instance, int bpf_program__nth_fd(struct bpf_program *prog, int n); /* - * Adjust type of bpf program. Default is kprobe. + * Adjust type of BPF program. Default is kprobe. */ int bpf_program__set_socket_filter(struct bpf_program *prog); int bpf_program__set_tracepoint(struct bpf_program *prog); @@ -206,10 +206,10 @@ bool bpf_program__is_xdp(struct bpf_program *prog); bool bpf_program__is_perf_event(struct bpf_program *prog); /* - * We don't need __attribute__((packed)) now since it is - * unnecessary for 'bpf_map_def' because they are all aligned. - * In addition, using it will trigger -Wpacked warning message, - * and will be treated as an error due to -Werror. + * No need for __attribute__((packed)), all members of 'bpf_map_def' + * are all aligned. In addition, using __attribute__((packed)) + * would trigger a -Wpacked warning message, and lead to an error + * if -Werror is set. */ struct bpf_map_def { unsigned int type; @@ -220,8 +220,8 @@ struct bpf_map_def { }; /* - * There is another 'struct bpf_map' in include/linux/map.h. However, - * it is not a uapi header so no need to consider name clash. + * The 'struct bpf_map' in include/linux/bpf.h is internal to the kernel, + * so no need to worry about a name clash. */ struct bpf_map; struct bpf_map * @@ -229,7 +229,7 @@ bpf_object__find_map_by_name(struct bpf_object *obj, const char *name); /* * Get bpf_map through the offset of corresponding struct bpf_map_def - * in the bpf object file. + * in the BPF object file. */ struct bpf_map * bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset); -- cgit v1.2.3 From 17387dd5ac2c9c4e5f7d38b5affcd70e059f0a8c Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 10 May 2018 10:24:42 -0700 Subject: tools: bpf: don't complain about no kernel version for networking code BPF programs only have to specify the target kernel version for tracing related hooks, in networking world that requirement does not really apply. Loosen the checks in libbpf to reflect that. bpf_object__open() users will continue to see the error for backward compatibility (and because prog_type is not available there). Error code for NULL file name is changed from ENOENT to EINVAL, as it seems more appropriate, hopefully, that's an OK change. Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann --- tools/lib/bpf/libbpf.c | 46 +++++++++++++++++++++++++++++++++++++++------- 1 file changed, 39 insertions(+), 7 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index ce96f1fe3f37..df54c4c9e48a 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1438,9 +1438,37 @@ bpf_object__load_progs(struct bpf_object *obj) return 0; } -static int bpf_object__validate(struct bpf_object *obj) +static bool bpf_prog_type__needs_kver(enum bpf_prog_type type) +{ + switch (type) { + case BPF_PROG_TYPE_SOCKET_FILTER: + case BPF_PROG_TYPE_SCHED_CLS: + case BPF_PROG_TYPE_SCHED_ACT: + case BPF_PROG_TYPE_XDP: + case BPF_PROG_TYPE_CGROUP_SKB: + case BPF_PROG_TYPE_CGROUP_SOCK: + case BPF_PROG_TYPE_LWT_IN: + case BPF_PROG_TYPE_LWT_OUT: + case BPF_PROG_TYPE_LWT_XMIT: + case BPF_PROG_TYPE_SOCK_OPS: + case BPF_PROG_TYPE_SK_SKB: + case BPF_PROG_TYPE_CGROUP_DEVICE: + case BPF_PROG_TYPE_SK_MSG: + case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: + return false; + case BPF_PROG_TYPE_UNSPEC: + case BPF_PROG_TYPE_KPROBE: + case BPF_PROG_TYPE_TRACEPOINT: + case BPF_PROG_TYPE_PERF_EVENT: + case BPF_PROG_TYPE_RAW_TRACEPOINT: + default: + return true; + } +} + +static int bpf_object__validate(struct bpf_object *obj, bool needs_kver) { - if (obj->kern_version == 0) { + if (needs_kver && obj->kern_version == 0) { pr_warning("%s doesn't provide kernel version\n", obj->path); return -LIBBPF_ERRNO__KVERSION; @@ -1449,7 +1477,8 @@ static int bpf_object__validate(struct bpf_object *obj) } static struct bpf_object * -__bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz) +__bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz, + bool needs_kver) { struct bpf_object *obj; int err; @@ -1467,7 +1496,7 @@ __bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz) CHECK_ERR(bpf_object__check_endianness(obj), err, out); CHECK_ERR(bpf_object__elf_collect(obj), err, out); CHECK_ERR(bpf_object__collect_reloc(obj), err, out); - CHECK_ERR(bpf_object__validate(obj), err, out); + CHECK_ERR(bpf_object__validate(obj, needs_kver), err, out); bpf_object__elf_finish(obj); return obj; @@ -1484,7 +1513,7 @@ struct bpf_object *bpf_object__open(const char *path) pr_debug("loading %s\n", path); - return __bpf_object__open(path, NULL, 0); + return __bpf_object__open(path, NULL, 0, true); } struct bpf_object *bpf_object__open_buffer(void *obj_buf, @@ -1507,7 +1536,7 @@ struct bpf_object *bpf_object__open_buffer(void *obj_buf, pr_debug("loading object '%s' from buffer\n", name); - return __bpf_object__open(name, obj_buf, obj_buf_sz); + return __bpf_object__open(name, obj_buf, obj_buf_sz, true); } int bpf_object__unload(struct bpf_object *obj) @@ -2164,8 +2193,11 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, if (!attr) return -EINVAL; + if (!attr->file) + return -EINVAL; - obj = bpf_object__open(attr->file); + obj = __bpf_object__open(attr->file, NULL, 0, + bpf_prog_type__needs_kver(attr->prog_type)); if (IS_ERR(obj)) return -ENOENT; -- cgit v1.2.3 From be5bca44aa6b37b88e900d5f5f155911d6984d86 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 10 May 2018 10:24:43 -0700 Subject: samples: bpf: convert some XDP samples from bpf_load to libbpf Now that we can use full powers of libbpf in BPF samples, we should perhaps make the simplest XDP programs not depend on bpf_load helpers. This way newcomers will be exposed to the recommended library from the start. Use of bpf_prog_load_xattr() will also make it trivial to later on request offload of the programs by simply adding ifindex to the xattr. Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann --- samples/bpf/Makefile | 8 +++---- samples/bpf/xdp1_user.c | 31 ++++++++++++++++--------- samples/bpf/xdp_adjust_tail_user.c | 36 +++++++++++++++++------------ samples/bpf/xdp_rxq_info_user.c | 46 +++++++++++++++++++++++++------------- 4 files changed, 78 insertions(+), 43 deletions(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 8ce72d211c3e..9e255ca4059a 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -79,9 +79,9 @@ test_cgrp2_attach-objs := test_cgrp2_attach.o $(LIBBPF) test_cgrp2_attach2-objs := test_cgrp2_attach2.o $(LIBBPF) $(CGROUP_HELPERS) test_cgrp2_sock-objs := test_cgrp2_sock.o $(LIBBPF) test_cgrp2_sock2-objs := bpf_load.o $(LIBBPF) test_cgrp2_sock2.o -xdp1-objs := bpf_load.o $(LIBBPF) xdp1_user.o +xdp1-objs := xdp1_user.o $(LIBBPF) # reuse xdp1 source intentionally -xdp2-objs := bpf_load.o $(LIBBPF) xdp1_user.o +xdp2-objs := xdp1_user.o $(LIBBPF) xdp_router_ipv4-objs := bpf_load.o $(LIBBPF) xdp_router_ipv4_user.o test_current_task_under_cgroup-objs := bpf_load.o $(LIBBPF) $(CGROUP_HELPERS) \ test_current_task_under_cgroup_user.o @@ -96,10 +96,10 @@ xdp_redirect-objs := bpf_load.o $(LIBBPF) xdp_redirect_user.o xdp_redirect_map-objs := bpf_load.o $(LIBBPF) xdp_redirect_map_user.o xdp_redirect_cpu-objs := bpf_load.o $(LIBBPF) xdp_redirect_cpu_user.o xdp_monitor-objs := bpf_load.o $(LIBBPF) xdp_monitor_user.o -xdp_rxq_info-objs := bpf_load.o $(LIBBPF) xdp_rxq_info_user.o +xdp_rxq_info-objs := xdp_rxq_info_user.o $(LIBBPF) syscall_tp-objs := bpf_load.o $(LIBBPF) syscall_tp_user.o cpustat-objs := bpf_load.o $(LIBBPF) cpustat_user.o -xdp_adjust_tail-objs := bpf_load.o $(LIBBPF) xdp_adjust_tail_user.o +xdp_adjust_tail-objs := xdp_adjust_tail_user.o $(LIBBPF) xdpsock-objs := bpf_load.o $(LIBBPF) xdpsock_user.o xdp_fwd-objs := bpf_load.o $(LIBBPF) xdp_fwd_user.o diff --git a/samples/bpf/xdp1_user.c b/samples/bpf/xdp1_user.c index b901ee2b3336..b02c531510ed 100644 --- a/samples/bpf/xdp1_user.c +++ b/samples/bpf/xdp1_user.c @@ -16,9 +16,9 @@ #include #include -#include "bpf_load.h" #include "bpf_util.h" -#include "libbpf.h" +#include "bpf/bpf.h" +#include "bpf/libbpf.h" static int ifindex; static __u32 xdp_flags; @@ -31,7 +31,7 @@ static void int_exit(int sig) /* simple per-protocol drop counter */ -static void poll_stats(int interval) +static void poll_stats(int map_fd, int interval) { unsigned int nr_cpus = bpf_num_possible_cpus(); const unsigned int nr_keys = 256; @@ -47,7 +47,7 @@ static void poll_stats(int interval) for (key = 0; key < nr_keys; key++) { __u64 sum = 0; - assert(bpf_map_lookup_elem(map_fd[0], &key, values) == 0); + assert(bpf_map_lookup_elem(map_fd, &key, values) == 0); for (i = 0; i < nr_cpus; i++) sum += (values[i] - prev[key][i]); if (sum) @@ -71,9 +71,14 @@ static void usage(const char *prog) int main(int argc, char **argv) { struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY}; + struct bpf_prog_load_attr prog_load_attr = { + .prog_type = BPF_PROG_TYPE_XDP, + }; const char *optstr = "SN"; + int prog_fd, map_fd, opt; + struct bpf_object *obj; + struct bpf_map *map; char filename[256]; - int opt; while ((opt = getopt(argc, argv, optstr)) != -1) { switch (opt) { @@ -102,13 +107,19 @@ int main(int argc, char **argv) ifindex = strtoul(argv[optind], NULL, 0); snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + prog_load_attr.file = filename; - if (load_bpf_file(filename)) { - printf("%s", bpf_log_buf); + if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd)) + return 1; + + map = bpf_map__next(NULL, obj); + if (!map) { + printf("finding a map in obj file failed\n"); return 1; } + map_fd = bpf_map__fd(map); - if (!prog_fd[0]) { + if (!prog_fd) { printf("load_bpf_file: %s\n", strerror(errno)); return 1; } @@ -116,12 +127,12 @@ int main(int argc, char **argv) signal(SIGINT, int_exit); signal(SIGTERM, int_exit); - if (bpf_set_link_xdp_fd(ifindex, prog_fd[0], xdp_flags) < 0) { + if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) { printf("link set xdp fd failed\n"); return 1; } - poll_stats(2); + poll_stats(map_fd, 2); return 0; } diff --git a/samples/bpf/xdp_adjust_tail_user.c b/samples/bpf/xdp_adjust_tail_user.c index f621a541b574..3042ce37dae8 100644 --- a/samples/bpf/xdp_adjust_tail_user.c +++ b/samples/bpf/xdp_adjust_tail_user.c @@ -18,9 +18,8 @@ #include #include #include -#include "bpf_load.h" -#include "libbpf.h" -#include "bpf_util.h" +#include "bpf/bpf.h" +#include "bpf/libbpf.h" #define STATS_INTERVAL_S 2U @@ -36,7 +35,7 @@ static void int_exit(int sig) /* simple "icmp packet too big sent" counter */ -static void poll_stats(unsigned int kill_after_s) +static void poll_stats(unsigned int map_fd, unsigned int kill_after_s) { time_t started_at = time(NULL); __u64 value = 0; @@ -46,7 +45,7 @@ static void poll_stats(unsigned int kill_after_s) while (!kill_after_s || time(NULL) - started_at <= kill_after_s) { sleep(STATS_INTERVAL_S); - assert(bpf_map_lookup_elem(map_fd[0], &key, &value) == 0); + assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0); printf("icmp \"packet too big\" sent: %10llu pkts\n", value); } @@ -66,14 +65,17 @@ static void usage(const char *cmd) int main(int argc, char **argv) { + struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY}; + struct bpf_prog_load_attr prog_load_attr = { + .prog_type = BPF_PROG_TYPE_XDP, + }; unsigned char opt_flags[256] = {}; unsigned int kill_after_s = 0; const char *optstr = "i:T:SNh"; - struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY}; + int i, prog_fd, map_fd, opt; + struct bpf_object *obj; + struct bpf_map *map; char filename[256]; - int opt; - int i; - for (i = 0; i < strlen(optstr); i++) if (optstr[i] != 'h' && 'a' <= optstr[i] && optstr[i] <= 'z') @@ -115,13 +117,19 @@ int main(int argc, char **argv) } snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + prog_load_attr.file = filename; + + if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd)) + return 1; - if (load_bpf_file(filename)) { - printf("%s", bpf_log_buf); + map = bpf_map__next(NULL, obj); + if (!map) { + printf("finding a map in obj file failed\n"); return 1; } + map_fd = bpf_map__fd(map); - if (!prog_fd[0]) { + if (!prog_fd) { printf("load_bpf_file: %s\n", strerror(errno)); return 1; } @@ -129,12 +137,12 @@ int main(int argc, char **argv) signal(SIGINT, int_exit); signal(SIGTERM, int_exit); - if (bpf_set_link_xdp_fd(ifindex, prog_fd[0], xdp_flags) < 0) { + if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) { printf("link set xdp fd failed\n"); return 1; } - poll_stats(kill_after_s); + poll_stats(map_fd, kill_after_s); bpf_set_link_xdp_fd(ifindex, -1, xdp_flags); diff --git a/samples/bpf/xdp_rxq_info_user.c b/samples/bpf/xdp_rxq_info_user.c index 478d95412de4..e4e9ba52bff0 100644 --- a/samples/bpf/xdp_rxq_info_user.c +++ b/samples/bpf/xdp_rxq_info_user.c @@ -22,8 +22,8 @@ static const char *__doc__ = " XDP RX-queue info extract example\n\n" #include #include -#include "libbpf.h" -#include "bpf_load.h" +#include "bpf/bpf.h" +#include "bpf/libbpf.h" #include "bpf_util.h" static int ifindex = -1; @@ -32,6 +32,9 @@ static char *ifname; static __u32 xdp_flags; +static struct bpf_map *stats_global_map; +static struct bpf_map *rx_queue_index_map; + /* Exit return codes */ #define EXIT_OK 0 #define EXIT_FAIL 1 @@ -174,7 +177,7 @@ static struct datarec *alloc_record_per_cpu(void) static struct record *alloc_record_per_rxq(void) { - unsigned int nr_rxqs = map_data[2].def.max_entries; + unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries; struct record *array; size_t size; @@ -190,7 +193,7 @@ static struct record *alloc_record_per_rxq(void) static struct stats_record *alloc_stats_record(void) { - unsigned int nr_rxqs = map_data[2].def.max_entries; + unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries; struct stats_record *rec; int i; @@ -210,7 +213,7 @@ static struct stats_record *alloc_stats_record(void) static void free_stats_record(struct stats_record *r) { - unsigned int nr_rxqs = map_data[2].def.max_entries; + unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries; int i; for (i = 0; i < nr_rxqs; i++) @@ -254,11 +257,11 @@ static void stats_collect(struct stats_record *rec) { int fd, i, max_rxqs; - fd = map_data[1].fd; /* map: stats_global_map */ + fd = bpf_map__fd(stats_global_map); map_collect_percpu(fd, 0, &rec->stats); - fd = map_data[2].fd; /* map: rx_queue_index_map */ - max_rxqs = map_data[2].def.max_entries; + fd = bpf_map__fd(rx_queue_index_map); + max_rxqs = bpf_map__def(rx_queue_index_map)->max_entries; for (i = 0; i < max_rxqs; i++) map_collect_percpu(fd, i, &rec->rxq[i]); } @@ -304,8 +307,8 @@ static void stats_print(struct stats_record *stats_rec, struct stats_record *stats_prev, int action) { + unsigned int nr_rxqs = bpf_map__def(rx_queue_index_map)->max_entries; unsigned int nr_cpus = bpf_num_possible_cpus(); - unsigned int nr_rxqs = map_data[2].def.max_entries; double pps = 0, err = 0; struct record *rec, *prev; double t; @@ -419,31 +422,44 @@ static void stats_poll(int interval, int action) int main(int argc, char **argv) { struct rlimit r = {10 * 1024 * 1024, RLIM_INFINITY}; + struct bpf_prog_load_attr prog_load_attr = { + .prog_type = BPF_PROG_TYPE_XDP, + }; + int prog_fd, map_fd, opt, err; bool use_separators = true; struct config cfg = { 0 }; + struct bpf_object *obj; + struct bpf_map *map; char filename[256]; int longindex = 0; int interval = 2; __u32 key = 0; - int opt, err; char action_str_buf[XDP_ACTION_MAX_STRLEN + 1 /* for \0 */] = { 0 }; int action = XDP_PASS; /* Default action */ char *action_str = NULL; snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + prog_load_attr.file = filename; if (setrlimit(RLIMIT_MEMLOCK, &r)) { perror("setrlimit(RLIMIT_MEMLOCK)"); return 1; } - if (load_bpf_file(filename)) { - fprintf(stderr, "ERR in load_bpf_file(): %s", bpf_log_buf); + if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd)) + return EXIT_FAIL; + + map = bpf_map__next(NULL, obj); + stats_global_map = bpf_map__next(map, obj); + rx_queue_index_map = bpf_map__next(stats_global_map, obj); + if (!map || !stats_global_map || !rx_queue_index_map) { + printf("finding a map in obj file failed\n"); return EXIT_FAIL; } + map_fd = bpf_map__fd(map); - if (!prog_fd[0]) { + if (!prog_fd) { fprintf(stderr, "ERR: load_bpf_file: %s\n", strerror(errno)); return EXIT_FAIL; } @@ -512,7 +528,7 @@ int main(int argc, char **argv) setlocale(LC_NUMERIC, "en_US"); /* User-side setup ifindex in config_map */ - err = bpf_map_update_elem(map_fd[0], &key, &cfg, 0); + err = bpf_map_update_elem(map_fd, &key, &cfg, 0); if (err) { fprintf(stderr, "Store config failed (err:%d)\n", err); exit(EXIT_FAIL_BPF); @@ -521,7 +537,7 @@ int main(int argc, char **argv) /* Remove XDP program when program is interrupted */ signal(SIGINT, int_exit); - if (bpf_set_link_xdp_fd(ifindex, prog_fd[0], xdp_flags) < 0) { + if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) { fprintf(stderr, "link set xdp fd failed\n"); return EXIT_FAIL_XDP; } -- cgit v1.2.3 From bae77c5eb5b2107e300fb02da2311f2aa0d8ee3c Mon Sep 17 00:00:00 2001 From: Song Liu Date: Mon, 7 May 2018 10:50:48 -0700 Subject: bpf: enable stackmap with build_id in nmi context Currently, we cannot parse build_id in nmi context because of up_read(¤t->mm->mmap_sem), this makes stackmap with build_id less useful. This patch enables parsing build_id in nmi by putting the up_read() call in irq_work. To avoid memory allocation in nmi context, we use per cpu variable for the irq_work. As a result, only one irq_work per cpu is allowed. If the irq_work is in-use, we fallback to only report ips. Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Peter Zijlstra Signed-off-by: Song Liu Signed-off-by: Daniel Borkmann --- init/Kconfig | 1 + kernel/bpf/stackmap.c | 59 +++++++++++++++++++++++++++++++++++++++++++++------ 2 files changed, 54 insertions(+), 6 deletions(-) diff --git a/init/Kconfig b/init/Kconfig index f013afc74b11..480a4f2713d9 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1391,6 +1391,7 @@ config BPF_SYSCALL bool "Enable bpf() system call" select ANON_INODES select BPF + select IRQ_WORK default n help Enable the bpf() system call that allows to manipulate eBPF diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 3ba102b41512..b59ace0f0f09 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -11,6 +11,7 @@ #include #include #include +#include #include "percpu_freelist.h" #define STACK_CREATE_FLAG_MASK \ @@ -32,6 +33,23 @@ struct bpf_stack_map { struct stack_map_bucket *buckets[]; }; +/* irq_work to run up_read() for build_id lookup in nmi context */ +struct stack_map_irq_work { + struct irq_work irq_work; + struct rw_semaphore *sem; +}; + +static void do_up_read(struct irq_work *entry) +{ + struct stack_map_irq_work *work; + + work = container_of(entry, struct stack_map_irq_work, irq_work); + up_read(work->sem); + work->sem = NULL; +} + +static DEFINE_PER_CPU(struct stack_map_irq_work, up_read_work); + static inline bool stack_map_use_build_id(struct bpf_map *map) { return (map->map_flags & BPF_F_STACK_BUILD_ID); @@ -267,17 +285,27 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs, { int i; struct vm_area_struct *vma; + bool in_nmi_ctx = in_nmi(); + bool irq_work_busy = false; + struct stack_map_irq_work *work; + + if (in_nmi_ctx) { + work = this_cpu_ptr(&up_read_work); + if (work->irq_work.flags & IRQ_WORK_BUSY) + /* cannot queue more up_read, fallback */ + irq_work_busy = true; + } /* - * We cannot do up_read() in nmi context, so build_id lookup is - * only supported for non-nmi events. If at some point, it is - * possible to run find_vma() without taking the semaphore, we - * would like to allow build_id lookup in nmi context. + * We cannot do up_read() in nmi context. To do build_id lookup + * in nmi context, we need to run up_read() in irq_work. We use + * a percpu variable to do the irq_work. If the irq_work is + * already used by another lookup, we fall back to report ips. * * Same fallback is used for kernel stack (!user) on a stackmap * with build_id. */ - if (!user || !current || !current->mm || in_nmi() || + if (!user || !current || !current->mm || irq_work_busy || down_read_trylock(¤t->mm->mmap_sem) == 0) { /* cannot access current->mm, fall back to ips */ for (i = 0; i < trace_nr; i++) { @@ -299,7 +327,13 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs, - vma->vm_start; id_offs[i].status = BPF_STACK_BUILD_ID_VALID; } - up_read(¤t->mm->mmap_sem); + + if (!in_nmi_ctx) { + up_read(¤t->mm->mmap_sem); + } else { + work->sem = ¤t->mm->mmap_sem; + irq_work_queue(&work->irq_work); + } } BPF_CALL_3(bpf_get_stackid, struct pt_regs *, regs, struct bpf_map *, map, @@ -575,3 +609,16 @@ const struct bpf_map_ops stack_map_ops = { .map_update_elem = stack_map_update_elem, .map_delete_elem = stack_map_delete_elem, }; + +static int __init stack_map_init(void) +{ + int cpu; + struct stack_map_irq_work *work; + + for_each_possible_cpu(cpu) { + work = per_cpu_ptr(&up_read_work, cpu); + init_irq_work(&work->irq_work, do_up_read); + } + return 0; +} +subsys_initcall(stack_map_init); -- cgit v1.2.3 From 13790d1cc72c22f6e7a1248e5f6d20d720797e95 Mon Sep 17 00:00:00 2001 From: Song Liu Date: Mon, 7 May 2018 10:50:49 -0700 Subject: bpf: add selftest for stackmap with build_id in NMI context This new test captures stackmap with build_id with hardware event PERF_COUNT_HW_CPU_CYCLES. Because we only support one ips-to-build_id lookup per cpu in NMI context, stack_amap will not be able to do the lookup in this test. Therefore, we didn't do compare_stack_ips(), as it will alwasy fail. urandom_read.c is extended to run configurable cycles so that it can be caught by the perf event. Signed-off-by: Song Liu Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/test_progs.c | 134 +++++++++++++++++++++++++++++ tools/testing/selftests/bpf/urandom_read.c | 10 ++- 2 files changed, 142 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c index f7731973ec68..3ecf733330c1 100644 --- a/tools/testing/selftests/bpf/test_progs.c +++ b/tools/testing/selftests/bpf/test_progs.c @@ -1272,6 +1272,139 @@ out: return; } +static void test_stacktrace_build_id_nmi(void) +{ + int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd; + const char *file = "./test_stacktrace_build_id.o"; + int err, pmu_fd, prog_fd; + struct perf_event_attr attr = { + .sample_freq = 5000, + .freq = 1, + .type = PERF_TYPE_HARDWARE, + .config = PERF_COUNT_HW_CPU_CYCLES, + }; + __u32 key, previous_key, val, duration = 0; + struct bpf_object *obj; + char buf[256]; + int i, j; + struct bpf_stack_build_id id_offs[PERF_MAX_STACK_DEPTH]; + int build_id_matches = 0; + + err = bpf_prog_load(file, BPF_PROG_TYPE_PERF_EVENT, &obj, &prog_fd); + if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno)) + return; + + pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */, + 0 /* cpu 0 */, -1 /* group id */, + 0 /* flags */); + if (CHECK(pmu_fd < 0, "perf_event_open", + "err %d errno %d. Does the test host support PERF_COUNT_HW_CPU_CYCLES?\n", + pmu_fd, errno)) + goto close_prog; + + err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0); + if (CHECK(err, "perf_event_ioc_enable", "err %d errno %d\n", + err, errno)) + goto close_pmu; + + err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd); + if (CHECK(err, "perf_event_ioc_set_bpf", "err %d errno %d\n", + err, errno)) + goto disable_pmu; + + /* find map fds */ + control_map_fd = bpf_find_map(__func__, obj, "control_map"); + if (CHECK(control_map_fd < 0, "bpf_find_map control_map", + "err %d errno %d\n", err, errno)) + goto disable_pmu; + + stackid_hmap_fd = bpf_find_map(__func__, obj, "stackid_hmap"); + if (CHECK(stackid_hmap_fd < 0, "bpf_find_map stackid_hmap", + "err %d errno %d\n", err, errno)) + goto disable_pmu; + + stackmap_fd = bpf_find_map(__func__, obj, "stackmap"); + if (CHECK(stackmap_fd < 0, "bpf_find_map stackmap", "err %d errno %d\n", + err, errno)) + goto disable_pmu; + + stack_amap_fd = bpf_find_map(__func__, obj, "stack_amap"); + if (CHECK(stack_amap_fd < 0, "bpf_find_map stack_amap", + "err %d errno %d\n", err, errno)) + goto disable_pmu; + + assert(system("dd if=/dev/urandom of=/dev/zero count=4 2> /dev/null") + == 0); + assert(system("taskset 0x1 ./urandom_read 100000") == 0); + /* disable stack trace collection */ + key = 0; + val = 1; + bpf_map_update_elem(control_map_fd, &key, &val, 0); + + /* for every element in stackid_hmap, we can find a corresponding one + * in stackmap, and vise versa. + */ + err = compare_map_keys(stackid_hmap_fd, stackmap_fd); + if (CHECK(err, "compare_map_keys stackid_hmap vs. stackmap", + "err %d errno %d\n", err, errno)) + goto disable_pmu; + + err = compare_map_keys(stackmap_fd, stackid_hmap_fd); + if (CHECK(err, "compare_map_keys stackmap vs. stackid_hmap", + "err %d errno %d\n", err, errno)) + goto disable_pmu; + + err = extract_build_id(buf, 256); + + if (CHECK(err, "get build_id with readelf", + "err %d errno %d\n", err, errno)) + goto disable_pmu; + + err = bpf_map_get_next_key(stackmap_fd, NULL, &key); + if (CHECK(err, "get_next_key from stackmap", + "err %d, errno %d\n", err, errno)) + goto disable_pmu; + + do { + char build_id[64]; + + err = bpf_map_lookup_elem(stackmap_fd, &key, id_offs); + if (CHECK(err, "lookup_elem from stackmap", + "err %d, errno %d\n", err, errno)) + goto disable_pmu; + for (i = 0; i < PERF_MAX_STACK_DEPTH; ++i) + if (id_offs[i].status == BPF_STACK_BUILD_ID_VALID && + id_offs[i].offset != 0) { + for (j = 0; j < 20; ++j) + sprintf(build_id + 2 * j, "%02x", + id_offs[i].build_id[j] & 0xff); + if (strstr(buf, build_id) != NULL) + build_id_matches = 1; + } + previous_key = key; + } while (bpf_map_get_next_key(stackmap_fd, &previous_key, &key) == 0); + + if (CHECK(build_id_matches < 1, "build id match", + "Didn't find expected build ID from the map\n")) + goto disable_pmu; + + /* + * We intentionally skip compare_stack_ips(). This is because we + * only support one in_nmi() ips-to-build_id translation per cpu + * at any time, thus stack_amap here will always fallback to + * BPF_STACK_BUILD_ID_IP; + */ + +disable_pmu: + ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE); + +close_pmu: + close(pmu_fd); + +close_prog: + bpf_object__close(obj); +} + #define MAX_CNT_RAWTP 10ull #define MAX_STACK_RAWTP 100 struct get_stack_trace_t { @@ -1425,6 +1558,7 @@ int main(void) test_tp_attach_query(); test_stacktrace_map(); test_stacktrace_build_id(); + test_stacktrace_build_id_nmi(); test_stacktrace_map_raw_tp(); test_get_stack_raw_tp(); diff --git a/tools/testing/selftests/bpf/urandom_read.c b/tools/testing/selftests/bpf/urandom_read.c index 4acfdebf36fa..9de8b7cb4e6d 100644 --- a/tools/testing/selftests/bpf/urandom_read.c +++ b/tools/testing/selftests/bpf/urandom_read.c @@ -6,15 +6,21 @@ #include #define BUF_SIZE 256 -int main(void) + +int main(int argc, char *argv[]) { int fd = open("/dev/urandom", O_RDONLY); int i; char buf[BUF_SIZE]; + int count = 4; if (fd < 0) return 1; - for (i = 0; i < 4; ++i) + + if (argc == 2) + count = atoi(argv[1]); + + for (i = 0; i < count; ++i) read(fd, buf, BUF_SIZE); close(fd); -- cgit v1.2.3 From 53ea24c20cea32b1dc70673402b496c4a5291d2d Mon Sep 17 00:00:00 2001 From: Prashant Bhole Date: Mon, 14 May 2018 17:29:15 +0900 Subject: samples/bpf: xdp_monitor, accept short options Updated optstring parameter for getopt_long() to accept short options. Also updated usage() function. Signed-off-by: Prashant Bhole Acked-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann --- samples/bpf/xdp_monitor_user.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/samples/bpf/xdp_monitor_user.c b/samples/bpf/xdp_monitor_user.c index 894bc64c2cac..05ad3f590c91 100644 --- a/samples/bpf/xdp_monitor_user.c +++ b/samples/bpf/xdp_monitor_user.c @@ -58,7 +58,7 @@ static void usage(char *argv[]) printf(" flag (internal value:%d)", *long_options[i].flag); else - printf("(internal short-option: -%c)", + printf("short-option: -%c", long_options[i].val); printf("\n"); } @@ -594,7 +594,7 @@ int main(int argc, char **argv) snprintf(bpf_obj_file, sizeof(bpf_obj_file), "%s_kern.o", argv[0]); /* Parse commands line args */ - while ((opt = getopt_long(argc, argv, "h", + while ((opt = getopt_long(argc, argv, "hDSs:", long_options, &longindex)) != -1) { switch (opt) { case 'D': -- cgit v1.2.3 From 0631b6583f66cef6f8af3387e7d320cb1f652b75 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Mon, 14 May 2018 23:22:27 +0200 Subject: bpf, mips: remove unused function The ool_skb_header_pointer() and size_to_len() is unused same as tmp_offset, therefore remove all of them. Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov --- arch/mips/net/ebpf_jit.c | 26 -------------------------- 1 file changed, 26 deletions(-) diff --git a/arch/mips/net/ebpf_jit.c b/arch/mips/net/ebpf_jit.c index 7ba7df9c28fc..aeb7b1b0f202 100644 --- a/arch/mips/net/ebpf_jit.c +++ b/arch/mips/net/ebpf_jit.c @@ -95,7 +95,6 @@ enum reg_val_type { * struct jit_ctx - JIT context * @skf: The sk_filter * @stack_size: eBPF stack size - * @tmp_offset: eBPF $sp offset to 8-byte temporary memory * @idx: Instruction index * @flags: JIT flags * @offsets: Instruction offsets @@ -105,7 +104,6 @@ enum reg_val_type { struct jit_ctx { const struct bpf_prog *skf; int stack_size; - int tmp_offset; u32 idx; u32 flags; u32 *offsets; @@ -293,7 +291,6 @@ static int gen_int_prologue(struct jit_ctx *ctx) locals_size = (ctx->flags & EBPF_SEEN_FP) ? MAX_BPF_STACK : 0; stack_adjust += locals_size; - ctx->tmp_offset = locals_size; ctx->stack_size = stack_adjust; @@ -399,7 +396,6 @@ static void gen_imm_to_reg(const struct bpf_insn *insn, int reg, emit_instr(ctx, lui, reg, upper >> 16); emit_instr(ctx, addiu, reg, reg, lower); } - } static int gen_imm_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, @@ -547,28 +543,6 @@ static int gen_imm_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, return 0; } -static void * __must_check -ool_skb_header_pointer(const struct sk_buff *skb, int offset, - int len, void *buffer) -{ - return skb_header_pointer(skb, offset, len, buffer); -} - -static int size_to_len(const struct bpf_insn *insn) -{ - switch (BPF_SIZE(insn->code)) { - case BPF_B: - return 1; - case BPF_H: - return 2; - case BPF_W: - return 4; - case BPF_DW: - return 8; - } - return 0; -} - static void emit_const_to_reg(struct jit_ctx *ctx, int dst, u64 value) { if (value >= 0xffffffffffff8000ull || value < 0x8000ull) { -- cgit v1.2.3 From 631b1e3b838ec25f509852247d1d5d10b8021444 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Mon, 14 May 2018 23:22:28 +0200 Subject: bpf, sparc: remove unused variable Since fe83963b7c38 ("bpf, sparc64: remove ld_abs/ld_ind") it's not used anymore therefore remove it. Signed-off-by: Daniel Borkmann Acked-by: David S. Miller Signed-off-by: Alexei Starovoitov --- arch/sparc/net/bpf_jit_comp_64.c | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/sparc/net/bpf_jit_comp_64.c b/arch/sparc/net/bpf_jit_comp_64.c index 9f5918e0693a..222785af550b 100644 --- a/arch/sparc/net/bpf_jit_comp_64.c +++ b/arch/sparc/net/bpf_jit_comp_64.c @@ -894,7 +894,6 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx) const int i = insn - ctx->prog->insnsi; const s16 off = insn->off; const s32 imm = insn->imm; - u32 *func; if (insn->src_reg == BPF_REG_FP) ctx->saw_frame_pointer = true; -- cgit v1.2.3 From 36256009b2d532621a5ee4b304da0e4b54e48acb Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Mon, 14 May 2018 23:22:29 +0200 Subject: bpf, x64: clean up retpoline emission slightly Make the RETPOLINE_{RA,ED}X_BPF_JIT() a bit more readable by cleaning up the macro, aligning comments and spacing. Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Signed-off-by: Alexei Starovoitov --- arch/x86/include/asm/nospec-branch.h | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-) diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h index 2cd344d1a6e5..2f700a1db851 100644 --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -301,9 +301,9 @@ do { \ * jmp *%edx for x86_32 */ #ifdef CONFIG_RETPOLINE -#ifdef CONFIG_X86_64 -# define RETPOLINE_RAX_BPF_JIT_SIZE 17 -# define RETPOLINE_RAX_BPF_JIT() \ +# ifdef CONFIG_X86_64 +# define RETPOLINE_RAX_BPF_JIT_SIZE 17 +# define RETPOLINE_RAX_BPF_JIT() \ do { \ EMIT1_off32(0xE8, 7); /* callq do_rop */ \ /* spec_trap: */ \ @@ -314,8 +314,8 @@ do { \ EMIT4(0x48, 0x89, 0x04, 0x24); /* mov %rax,(%rsp) */ \ EMIT1(0xC3); /* retq */ \ } while (0) -#else -# define RETPOLINE_EDX_BPF_JIT() \ +# else /* !CONFIG_X86_64 */ +# define RETPOLINE_EDX_BPF_JIT() \ do { \ EMIT1_off32(0xE8, 7); /* call do_rop */ \ /* spec_trap: */ \ @@ -326,17 +326,16 @@ do { \ EMIT3(0x89, 0x14, 0x24); /* mov %edx,(%esp) */ \ EMIT1(0xC3); /* ret */ \ } while (0) -#endif +# endif #else /* !CONFIG_RETPOLINE */ - -#ifdef CONFIG_X86_64 -# define RETPOLINE_RAX_BPF_JIT_SIZE 2 -# define RETPOLINE_RAX_BPF_JIT() \ - EMIT2(0xFF, 0xE0); /* jmp *%rax */ -#else -# define RETPOLINE_EDX_BPF_JIT() \ - EMIT2(0xFF, 0xE2) /* jmp *%edx */ -#endif +# ifdef CONFIG_X86_64 +# define RETPOLINE_RAX_BPF_JIT_SIZE 2 +# define RETPOLINE_RAX_BPF_JIT() \ + EMIT2(0xFF, 0xE0); /* jmp *%rax */ +# else /* !CONFIG_X86_64 */ +# define RETPOLINE_EDX_BPF_JIT() \ + EMIT2(0xFF, 0xE2) /* jmp *%edx */ +# endif #endif #endif /* _ASM_X86_NOSPEC_BRANCH_H_ */ -- cgit v1.2.3 From 38ca930601631585fbd7826f8f6908055a8dbc9e Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Mon, 14 May 2018 23:22:30 +0200 Subject: bpf, arm32: save 4 bytes of unneeded stack space The extra skb_copy_bits() buffer is not used anymore, therefore remove the extra 4 byte stack space requirement. Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov --- arch/arm/net/bpf_jit_32.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c index 82689b999257..d3ea6454e775 100644 --- a/arch/arm/net/bpf_jit_32.c +++ b/arch/arm/net/bpf_jit_32.c @@ -234,18 +234,11 @@ static void jit_fill_hole(void *area, unsigned int size) #define SCRATCH_SIZE 80 /* total stack size used in JITed code */ -#define _STACK_SIZE \ - (ctx->prog->aux->stack_depth + \ - + SCRATCH_SIZE + \ - + 4 /* extra for skb_copy_bits buffer */) - -#define STACK_SIZE ALIGN(_STACK_SIZE, STACK_ALIGNMENT) +#define _STACK_SIZE (ctx->prog->aux->stack_depth + SCRATCH_SIZE) +#define STACK_SIZE ALIGN(_STACK_SIZE, STACK_ALIGNMENT) /* Get the offset of eBPF REGISTERs stored on scratch space. */ -#define STACK_VAR(off) (STACK_SIZE-off-4) - -/* Offset of skb_copy_bits buffer */ -#define SKB_BUFFER STACK_VAR(SCRATCH_SIZE) +#define STACK_VAR(off) (STACK_SIZE - off) #if __LINUX_ARM_ARCH__ < 7 -- cgit v1.2.3 From 09ece3d0f2ee524b8d1d3c775d9eeb50c40558d8 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Mon, 14 May 2018 23:22:31 +0200 Subject: bpf, arm64: save 4 bytes of unneeded stack space Follow-up to 816d9ef32a8b ("bpf, arm64: remove ld_abs/ld_ind") in that the extra 4 byte JIT scratchpad is not needed anymore since it was in ld_abs/ld_ind as stack buffer for bpf_load_pointer(). Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov --- arch/arm64/net/bpf_jit_comp.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index 0b40c8fb0706..85113cab2046 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -21,7 +21,6 @@ #include #include #include -#include #include #include @@ -188,7 +187,7 @@ static int build_prologue(struct jit_ctx *ctx) * | ... | BPF prog stack * | | * +-----+ <= (BPF_FP - prog->aux->stack_depth) - * |RSVD | JIT scratchpad + * |RSVD | padding * current A64_SP => +-----+ <= (BPF_FP - ctx->stack_size) * | | * | ... | Function call stack @@ -220,9 +219,7 @@ static int build_prologue(struct jit_ctx *ctx) return -1; } - /* 4 byte extra for skb_copy_bits buffer */ - ctx->stack_size = prog->aux->stack_depth + 4; - ctx->stack_size = STACK_ALIGN(ctx->stack_size); + ctx->stack_size = STACK_ALIGN(prog->aux->stack_depth); /* Set up function call stack */ emit(A64_SUB_I(1, A64_SP, A64_SP, ctx->stack_size), ctx); -- cgit v1.2.3 From 6d2eea6fb0791bf191043a68937c9aa59c5ea678 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Mon, 14 May 2018 23:22:32 +0200 Subject: bpf, arm64: optimize 32/64 immediate emission Improve the JIT to emit 64 and 32 bit immediates, the current algorithm is not optimal and we often emit more instructions than actually needed. arm64 has movz, movn, movk variants but for the current 64 bit immediates we only use movz with a series of movk when needed. For example loading ffffffffffffabab emits the following 4 instructions in the JIT today: * movz: abab, shift: 0, result: 000000000000abab * movk: ffff, shift: 16, result: 00000000ffffabab * movk: ffff, shift: 32, result: 0000ffffffffabab * movk: ffff, shift: 48, result: ffffffffffffabab Whereas after the patch the same load only needs a single instruction: * movn: 5454, shift: 0, result: ffffffffffffabab Another example where two extra instructions can be saved: * movz: abab, shift: 0, result: 000000000000abab * movk: 1f2f, shift: 16, result: 000000001f2fabab * movk: ffff, shift: 32, result: 0000ffff1f2fabab * movk: ffff, shift: 48, result: ffffffff1f2fabab After the patch: * movn: e0d0, shift: 16, result: ffffffff1f2fffff * movk: abab, shift: 0, result: ffffffff1f2fabab Another example with movz, before: * movz: 0000, shift: 0, result: 0000000000000000 * movk: fea0, shift: 32, result: 0000fea000000000 After: * movz: fea0, shift: 32, result: 0000fea000000000 Moreover, reuse emit_a64_mov_i() for 32 bit immediates that are loaded via emit_a64_mov_i64() which is a similar optimization as done in 6fe8b9c1f41d ("bpf, x64: save several bytes by using mov over movabsq when possible"). On arm64, the latter allows to use a single instruction with movn due to zero extension where otherwise two would be needed. And last but not least add a missing optimization in emit_a64_mov_i() where movn is used but the subsequent movk not needed. With some of the Cilium programs in use, this shrinks the needed instructions by about three percent. Tested on Cavium ThunderX CN8890. Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov --- arch/arm64/net/bpf_jit_comp.c | 85 +++++++++++++++++++++++++++---------------- 1 file changed, 54 insertions(+), 31 deletions(-) diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index 85113cab2046..c8a2620312c0 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -79,23 +79,66 @@ static inline void emit(const u32 insn, struct jit_ctx *ctx) ctx->idx++; } +static inline void emit_a64_mov_i(const int is64, const int reg, + const s32 val, struct jit_ctx *ctx) +{ + u16 hi = val >> 16; + u16 lo = val & 0xffff; + + if (hi & 0x8000) { + if (hi == 0xffff) { + emit(A64_MOVN(is64, reg, (u16)~lo, 0), ctx); + } else { + emit(A64_MOVN(is64, reg, (u16)~hi, 16), ctx); + if (lo != 0xffff) + emit(A64_MOVK(is64, reg, lo, 0), ctx); + } + } else { + emit(A64_MOVZ(is64, reg, lo, 0), ctx); + if (hi) + emit(A64_MOVK(is64, reg, hi, 16), ctx); + } +} + +static int i64_i16_blocks(const u64 val, bool inverse) +{ + return (((val >> 0) & 0xffff) != (inverse ? 0xffff : 0x0000)) + + (((val >> 16) & 0xffff) != (inverse ? 0xffff : 0x0000)) + + (((val >> 32) & 0xffff) != (inverse ? 0xffff : 0x0000)) + + (((val >> 48) & 0xffff) != (inverse ? 0xffff : 0x0000)); +} + static inline void emit_a64_mov_i64(const int reg, const u64 val, struct jit_ctx *ctx) { - u64 tmp = val; - int shift = 0; - - emit(A64_MOVZ(1, reg, tmp & 0xffff, shift), ctx); - tmp >>= 16; - shift += 16; - while (tmp) { - if (tmp & 0xffff) - emit(A64_MOVK(1, reg, tmp & 0xffff, shift), ctx); - tmp >>= 16; - shift += 16; + u64 nrm_tmp = val, rev_tmp = ~val; + bool inverse; + int shift; + + if (!(nrm_tmp >> 32)) + return emit_a64_mov_i(0, reg, (u32)val, ctx); + + inverse = i64_i16_blocks(nrm_tmp, true) < i64_i16_blocks(nrm_tmp, false); + shift = max(round_down((inverse ? (fls64(rev_tmp) - 1) : + (fls64(nrm_tmp) - 1)), 16), 0); + if (inverse) + emit(A64_MOVN(1, reg, (rev_tmp >> shift) & 0xffff, shift), ctx); + else + emit(A64_MOVZ(1, reg, (nrm_tmp >> shift) & 0xffff, shift), ctx); + shift -= 16; + while (shift >= 0) { + if (((nrm_tmp >> shift) & 0xffff) != (inverse ? 0xffff : 0x0000)) + emit(A64_MOVK(1, reg, (nrm_tmp >> shift) & 0xffff, shift), ctx); + shift -= 16; } } +/* + * This is an unoptimized 64 immediate emission used for BPF to BPF call + * addresses. It will always do a full 64 bit decomposition as otherwise + * more complexity in the last extra pass is required since we previously + * reserved 4 instructions for the address. + */ static inline void emit_addr_mov_i64(const int reg, const u64 val, struct jit_ctx *ctx) { @@ -110,26 +153,6 @@ static inline void emit_addr_mov_i64(const int reg, const u64 val, } } -static inline void emit_a64_mov_i(const int is64, const int reg, - const s32 val, struct jit_ctx *ctx) -{ - u16 hi = val >> 16; - u16 lo = val & 0xffff; - - if (hi & 0x8000) { - if (hi == 0xffff) { - emit(A64_MOVN(is64, reg, (u16)~lo, 0), ctx); - } else { - emit(A64_MOVN(is64, reg, (u16)~hi, 16), ctx); - emit(A64_MOVK(is64, reg, lo, 0), ctx); - } - } else { - emit(A64_MOVZ(is64, reg, lo, 0), ctx); - if (hi) - emit(A64_MOVK(is64, reg, hi, 16), ctx); - } -} - static inline int bpf2a64_offset(int bpf_to, int bpf_from, const struct jit_ctx *ctx) { -- cgit v1.2.3 From 56ea6a8b4949c66d550d05e92da8ef4351b90027 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Mon, 14 May 2018 23:22:33 +0200 Subject: bpf, arm64: save 4 bytes in prologue when ebpf insns came from cbpf We can trivially save 4 bytes in prologue for cBPF since tail calls can never be used from there. The register push/pop is pairwise, here, x25 (fp) and x26 (tcc), so no point in changing that, only reset to zero is not needed. Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov --- arch/arm64/net/bpf_jit_comp.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index c8a2620312c0..a6fdaea07c63 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -185,7 +185,7 @@ static inline int epilogue_offset(const struct jit_ctx *ctx) /* Tail call offset to jump into */ #define PROLOGUE_OFFSET 7 -static int build_prologue(struct jit_ctx *ctx) +static int build_prologue(struct jit_ctx *ctx, bool ebpf_from_cbpf) { const struct bpf_prog *prog = ctx->prog; const u8 r6 = bpf2a64[BPF_REG_6]; @@ -232,14 +232,16 @@ static int build_prologue(struct jit_ctx *ctx) /* Set up BPF prog stack base register */ emit(A64_MOV(1, fp, A64_SP), ctx); - /* Initialize tail_call_cnt */ - emit(A64_MOVZ(1, tcc, 0, 0), ctx); + if (!ebpf_from_cbpf) { + /* Initialize tail_call_cnt */ + emit(A64_MOVZ(1, tcc, 0, 0), ctx); - cur_offset = ctx->idx - idx0; - if (cur_offset != PROLOGUE_OFFSET) { - pr_err_once("PROLOGUE_OFFSET = %d, expected %d!\n", - cur_offset, PROLOGUE_OFFSET); - return -1; + cur_offset = ctx->idx - idx0; + if (cur_offset != PROLOGUE_OFFSET) { + pr_err_once("PROLOGUE_OFFSET = %d, expected %d!\n", + cur_offset, PROLOGUE_OFFSET); + return -1; + } } ctx->stack_size = STACK_ALIGN(prog->aux->stack_depth); @@ -806,6 +808,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) struct bpf_prog *tmp, *orig_prog = prog; struct bpf_binary_header *header; struct arm64_jit_data *jit_data; + bool was_classic = bpf_prog_was_classic(prog); bool tmp_blinded = false; bool extra_pass = false; struct jit_ctx ctx; @@ -860,7 +863,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) goto out_off; } - if (build_prologue(&ctx)) { + if (build_prologue(&ctx, was_classic)) { prog = orig_prog; goto out_off; } @@ -883,7 +886,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) skip_init_ctx: ctx.idx = 0; - build_prologue(&ctx); + build_prologue(&ctx, was_classic); if (build_body(&ctx)) { bpf_jit_binary_free(header); -- cgit v1.2.3 From a82d8cd398716b41f0fbe3882e3fe3f5ccf9f9cf Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Mon, 14 May 2018 23:22:34 +0200 Subject: bpf: add ld64 imm test cases Add test cases where we combine semi-random imm values, mainly for testing JITs when they have different encoding options for 64 bit immediates in order to reduce resulting image size. Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov --- tools/testing/selftests/bpf/bpf_rand.h | 80 +++++++++++++++++++++++++++++ tools/testing/selftests/bpf/test_verifier.c | 62 ++++++++++++++++++++++ 2 files changed, 142 insertions(+) create mode 100644 tools/testing/selftests/bpf/bpf_rand.h diff --git a/tools/testing/selftests/bpf/bpf_rand.h b/tools/testing/selftests/bpf/bpf_rand.h new file mode 100644 index 000000000000..59bf3e1a9371 --- /dev/null +++ b/tools/testing/selftests/bpf/bpf_rand.h @@ -0,0 +1,80 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __BPF_RAND__ +#define __BPF_RAND__ + +#include +#include +#include + +static inline uint64_t bpf_rand_mask(uint64_t mask) +{ + return (((uint64_t)(uint32_t)rand()) | + ((uint64_t)(uint32_t)rand() << 32)) & mask; +} + +#define bpf_rand_ux(x, m) \ +static inline uint64_t bpf_rand_u##x(int shift) \ +{ \ + return bpf_rand_mask((m)) << shift; \ +} + +bpf_rand_ux( 8, 0xffULL) +bpf_rand_ux(16, 0xffffULL) +bpf_rand_ux(24, 0xffffffULL) +bpf_rand_ux(32, 0xffffffffULL) +bpf_rand_ux(40, 0xffffffffffULL) +bpf_rand_ux(48, 0xffffffffffffULL) +bpf_rand_ux(56, 0xffffffffffffffULL) +bpf_rand_ux(64, 0xffffffffffffffffULL) + +static inline void bpf_semi_rand_init(void) +{ + srand(time(NULL)); +} + +static inline uint64_t bpf_semi_rand_get(void) +{ + switch (rand() % 39) { + case 0: return 0x000000ff00000000ULL | bpf_rand_u8(0); + case 1: return 0xffffffff00000000ULL | bpf_rand_u16(0); + case 2: return 0x00000000ffff0000ULL | bpf_rand_u16(0); + case 3: return 0x8000000000000000ULL | bpf_rand_u32(0); + case 4: return 0x00000000f0000000ULL | bpf_rand_u32(0); + case 5: return 0x0000000100000000ULL | bpf_rand_u24(0); + case 6: return 0x800ff00000000000ULL | bpf_rand_u32(0); + case 7: return 0x7fffffff00000000ULL | bpf_rand_u32(0); + case 8: return 0xffffffffffffff00ULL ^ bpf_rand_u32(24); + case 9: return 0xffffffffffffff00ULL | bpf_rand_u8(0); + case 10: return 0x0000000010000000ULL | bpf_rand_u32(0); + case 11: return 0xf000000000000000ULL | bpf_rand_u8(0); + case 12: return 0x0000f00000000000ULL | bpf_rand_u8(8); + case 13: return 0x000000000f000000ULL | bpf_rand_u8(16); + case 14: return 0x0000000000000f00ULL | bpf_rand_u8(32); + case 15: return 0x00fff00000000f00ULL | bpf_rand_u8(48); + case 16: return 0x00007fffffffffffULL ^ bpf_rand_u32(1); + case 17: return 0xffff800000000000ULL | bpf_rand_u8(4); + case 18: return 0xffff800000000000ULL | bpf_rand_u8(20); + case 19: return (0xffffffc000000000ULL + 0x80000ULL) | bpf_rand_u32(0); + case 20: return (0xffffffc000000000ULL - 0x04000000ULL) | bpf_rand_u32(0); + case 21: return 0x0000000000000000ULL | bpf_rand_u8(55) | bpf_rand_u32(20); + case 22: return 0xffffffffffffffffULL ^ bpf_rand_u8(3) ^ bpf_rand_u32(40); + case 23: return 0x0000000000000000ULL | bpf_rand_u8(bpf_rand_u8(0) % 64); + case 24: return 0x0000000000000000ULL | bpf_rand_u16(bpf_rand_u8(0) % 64); + case 25: return 0xffffffffffffffffULL ^ bpf_rand_u8(bpf_rand_u8(0) % 64); + case 26: return 0xffffffffffffffffULL ^ bpf_rand_u40(bpf_rand_u8(0) % 64); + case 27: return 0x0000800000000000ULL; + case 28: return 0x8000000000000000ULL; + case 29: return 0x0000000000000000ULL; + case 30: return 0xffffffffffffffffULL; + case 31: return bpf_rand_u16(bpf_rand_u8(0) % 64); + case 32: return bpf_rand_u24(bpf_rand_u8(0) % 64); + case 33: return bpf_rand_u32(bpf_rand_u8(0) % 64); + case 34: return bpf_rand_u40(bpf_rand_u8(0) % 64); + case 35: return bpf_rand_u48(bpf_rand_u8(0) % 64); + case 36: return bpf_rand_u56(bpf_rand_u8(0) % 64); + case 37: return bpf_rand_u64(bpf_rand_u8(0) % 64); + default: return bpf_rand_u64(0); + } +} + +#endif /* __BPF_RAND__ */ diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index 275b4570b5b8..a877af00605d 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -41,6 +41,7 @@ # endif #endif #include "bpf_rlimit.h" +#include "bpf_rand.h" #include "../../../include/linux/filter.h" #ifndef ARRAY_SIZE @@ -152,6 +153,30 @@ static void bpf_fill_jump_around_ld_abs(struct bpf_test *self) insn[i] = BPF_EXIT_INSN(); } +static void bpf_fill_rand_ld_dw(struct bpf_test *self) +{ + struct bpf_insn *insn = self->insns; + uint64_t res = 0; + int i = 0; + + insn[i++] = BPF_MOV32_IMM(BPF_REG_0, 0); + while (i < self->retval) { + uint64_t val = bpf_semi_rand_get(); + struct bpf_insn tmp[2] = { BPF_LD_IMM64(BPF_REG_1, val) }; + + res ^= val; + insn[i++] = tmp[0]; + insn[i++] = tmp[1]; + insn[i++] = BPF_ALU64_REG(BPF_XOR, BPF_REG_0, BPF_REG_1); + } + insn[i++] = BPF_MOV64_REG(BPF_REG_1, BPF_REG_0); + insn[i++] = BPF_ALU64_IMM(BPF_RSH, BPF_REG_1, 32); + insn[i++] = BPF_ALU64_REG(BPF_XOR, BPF_REG_0, BPF_REG_1); + insn[i] = BPF_EXIT_INSN(); + res ^= (res >> 32); + self->retval = (uint32_t)res; +} + static struct bpf_test tests[] = { { "add+sub+mul", @@ -11974,6 +11999,42 @@ static struct bpf_test tests[] = { .result = ACCEPT, .retval = 10, }, + { + "ld_dw: xor semi-random 64 bit imms, test 1", + .insns = { }, + .data = { }, + .fill_helper = bpf_fill_rand_ld_dw, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = ACCEPT, + .retval = 4090, + }, + { + "ld_dw: xor semi-random 64 bit imms, test 2", + .insns = { }, + .data = { }, + .fill_helper = bpf_fill_rand_ld_dw, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = ACCEPT, + .retval = 2047, + }, + { + "ld_dw: xor semi-random 64 bit imms, test 3", + .insns = { }, + .data = { }, + .fill_helper = bpf_fill_rand_ld_dw, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = ACCEPT, + .retval = 511, + }, + { + "ld_dw: xor semi-random 64 bit imms, test 4", + .insns = { }, + .data = { }, + .fill_helper = bpf_fill_rand_ld_dw, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = ACCEPT, + .retval = 5, + }, }; static int probe_filter_length(const struct bpf_insn *fp) @@ -12346,5 +12407,6 @@ int main(int argc, char **argv) return EXIT_FAILURE; } + bpf_semi_rand_init(); return do_test(unpriv, from, to); } -- cgit v1.2.3 From 2bf3e2ef425bc2a164f10b554b7db6a8b4090ef4 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 14 May 2018 22:35:02 -0700 Subject: samples: bpf: include bpf/bpf.h instead of local libbpf.h There are two files in the tree called libbpf.h which is becoming problematic. Most samples don't actually need the local libbpf.h they simply include it to get to bpf/bpf.h. Include bpf/bpf.h directly instead. Signed-off-by: Jakub Kicinski Acked-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov --- samples/bpf/bpf_load.c | 2 +- samples/bpf/bpf_load.h | 2 +- samples/bpf/cpustat_user.c | 2 +- samples/bpf/lathist_user.c | 2 +- samples/bpf/load_sock_ops.c | 2 +- samples/bpf/lwt_len_hist_user.c | 2 +- samples/bpf/map_perf_test_user.c | 2 +- samples/bpf/sock_example.h | 1 - samples/bpf/sockex1_user.c | 2 +- samples/bpf/sockex2_user.c | 2 +- samples/bpf/sockex3_user.c | 2 +- samples/bpf/syscall_tp_user.c | 2 +- samples/bpf/tc_l2_redirect_user.c | 2 +- samples/bpf/test_cgrp2_array_pin.c | 2 +- samples/bpf/test_current_task_under_cgroup_user.c | 2 +- samples/bpf/test_lru_dist.c | 2 +- samples/bpf/test_map_in_map_user.c | 2 +- samples/bpf/test_overhead_user.c | 2 +- samples/bpf/test_probe_write_user_user.c | 2 +- samples/bpf/trace_output_user.c | 2 +- samples/bpf/tracex1_user.c | 2 +- samples/bpf/tracex2_user.c | 2 +- samples/bpf/tracex3_user.c | 2 +- samples/bpf/tracex4_user.c | 2 +- samples/bpf/tracex5_user.c | 2 +- samples/bpf/tracex6_user.c | 2 +- samples/bpf/tracex7_user.c | 2 +- samples/bpf/xdp_fwd_user.c | 2 +- samples/bpf/xdp_monitor_user.c | 2 +- samples/bpf/xdp_redirect_cpu_user.c | 2 +- samples/bpf/xdp_redirect_map_user.c | 2 +- samples/bpf/xdp_redirect_user.c | 2 +- samples/bpf/xdp_router_ipv4_user.c | 2 +- samples/bpf/xdp_tx_iptunnel_user.c | 2 +- samples/bpf/xdpsock_user.c | 2 +- 35 files changed, 34 insertions(+), 35 deletions(-) diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c index a6b290de5632..89161c9ed466 100644 --- a/samples/bpf/bpf_load.c +++ b/samples/bpf/bpf_load.c @@ -24,7 +24,7 @@ #include #include #include -#include "libbpf.h" +#include #include "bpf_load.h" #include "perf-sys.h" diff --git a/samples/bpf/bpf_load.h b/samples/bpf/bpf_load.h index f9da59bca0cc..814894a12974 100644 --- a/samples/bpf/bpf_load.h +++ b/samples/bpf/bpf_load.h @@ -2,7 +2,7 @@ #ifndef __BPF_LOAD_H #define __BPF_LOAD_H -#include "libbpf.h" +#include #define MAX_MAPS 32 #define MAX_PROGS 32 diff --git a/samples/bpf/cpustat_user.c b/samples/bpf/cpustat_user.c index 2b4cd1ae57c5..869a99406dbf 100644 --- a/samples/bpf/cpustat_user.c +++ b/samples/bpf/cpustat_user.c @@ -17,7 +17,7 @@ #include #include -#include "libbpf.h" +#include #include "bpf_load.h" #define MAX_CPU 8 diff --git a/samples/bpf/lathist_user.c b/samples/bpf/lathist_user.c index 6477bad5b4e2..c8e88cc84e61 100644 --- a/samples/bpf/lathist_user.c +++ b/samples/bpf/lathist_user.c @@ -10,7 +10,7 @@ #include #include #include -#include "libbpf.h" +#include #include "bpf_load.h" #define MAX_ENTRIES 20 diff --git a/samples/bpf/load_sock_ops.c b/samples/bpf/load_sock_ops.c index e5da6cf71a3e..8ecb41ea0c03 100644 --- a/samples/bpf/load_sock_ops.c +++ b/samples/bpf/load_sock_ops.c @@ -8,7 +8,7 @@ #include #include #include -#include "libbpf.h" +#include #include "bpf_load.h" #include #include diff --git a/samples/bpf/lwt_len_hist_user.c b/samples/bpf/lwt_len_hist_user.c index 7fcb94c09112..587b68b1f8dd 100644 --- a/samples/bpf/lwt_len_hist_user.c +++ b/samples/bpf/lwt_len_hist_user.c @@ -9,7 +9,7 @@ #include #include -#include "libbpf.h" +#include #include "bpf_util.h" #define MAX_INDEX 64 diff --git a/samples/bpf/map_perf_test_user.c b/samples/bpf/map_perf_test_user.c index 519d9af4b04a..38b7b1a96cc2 100644 --- a/samples/bpf/map_perf_test_user.c +++ b/samples/bpf/map_perf_test_user.c @@ -21,7 +21,7 @@ #include #include -#include "libbpf.h" +#include #include "bpf_load.h" #define TEST_BIT(t) (1U << (t)) diff --git a/samples/bpf/sock_example.h b/samples/bpf/sock_example.h index 772d5dad8465..a27d7579bc73 100644 --- a/samples/bpf/sock_example.h +++ b/samples/bpf/sock_example.h @@ -9,7 +9,6 @@ #include #include #include -#include "libbpf.h" static inline int open_raw_sock(const char *name) { diff --git a/samples/bpf/sockex1_user.c b/samples/bpf/sockex1_user.c index 2be935c2627d..93ec01c56104 100644 --- a/samples/bpf/sockex1_user.c +++ b/samples/bpf/sockex1_user.c @@ -2,7 +2,7 @@ #include #include #include -#include "libbpf.h" +#include #include "bpf_load.h" #include "sock_example.h" #include diff --git a/samples/bpf/sockex2_user.c b/samples/bpf/sockex2_user.c index 44fe0805b087..1d5c6e9a6d27 100644 --- a/samples/bpf/sockex2_user.c +++ b/samples/bpf/sockex2_user.c @@ -2,7 +2,7 @@ #include #include #include -#include "libbpf.h" +#include #include "bpf_load.h" #include "sock_example.h" #include diff --git a/samples/bpf/sockex3_user.c b/samples/bpf/sockex3_user.c index 495ee02e2fb7..5ba3ae9d180b 100644 --- a/samples/bpf/sockex3_user.c +++ b/samples/bpf/sockex3_user.c @@ -2,7 +2,7 @@ #include #include #include -#include "libbpf.h" +#include #include "bpf_load.h" #include "sock_example.h" #include diff --git a/samples/bpf/syscall_tp_user.c b/samples/bpf/syscall_tp_user.c index 9169d3207f18..1a1d0059a277 100644 --- a/samples/bpf/syscall_tp_user.c +++ b/samples/bpf/syscall_tp_user.c @@ -16,7 +16,7 @@ #include #include #include -#include "libbpf.h" +#include #include "bpf_load.h" /* This program verifies bpf attachment to tracepoint sys_enter_* and sys_exit_*. diff --git a/samples/bpf/tc_l2_redirect_user.c b/samples/bpf/tc_l2_redirect_user.c index 28995a776560..7ec45c3e8f56 100644 --- a/samples/bpf/tc_l2_redirect_user.c +++ b/samples/bpf/tc_l2_redirect_user.c @@ -13,7 +13,7 @@ #include #include -#include "libbpf.h" +#include static void usage(void) { diff --git a/samples/bpf/test_cgrp2_array_pin.c b/samples/bpf/test_cgrp2_array_pin.c index 8a1b8b5d8def..242184292f59 100644 --- a/samples/bpf/test_cgrp2_array_pin.c +++ b/samples/bpf/test_cgrp2_array_pin.c @@ -14,7 +14,7 @@ #include #include -#include "libbpf.h" +#include static void usage(void) { diff --git a/samples/bpf/test_current_task_under_cgroup_user.c b/samples/bpf/test_current_task_under_cgroup_user.c index 65b5fb51c1db..4be4874ca2bc 100644 --- a/samples/bpf/test_current_task_under_cgroup_user.c +++ b/samples/bpf/test_current_task_under_cgroup_user.c @@ -9,7 +9,7 @@ #include #include #include -#include "libbpf.h" +#include #include "bpf_load.h" #include #include "cgroup_helpers.h" diff --git a/samples/bpf/test_lru_dist.c b/samples/bpf/test_lru_dist.c index 73c357142268..eec3e2509ce8 100644 --- a/samples/bpf/test_lru_dist.c +++ b/samples/bpf/test_lru_dist.c @@ -21,7 +21,7 @@ #include #include -#include "libbpf.h" +#include #include "bpf_util.h" #define min(a, b) ((a) < (b) ? (a) : (b)) diff --git a/samples/bpf/test_map_in_map_user.c b/samples/bpf/test_map_in_map_user.c index 1aca18539d8d..e308858f7bcf 100644 --- a/samples/bpf/test_map_in_map_user.c +++ b/samples/bpf/test_map_in_map_user.c @@ -13,7 +13,7 @@ #include #include #include -#include "libbpf.h" +#include #include "bpf_load.h" #define PORT_A (map_fd[0]) diff --git a/samples/bpf/test_overhead_user.c b/samples/bpf/test_overhead_user.c index e1d35e07a10e..6caf47afa635 100644 --- a/samples/bpf/test_overhead_user.c +++ b/samples/bpf/test_overhead_user.c @@ -19,7 +19,7 @@ #include #include #include -#include "libbpf.h" +#include #include "bpf_load.h" #define MAX_CNT 1000000 diff --git a/samples/bpf/test_probe_write_user_user.c b/samples/bpf/test_probe_write_user_user.c index bf8e3a9f3067..045eb5e30f54 100644 --- a/samples/bpf/test_probe_write_user_user.c +++ b/samples/bpf/test_probe_write_user_user.c @@ -3,7 +3,7 @@ #include #include #include -#include "libbpf.h" +#include #include "bpf_load.h" #include #include diff --git a/samples/bpf/trace_output_user.c b/samples/bpf/trace_output_user.c index da98be721001..4837d73edefe 100644 --- a/samples/bpf/trace_output_user.c +++ b/samples/bpf/trace_output_user.c @@ -18,7 +18,7 @@ #include #include #include -#include "libbpf.h" +#include #include "bpf_load.h" #include "perf-sys.h" #include "trace_helpers.h" diff --git a/samples/bpf/tracex1_user.c b/samples/bpf/tracex1_user.c index 3dcb475fb135..af8c20608ab5 100644 --- a/samples/bpf/tracex1_user.c +++ b/samples/bpf/tracex1_user.c @@ -2,7 +2,7 @@ #include #include #include -#include "libbpf.h" +#include #include "bpf_load.h" int main(int ac, char **argv) diff --git a/samples/bpf/tracex2_user.c b/samples/bpf/tracex2_user.c index efb5e61918df..1a81e6a5c2ea 100644 --- a/samples/bpf/tracex2_user.c +++ b/samples/bpf/tracex2_user.c @@ -7,7 +7,7 @@ #include #include -#include "libbpf.h" +#include #include "bpf_load.h" #include "bpf_util.h" diff --git a/samples/bpf/tracex3_user.c b/samples/bpf/tracex3_user.c index fe372239d505..6c6b10f4c3ee 100644 --- a/samples/bpf/tracex3_user.c +++ b/samples/bpf/tracex3_user.c @@ -13,7 +13,7 @@ #include #include -#include "libbpf.h" +#include #include "bpf_load.h" #include "bpf_util.h" diff --git a/samples/bpf/tracex4_user.c b/samples/bpf/tracex4_user.c index 22c644f1f4c3..14625c898e43 100644 --- a/samples/bpf/tracex4_user.c +++ b/samples/bpf/tracex4_user.c @@ -14,7 +14,7 @@ #include #include -#include "libbpf.h" +#include #include "bpf_load.h" struct pair { diff --git a/samples/bpf/tracex5_user.c b/samples/bpf/tracex5_user.c index 4e2774b731f0..c4ab91c89494 100644 --- a/samples/bpf/tracex5_user.c +++ b/samples/bpf/tracex5_user.c @@ -5,7 +5,7 @@ #include #include #include -#include "libbpf.h" +#include #include "bpf_load.h" #include diff --git a/samples/bpf/tracex6_user.c b/samples/bpf/tracex6_user.c index 89ab8d408474..4bb3c830adb2 100644 --- a/samples/bpf/tracex6_user.c +++ b/samples/bpf/tracex6_user.c @@ -16,7 +16,7 @@ #include #include "bpf_load.h" -#include "libbpf.h" +#include #include "perf-sys.h" #define SAMPLE_PERIOD 0x7fffffffffffffffULL diff --git a/samples/bpf/tracex7_user.c b/samples/bpf/tracex7_user.c index 8a52ac492e8b..ea6dae78f0df 100644 --- a/samples/bpf/tracex7_user.c +++ b/samples/bpf/tracex7_user.c @@ -3,7 +3,7 @@ #include #include #include -#include "libbpf.h" +#include #include "bpf_load.h" int main(int argc, char **argv) diff --git a/samples/bpf/xdp_fwd_user.c b/samples/bpf/xdp_fwd_user.c index 9c6606f57126..a87a2048ed32 100644 --- a/samples/bpf/xdp_fwd_user.c +++ b/samples/bpf/xdp_fwd_user.c @@ -26,7 +26,7 @@ #include "bpf_load.h" #include "bpf_util.h" -#include "libbpf.h" +#include static int do_attach(int idx, int fd, const char *name) diff --git a/samples/bpf/xdp_monitor_user.c b/samples/bpf/xdp_monitor_user.c index 05ad3f590c91..bf09b5188acd 100644 --- a/samples/bpf/xdp_monitor_user.c +++ b/samples/bpf/xdp_monitor_user.c @@ -26,7 +26,7 @@ static const char *__doc_err_only__= #include #include -#include "libbpf.h" +#include #include "bpf_load.h" #include "bpf_util.h" diff --git a/samples/bpf/xdp_redirect_cpu_user.c b/samples/bpf/xdp_redirect_cpu_user.c index 23744a8aaf21..f6efaefd485b 100644 --- a/samples/bpf/xdp_redirect_cpu_user.c +++ b/samples/bpf/xdp_redirect_cpu_user.c @@ -28,7 +28,7 @@ static const char *__doc__ = * use bpf/libbpf.h), but cannot as (currently) needed for XDP * attaching to a device via bpf_set_link_xdp_fd() */ -#include "libbpf.h" +#include #include "bpf_load.h" #include "bpf_util.h" diff --git a/samples/bpf/xdp_redirect_map_user.c b/samples/bpf/xdp_redirect_map_user.c index 7eae07d7293e..4445e76854b5 100644 --- a/samples/bpf/xdp_redirect_map_user.c +++ b/samples/bpf/xdp_redirect_map_user.c @@ -24,7 +24,7 @@ #include "bpf_load.h" #include "bpf_util.h" -#include "libbpf.h" +#include static int ifindex_in; static int ifindex_out; diff --git a/samples/bpf/xdp_redirect_user.c b/samples/bpf/xdp_redirect_user.c index b701b5c21342..81a69e36cb78 100644 --- a/samples/bpf/xdp_redirect_user.c +++ b/samples/bpf/xdp_redirect_user.c @@ -24,7 +24,7 @@ #include "bpf_load.h" #include "bpf_util.h" -#include "libbpf.h" +#include static int ifindex_in; static int ifindex_out; diff --git a/samples/bpf/xdp_router_ipv4_user.c b/samples/bpf/xdp_router_ipv4_user.c index 6296741c1fbd..b2b4dfa776c8 100644 --- a/samples/bpf/xdp_router_ipv4_user.c +++ b/samples/bpf/xdp_router_ipv4_user.c @@ -16,7 +16,7 @@ #include #include #include "bpf_load.h" -#include "libbpf.h" +#include #include #include #include diff --git a/samples/bpf/xdp_tx_iptunnel_user.c b/samples/bpf/xdp_tx_iptunnel_user.c index f0a787268a87..a4ccc33adac0 100644 --- a/samples/bpf/xdp_tx_iptunnel_user.c +++ b/samples/bpf/xdp_tx_iptunnel_user.c @@ -18,7 +18,7 @@ #include #include #include "bpf_load.h" -#include "libbpf.h" +#include #include "bpf_util.h" #include "xdp_tx_iptunnel_common.h" diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c index 4b8a7cf3e63b..7fe60f6f7d53 100644 --- a/samples/bpf/xdpsock_user.c +++ b/samples/bpf/xdpsock_user.c @@ -38,7 +38,7 @@ #include "bpf_load.h" #include "bpf_util.h" -#include "libbpf.h" +#include #include "xdpsock.h" -- cgit v1.2.3 From 8d93045077aeede62127b6d6663bfdd31f6240da Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 14 May 2018 22:35:03 -0700 Subject: samples: bpf: rename libbpf.h to bpf_insn.h The libbpf.h file in samples is clashing with libbpf's header. Since it only includes a subset of filter.h instruction helpers rename it to bpf_insn.h. Drop the unnecessary include of bpf/bpf.h. Signed-off-by: Jakub Kicinski Acked-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov --- samples/bpf/bpf_insn.h | 197 +++++++++++++++++++++++++++++++ samples/bpf/cookie_uid_helper_example.c | 2 +- samples/bpf/fds_example.c | 4 +- samples/bpf/libbpf.h | 199 -------------------------------- samples/bpf/sock_example.c | 3 +- samples/bpf/test_cgrp2_attach.c | 3 +- samples/bpf/test_cgrp2_attach2.c | 3 +- samples/bpf/test_cgrp2_sock.c | 3 +- samples/bpf/test_cgrp2_sock2.c | 3 +- 9 files changed, 211 insertions(+), 206 deletions(-) create mode 100644 samples/bpf/bpf_insn.h delete mode 100644 samples/bpf/libbpf.h diff --git a/samples/bpf/bpf_insn.h b/samples/bpf/bpf_insn.h new file mode 100644 index 000000000000..20dc5cefec84 --- /dev/null +++ b/samples/bpf/bpf_insn.h @@ -0,0 +1,197 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* eBPF instruction mini library */ +#ifndef __BPF_INSN_H +#define __BPF_INSN_H + +struct bpf_insn; + +/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */ + +#define BPF_ALU64_REG(OP, DST, SRC) \ + ((struct bpf_insn) { \ + .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = 0, \ + .imm = 0 }) + +#define BPF_ALU32_REG(OP, DST, SRC) \ + ((struct bpf_insn) { \ + .code = BPF_ALU | BPF_OP(OP) | BPF_X, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = 0, \ + .imm = 0 }) + +/* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */ + +#define BPF_ALU64_IMM(OP, DST, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \ + .dst_reg = DST, \ + .src_reg = 0, \ + .off = 0, \ + .imm = IMM }) + +#define BPF_ALU32_IMM(OP, DST, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_ALU | BPF_OP(OP) | BPF_K, \ + .dst_reg = DST, \ + .src_reg = 0, \ + .off = 0, \ + .imm = IMM }) + +/* Short form of mov, dst_reg = src_reg */ + +#define BPF_MOV64_REG(DST, SRC) \ + ((struct bpf_insn) { \ + .code = BPF_ALU64 | BPF_MOV | BPF_X, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = 0, \ + .imm = 0 }) + +#define BPF_MOV32_REG(DST, SRC) \ + ((struct bpf_insn) { \ + .code = BPF_ALU | BPF_MOV | BPF_X, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = 0, \ + .imm = 0 }) + +/* Short form of mov, dst_reg = imm32 */ + +#define BPF_MOV64_IMM(DST, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_ALU64 | BPF_MOV | BPF_K, \ + .dst_reg = DST, \ + .src_reg = 0, \ + .off = 0, \ + .imm = IMM }) + +#define BPF_MOV32_IMM(DST, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_ALU | BPF_MOV | BPF_K, \ + .dst_reg = DST, \ + .src_reg = 0, \ + .off = 0, \ + .imm = IMM }) + +/* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */ +#define BPF_LD_IMM64(DST, IMM) \ + BPF_LD_IMM64_RAW(DST, 0, IMM) + +#define BPF_LD_IMM64_RAW(DST, SRC, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_LD | BPF_DW | BPF_IMM, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = 0, \ + .imm = (__u32) (IMM) }), \ + ((struct bpf_insn) { \ + .code = 0, /* zero is reserved opcode */ \ + .dst_reg = 0, \ + .src_reg = 0, \ + .off = 0, \ + .imm = ((__u64) (IMM)) >> 32 }) + +#ifndef BPF_PSEUDO_MAP_FD +# define BPF_PSEUDO_MAP_FD 1 +#endif + +/* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */ +#define BPF_LD_MAP_FD(DST, MAP_FD) \ + BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD) + + +/* Direct packet access, R0 = *(uint *) (skb->data + imm32) */ + +#define BPF_LD_ABS(SIZE, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \ + .dst_reg = 0, \ + .src_reg = 0, \ + .off = 0, \ + .imm = IMM }) + +/* Memory load, dst_reg = *(uint *) (src_reg + off16) */ + +#define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \ + ((struct bpf_insn) { \ + .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = OFF, \ + .imm = 0 }) + +/* Memory store, *(uint *) (dst_reg + off16) = src_reg */ + +#define BPF_STX_MEM(SIZE, DST, SRC, OFF) \ + ((struct bpf_insn) { \ + .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = OFF, \ + .imm = 0 }) + +/* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */ + +#define BPF_STX_XADD(SIZE, DST, SRC, OFF) \ + ((struct bpf_insn) { \ + .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = OFF, \ + .imm = 0 }) + +/* Memory store, *(uint *) (dst_reg + off16) = imm32 */ + +#define BPF_ST_MEM(SIZE, DST, OFF, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \ + .dst_reg = DST, \ + .src_reg = 0, \ + .off = OFF, \ + .imm = IMM }) + +/* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */ + +#define BPF_JMP_REG(OP, DST, SRC, OFF) \ + ((struct bpf_insn) { \ + .code = BPF_JMP | BPF_OP(OP) | BPF_X, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = OFF, \ + .imm = 0 }) + +/* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */ + +#define BPF_JMP_IMM(OP, DST, IMM, OFF) \ + ((struct bpf_insn) { \ + .code = BPF_JMP | BPF_OP(OP) | BPF_K, \ + .dst_reg = DST, \ + .src_reg = 0, \ + .off = OFF, \ + .imm = IMM }) + +/* Raw code statement block */ + +#define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \ + ((struct bpf_insn) { \ + .code = CODE, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = OFF, \ + .imm = IMM }) + +/* Program exit */ + +#define BPF_EXIT_INSN() \ + ((struct bpf_insn) { \ + .code = BPF_JMP | BPF_EXIT, \ + .dst_reg = 0, \ + .src_reg = 0, \ + .off = 0, \ + .imm = 0 }) + +#endif diff --git a/samples/bpf/cookie_uid_helper_example.c b/samples/bpf/cookie_uid_helper_example.c index 8eca27e595ae..deb0e3e0324d 100644 --- a/samples/bpf/cookie_uid_helper_example.c +++ b/samples/bpf/cookie_uid_helper_example.c @@ -51,7 +51,7 @@ #include #include #include -#include "libbpf.h" +#include "bpf_insn.h" #define PORT 8888 diff --git a/samples/bpf/fds_example.c b/samples/bpf/fds_example.c index e29bd52ff9e8..9854854f05d1 100644 --- a/samples/bpf/fds_example.c +++ b/samples/bpf/fds_example.c @@ -12,8 +12,10 @@ #include #include +#include + +#include "bpf_insn.h" #include "bpf_load.h" -#include "libbpf.h" #include "sock_example.h" #define BPF_F_PIN (1 << 0) diff --git a/samples/bpf/libbpf.h b/samples/bpf/libbpf.h deleted file mode 100644 index 18bfee5aab6b..000000000000 --- a/samples/bpf/libbpf.h +++ /dev/null @@ -1,199 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* eBPF mini library */ -#ifndef __LIBBPF_H -#define __LIBBPF_H - -#include - -struct bpf_insn; - -/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */ - -#define BPF_ALU64_REG(OP, DST, SRC) \ - ((struct bpf_insn) { \ - .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \ - .dst_reg = DST, \ - .src_reg = SRC, \ - .off = 0, \ - .imm = 0 }) - -#define BPF_ALU32_REG(OP, DST, SRC) \ - ((struct bpf_insn) { \ - .code = BPF_ALU | BPF_OP(OP) | BPF_X, \ - .dst_reg = DST, \ - .src_reg = SRC, \ - .off = 0, \ - .imm = 0 }) - -/* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */ - -#define BPF_ALU64_IMM(OP, DST, IMM) \ - ((struct bpf_insn) { \ - .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \ - .dst_reg = DST, \ - .src_reg = 0, \ - .off = 0, \ - .imm = IMM }) - -#define BPF_ALU32_IMM(OP, DST, IMM) \ - ((struct bpf_insn) { \ - .code = BPF_ALU | BPF_OP(OP) | BPF_K, \ - .dst_reg = DST, \ - .src_reg = 0, \ - .off = 0, \ - .imm = IMM }) - -/* Short form of mov, dst_reg = src_reg */ - -#define BPF_MOV64_REG(DST, SRC) \ - ((struct bpf_insn) { \ - .code = BPF_ALU64 | BPF_MOV | BPF_X, \ - .dst_reg = DST, \ - .src_reg = SRC, \ - .off = 0, \ - .imm = 0 }) - -#define BPF_MOV32_REG(DST, SRC) \ - ((struct bpf_insn) { \ - .code = BPF_ALU | BPF_MOV | BPF_X, \ - .dst_reg = DST, \ - .src_reg = SRC, \ - .off = 0, \ - .imm = 0 }) - -/* Short form of mov, dst_reg = imm32 */ - -#define BPF_MOV64_IMM(DST, IMM) \ - ((struct bpf_insn) { \ - .code = BPF_ALU64 | BPF_MOV | BPF_K, \ - .dst_reg = DST, \ - .src_reg = 0, \ - .off = 0, \ - .imm = IMM }) - -#define BPF_MOV32_IMM(DST, IMM) \ - ((struct bpf_insn) { \ - .code = BPF_ALU | BPF_MOV | BPF_K, \ - .dst_reg = DST, \ - .src_reg = 0, \ - .off = 0, \ - .imm = IMM }) - -/* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */ -#define BPF_LD_IMM64(DST, IMM) \ - BPF_LD_IMM64_RAW(DST, 0, IMM) - -#define BPF_LD_IMM64_RAW(DST, SRC, IMM) \ - ((struct bpf_insn) { \ - .code = BPF_LD | BPF_DW | BPF_IMM, \ - .dst_reg = DST, \ - .src_reg = SRC, \ - .off = 0, \ - .imm = (__u32) (IMM) }), \ - ((struct bpf_insn) { \ - .code = 0, /* zero is reserved opcode */ \ - .dst_reg = 0, \ - .src_reg = 0, \ - .off = 0, \ - .imm = ((__u64) (IMM)) >> 32 }) - -#ifndef BPF_PSEUDO_MAP_FD -# define BPF_PSEUDO_MAP_FD 1 -#endif - -/* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */ -#define BPF_LD_MAP_FD(DST, MAP_FD) \ - BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD) - - -/* Direct packet access, R0 = *(uint *) (skb->data + imm32) */ - -#define BPF_LD_ABS(SIZE, IMM) \ - ((struct bpf_insn) { \ - .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \ - .dst_reg = 0, \ - .src_reg = 0, \ - .off = 0, \ - .imm = IMM }) - -/* Memory load, dst_reg = *(uint *) (src_reg + off16) */ - -#define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \ - ((struct bpf_insn) { \ - .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \ - .dst_reg = DST, \ - .src_reg = SRC, \ - .off = OFF, \ - .imm = 0 }) - -/* Memory store, *(uint *) (dst_reg + off16) = src_reg */ - -#define BPF_STX_MEM(SIZE, DST, SRC, OFF) \ - ((struct bpf_insn) { \ - .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \ - .dst_reg = DST, \ - .src_reg = SRC, \ - .off = OFF, \ - .imm = 0 }) - -/* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */ - -#define BPF_STX_XADD(SIZE, DST, SRC, OFF) \ - ((struct bpf_insn) { \ - .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \ - .dst_reg = DST, \ - .src_reg = SRC, \ - .off = OFF, \ - .imm = 0 }) - -/* Memory store, *(uint *) (dst_reg + off16) = imm32 */ - -#define BPF_ST_MEM(SIZE, DST, OFF, IMM) \ - ((struct bpf_insn) { \ - .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \ - .dst_reg = DST, \ - .src_reg = 0, \ - .off = OFF, \ - .imm = IMM }) - -/* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */ - -#define BPF_JMP_REG(OP, DST, SRC, OFF) \ - ((struct bpf_insn) { \ - .code = BPF_JMP | BPF_OP(OP) | BPF_X, \ - .dst_reg = DST, \ - .src_reg = SRC, \ - .off = OFF, \ - .imm = 0 }) - -/* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */ - -#define BPF_JMP_IMM(OP, DST, IMM, OFF) \ - ((struct bpf_insn) { \ - .code = BPF_JMP | BPF_OP(OP) | BPF_K, \ - .dst_reg = DST, \ - .src_reg = 0, \ - .off = OFF, \ - .imm = IMM }) - -/* Raw code statement block */ - -#define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \ - ((struct bpf_insn) { \ - .code = CODE, \ - .dst_reg = DST, \ - .src_reg = SRC, \ - .off = OFF, \ - .imm = IMM }) - -/* Program exit */ - -#define BPF_EXIT_INSN() \ - ((struct bpf_insn) { \ - .code = BPF_JMP | BPF_EXIT, \ - .dst_reg = 0, \ - .src_reg = 0, \ - .off = 0, \ - .imm = 0 }) - -#endif diff --git a/samples/bpf/sock_example.c b/samples/bpf/sock_example.c index 33a637507c00..60ec467c78ab 100644 --- a/samples/bpf/sock_example.c +++ b/samples/bpf/sock_example.c @@ -26,7 +26,8 @@ #include #include #include -#include "libbpf.h" +#include +#include "bpf_insn.h" #include "sock_example.h" char bpf_log_buf[BPF_LOG_BUF_SIZE]; diff --git a/samples/bpf/test_cgrp2_attach.c b/samples/bpf/test_cgrp2_attach.c index 4bfcaf93fcf3..20fbd1241db3 100644 --- a/samples/bpf/test_cgrp2_attach.c +++ b/samples/bpf/test_cgrp2_attach.c @@ -28,8 +28,9 @@ #include #include +#include -#include "libbpf.h" +#include "bpf_insn.h" enum { MAP_KEY_PACKETS, diff --git a/samples/bpf/test_cgrp2_attach2.c b/samples/bpf/test_cgrp2_attach2.c index 1af412ec6007..b453e6a161be 100644 --- a/samples/bpf/test_cgrp2_attach2.c +++ b/samples/bpf/test_cgrp2_attach2.c @@ -24,8 +24,9 @@ #include #include +#include -#include "libbpf.h" +#include "bpf_insn.h" #include "cgroup_helpers.h" #define FOO "/foo" diff --git a/samples/bpf/test_cgrp2_sock.c b/samples/bpf/test_cgrp2_sock.c index e79594dd629b..b0811da5a00f 100644 --- a/samples/bpf/test_cgrp2_sock.c +++ b/samples/bpf/test_cgrp2_sock.c @@ -21,8 +21,9 @@ #include #include #include +#include -#include "libbpf.h" +#include "bpf_insn.h" char bpf_log_buf[BPF_LOG_BUF_SIZE]; diff --git a/samples/bpf/test_cgrp2_sock2.c b/samples/bpf/test_cgrp2_sock2.c index e53f1f6f0867..3b5be2364975 100644 --- a/samples/bpf/test_cgrp2_sock2.c +++ b/samples/bpf/test_cgrp2_sock2.c @@ -19,8 +19,9 @@ #include #include #include +#include -#include "libbpf.h" +#include "bpf_insn.h" #include "bpf_load.h" static int usage(const char *argv0) -- cgit v1.2.3 From 787360f8c2b87d4ae4858bb8736a19c289904885 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 14 May 2018 22:35:04 -0700 Subject: samples: bpf: fix build after move to compiling full libbpf.a MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There are many ways users may compile samples, some of them got broken by commit 5f9380572b4b ("samples: bpf: compile and link against full libbpf"). Improve path resolution and make libbpf building a dependency of source files to force its build. Samples should now again build with any of: cd samples/bpf; make make samples/bpf/ make -C samples/bpf cd samples/bpf; make O=builddir make samples/bpf/ O=builddir make -C samples/bpf O=builddir export KBUILD_OUTPUT=builddir make samples/bpf/ make -C samples/bpf Fixes: 5f9380572b4b ("samples: bpf: compile and link against full libbpf") Reported-by: Björn Töpel Signed-off-by: Jakub Kicinski Signed-off-by: Alexei Starovoitov --- samples/bpf/Makefile | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 9e255ca4059a..0dae77c88d2e 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -1,4 +1,8 @@ # SPDX-License-Identifier: GPL-2.0 + +BPF_SAMPLES_PATH ?= $(abspath $(srctree)/$(src)) +TOOLS_PATH := $(BPF_SAMPLES_PATH)/../../tools + # List of programs to build hostprogs-y := test_lru_dist hostprogs-y += sock_example @@ -49,7 +53,8 @@ hostprogs-y += xdpsock hostprogs-y += xdp_fwd # Libbpf dependencies -LIBBPF := ../../tools/lib/bpf/libbpf.a +LIBBPF = $(TOOLS_PATH)/lib/bpf/libbpf.a + CGROUP_HELPERS := ../../tools/testing/selftests/bpf/cgroup_helpers.o TRACE_HELPERS := ../../tools/testing/selftests/bpf/trace_helpers.o @@ -233,15 +238,16 @@ CLANG_ARCH_ARGS = -target $(ARCH) endif # Trick to allow make to be run from this directory -all: $(LIBBPF) - $(MAKE) -C ../../ $(CURDIR)/ +all: + $(MAKE) -C ../../ $(CURDIR)/ BPF_SAMPLES_PATH=$(CURDIR) clean: $(MAKE) -C ../../ M=$(CURDIR) clean @rm -f *~ $(LIBBPF): FORCE - $(MAKE) -C $(dir $@) +# Fix up variables inherited from Kbuild that tools/ build system won't like + $(MAKE) -C $(dir $@) RM='rm -rf' LDFLAGS= srctree=$(BPF_SAMPLES_PATH)/../../ O= $(obj)/syscall_nrs.s: $(src)/syscall_nrs.c $(call if_changed_dep,cc_s_c) @@ -272,7 +278,8 @@ verify_target_bpf: verify_cmds exit 2; \ else true; fi -$(src)/*.c: verify_target_bpf +$(BPF_SAMPLES_PATH)/*.c: verify_target_bpf $(LIBBPF) +$(src)/*.c: verify_target_bpf $(LIBBPF) $(obj)/tracex5_kern.o: $(obj)/syscall_nrs.h -- cgit v1.2.3 From 0cc54db1818ad38f400be9f24871f3b7bf09e911 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 14 May 2018 22:35:05 -0700 Subject: samples: bpf: move libbpf from object dependencies to libs Make complains that it doesn't know how to make libbpf.a: scripts/Makefile.host:106: target 'samples/bpf/../../tools/lib/bpf/libbpf.a' doesn't match the target pattern Now that we have it as a dependency of the sources simply add libbpf.a to libraries not objects. Signed-off-by: Jakub Kicinski Acked-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov --- samples/bpf/Makefile | 145 ++++++++++++++++++--------------------------------- 1 file changed, 51 insertions(+), 94 deletions(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 0dae77c88d2e..0036a77c2d97 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -58,55 +58,53 @@ LIBBPF = $(TOOLS_PATH)/lib/bpf/libbpf.a CGROUP_HELPERS := ../../tools/testing/selftests/bpf/cgroup_helpers.o TRACE_HELPERS := ../../tools/testing/selftests/bpf/trace_helpers.o -test_lru_dist-objs := test_lru_dist.o $(LIBBPF) -sock_example-objs := sock_example.o $(LIBBPF) -fds_example-objs := bpf_load.o $(LIBBPF) fds_example.o -sockex1-objs := bpf_load.o $(LIBBPF) sockex1_user.o -sockex2-objs := bpf_load.o $(LIBBPF) sockex2_user.o -sockex3-objs := bpf_load.o $(LIBBPF) sockex3_user.o -tracex1-objs := bpf_load.o $(LIBBPF) tracex1_user.o -tracex2-objs := bpf_load.o $(LIBBPF) tracex2_user.o -tracex3-objs := bpf_load.o $(LIBBPF) tracex3_user.o -tracex4-objs := bpf_load.o $(LIBBPF) tracex4_user.o -tracex5-objs := bpf_load.o $(LIBBPF) tracex5_user.o -tracex6-objs := bpf_load.o $(LIBBPF) tracex6_user.o -tracex7-objs := bpf_load.o $(LIBBPF) tracex7_user.o -load_sock_ops-objs := bpf_load.o $(LIBBPF) load_sock_ops.o -test_probe_write_user-objs := bpf_load.o $(LIBBPF) test_probe_write_user_user.o -trace_output-objs := bpf_load.o $(LIBBPF) trace_output_user.o $(TRACE_HELPERS) -lathist-objs := bpf_load.o $(LIBBPF) lathist_user.o -offwaketime-objs := bpf_load.o $(LIBBPF) offwaketime_user.o $(TRACE_HELPERS) -spintest-objs := bpf_load.o $(LIBBPF) spintest_user.o $(TRACE_HELPERS) -map_perf_test-objs := bpf_load.o $(LIBBPF) map_perf_test_user.o -test_overhead-objs := bpf_load.o $(LIBBPF) test_overhead_user.o -test_cgrp2_array_pin-objs := test_cgrp2_array_pin.o $(LIBBPF) -test_cgrp2_attach-objs := test_cgrp2_attach.o $(LIBBPF) -test_cgrp2_attach2-objs := test_cgrp2_attach2.o $(LIBBPF) $(CGROUP_HELPERS) -test_cgrp2_sock-objs := test_cgrp2_sock.o $(LIBBPF) -test_cgrp2_sock2-objs := bpf_load.o $(LIBBPF) test_cgrp2_sock2.o -xdp1-objs := xdp1_user.o $(LIBBPF) +fds_example-objs := bpf_load.o fds_example.o +sockex1-objs := bpf_load.o sockex1_user.o +sockex2-objs := bpf_load.o sockex2_user.o +sockex3-objs := bpf_load.o sockex3_user.o +tracex1-objs := bpf_load.o tracex1_user.o +tracex2-objs := bpf_load.o tracex2_user.o +tracex3-objs := bpf_load.o tracex3_user.o +tracex4-objs := bpf_load.o tracex4_user.o +tracex5-objs := bpf_load.o tracex5_user.o +tracex6-objs := bpf_load.o tracex6_user.o +tracex7-objs := bpf_load.o tracex7_user.o +load_sock_ops-objs := bpf_load.o load_sock_ops.o +test_probe_write_user-objs := bpf_load.o test_probe_write_user_user.o +trace_output-objs := bpf_load.o trace_output_user.o $(TRACE_HELPERS) +lathist-objs := bpf_load.o lathist_user.o +offwaketime-objs := bpf_load.o offwaketime_user.o $(TRACE_HELPERS) +spintest-objs := bpf_load.o spintest_user.o $(TRACE_HELPERS) +map_perf_test-objs := bpf_load.o map_perf_test_user.o +test_overhead-objs := bpf_load.o test_overhead_user.o +test_cgrp2_array_pin-objs := test_cgrp2_array_pin.o +test_cgrp2_attach-objs := test_cgrp2_attach.o +test_cgrp2_attach2-objs := test_cgrp2_attach2.o $(CGROUP_HELPERS) +test_cgrp2_sock-objs := test_cgrp2_sock.o +test_cgrp2_sock2-objs := bpf_load.o test_cgrp2_sock2.o +xdp1-objs := xdp1_user.o # reuse xdp1 source intentionally -xdp2-objs := xdp1_user.o $(LIBBPF) -xdp_router_ipv4-objs := bpf_load.o $(LIBBPF) xdp_router_ipv4_user.o -test_current_task_under_cgroup-objs := bpf_load.o $(LIBBPF) $(CGROUP_HELPERS) \ +xdp2-objs := xdp1_user.o +xdp_router_ipv4-objs := bpf_load.o xdp_router_ipv4_user.o +test_current_task_under_cgroup-objs := bpf_load.o $(CGROUP_HELPERS) \ test_current_task_under_cgroup_user.o -trace_event-objs := bpf_load.o $(LIBBPF) trace_event_user.o $(TRACE_HELPERS) -sampleip-objs := bpf_load.o $(LIBBPF) sampleip_user.o $(TRACE_HELPERS) -tc_l2_redirect-objs := bpf_load.o $(LIBBPF) tc_l2_redirect_user.o -lwt_len_hist-objs := bpf_load.o $(LIBBPF) lwt_len_hist_user.o -xdp_tx_iptunnel-objs := bpf_load.o $(LIBBPF) xdp_tx_iptunnel_user.o -test_map_in_map-objs := bpf_load.o $(LIBBPF) test_map_in_map_user.o -per_socket_stats_example-objs := cookie_uid_helper_example.o $(LIBBPF) -xdp_redirect-objs := bpf_load.o $(LIBBPF) xdp_redirect_user.o -xdp_redirect_map-objs := bpf_load.o $(LIBBPF) xdp_redirect_map_user.o -xdp_redirect_cpu-objs := bpf_load.o $(LIBBPF) xdp_redirect_cpu_user.o -xdp_monitor-objs := bpf_load.o $(LIBBPF) xdp_monitor_user.o -xdp_rxq_info-objs := xdp_rxq_info_user.o $(LIBBPF) -syscall_tp-objs := bpf_load.o $(LIBBPF) syscall_tp_user.o -cpustat-objs := bpf_load.o $(LIBBPF) cpustat_user.o -xdp_adjust_tail-objs := xdp_adjust_tail_user.o $(LIBBPF) -xdpsock-objs := bpf_load.o $(LIBBPF) xdpsock_user.o -xdp_fwd-objs := bpf_load.o $(LIBBPF) xdp_fwd_user.o +trace_event-objs := bpf_load.o trace_event_user.o $(TRACE_HELPERS) +sampleip-objs := bpf_load.o sampleip_user.o $(TRACE_HELPERS) +tc_l2_redirect-objs := bpf_load.o tc_l2_redirect_user.o +lwt_len_hist-objs := bpf_load.o lwt_len_hist_user.o +xdp_tx_iptunnel-objs := bpf_load.o xdp_tx_iptunnel_user.o +test_map_in_map-objs := bpf_load.o test_map_in_map_user.o +per_socket_stats_example-objs := cookie_uid_helper_example.o +xdp_redirect-objs := bpf_load.o xdp_redirect_user.o +xdp_redirect_map-objs := bpf_load.o xdp_redirect_map_user.o +xdp_redirect_cpu-objs := bpf_load.o xdp_redirect_cpu_user.o +xdp_monitor-objs := bpf_load.o xdp_monitor_user.o +xdp_rxq_info-objs := xdp_rxq_info_user.o +syscall_tp-objs := bpf_load.o syscall_tp_user.o +cpustat-objs := bpf_load.o cpustat_user.o +xdp_adjust_tail-objs := xdp_adjust_tail_user.o +xdpsock-objs := bpf_load.o xdpsock_user.o +xdp_fwd-objs := bpf_load.o xdp_fwd_user.o # Tell kbuild to always build the programs always := $(hostprogs-y) @@ -178,53 +176,12 @@ HOSTCFLAGS_spintest_user.o += -I$(srctree)/tools/lib/bpf/ HOSTCFLAGS_trace_event_user.o += -I$(srctree)/tools/lib/bpf/ HOSTCFLAGS_sampleip_user.o += -I$(srctree)/tools/lib/bpf/ -HOSTLOADLIBES_test_lru_dist += -lelf -HOSTLOADLIBES_sock_example += -lelf -HOSTLOADLIBES_fds_example += -lelf -HOSTLOADLIBES_sockex1 += -lelf -HOSTLOADLIBES_sockex2 += -lelf -HOSTLOADLIBES_sockex3 += -lelf -HOSTLOADLIBES_tracex1 += -lelf -HOSTLOADLIBES_tracex2 += -lelf -HOSTLOADLIBES_tracex3 += -lelf -HOSTLOADLIBES_tracex4 += -lelf -lrt -HOSTLOADLIBES_tracex5 += -lelf -HOSTLOADLIBES_tracex6 += -lelf -HOSTLOADLIBES_tracex7 += -lelf -HOSTLOADLIBES_test_cgrp2_array_pin += -lelf -HOSTLOADLIBES_test_cgrp2_attach += -lelf -HOSTLOADLIBES_test_cgrp2_attach2 += -lelf -HOSTLOADLIBES_test_cgrp2_sock += -lelf -HOSTLOADLIBES_test_cgrp2_sock2 += -lelf -HOSTLOADLIBES_load_sock_ops += -lelf -HOSTLOADLIBES_test_probe_write_user += -lelf -HOSTLOADLIBES_trace_output += -lelf -lrt -HOSTLOADLIBES_lathist += -lelf -HOSTLOADLIBES_offwaketime += -lelf -HOSTLOADLIBES_spintest += -lelf -HOSTLOADLIBES_map_perf_test += -lelf -lrt -HOSTLOADLIBES_test_overhead += -lelf -lrt -HOSTLOADLIBES_xdp1 += -lelf -HOSTLOADLIBES_xdp2 += -lelf -HOSTLOADLIBES_xdp_router_ipv4 += -lelf -HOSTLOADLIBES_test_current_task_under_cgroup += -lelf -HOSTLOADLIBES_trace_event += -lelf -HOSTLOADLIBES_sampleip += -lelf -HOSTLOADLIBES_tc_l2_redirect += -l elf -HOSTLOADLIBES_lwt_len_hist += -l elf -HOSTLOADLIBES_xdp_tx_iptunnel += -lelf -HOSTLOADLIBES_test_map_in_map += -lelf -HOSTLOADLIBES_per_socket_stats_example += -lelf -HOSTLOADLIBES_xdp_redirect += -lelf -HOSTLOADLIBES_xdp_redirect_map += -lelf -HOSTLOADLIBES_xdp_redirect_cpu += -lelf -HOSTLOADLIBES_xdp_monitor += -lelf -HOSTLOADLIBES_xdp_rxq_info += -lelf -HOSTLOADLIBES_syscall_tp += -lelf -HOSTLOADLIBES_cpustat += -lelf -HOSTLOADLIBES_xdp_adjust_tail += -lelf -HOSTLOADLIBES_xdpsock += -lelf -pthread -HOSTLOADLIBES_xdp_fwd += -lelf +HOST_LOADLIBES += $(LIBBPF) -lelf +HOSTLOADLIBES_tracex4 += -lrt +HOSTLOADLIBES_trace_output += -lrt +HOSTLOADLIBES_map_perf_test += -lrt +HOSTLOADLIBES_test_overhead += -lrt +HOSTLOADLIBES_xdpsock += -pthread # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline: # make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang -- cgit v1.2.3 From 768759edb9a1bd1b3fc38313b6578e5c8b252aee Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 14 May 2018 22:35:06 -0700 Subject: samples: bpf: make the build less noisy Building samples with clang ignores the $(Q) setting, always printing full command to the output. Make it less verbose. Signed-off-by: Jakub Kicinski Signed-off-by: Alexei Starovoitov --- samples/bpf/Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 0036a77c2d97..62d1aa1a4cf3 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -244,7 +244,8 @@ $(obj)/tracex5_kern.o: $(obj)/syscall_nrs.h # But, there is no easy way to fix it, so just exclude it since it is # useless for BPF samples. $(obj)/%.o: $(src)/%.c - $(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) -I$(obj) \ + @echo " CLANG-bpf " $@ + $(Q)$(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) -I$(obj) \ -I$(srctree)/tools/testing/selftests/bpf/ \ -D__KERNEL__ -Wno-unused-value -Wno-pointer-sign \ -D__TARGET_ARCH_$(ARCH) -Wno-compare-distinct-pointer-types \ -- cgit v1.2.3 From 4712c1b203dd04d9b0f3139000bc4bfbb94b0c05 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Mon, 14 May 2018 15:42:12 +0200 Subject: bpf, doc: add basic README.rst file A README.rst file in a directory have special meaning for sites like github, which auto renders the contents. Plus search engines like Google also index these README.rst files. Auto rendering allow us to use links, for (re)directing eBPF users to other places where docs live. The end-goal would be to direct users towards https://www.kernel.org/doc/html/latest but we haven't written the full docs yet, so we start out small and take this incrementally. This directory itself contains some useful docs, which can be linked to from the README.rst file (verified this works for github). Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov --- Documentation/bpf/README.rst | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 Documentation/bpf/README.rst diff --git a/Documentation/bpf/README.rst b/Documentation/bpf/README.rst new file mode 100644 index 000000000000..329469c33db8 --- /dev/null +++ b/Documentation/bpf/README.rst @@ -0,0 +1,36 @@ +================= +BPF documentation +================= + +This directory contains documentation for the BPF (Berkeley Packet +Filter) facility, with a focus on the extended BPF version (eBPF). + +This kernel side documentation is still work in progress. The main +textual documentation is (for historical reasons) described in +`Documentation/networking/filter.txt`_, which describe both classical +and extended BPF instruction-set. +The Cilium project also maintains a `BPF and XDP Reference Guide`_ +that goes into great technical depth about the BPF Architecture. + +The primary info for the bpf syscall is available in the `man-pages`_ +for `bpf(2)`_. + + + +Frequently asked questions (FAQ) +================================ + +Two sets of Questions and Answers (Q&A) are maintained. + +* QA for common questions about BPF see: bpf_design_QA_ + +* QA for developers interacting with BPF subsystem: bpf_devel_QA_ + + +.. Links: +.. _bpf_design_QA: bpf_design_QA.txt +.. _bpf_devel_QA: bpf_devel_QA.txt +.. _Documentation/networking/filter.txt: ../networking/filter.txt +.. _man-pages: https://www.kernel.org/doc/man-pages/ +.. _bpf(2): http://man7.org/linux/man-pages/man2/bpf.2.html +.. _BPF and XDP Reference Guide: http://cilium.readthedocs.io/en/latest/bpf/ -- cgit v1.2.3 From 192092faa02dd5e5d1ff875d7512a5d803db95a0 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Mon, 14 May 2018 15:42:17 +0200 Subject: bpf, doc: rename txt files to rst files This will cause them to get auto rendered, e.g. when viewing them on GitHub. Followup patches will correct the content to be RST compliant. Also adjust README.rst to point to the renamed files. Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov --- Documentation/bpf/README.rst | 4 +- Documentation/bpf/bpf_design_QA.rst | 156 ++++++++++ Documentation/bpf/bpf_design_QA.txt | 156 ---------- Documentation/bpf/bpf_devel_QA.rst | 570 ++++++++++++++++++++++++++++++++++++ Documentation/bpf/bpf_devel_QA.txt | 570 ------------------------------------ 5 files changed, 728 insertions(+), 728 deletions(-) create mode 100644 Documentation/bpf/bpf_design_QA.rst delete mode 100644 Documentation/bpf/bpf_design_QA.txt create mode 100644 Documentation/bpf/bpf_devel_QA.rst delete mode 100644 Documentation/bpf/bpf_devel_QA.txt diff --git a/Documentation/bpf/README.rst b/Documentation/bpf/README.rst index 329469c33db8..b9a80c9e9392 100644 --- a/Documentation/bpf/README.rst +++ b/Documentation/bpf/README.rst @@ -28,8 +28,8 @@ Two sets of Questions and Answers (Q&A) are maintained. .. Links: -.. _bpf_design_QA: bpf_design_QA.txt -.. _bpf_devel_QA: bpf_devel_QA.txt +.. _bpf_design_QA: bpf_design_QA.rst +.. _bpf_devel_QA: bpf_devel_QA.rst .. _Documentation/networking/filter.txt: ../networking/filter.txt .. _man-pages: https://www.kernel.org/doc/man-pages/ .. _bpf(2): http://man7.org/linux/man-pages/man2/bpf.2.html diff --git a/Documentation/bpf/bpf_design_QA.rst b/Documentation/bpf/bpf_design_QA.rst new file mode 100644 index 000000000000..f3e458a0bb2f --- /dev/null +++ b/Documentation/bpf/bpf_design_QA.rst @@ -0,0 +1,156 @@ +BPF extensibility and applicability to networking, tracing, security +in the linux kernel and several user space implementations of BPF +virtual machine led to a number of misunderstanding on what BPF actually is. +This short QA is an attempt to address that and outline a direction +of where BPF is heading long term. + +Q: Is BPF a generic instruction set similar to x64 and arm64? +A: NO. + +Q: Is BPF a generic virtual machine ? +A: NO. + +BPF is generic instruction set _with_ C calling convention. + +Q: Why C calling convention was chosen? +A: Because BPF programs are designed to run in the linux kernel + which is written in C, hence BPF defines instruction set compatible + with two most used architectures x64 and arm64 (and takes into + consideration important quirks of other architectures) and + defines calling convention that is compatible with C calling + convention of the linux kernel on those architectures. + +Q: can multiple return values be supported in the future? +A: NO. BPF allows only register R0 to be used as return value. + +Q: can more than 5 function arguments be supported in the future? +A: NO. BPF calling convention only allows registers R1-R5 to be used + as arguments. BPF is not a standalone instruction set. + (unlike x64 ISA that allows msft, cdecl and other conventions) + +Q: can BPF programs access instruction pointer or return address? +A: NO. + +Q: can BPF programs access stack pointer ? +A: NO. Only frame pointer (register R10) is accessible. + From compiler point of view it's necessary to have stack pointer. + For example LLVM defines register R11 as stack pointer in its + BPF backend, but it makes sure that generated code never uses it. + +Q: Does C-calling convention diminishes possible use cases? +A: YES. BPF design forces addition of major functionality in the form + of kernel helper functions and kernel objects like BPF maps with + seamless interoperability between them. It lets kernel call into + BPF programs and programs call kernel helpers with zero overhead. + As all of them were native C code. That is particularly the case + for JITed BPF programs that are indistinguishable from + native kernel C code. + +Q: Does it mean that 'innovative' extensions to BPF code are disallowed? +A: Soft yes. At least for now until BPF core has support for + bpf-to-bpf calls, indirect calls, loops, global variables, + jump tables, read only sections and all other normal constructs + that C code can produce. + +Q: Can loops be supported in a safe way? +A: It's not clear yet. BPF developers are trying to find a way to + support bounded loops where the verifier can guarantee that + the program terminates in less than 4096 instructions. + +Q: How come LD_ABS and LD_IND instruction are present in BPF whereas + C code cannot express them and has to use builtin intrinsics? +A: This is artifact of compatibility with classic BPF. Modern + networking code in BPF performs better without them. + See 'direct packet access'. + +Q: It seems not all BPF instructions are one-to-one to native CPU. + For example why BPF_JNE and other compare and jumps are not cpu-like? +A: This was necessary to avoid introducing flags into ISA which are + impossible to make generic and efficient across CPU architectures. + +Q: why BPF_DIV instruction doesn't map to x64 div? +A: Because if we picked one-to-one relationship to x64 it would have made + it more complicated to support on arm64 and other archs. Also it + needs div-by-zero runtime check. + +Q: why there is no BPF_SDIV for signed divide operation? +A: Because it would be rarely used. llvm errors in such case and + prints a suggestion to use unsigned divide instead + +Q: Why BPF has implicit prologue and epilogue? +A: Because architectures like sparc have register windows and in general + there are enough subtle differences between architectures, so naive + store return address into stack won't work. Another reason is BPF has + to be safe from division by zero (and legacy exception path + of LD_ABS insn). Those instructions need to invoke epilogue and + return implicitly. + +Q: Why BPF_JLT and BPF_JLE instructions were not introduced in the beginning? +A: Because classic BPF didn't have them and BPF authors felt that compiler + workaround would be acceptable. Turned out that programs lose performance + due to lack of these compare instructions and they were added. + These two instructions is a perfect example what kind of new BPF + instructions are acceptable and can be added in the future. + These two already had equivalent instructions in native CPUs. + New instructions that don't have one-to-one mapping to HW instructions + will not be accepted. + +Q: BPF 32-bit subregisters have a requirement to zero upper 32-bits of BPF + registers which makes BPF inefficient virtual machine for 32-bit + CPU architectures and 32-bit HW accelerators. Can true 32-bit registers + be added to BPF in the future? +A: NO. The first thing to improve performance on 32-bit archs is to teach + LLVM to generate code that uses 32-bit subregisters. Then second step + is to teach verifier to mark operations where zero-ing upper bits + is unnecessary. Then JITs can take advantage of those markings and + drastically reduce size of generated code and improve performance. + +Q: Does BPF have a stable ABI? +A: YES. BPF instructions, arguments to BPF programs, set of helper + functions and their arguments, recognized return codes are all part + of ABI. However when tracing programs are using bpf_probe_read() helper + to walk kernel internal datastructures and compile with kernel + internal headers these accesses can and will break with newer + kernels. The union bpf_attr -> kern_version is checked at load time + to prevent accidentally loading kprobe-based bpf programs written + for a different kernel. Networking programs don't do kern_version check. + +Q: How much stack space a BPF program uses? +A: Currently all program types are limited to 512 bytes of stack + space, but the verifier computes the actual amount of stack used + and both interpreter and most JITed code consume necessary amount. + +Q: Can BPF be offloaded to HW? +A: YES. BPF HW offload is supported by NFP driver. + +Q: Does classic BPF interpreter still exist? +A: NO. Classic BPF programs are converted into extend BPF instructions. + +Q: Can BPF call arbitrary kernel functions? +A: NO. BPF programs can only call a set of helper functions which + is defined for every program type. + +Q: Can BPF overwrite arbitrary kernel memory? +A: NO. Tracing bpf programs can _read_ arbitrary memory with bpf_probe_read() + and bpf_probe_read_str() helpers. Networking programs cannot read + arbitrary memory, since they don't have access to these helpers. + Programs can never read or write arbitrary memory directly. + +Q: Can BPF overwrite arbitrary user memory? +A: Sort-of. Tracing BPF programs can overwrite the user memory + of the current task with bpf_probe_write_user(). Every time such + program is loaded the kernel will print warning message, so + this helper is only useful for experiments and prototypes. + Tracing BPF programs are root only. + +Q: When bpf_trace_printk() helper is used the kernel prints nasty + warning message. Why is that? +A: This is done to nudge program authors into better interfaces when + programs need to pass data to user space. Like bpf_perf_event_output() + can be used to efficiently stream data via perf ring buffer. + BPF maps can be used for asynchronous data sharing between kernel + and user space. bpf_trace_printk() should only be used for debugging. + +Q: Can BPF functionality such as new program or map types, new + helpers, etc be added out of kernel module code? +A: NO. diff --git a/Documentation/bpf/bpf_design_QA.txt b/Documentation/bpf/bpf_design_QA.txt deleted file mode 100644 index f3e458a0bb2f..000000000000 --- a/Documentation/bpf/bpf_design_QA.txt +++ /dev/null @@ -1,156 +0,0 @@ -BPF extensibility and applicability to networking, tracing, security -in the linux kernel and several user space implementations of BPF -virtual machine led to a number of misunderstanding on what BPF actually is. -This short QA is an attempt to address that and outline a direction -of where BPF is heading long term. - -Q: Is BPF a generic instruction set similar to x64 and arm64? -A: NO. - -Q: Is BPF a generic virtual machine ? -A: NO. - -BPF is generic instruction set _with_ C calling convention. - -Q: Why C calling convention was chosen? -A: Because BPF programs are designed to run in the linux kernel - which is written in C, hence BPF defines instruction set compatible - with two most used architectures x64 and arm64 (and takes into - consideration important quirks of other architectures) and - defines calling convention that is compatible with C calling - convention of the linux kernel on those architectures. - -Q: can multiple return values be supported in the future? -A: NO. BPF allows only register R0 to be used as return value. - -Q: can more than 5 function arguments be supported in the future? -A: NO. BPF calling convention only allows registers R1-R5 to be used - as arguments. BPF is not a standalone instruction set. - (unlike x64 ISA that allows msft, cdecl and other conventions) - -Q: can BPF programs access instruction pointer or return address? -A: NO. - -Q: can BPF programs access stack pointer ? -A: NO. Only frame pointer (register R10) is accessible. - From compiler point of view it's necessary to have stack pointer. - For example LLVM defines register R11 as stack pointer in its - BPF backend, but it makes sure that generated code never uses it. - -Q: Does C-calling convention diminishes possible use cases? -A: YES. BPF design forces addition of major functionality in the form - of kernel helper functions and kernel objects like BPF maps with - seamless interoperability between them. It lets kernel call into - BPF programs and programs call kernel helpers with zero overhead. - As all of them were native C code. That is particularly the case - for JITed BPF programs that are indistinguishable from - native kernel C code. - -Q: Does it mean that 'innovative' extensions to BPF code are disallowed? -A: Soft yes. At least for now until BPF core has support for - bpf-to-bpf calls, indirect calls, loops, global variables, - jump tables, read only sections and all other normal constructs - that C code can produce. - -Q: Can loops be supported in a safe way? -A: It's not clear yet. BPF developers are trying to find a way to - support bounded loops where the verifier can guarantee that - the program terminates in less than 4096 instructions. - -Q: How come LD_ABS and LD_IND instruction are present in BPF whereas - C code cannot express them and has to use builtin intrinsics? -A: This is artifact of compatibility with classic BPF. Modern - networking code in BPF performs better without them. - See 'direct packet access'. - -Q: It seems not all BPF instructions are one-to-one to native CPU. - For example why BPF_JNE and other compare and jumps are not cpu-like? -A: This was necessary to avoid introducing flags into ISA which are - impossible to make generic and efficient across CPU architectures. - -Q: why BPF_DIV instruction doesn't map to x64 div? -A: Because if we picked one-to-one relationship to x64 it would have made - it more complicated to support on arm64 and other archs. Also it - needs div-by-zero runtime check. - -Q: why there is no BPF_SDIV for signed divide operation? -A: Because it would be rarely used. llvm errors in such case and - prints a suggestion to use unsigned divide instead - -Q: Why BPF has implicit prologue and epilogue? -A: Because architectures like sparc have register windows and in general - there are enough subtle differences between architectures, so naive - store return address into stack won't work. Another reason is BPF has - to be safe from division by zero (and legacy exception path - of LD_ABS insn). Those instructions need to invoke epilogue and - return implicitly. - -Q: Why BPF_JLT and BPF_JLE instructions were not introduced in the beginning? -A: Because classic BPF didn't have them and BPF authors felt that compiler - workaround would be acceptable. Turned out that programs lose performance - due to lack of these compare instructions and they were added. - These two instructions is a perfect example what kind of new BPF - instructions are acceptable and can be added in the future. - These two already had equivalent instructions in native CPUs. - New instructions that don't have one-to-one mapping to HW instructions - will not be accepted. - -Q: BPF 32-bit subregisters have a requirement to zero upper 32-bits of BPF - registers which makes BPF inefficient virtual machine for 32-bit - CPU architectures and 32-bit HW accelerators. Can true 32-bit registers - be added to BPF in the future? -A: NO. The first thing to improve performance on 32-bit archs is to teach - LLVM to generate code that uses 32-bit subregisters. Then second step - is to teach verifier to mark operations where zero-ing upper bits - is unnecessary. Then JITs can take advantage of those markings and - drastically reduce size of generated code and improve performance. - -Q: Does BPF have a stable ABI? -A: YES. BPF instructions, arguments to BPF programs, set of helper - functions and their arguments, recognized return codes are all part - of ABI. However when tracing programs are using bpf_probe_read() helper - to walk kernel internal datastructures and compile with kernel - internal headers these accesses can and will break with newer - kernels. The union bpf_attr -> kern_version is checked at load time - to prevent accidentally loading kprobe-based bpf programs written - for a different kernel. Networking programs don't do kern_version check. - -Q: How much stack space a BPF program uses? -A: Currently all program types are limited to 512 bytes of stack - space, but the verifier computes the actual amount of stack used - and both interpreter and most JITed code consume necessary amount. - -Q: Can BPF be offloaded to HW? -A: YES. BPF HW offload is supported by NFP driver. - -Q: Does classic BPF interpreter still exist? -A: NO. Classic BPF programs are converted into extend BPF instructions. - -Q: Can BPF call arbitrary kernel functions? -A: NO. BPF programs can only call a set of helper functions which - is defined for every program type. - -Q: Can BPF overwrite arbitrary kernel memory? -A: NO. Tracing bpf programs can _read_ arbitrary memory with bpf_probe_read() - and bpf_probe_read_str() helpers. Networking programs cannot read - arbitrary memory, since they don't have access to these helpers. - Programs can never read or write arbitrary memory directly. - -Q: Can BPF overwrite arbitrary user memory? -A: Sort-of. Tracing BPF programs can overwrite the user memory - of the current task with bpf_probe_write_user(). Every time such - program is loaded the kernel will print warning message, so - this helper is only useful for experiments and prototypes. - Tracing BPF programs are root only. - -Q: When bpf_trace_printk() helper is used the kernel prints nasty - warning message. Why is that? -A: This is done to nudge program authors into better interfaces when - programs need to pass data to user space. Like bpf_perf_event_output() - can be used to efficiently stream data via perf ring buffer. - BPF maps can be used for asynchronous data sharing between kernel - and user space. bpf_trace_printk() should only be used for debugging. - -Q: Can BPF functionality such as new program or map types, new - helpers, etc be added out of kernel module code? -A: NO. diff --git a/Documentation/bpf/bpf_devel_QA.rst b/Documentation/bpf/bpf_devel_QA.rst new file mode 100644 index 000000000000..da57601153a0 --- /dev/null +++ b/Documentation/bpf/bpf_devel_QA.rst @@ -0,0 +1,570 @@ +This document provides information for the BPF subsystem about various +workflows related to reporting bugs, submitting patches, and queueing +patches for stable kernels. + +For general information about submitting patches, please refer to +Documentation/process/. This document only describes additional specifics +related to BPF. + +Reporting bugs: +--------------- + +Q: How do I report bugs for BPF kernel code? + +A: Since all BPF kernel development as well as bpftool and iproute2 BPF + loader development happens through the netdev kernel mailing list, + please report any found issues around BPF to the following mailing + list: + + netdev@vger.kernel.org + + This may also include issues related to XDP, BPF tracing, etc. + + Given netdev has a high volume of traffic, please also add the BPF + maintainers to Cc (from kernel MAINTAINERS file): + + Alexei Starovoitov + Daniel Borkmann + + In case a buggy commit has already been identified, make sure to keep + the actual commit authors in Cc as well for the report. They can + typically be identified through the kernel's git tree. + + Please do *not* report BPF issues to bugzilla.kernel.org since it + is a guarantee that the reported issue will be overlooked. + +Submitting patches: +------------------- + +Q: To which mailing list do I need to submit my BPF patches? + +A: Please submit your BPF patches to the netdev kernel mailing list: + + netdev@vger.kernel.org + + Historically, BPF came out of networking and has always been maintained + by the kernel networking community. Although these days BPF touches + many other subsystems as well, the patches are still routed mainly + through the networking community. + + In case your patch has changes in various different subsystems (e.g. + tracing, security, etc), make sure to Cc the related kernel mailing + lists and maintainers from there as well, so they are able to review + the changes and provide their Acked-by's to the patches. + +Q: Where can I find patches currently under discussion for BPF subsystem? + +A: All patches that are Cc'ed to netdev are queued for review under netdev + patchwork project: + + http://patchwork.ozlabs.org/project/netdev/list/ + + Those patches which target BPF, are assigned to a 'bpf' delegate for + further processing from BPF maintainers. The current queue with + patches under review can be found at: + + https://patchwork.ozlabs.org/project/netdev/list/?delegate=77147 + + Once the patches have been reviewed by the BPF community as a whole + and approved by the BPF maintainers, their status in patchwork will be + changed to 'Accepted' and the submitter will be notified by mail. This + means that the patches look good from a BPF perspective and have been + applied to one of the two BPF kernel trees. + + In case feedback from the community requires a respin of the patches, + their status in patchwork will be set to 'Changes Requested', and purged + from the current review queue. Likewise for cases where patches would + get rejected or are not applicable to the BPF trees (but assigned to + the 'bpf' delegate). + +Q: How do the changes make their way into Linux? + +A: There are two BPF kernel trees (git repositories). Once patches have + been accepted by the BPF maintainers, they will be applied to one + of the two BPF trees: + + https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/ + https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/ + + The bpf tree itself is for fixes only, whereas bpf-next for features, + cleanups or other kind of improvements ("next-like" content). This is + analogous to net and net-next trees for networking. Both bpf and + bpf-next will only have a master branch in order to simplify against + which branch patches should get rebased to. + + Accumulated BPF patches in the bpf tree will regularly get pulled + into the net kernel tree. Likewise, accumulated BPF patches accepted + into the bpf-next tree will make their way into net-next tree. net and + net-next are both run by David S. Miller. From there, they will go + into the kernel mainline tree run by Linus Torvalds. To read up on the + process of net and net-next being merged into the mainline tree, see + the netdev FAQ under: + + Documentation/networking/netdev-FAQ.txt + + Occasionally, to prevent merge conflicts, we might send pull requests + to other trees (e.g. tracing) with a small subset of the patches, but + net and net-next are always the main trees targeted for integration. + + The pull requests will contain a high-level summary of the accumulated + patches and can be searched on netdev kernel mailing list through the + following subject lines (yyyy-mm-dd is the date of the pull request): + + pull-request: bpf yyyy-mm-dd + pull-request: bpf-next yyyy-mm-dd + +Q: How do I indicate which tree (bpf vs. bpf-next) my patch should be + applied to? + +A: The process is the very same as described in the netdev FAQ, so + please read up on it. The subject line must indicate whether the + patch is a fix or rather "next-like" content in order to let the + maintainers know whether it is targeted at bpf or bpf-next. + + For fixes eventually landing in bpf -> net tree, the subject must + look like: + + git format-patch --subject-prefix='PATCH bpf' start..finish + + For features/improvements/etc that should eventually land in + bpf-next -> net-next, the subject must look like: + + git format-patch --subject-prefix='PATCH bpf-next' start..finish + + If unsure whether the patch or patch series should go into bpf + or net directly, or bpf-next or net-next directly, it is not a + problem either if the subject line says net or net-next as target. + It is eventually up to the maintainers to do the delegation of + the patches. + + If it is clear that patches should go into bpf or bpf-next tree, + please make sure to rebase the patches against those trees in + order to reduce potential conflicts. + + In case the patch or patch series has to be reworked and sent out + again in a second or later revision, it is also required to add a + version number (v2, v3, ...) into the subject prefix: + + git format-patch --subject-prefix='PATCH net-next v2' start..finish + + When changes have been requested to the patch series, always send the + whole patch series again with the feedback incorporated (never send + individual diffs on top of the old series). + +Q: What does it mean when a patch gets applied to bpf or bpf-next tree? + +A: It means that the patch looks good for mainline inclusion from + a BPF point of view. + + Be aware that this is not a final verdict that the patch will + automatically get accepted into net or net-next trees eventually: + + On the netdev kernel mailing list reviews can come in at any point + in time. If discussions around a patch conclude that they cannot + get included as-is, we will either apply a follow-up fix or drop + them from the trees entirely. Therefore, we also reserve to rebase + the trees when deemed necessary. After all, the purpose of the tree + is to i) accumulate and stage BPF patches for integration into trees + like net and net-next, and ii) run extensive BPF test suite and + workloads on the patches before they make their way any further. + + Once the BPF pull request was accepted by David S. Miller, then + the patches end up in net or net-next tree, respectively, and + make their way from there further into mainline. Again, see the + netdev FAQ for additional information e.g. on how often they are + merged to mainline. + +Q: How long do I need to wait for feedback on my BPF patches? + +A: We try to keep the latency low. The usual time to feedback will + be around 2 or 3 business days. It may vary depending on the + complexity of changes and current patch load. + +Q: How often do you send pull requests to major kernel trees like + net or net-next? + +A: Pull requests will be sent out rather often in order to not + accumulate too many patches in bpf or bpf-next. + + As a rule of thumb, expect pull requests for each tree regularly + at the end of the week. In some cases pull requests could additionally + come also in the middle of the week depending on the current patch + load or urgency. + +Q: Are patches applied to bpf-next when the merge window is open? + +A: For the time when the merge window is open, bpf-next will not be + processed. This is roughly analogous to net-next patch processing, + so feel free to read up on the netdev FAQ about further details. + + During those two weeks of merge window, we might ask you to resend + your patch series once bpf-next is open again. Once Linus released + a v*-rc1 after the merge window, we continue processing of bpf-next. + + For non-subscribers to kernel mailing lists, there is also a status + page run by David S. Miller on net-next that provides guidance: + + http://vger.kernel.org/~davem/net-next.html + +Q: I made a BPF verifier change, do I need to add test cases for + BPF kernel selftests? + +A: If the patch has changes to the behavior of the verifier, then yes, + it is absolutely necessary to add test cases to the BPF kernel + selftests suite. If they are not present and we think they are + needed, then we might ask for them before accepting any changes. + + In particular, test_verifier.c is tracking a high number of BPF test + cases, including a lot of corner cases that LLVM BPF back end may + generate out of the restricted C code. Thus, adding test cases is + absolutely crucial to make sure future changes do not accidentally + affect prior use-cases. Thus, treat those test cases as: verifier + behavior that is not tracked in test_verifier.c could potentially + be subject to change. + +Q: When should I add code to samples/bpf/ and when to BPF kernel + selftests? + +A: In general, we prefer additions to BPF kernel selftests rather than + samples/bpf/. The rationale is very simple: kernel selftests are + regularly run by various bots to test for kernel regressions. + + The more test cases we add to BPF selftests, the better the coverage + and the less likely it is that those could accidentally break. It is + not that BPF kernel selftests cannot demo how a specific feature can + be used. + + That said, samples/bpf/ may be a good place for people to get started, + so it might be advisable that simple demos of features could go into + samples/bpf/, but advanced functional and corner-case testing rather + into kernel selftests. + + If your sample looks like a test case, then go for BPF kernel selftests + instead! + +Q: When should I add code to the bpftool? + +A: The main purpose of bpftool (under tools/bpf/bpftool/) is to provide + a central user space tool for debugging and introspection of BPF programs + and maps that are active in the kernel. If UAPI changes related to BPF + enable for dumping additional information of programs or maps, then + bpftool should be extended as well to support dumping them. + +Q: When should I add code to iproute2's BPF loader? + +A: For UAPI changes related to the XDP or tc layer (e.g. cls_bpf), the + convention is that those control-path related changes are added to + iproute2's BPF loader as well from user space side. This is not only + useful to have UAPI changes properly designed to be usable, but also + to make those changes available to a wider user base of major + downstream distributions. + +Q: Do you accept patches as well for iproute2's BPF loader? + +A: Patches for the iproute2's BPF loader have to be sent to: + + netdev@vger.kernel.org + + While those patches are not processed by the BPF kernel maintainers, + please keep them in Cc as well, so they can be reviewed. + + The official git repository for iproute2 is run by Stephen Hemminger + and can be found at: + + https://git.kernel.org/pub/scm/linux/kernel/git/shemminger/iproute2.git/ + + The patches need to have a subject prefix of '[PATCH iproute2 master]' + or '[PATCH iproute2 net-next]'. 'master' or 'net-next' describes the + target branch where the patch should be applied to. Meaning, if kernel + changes went into the net-next kernel tree, then the related iproute2 + changes need to go into the iproute2 net-next branch, otherwise they + can be targeted at master branch. The iproute2 net-next branch will get + merged into the master branch after the current iproute2 version from + master has been released. + + Like BPF, the patches end up in patchwork under the netdev project and + are delegated to 'shemminger' for further processing: + + http://patchwork.ozlabs.org/project/netdev/list/?delegate=389 + +Q: What is the minimum requirement before I submit my BPF patches? + +A: When submitting patches, always take the time and properly test your + patches *prior* to submission. Never rush them! If maintainers find + that your patches have not been properly tested, it is a good way to + get them grumpy. Testing patch submissions is a hard requirement! + + Note, fixes that go to bpf tree *must* have a Fixes: tag included. The + same applies to fixes that target bpf-next, where the affected commit + is in net-next (or in some cases bpf-next). The Fixes: tag is crucial + in order to identify follow-up commits and tremendously helps for people + having to do backporting, so it is a must have! + + We also don't accept patches with an empty commit message. Take your + time and properly write up a high quality commit message, it is + essential! + + Think about it this way: other developers looking at your code a month + from now need to understand *why* a certain change has been done that + way, and whether there have been flaws in the analysis or assumptions + that the original author did. Thus providing a proper rationale and + describing the use-case for the changes is a must. + + Patch submissions with >1 patch must have a cover letter which includes + a high level description of the series. This high level summary will + then be placed into the merge commit by the BPF maintainers such that + it is also accessible from the git log for future reference. + +Q: What do I need to consider when adding a new instruction or feature + that would require BPF JIT and/or LLVM integration as well? + +A: We try hard to keep all BPF JITs up to date such that the same user + experience can be guaranteed when running BPF programs on different + architectures without having the program punt to the less efficient + interpreter in case the in-kernel BPF JIT is enabled. + + If you are unable to implement or test the required JIT changes for + certain architectures, please work together with the related BPF JIT + developers in order to get the feature implemented in a timely manner. + Please refer to the git log (arch/*/net/) to locate the necessary + people for helping out. + + Also always make sure to add BPF test cases (e.g. test_bpf.c and + test_verifier.c) for new instructions, so that they can receive + broad test coverage and help run-time testing the various BPF JITs. + + In case of new BPF instructions, once the changes have been accepted + into the Linux kernel, please implement support into LLVM's BPF back + end. See LLVM section below for further information. + +Stable submission: +------------------ + +Q: I need a specific BPF commit in stable kernels. What should I do? + +A: In case you need a specific fix in stable kernels, first check whether + the commit has already been applied in the related linux-*.y branches: + + https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/ + + If not the case, then drop an email to the BPF maintainers with the + netdev kernel mailing list in Cc and ask for the fix to be queued up: + + netdev@vger.kernel.org + + The process in general is the same as on netdev itself, see also the + netdev FAQ document. + +Q: Do you also backport to kernels not currently maintained as stable? + +A: No. If you need a specific BPF commit in kernels that are currently not + maintained by the stable maintainers, then you are on your own. + + The current stable and longterm stable kernels are all listed here: + + https://www.kernel.org/ + +Q: The BPF patch I am about to submit needs to go to stable as well. What + should I do? + +A: The same rules apply as with netdev patch submissions in general, see + netdev FAQ under: + + Documentation/networking/netdev-FAQ.txt + + Never add "Cc: stable@vger.kernel.org" to the patch description, but + ask the BPF maintainers to queue the patches instead. This can be done + with a note, for example, under the "---" part of the patch which does + not go into the git log. Alternatively, this can be done as a simple + request by mail instead. + +Q: Where do I find currently queued BPF patches that will be submitted + to stable? + +A: Once patches that fix critical bugs got applied into the bpf tree, they + are queued up for stable submission under: + + http://patchwork.ozlabs.org/bundle/bpf/stable/?state=* + + They will be on hold there at minimum until the related commit made its + way into the mainline kernel tree. + + After having been under broader exposure, the queued patches will be + submitted by the BPF maintainers to the stable maintainers. + +Testing patches: +---------------- + +Q: Which BPF kernel selftests version should I run my kernel against? + +A: If you run a kernel xyz, then always run the BPF kernel selftests from + that kernel xyz as well. Do not expect that the BPF selftest from the + latest mainline tree will pass all the time. + + In particular, test_bpf.c and test_verifier.c have a large number of + test cases and are constantly updated with new BPF test sequences, or + existing ones are adapted to verifier changes e.g. due to verifier + becoming smarter and being able to better track certain things. + +LLVM: +----- + +Q: Where do I find LLVM with BPF support? + +A: The BPF back end for LLVM is upstream in LLVM since version 3.7.1. + + All major distributions these days ship LLVM with BPF back end enabled, + so for the majority of use-cases it is not required to compile LLVM by + hand anymore, just install the distribution provided package. + + LLVM's static compiler lists the supported targets through 'llc --version', + make sure BPF targets are listed. Example: + + $ llc --version + LLVM (http://llvm.org/): + LLVM version 6.0.0svn + Optimized build. + Default target: x86_64-unknown-linux-gnu + Host CPU: skylake + + Registered Targets: + bpf - BPF (host endian) + bpfeb - BPF (big endian) + bpfel - BPF (little endian) + x86 - 32-bit X86: Pentium-Pro and above + x86-64 - 64-bit X86: EM64T and AMD64 + + For developers in order to utilize the latest features added to LLVM's + BPF back end, it is advisable to run the latest LLVM releases. Support + for new BPF kernel features such as additions to the BPF instruction + set are often developed together. + + All LLVM releases can be found at: http://releases.llvm.org/ + +Q: Got it, so how do I build LLVM manually anyway? + +A: You need cmake and gcc-c++ as build requisites for LLVM. Once you have + that set up, proceed with building the latest LLVM and clang version + from the git repositories: + + $ git clone http://llvm.org/git/llvm.git + $ cd llvm/tools + $ git clone --depth 1 http://llvm.org/git/clang.git + $ cd ..; mkdir build; cd build + $ cmake .. -DLLVM_TARGETS_TO_BUILD="BPF;X86" \ + -DBUILD_SHARED_LIBS=OFF \ + -DCMAKE_BUILD_TYPE=Release \ + -DLLVM_BUILD_RUNTIME=OFF + $ make -j $(getconf _NPROCESSORS_ONLN) + + The built binaries can then be found in the build/bin/ directory, where + you can point the PATH variable to. + +Q: Should I notify BPF kernel maintainers about issues in LLVM's BPF code + generation back end or about LLVM generated code that the verifier + refuses to accept? + +A: Yes, please do! LLVM's BPF back end is a key piece of the whole BPF + infrastructure and it ties deeply into verification of programs from the + kernel side. Therefore, any issues on either side need to be investigated + and fixed whenever necessary. + + Therefore, please make sure to bring them up at netdev kernel mailing + list and Cc BPF maintainers for LLVM and kernel bits: + + Yonghong Song + Alexei Starovoitov + Daniel Borkmann + + LLVM also has an issue tracker where BPF related bugs can be found: + + https://bugs.llvm.org/buglist.cgi?quicksearch=bpf + + However, it is better to reach out through mailing lists with having + maintainers in Cc. + +Q: I have added a new BPF instruction to the kernel, how can I integrate + it into LLVM? + +A: LLVM has a -mcpu selector for the BPF back end in order to allow the + selection of BPF instruction set extensions. By default the 'generic' + processor target is used, which is the base instruction set (v1) of BPF. + + LLVM has an option to select -mcpu=probe where it will probe the host + kernel for supported BPF instruction set extensions and selects the + optimal set automatically. + + For cross-compilation, a specific version can be select manually as well. + + $ llc -march bpf -mcpu=help + Available CPUs for this target: + + generic - Select the generic processor. + probe - Select the probe processor. + v1 - Select the v1 processor. + v2 - Select the v2 processor. + [...] + + Newly added BPF instructions to the Linux kernel need to follow the same + scheme, bump the instruction set version and implement probing for the + extensions such that -mcpu=probe users can benefit from the optimization + transparently when upgrading their kernels. + + If you are unable to implement support for the newly added BPF instruction + please reach out to BPF developers for help. + + By the way, the BPF kernel selftests run with -mcpu=probe for better + test coverage. + +Q: In some cases clang flag "-target bpf" is used but in other cases the + default clang target, which matches the underlying architecture, is used. + What is the difference and when I should use which? + +A: Although LLVM IR generation and optimization try to stay architecture + independent, "-target " still has some impact on generated code: + + - BPF program may recursively include header file(s) with file scope + inline assembly codes. The default target can handle this well, + while bpf target may fail if bpf backend assembler does not + understand these assembly codes, which is true in most cases. + + - When compiled without -g, additional elf sections, e.g., + .eh_frame and .rela.eh_frame, may be present in the object file + with default target, but not with bpf target. + + - The default target may turn a C switch statement into a switch table + lookup and jump operation. Since the switch table is placed + in the global readonly section, the bpf program will fail to load. + The bpf target does not support switch table optimization. + The clang option "-fno-jump-tables" can be used to disable + switch table generation. + + - For clang -target bpf, it is guaranteed that pointer or long / + unsigned long types will always have a width of 64 bit, no matter + whether underlying clang binary or default target (or kernel) is + 32 bit. However, when native clang target is used, then it will + compile these types based on the underlying architecture's conventions, + meaning in case of 32 bit architecture, pointer or long / unsigned + long types e.g. in BPF context structure will have width of 32 bit + while the BPF LLVM back end still operates in 64 bit. The native + target is mostly needed in tracing for the case of walking pt_regs + or other kernel structures where CPU's register width matters. + Otherwise, clang -target bpf is generally recommended. + + You should use default target when: + + - Your program includes a header file, e.g., ptrace.h, which eventually + pulls in some header files containing file scope host assembly codes. + - You can add "-fno-jump-tables" to work around the switch table issue. + + Otherwise, you can use bpf target. Additionally, you _must_ use bpf target + when: + + - Your program uses data structures with pointer or long / unsigned long + types that interface with BPF helpers or context data structures. Access + into these structures is verified by the BPF verifier and may result + in verification failures if the native architecture is not aligned with + the BPF architecture, e.g. 64-bit. An example of this is + BPF_PROG_TYPE_SK_MSG require '-target bpf' + +Happy BPF hacking! diff --git a/Documentation/bpf/bpf_devel_QA.txt b/Documentation/bpf/bpf_devel_QA.txt deleted file mode 100644 index da57601153a0..000000000000 --- a/Documentation/bpf/bpf_devel_QA.txt +++ /dev/null @@ -1,570 +0,0 @@ -This document provides information for the BPF subsystem about various -workflows related to reporting bugs, submitting patches, and queueing -patches for stable kernels. - -For general information about submitting patches, please refer to -Documentation/process/. This document only describes additional specifics -related to BPF. - -Reporting bugs: ---------------- - -Q: How do I report bugs for BPF kernel code? - -A: Since all BPF kernel development as well as bpftool and iproute2 BPF - loader development happens through the netdev kernel mailing list, - please report any found issues around BPF to the following mailing - list: - - netdev@vger.kernel.org - - This may also include issues related to XDP, BPF tracing, etc. - - Given netdev has a high volume of traffic, please also add the BPF - maintainers to Cc (from kernel MAINTAINERS file): - - Alexei Starovoitov - Daniel Borkmann - - In case a buggy commit has already been identified, make sure to keep - the actual commit authors in Cc as well for the report. They can - typically be identified through the kernel's git tree. - - Please do *not* report BPF issues to bugzilla.kernel.org since it - is a guarantee that the reported issue will be overlooked. - -Submitting patches: -------------------- - -Q: To which mailing list do I need to submit my BPF patches? - -A: Please submit your BPF patches to the netdev kernel mailing list: - - netdev@vger.kernel.org - - Historically, BPF came out of networking and has always been maintained - by the kernel networking community. Although these days BPF touches - many other subsystems as well, the patches are still routed mainly - through the networking community. - - In case your patch has changes in various different subsystems (e.g. - tracing, security, etc), make sure to Cc the related kernel mailing - lists and maintainers from there as well, so they are able to review - the changes and provide their Acked-by's to the patches. - -Q: Where can I find patches currently under discussion for BPF subsystem? - -A: All patches that are Cc'ed to netdev are queued for review under netdev - patchwork project: - - http://patchwork.ozlabs.org/project/netdev/list/ - - Those patches which target BPF, are assigned to a 'bpf' delegate for - further processing from BPF maintainers. The current queue with - patches under review can be found at: - - https://patchwork.ozlabs.org/project/netdev/list/?delegate=77147 - - Once the patches have been reviewed by the BPF community as a whole - and approved by the BPF maintainers, their status in patchwork will be - changed to 'Accepted' and the submitter will be notified by mail. This - means that the patches look good from a BPF perspective and have been - applied to one of the two BPF kernel trees. - - In case feedback from the community requires a respin of the patches, - their status in patchwork will be set to 'Changes Requested', and purged - from the current review queue. Likewise for cases where patches would - get rejected or are not applicable to the BPF trees (but assigned to - the 'bpf' delegate). - -Q: How do the changes make their way into Linux? - -A: There are two BPF kernel trees (git repositories). Once patches have - been accepted by the BPF maintainers, they will be applied to one - of the two BPF trees: - - https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/ - https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/ - - The bpf tree itself is for fixes only, whereas bpf-next for features, - cleanups or other kind of improvements ("next-like" content). This is - analogous to net and net-next trees for networking. Both bpf and - bpf-next will only have a master branch in order to simplify against - which branch patches should get rebased to. - - Accumulated BPF patches in the bpf tree will regularly get pulled - into the net kernel tree. Likewise, accumulated BPF patches accepted - into the bpf-next tree will make their way into net-next tree. net and - net-next are both run by David S. Miller. From there, they will go - into the kernel mainline tree run by Linus Torvalds. To read up on the - process of net and net-next being merged into the mainline tree, see - the netdev FAQ under: - - Documentation/networking/netdev-FAQ.txt - - Occasionally, to prevent merge conflicts, we might send pull requests - to other trees (e.g. tracing) with a small subset of the patches, but - net and net-next are always the main trees targeted for integration. - - The pull requests will contain a high-level summary of the accumulated - patches and can be searched on netdev kernel mailing list through the - following subject lines (yyyy-mm-dd is the date of the pull request): - - pull-request: bpf yyyy-mm-dd - pull-request: bpf-next yyyy-mm-dd - -Q: How do I indicate which tree (bpf vs. bpf-next) my patch should be - applied to? - -A: The process is the very same as described in the netdev FAQ, so - please read up on it. The subject line must indicate whether the - patch is a fix or rather "next-like" content in order to let the - maintainers know whether it is targeted at bpf or bpf-next. - - For fixes eventually landing in bpf -> net tree, the subject must - look like: - - git format-patch --subject-prefix='PATCH bpf' start..finish - - For features/improvements/etc that should eventually land in - bpf-next -> net-next, the subject must look like: - - git format-patch --subject-prefix='PATCH bpf-next' start..finish - - If unsure whether the patch or patch series should go into bpf - or net directly, or bpf-next or net-next directly, it is not a - problem either if the subject line says net or net-next as target. - It is eventually up to the maintainers to do the delegation of - the patches. - - If it is clear that patches should go into bpf or bpf-next tree, - please make sure to rebase the patches against those trees in - order to reduce potential conflicts. - - In case the patch or patch series has to be reworked and sent out - again in a second or later revision, it is also required to add a - version number (v2, v3, ...) into the subject prefix: - - git format-patch --subject-prefix='PATCH net-next v2' start..finish - - When changes have been requested to the patch series, always send the - whole patch series again with the feedback incorporated (never send - individual diffs on top of the old series). - -Q: What does it mean when a patch gets applied to bpf or bpf-next tree? - -A: It means that the patch looks good for mainline inclusion from - a BPF point of view. - - Be aware that this is not a final verdict that the patch will - automatically get accepted into net or net-next trees eventually: - - On the netdev kernel mailing list reviews can come in at any point - in time. If discussions around a patch conclude that they cannot - get included as-is, we will either apply a follow-up fix or drop - them from the trees entirely. Therefore, we also reserve to rebase - the trees when deemed necessary. After all, the purpose of the tree - is to i) accumulate and stage BPF patches for integration into trees - like net and net-next, and ii) run extensive BPF test suite and - workloads on the patches before they make their way any further. - - Once the BPF pull request was accepted by David S. Miller, then - the patches end up in net or net-next tree, respectively, and - make their way from there further into mainline. Again, see the - netdev FAQ for additional information e.g. on how often they are - merged to mainline. - -Q: How long do I need to wait for feedback on my BPF patches? - -A: We try to keep the latency low. The usual time to feedback will - be around 2 or 3 business days. It may vary depending on the - complexity of changes and current patch load. - -Q: How often do you send pull requests to major kernel trees like - net or net-next? - -A: Pull requests will be sent out rather often in order to not - accumulate too many patches in bpf or bpf-next. - - As a rule of thumb, expect pull requests for each tree regularly - at the end of the week. In some cases pull requests could additionally - come also in the middle of the week depending on the current patch - load or urgency. - -Q: Are patches applied to bpf-next when the merge window is open? - -A: For the time when the merge window is open, bpf-next will not be - processed. This is roughly analogous to net-next patch processing, - so feel free to read up on the netdev FAQ about further details. - - During those two weeks of merge window, we might ask you to resend - your patch series once bpf-next is open again. Once Linus released - a v*-rc1 after the merge window, we continue processing of bpf-next. - - For non-subscribers to kernel mailing lists, there is also a status - page run by David S. Miller on net-next that provides guidance: - - http://vger.kernel.org/~davem/net-next.html - -Q: I made a BPF verifier change, do I need to add test cases for - BPF kernel selftests? - -A: If the patch has changes to the behavior of the verifier, then yes, - it is absolutely necessary to add test cases to the BPF kernel - selftests suite. If they are not present and we think they are - needed, then we might ask for them before accepting any changes. - - In particular, test_verifier.c is tracking a high number of BPF test - cases, including a lot of corner cases that LLVM BPF back end may - generate out of the restricted C code. Thus, adding test cases is - absolutely crucial to make sure future changes do not accidentally - affect prior use-cases. Thus, treat those test cases as: verifier - behavior that is not tracked in test_verifier.c could potentially - be subject to change. - -Q: When should I add code to samples/bpf/ and when to BPF kernel - selftests? - -A: In general, we prefer additions to BPF kernel selftests rather than - samples/bpf/. The rationale is very simple: kernel selftests are - regularly run by various bots to test for kernel regressions. - - The more test cases we add to BPF selftests, the better the coverage - and the less likely it is that those could accidentally break. It is - not that BPF kernel selftests cannot demo how a specific feature can - be used. - - That said, samples/bpf/ may be a good place for people to get started, - so it might be advisable that simple demos of features could go into - samples/bpf/, but advanced functional and corner-case testing rather - into kernel selftests. - - If your sample looks like a test case, then go for BPF kernel selftests - instead! - -Q: When should I add code to the bpftool? - -A: The main purpose of bpftool (under tools/bpf/bpftool/) is to provide - a central user space tool for debugging and introspection of BPF programs - and maps that are active in the kernel. If UAPI changes related to BPF - enable for dumping additional information of programs or maps, then - bpftool should be extended as well to support dumping them. - -Q: When should I add code to iproute2's BPF loader? - -A: For UAPI changes related to the XDP or tc layer (e.g. cls_bpf), the - convention is that those control-path related changes are added to - iproute2's BPF loader as well from user space side. This is not only - useful to have UAPI changes properly designed to be usable, but also - to make those changes available to a wider user base of major - downstream distributions. - -Q: Do you accept patches as well for iproute2's BPF loader? - -A: Patches for the iproute2's BPF loader have to be sent to: - - netdev@vger.kernel.org - - While those patches are not processed by the BPF kernel maintainers, - please keep them in Cc as well, so they can be reviewed. - - The official git repository for iproute2 is run by Stephen Hemminger - and can be found at: - - https://git.kernel.org/pub/scm/linux/kernel/git/shemminger/iproute2.git/ - - The patches need to have a subject prefix of '[PATCH iproute2 master]' - or '[PATCH iproute2 net-next]'. 'master' or 'net-next' describes the - target branch where the patch should be applied to. Meaning, if kernel - changes went into the net-next kernel tree, then the related iproute2 - changes need to go into the iproute2 net-next branch, otherwise they - can be targeted at master branch. The iproute2 net-next branch will get - merged into the master branch after the current iproute2 version from - master has been released. - - Like BPF, the patches end up in patchwork under the netdev project and - are delegated to 'shemminger' for further processing: - - http://patchwork.ozlabs.org/project/netdev/list/?delegate=389 - -Q: What is the minimum requirement before I submit my BPF patches? - -A: When submitting patches, always take the time and properly test your - patches *prior* to submission. Never rush them! If maintainers find - that your patches have not been properly tested, it is a good way to - get them grumpy. Testing patch submissions is a hard requirement! - - Note, fixes that go to bpf tree *must* have a Fixes: tag included. The - same applies to fixes that target bpf-next, where the affected commit - is in net-next (or in some cases bpf-next). The Fixes: tag is crucial - in order to identify follow-up commits and tremendously helps for people - having to do backporting, so it is a must have! - - We also don't accept patches with an empty commit message. Take your - time and properly write up a high quality commit message, it is - essential! - - Think about it this way: other developers looking at your code a month - from now need to understand *why* a certain change has been done that - way, and whether there have been flaws in the analysis or assumptions - that the original author did. Thus providing a proper rationale and - describing the use-case for the changes is a must. - - Patch submissions with >1 patch must have a cover letter which includes - a high level description of the series. This high level summary will - then be placed into the merge commit by the BPF maintainers such that - it is also accessible from the git log for future reference. - -Q: What do I need to consider when adding a new instruction or feature - that would require BPF JIT and/or LLVM integration as well? - -A: We try hard to keep all BPF JITs up to date such that the same user - experience can be guaranteed when running BPF programs on different - architectures without having the program punt to the less efficient - interpreter in case the in-kernel BPF JIT is enabled. - - If you are unable to implement or test the required JIT changes for - certain architectures, please work together with the related BPF JIT - developers in order to get the feature implemented in a timely manner. - Please refer to the git log (arch/*/net/) to locate the necessary - people for helping out. - - Also always make sure to add BPF test cases (e.g. test_bpf.c and - test_verifier.c) for new instructions, so that they can receive - broad test coverage and help run-time testing the various BPF JITs. - - In case of new BPF instructions, once the changes have been accepted - into the Linux kernel, please implement support into LLVM's BPF back - end. See LLVM section below for further information. - -Stable submission: ------------------- - -Q: I need a specific BPF commit in stable kernels. What should I do? - -A: In case you need a specific fix in stable kernels, first check whether - the commit has already been applied in the related linux-*.y branches: - - https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/ - - If not the case, then drop an email to the BPF maintainers with the - netdev kernel mailing list in Cc and ask for the fix to be queued up: - - netdev@vger.kernel.org - - The process in general is the same as on netdev itself, see also the - netdev FAQ document. - -Q: Do you also backport to kernels not currently maintained as stable? - -A: No. If you need a specific BPF commit in kernels that are currently not - maintained by the stable maintainers, then you are on your own. - - The current stable and longterm stable kernels are all listed here: - - https://www.kernel.org/ - -Q: The BPF patch I am about to submit needs to go to stable as well. What - should I do? - -A: The same rules apply as with netdev patch submissions in general, see - netdev FAQ under: - - Documentation/networking/netdev-FAQ.txt - - Never add "Cc: stable@vger.kernel.org" to the patch description, but - ask the BPF maintainers to queue the patches instead. This can be done - with a note, for example, under the "---" part of the patch which does - not go into the git log. Alternatively, this can be done as a simple - request by mail instead. - -Q: Where do I find currently queued BPF patches that will be submitted - to stable? - -A: Once patches that fix critical bugs got applied into the bpf tree, they - are queued up for stable submission under: - - http://patchwork.ozlabs.org/bundle/bpf/stable/?state=* - - They will be on hold there at minimum until the related commit made its - way into the mainline kernel tree. - - After having been under broader exposure, the queued patches will be - submitted by the BPF maintainers to the stable maintainers. - -Testing patches: ----------------- - -Q: Which BPF kernel selftests version should I run my kernel against? - -A: If you run a kernel xyz, then always run the BPF kernel selftests from - that kernel xyz as well. Do not expect that the BPF selftest from the - latest mainline tree will pass all the time. - - In particular, test_bpf.c and test_verifier.c have a large number of - test cases and are constantly updated with new BPF test sequences, or - existing ones are adapted to verifier changes e.g. due to verifier - becoming smarter and being able to better track certain things. - -LLVM: ------ - -Q: Where do I find LLVM with BPF support? - -A: The BPF back end for LLVM is upstream in LLVM since version 3.7.1. - - All major distributions these days ship LLVM with BPF back end enabled, - so for the majority of use-cases it is not required to compile LLVM by - hand anymore, just install the distribution provided package. - - LLVM's static compiler lists the supported targets through 'llc --version', - make sure BPF targets are listed. Example: - - $ llc --version - LLVM (http://llvm.org/): - LLVM version 6.0.0svn - Optimized build. - Default target: x86_64-unknown-linux-gnu - Host CPU: skylake - - Registered Targets: - bpf - BPF (host endian) - bpfeb - BPF (big endian) - bpfel - BPF (little endian) - x86 - 32-bit X86: Pentium-Pro and above - x86-64 - 64-bit X86: EM64T and AMD64 - - For developers in order to utilize the latest features added to LLVM's - BPF back end, it is advisable to run the latest LLVM releases. Support - for new BPF kernel features such as additions to the BPF instruction - set are often developed together. - - All LLVM releases can be found at: http://releases.llvm.org/ - -Q: Got it, so how do I build LLVM manually anyway? - -A: You need cmake and gcc-c++ as build requisites for LLVM. Once you have - that set up, proceed with building the latest LLVM and clang version - from the git repositories: - - $ git clone http://llvm.org/git/llvm.git - $ cd llvm/tools - $ git clone --depth 1 http://llvm.org/git/clang.git - $ cd ..; mkdir build; cd build - $ cmake .. -DLLVM_TARGETS_TO_BUILD="BPF;X86" \ - -DBUILD_SHARED_LIBS=OFF \ - -DCMAKE_BUILD_TYPE=Release \ - -DLLVM_BUILD_RUNTIME=OFF - $ make -j $(getconf _NPROCESSORS_ONLN) - - The built binaries can then be found in the build/bin/ directory, where - you can point the PATH variable to. - -Q: Should I notify BPF kernel maintainers about issues in LLVM's BPF code - generation back end or about LLVM generated code that the verifier - refuses to accept? - -A: Yes, please do! LLVM's BPF back end is a key piece of the whole BPF - infrastructure and it ties deeply into verification of programs from the - kernel side. Therefore, any issues on either side need to be investigated - and fixed whenever necessary. - - Therefore, please make sure to bring them up at netdev kernel mailing - list and Cc BPF maintainers for LLVM and kernel bits: - - Yonghong Song - Alexei Starovoitov - Daniel Borkmann - - LLVM also has an issue tracker where BPF related bugs can be found: - - https://bugs.llvm.org/buglist.cgi?quicksearch=bpf - - However, it is better to reach out through mailing lists with having - maintainers in Cc. - -Q: I have added a new BPF instruction to the kernel, how can I integrate - it into LLVM? - -A: LLVM has a -mcpu selector for the BPF back end in order to allow the - selection of BPF instruction set extensions. By default the 'generic' - processor target is used, which is the base instruction set (v1) of BPF. - - LLVM has an option to select -mcpu=probe where it will probe the host - kernel for supported BPF instruction set extensions and selects the - optimal set automatically. - - For cross-compilation, a specific version can be select manually as well. - - $ llc -march bpf -mcpu=help - Available CPUs for this target: - - generic - Select the generic processor. - probe - Select the probe processor. - v1 - Select the v1 processor. - v2 - Select the v2 processor. - [...] - - Newly added BPF instructions to the Linux kernel need to follow the same - scheme, bump the instruction set version and implement probing for the - extensions such that -mcpu=probe users can benefit from the optimization - transparently when upgrading their kernels. - - If you are unable to implement support for the newly added BPF instruction - please reach out to BPF developers for help. - - By the way, the BPF kernel selftests run with -mcpu=probe for better - test coverage. - -Q: In some cases clang flag "-target bpf" is used but in other cases the - default clang target, which matches the underlying architecture, is used. - What is the difference and when I should use which? - -A: Although LLVM IR generation and optimization try to stay architecture - independent, "-target " still has some impact on generated code: - - - BPF program may recursively include header file(s) with file scope - inline assembly codes. The default target can handle this well, - while bpf target may fail if bpf backend assembler does not - understand these assembly codes, which is true in most cases. - - - When compiled without -g, additional elf sections, e.g., - .eh_frame and .rela.eh_frame, may be present in the object file - with default target, but not with bpf target. - - - The default target may turn a C switch statement into a switch table - lookup and jump operation. Since the switch table is placed - in the global readonly section, the bpf program will fail to load. - The bpf target does not support switch table optimization. - The clang option "-fno-jump-tables" can be used to disable - switch table generation. - - - For clang -target bpf, it is guaranteed that pointer or long / - unsigned long types will always have a width of 64 bit, no matter - whether underlying clang binary or default target (or kernel) is - 32 bit. However, when native clang target is used, then it will - compile these types based on the underlying architecture's conventions, - meaning in case of 32 bit architecture, pointer or long / unsigned - long types e.g. in BPF context structure will have width of 32 bit - while the BPF LLVM back end still operates in 64 bit. The native - target is mostly needed in tracing for the case of walking pt_regs - or other kernel structures where CPU's register width matters. - Otherwise, clang -target bpf is generally recommended. - - You should use default target when: - - - Your program includes a header file, e.g., ptrace.h, which eventually - pulls in some header files containing file scope host assembly codes. - - You can add "-fno-jump-tables" to work around the switch table issue. - - Otherwise, you can use bpf target. Additionally, you _must_ use bpf target - when: - - - Your program uses data structures with pointer or long / unsigned long - types that interface with BPF helpers or context data structures. Access - into these structures is verified by the BPF verifier and may result - in verification failures if the native architecture is not aligned with - the BPF architecture, e.g. 64-bit. An example of this is - BPF_PROG_TYPE_SK_MSG require '-target bpf' - -Happy BPF hacking! -- cgit v1.2.3 From 1a6ac1d59dc3b4077c643c3be70f9e650e267afe Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Mon, 14 May 2018 15:42:22 +0200 Subject: bpf, doc: convert bpf_design_QA.rst to use RST formatting The RST formatting is done such that that when rendered or converted to different formats, an automatic index with links are created to the subsections. Thus, the questions are created as sections (or subsections), in-order to get the wanted auto-generated FAQ/QA index. Special thanks to Quentin Monnet who have reviewed and corrected both RST formatting and GitHub rendering issues in this file. Those commits have been squashed. I've manually tested that this also renders nicely if included as part of the kernel 'make htmldocs'. As the end-goal is for this to become more integrated with kernel-doc project/movement. Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov --- Documentation/bpf/bpf_design_QA.rst | 223 +++++++++++++++++++++++------------- 1 file changed, 144 insertions(+), 79 deletions(-) diff --git a/Documentation/bpf/bpf_design_QA.rst b/Documentation/bpf/bpf_design_QA.rst index f3e458a0bb2f..6780a6d81745 100644 --- a/Documentation/bpf/bpf_design_QA.rst +++ b/Documentation/bpf/bpf_design_QA.rst @@ -1,156 +1,221 @@ +============== +BPF Design Q&A +============== + BPF extensibility and applicability to networking, tracing, security in the linux kernel and several user space implementations of BPF virtual machine led to a number of misunderstanding on what BPF actually is. This short QA is an attempt to address that and outline a direction of where BPF is heading long term. +.. contents:: + :local: + :depth: 3 + +Questions and Answers +===================== + Q: Is BPF a generic instruction set similar to x64 and arm64? +------------------------------------------------------------- A: NO. Q: Is BPF a generic virtual machine ? +------------------------------------- A: NO. -BPF is generic instruction set _with_ C calling convention. +BPF is generic instruction set *with* C calling convention. +----------------------------------------------------------- Q: Why C calling convention was chosen? +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + A: Because BPF programs are designed to run in the linux kernel - which is written in C, hence BPF defines instruction set compatible - with two most used architectures x64 and arm64 (and takes into - consideration important quirks of other architectures) and - defines calling convention that is compatible with C calling - convention of the linux kernel on those architectures. +which is written in C, hence BPF defines instruction set compatible +with two most used architectures x64 and arm64 (and takes into +consideration important quirks of other architectures) and +defines calling convention that is compatible with C calling +convention of the linux kernel on those architectures. Q: can multiple return values be supported in the future? +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A: NO. BPF allows only register R0 to be used as return value. Q: can more than 5 function arguments be supported in the future? +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A: NO. BPF calling convention only allows registers R1-R5 to be used - as arguments. BPF is not a standalone instruction set. - (unlike x64 ISA that allows msft, cdecl and other conventions) +as arguments. BPF is not a standalone instruction set. +(unlike x64 ISA that allows msft, cdecl and other conventions) Q: can BPF programs access instruction pointer or return address? +----------------------------------------------------------------- A: NO. Q: can BPF programs access stack pointer ? -A: NO. Only frame pointer (register R10) is accessible. - From compiler point of view it's necessary to have stack pointer. - For example LLVM defines register R11 as stack pointer in its - BPF backend, but it makes sure that generated code never uses it. +------------------------------------------ +A: NO. + +Only frame pointer (register R10) is accessible. +From compiler point of view it's necessary to have stack pointer. +For example LLVM defines register R11 as stack pointer in its +BPF backend, but it makes sure that generated code never uses it. Q: Does C-calling convention diminishes possible use cases? -A: YES. BPF design forces addition of major functionality in the form - of kernel helper functions and kernel objects like BPF maps with - seamless interoperability between them. It lets kernel call into - BPF programs and programs call kernel helpers with zero overhead. - As all of them were native C code. That is particularly the case - for JITed BPF programs that are indistinguishable from - native kernel C code. +----------------------------------------------------------- +A: YES. + +BPF design forces addition of major functionality in the form +of kernel helper functions and kernel objects like BPF maps with +seamless interoperability between them. It lets kernel call into +BPF programs and programs call kernel helpers with zero overhead. +As all of them were native C code. That is particularly the case +for JITed BPF programs that are indistinguishable from +native kernel C code. Q: Does it mean that 'innovative' extensions to BPF code are disallowed? -A: Soft yes. At least for now until BPF core has support for - bpf-to-bpf calls, indirect calls, loops, global variables, - jump tables, read only sections and all other normal constructs - that C code can produce. +------------------------------------------------------------------------ +A: Soft yes. + +At least for now until BPF core has support for +bpf-to-bpf calls, indirect calls, loops, global variables, +jump tables, read only sections and all other normal constructs +that C code can produce. Q: Can loops be supported in a safe way? -A: It's not clear yet. BPF developers are trying to find a way to - support bounded loops where the verifier can guarantee that - the program terminates in less than 4096 instructions. +---------------------------------------- +A: It's not clear yet. + +BPF developers are trying to find a way to +support bounded loops where the verifier can guarantee that +the program terminates in less than 4096 instructions. + +Instruction level questions +--------------------------- + +Q: LD_ABS and LD_IND instructions vs C code +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Q: How come LD_ABS and LD_IND instruction are present in BPF whereas - C code cannot express them and has to use builtin intrinsics? +C code cannot express them and has to use builtin intrinsics? + A: This is artifact of compatibility with classic BPF. Modern - networking code in BPF performs better without them. - See 'direct packet access'. +networking code in BPF performs better without them. +See 'direct packet access'. +Q: BPF instructions mapping not one-to-one to native CPU +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Q: It seems not all BPF instructions are one-to-one to native CPU. - For example why BPF_JNE and other compare and jumps are not cpu-like? +For example why BPF_JNE and other compare and jumps are not cpu-like? + A: This was necessary to avoid introducing flags into ISA which are - impossible to make generic and efficient across CPU architectures. +impossible to make generic and efficient across CPU architectures. Q: why BPF_DIV instruction doesn't map to x64 div? +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A: Because if we picked one-to-one relationship to x64 it would have made - it more complicated to support on arm64 and other archs. Also it - needs div-by-zero runtime check. +it more complicated to support on arm64 and other archs. Also it +needs div-by-zero runtime check. Q: why there is no BPF_SDIV for signed divide operation? +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A: Because it would be rarely used. llvm errors in such case and - prints a suggestion to use unsigned divide instead +prints a suggestion to use unsigned divide instead Q: Why BPF has implicit prologue and epilogue? +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A: Because architectures like sparc have register windows and in general - there are enough subtle differences between architectures, so naive - store return address into stack won't work. Another reason is BPF has - to be safe from division by zero (and legacy exception path - of LD_ABS insn). Those instructions need to invoke epilogue and - return implicitly. +there are enough subtle differences between architectures, so naive +store return address into stack won't work. Another reason is BPF has +to be safe from division by zero (and legacy exception path +of LD_ABS insn). Those instructions need to invoke epilogue and +return implicitly. Q: Why BPF_JLT and BPF_JLE instructions were not introduced in the beginning? +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A: Because classic BPF didn't have them and BPF authors felt that compiler - workaround would be acceptable. Turned out that programs lose performance - due to lack of these compare instructions and they were added. - These two instructions is a perfect example what kind of new BPF - instructions are acceptable and can be added in the future. - These two already had equivalent instructions in native CPUs. - New instructions that don't have one-to-one mapping to HW instructions - will not be accepted. - +workaround would be acceptable. Turned out that programs lose performance +due to lack of these compare instructions and they were added. +These two instructions is a perfect example what kind of new BPF +instructions are acceptable and can be added in the future. +These two already had equivalent instructions in native CPUs. +New instructions that don't have one-to-one mapping to HW instructions +will not be accepted. + +Q: BPF 32-bit subregister requirements +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Q: BPF 32-bit subregisters have a requirement to zero upper 32-bits of BPF - registers which makes BPF inefficient virtual machine for 32-bit - CPU architectures and 32-bit HW accelerators. Can true 32-bit registers - be added to BPF in the future? +registers which makes BPF inefficient virtual machine for 32-bit +CPU architectures and 32-bit HW accelerators. Can true 32-bit registers +be added to BPF in the future? + A: NO. The first thing to improve performance on 32-bit archs is to teach - LLVM to generate code that uses 32-bit subregisters. Then second step - is to teach verifier to mark operations where zero-ing upper bits - is unnecessary. Then JITs can take advantage of those markings and - drastically reduce size of generated code and improve performance. +LLVM to generate code that uses 32-bit subregisters. Then second step +is to teach verifier to mark operations where zero-ing upper bits +is unnecessary. Then JITs can take advantage of those markings and +drastically reduce size of generated code and improve performance. Q: Does BPF have a stable ABI? +------------------------------ A: YES. BPF instructions, arguments to BPF programs, set of helper - functions and their arguments, recognized return codes are all part - of ABI. However when tracing programs are using bpf_probe_read() helper - to walk kernel internal datastructures and compile with kernel - internal headers these accesses can and will break with newer - kernels. The union bpf_attr -> kern_version is checked at load time - to prevent accidentally loading kprobe-based bpf programs written - for a different kernel. Networking programs don't do kern_version check. +functions and their arguments, recognized return codes are all part +of ABI. However when tracing programs are using bpf_probe_read() helper +to walk kernel internal datastructures and compile with kernel +internal headers these accesses can and will break with newer +kernels. The union bpf_attr -> kern_version is checked at load time +to prevent accidentally loading kprobe-based bpf programs written +for a different kernel. Networking programs don't do kern_version check. Q: How much stack space a BPF program uses? +------------------------------------------- A: Currently all program types are limited to 512 bytes of stack - space, but the verifier computes the actual amount of stack used - and both interpreter and most JITed code consume necessary amount. +space, but the verifier computes the actual amount of stack used +and both interpreter and most JITed code consume necessary amount. Q: Can BPF be offloaded to HW? +------------------------------ A: YES. BPF HW offload is supported by NFP driver. Q: Does classic BPF interpreter still exist? +-------------------------------------------- A: NO. Classic BPF programs are converted into extend BPF instructions. Q: Can BPF call arbitrary kernel functions? +------------------------------------------- A: NO. BPF programs can only call a set of helper functions which - is defined for every program type. +is defined for every program type. Q: Can BPF overwrite arbitrary kernel memory? -A: NO. Tracing bpf programs can _read_ arbitrary memory with bpf_probe_read() - and bpf_probe_read_str() helpers. Networking programs cannot read - arbitrary memory, since they don't have access to these helpers. - Programs can never read or write arbitrary memory directly. +--------------------------------------------- +A: NO. + +Tracing bpf programs can *read* arbitrary memory with bpf_probe_read() +and bpf_probe_read_str() helpers. Networking programs cannot read +arbitrary memory, since they don't have access to these helpers. +Programs can never read or write arbitrary memory directly. Q: Can BPF overwrite arbitrary user memory? -A: Sort-of. Tracing BPF programs can overwrite the user memory - of the current task with bpf_probe_write_user(). Every time such - program is loaded the kernel will print warning message, so - this helper is only useful for experiments and prototypes. - Tracing BPF programs are root only. +------------------------------------------- +A: Sort-of. + +Tracing BPF programs can overwrite the user memory +of the current task with bpf_probe_write_user(). Every time such +program is loaded the kernel will print warning message, so +this helper is only useful for experiments and prototypes. +Tracing BPF programs are root only. +Q: bpf_trace_printk() helper warning +------------------------------------ Q: When bpf_trace_printk() helper is used the kernel prints nasty - warning message. Why is that? +warning message. Why is that? + A: This is done to nudge program authors into better interfaces when - programs need to pass data to user space. Like bpf_perf_event_output() - can be used to efficiently stream data via perf ring buffer. - BPF maps can be used for asynchronous data sharing between kernel - and user space. bpf_trace_printk() should only be used for debugging. +programs need to pass data to user space. Like bpf_perf_event_output() +can be used to efficiently stream data via perf ring buffer. +BPF maps can be used for asynchronous data sharing between kernel +and user space. bpf_trace_printk() should only be used for debugging. +Q: New functionality via kernel modules? +---------------------------------------- Q: Can BPF functionality such as new program or map types, new - helpers, etc be added out of kernel module code? +helpers, etc be added out of kernel module code? + A: NO. -- cgit v1.2.3 From 542228384888f5ad11fa6ffd59947a29a1f4452e Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Mon, 14 May 2018 15:42:27 +0200 Subject: bpf, doc: convert bpf_devel_QA.rst to use RST formatting Same story as bpf_design_QA.rst RST format conversion. Again thanks to Quentin Monnet for fixes and patches that have been squashed. Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov --- Documentation/bpf/bpf_devel_QA.rst | 799 +++++++++++++++++++------------------ 1 file changed, 420 insertions(+), 379 deletions(-) diff --git a/Documentation/bpf/bpf_devel_QA.rst b/Documentation/bpf/bpf_devel_QA.rst index da57601153a0..2254bdeae990 100644 --- a/Documentation/bpf/bpf_devel_QA.rst +++ b/Documentation/bpf/bpf_devel_QA.rst @@ -1,424 +1,446 @@ +================================= +HOWTO interact with BPF subsystem +================================= + This document provides information for the BPF subsystem about various workflows related to reporting bugs, submitting patches, and queueing patches for stable kernels. For general information about submitting patches, please refer to -Documentation/process/. This document only describes additional specifics +`Documentation/process/`_. This document only describes additional specifics related to BPF. -Reporting bugs: ---------------- +.. contents:: + :local: + :depth: 2 -Q: How do I report bugs for BPF kernel code? +Reporting bugs +============== +Q: How do I report bugs for BPF kernel code? +-------------------------------------------- A: Since all BPF kernel development as well as bpftool and iproute2 BPF - loader development happens through the netdev kernel mailing list, - please report any found issues around BPF to the following mailing - list: +loader development happens through the netdev kernel mailing list, +please report any found issues around BPF to the following mailing +list: - netdev@vger.kernel.org + netdev@vger.kernel.org - This may also include issues related to XDP, BPF tracing, etc. +This may also include issues related to XDP, BPF tracing, etc. - Given netdev has a high volume of traffic, please also add the BPF - maintainers to Cc (from kernel MAINTAINERS file): +Given netdev has a high volume of traffic, please also add the BPF +maintainers to Cc (from kernel MAINTAINERS_ file): - Alexei Starovoitov - Daniel Borkmann +* Alexei Starovoitov +* Daniel Borkmann - In case a buggy commit has already been identified, make sure to keep - the actual commit authors in Cc as well for the report. They can - typically be identified through the kernel's git tree. +In case a buggy commit has already been identified, make sure to keep +the actual commit authors in Cc as well for the report. They can +typically be identified through the kernel's git tree. - Please do *not* report BPF issues to bugzilla.kernel.org since it - is a guarantee that the reported issue will be overlooked. +**Please do NOT report BPF issues to bugzilla.kernel.org since it +is a guarantee that the reported issue will be overlooked.** -Submitting patches: -------------------- +Submitting patches +================== Q: To which mailing list do I need to submit my BPF patches? - +------------------------------------------------------------ A: Please submit your BPF patches to the netdev kernel mailing list: - netdev@vger.kernel.org + netdev@vger.kernel.org - Historically, BPF came out of networking and has always been maintained - by the kernel networking community. Although these days BPF touches - many other subsystems as well, the patches are still routed mainly - through the networking community. +Historically, BPF came out of networking and has always been maintained +by the kernel networking community. Although these days BPF touches +many other subsystems as well, the patches are still routed mainly +through the networking community. - In case your patch has changes in various different subsystems (e.g. - tracing, security, etc), make sure to Cc the related kernel mailing - lists and maintainers from there as well, so they are able to review - the changes and provide their Acked-by's to the patches. +In case your patch has changes in various different subsystems (e.g. +tracing, security, etc), make sure to Cc the related kernel mailing +lists and maintainers from there as well, so they are able to review +the changes and provide their Acked-by's to the patches. Q: Where can I find patches currently under discussion for BPF subsystem? - +------------------------------------------------------------------------- A: All patches that are Cc'ed to netdev are queued for review under netdev - patchwork project: +patchwork project: - http://patchwork.ozlabs.org/project/netdev/list/ + http://patchwork.ozlabs.org/project/netdev/list/ - Those patches which target BPF, are assigned to a 'bpf' delegate for - further processing from BPF maintainers. The current queue with - patches under review can be found at: +Those patches which target BPF, are assigned to a 'bpf' delegate for +further processing from BPF maintainers. The current queue with +patches under review can be found at: - https://patchwork.ozlabs.org/project/netdev/list/?delegate=77147 + https://patchwork.ozlabs.org/project/netdev/list/?delegate=77147 - Once the patches have been reviewed by the BPF community as a whole - and approved by the BPF maintainers, their status in patchwork will be - changed to 'Accepted' and the submitter will be notified by mail. This - means that the patches look good from a BPF perspective and have been - applied to one of the two BPF kernel trees. +Once the patches have been reviewed by the BPF community as a whole +and approved by the BPF maintainers, their status in patchwork will be +changed to 'Accepted' and the submitter will be notified by mail. This +means that the patches look good from a BPF perspective and have been +applied to one of the two BPF kernel trees. - In case feedback from the community requires a respin of the patches, - their status in patchwork will be set to 'Changes Requested', and purged - from the current review queue. Likewise for cases where patches would - get rejected or are not applicable to the BPF trees (but assigned to - the 'bpf' delegate). +In case feedback from the community requires a respin of the patches, +their status in patchwork will be set to 'Changes Requested', and purged +from the current review queue. Likewise for cases where patches would +get rejected or are not applicable to the BPF trees (but assigned to +the 'bpf' delegate). Q: How do the changes make their way into Linux? - +------------------------------------------------ A: There are two BPF kernel trees (git repositories). Once patches have - been accepted by the BPF maintainers, they will be applied to one - of the two BPF trees: +been accepted by the BPF maintainers, they will be applied to one +of the two BPF trees: - https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/ - https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/ + * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/ + * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/ - The bpf tree itself is for fixes only, whereas bpf-next for features, - cleanups or other kind of improvements ("next-like" content). This is - analogous to net and net-next trees for networking. Both bpf and - bpf-next will only have a master branch in order to simplify against - which branch patches should get rebased to. +The bpf tree itself is for fixes only, whereas bpf-next for features, +cleanups or other kind of improvements ("next-like" content). This is +analogous to net and net-next trees for networking. Both bpf and +bpf-next will only have a master branch in order to simplify against +which branch patches should get rebased to. - Accumulated BPF patches in the bpf tree will regularly get pulled - into the net kernel tree. Likewise, accumulated BPF patches accepted - into the bpf-next tree will make their way into net-next tree. net and - net-next are both run by David S. Miller. From there, they will go - into the kernel mainline tree run by Linus Torvalds. To read up on the - process of net and net-next being merged into the mainline tree, see - the netdev FAQ under: +Accumulated BPF patches in the bpf tree will regularly get pulled +into the net kernel tree. Likewise, accumulated BPF patches accepted +into the bpf-next tree will make their way into net-next tree. net and +net-next are both run by David S. Miller. From there, they will go +into the kernel mainline tree run by Linus Torvalds. To read up on the +process of net and net-next being merged into the mainline tree, see +the `netdev FAQ`_ under: - Documentation/networking/netdev-FAQ.txt + `Documentation/networking/netdev-FAQ.txt`_ - Occasionally, to prevent merge conflicts, we might send pull requests - to other trees (e.g. tracing) with a small subset of the patches, but - net and net-next are always the main trees targeted for integration. +Occasionally, to prevent merge conflicts, we might send pull requests +to other trees (e.g. tracing) with a small subset of the patches, but +net and net-next are always the main trees targeted for integration. - The pull requests will contain a high-level summary of the accumulated - patches and can be searched on netdev kernel mailing list through the - following subject lines (yyyy-mm-dd is the date of the pull request): +The pull requests will contain a high-level summary of the accumulated +patches and can be searched on netdev kernel mailing list through the +following subject lines (``yyyy-mm-dd`` is the date of the pull +request):: - pull-request: bpf yyyy-mm-dd - pull-request: bpf-next yyyy-mm-dd + pull-request: bpf yyyy-mm-dd + pull-request: bpf-next yyyy-mm-dd -Q: How do I indicate which tree (bpf vs. bpf-next) my patch should be - applied to? +Q: How do I indicate which tree (bpf vs. bpf-next) my patch should be applied to? +--------------------------------------------------------------------------------- -A: The process is the very same as described in the netdev FAQ, so - please read up on it. The subject line must indicate whether the - patch is a fix or rather "next-like" content in order to let the - maintainers know whether it is targeted at bpf or bpf-next. +A: The process is the very same as described in the `netdev FAQ`_, so +please read up on it. The subject line must indicate whether the +patch is a fix or rather "next-like" content in order to let the +maintainers know whether it is targeted at bpf or bpf-next. - For fixes eventually landing in bpf -> net tree, the subject must - look like: +For fixes eventually landing in bpf -> net tree, the subject must +look like:: - git format-patch --subject-prefix='PATCH bpf' start..finish + git format-patch --subject-prefix='PATCH bpf' start..finish - For features/improvements/etc that should eventually land in - bpf-next -> net-next, the subject must look like: +For features/improvements/etc that should eventually land in +bpf-next -> net-next, the subject must look like:: - git format-patch --subject-prefix='PATCH bpf-next' start..finish + git format-patch --subject-prefix='PATCH bpf-next' start..finish - If unsure whether the patch or patch series should go into bpf - or net directly, or bpf-next or net-next directly, it is not a - problem either if the subject line says net or net-next as target. - It is eventually up to the maintainers to do the delegation of - the patches. +If unsure whether the patch or patch series should go into bpf +or net directly, or bpf-next or net-next directly, it is not a +problem either if the subject line says net or net-next as target. +It is eventually up to the maintainers to do the delegation of +the patches. - If it is clear that patches should go into bpf or bpf-next tree, - please make sure to rebase the patches against those trees in - order to reduce potential conflicts. +If it is clear that patches should go into bpf or bpf-next tree, +please make sure to rebase the patches against those trees in +order to reduce potential conflicts. - In case the patch or patch series has to be reworked and sent out - again in a second or later revision, it is also required to add a - version number (v2, v3, ...) into the subject prefix: +In case the patch or patch series has to be reworked and sent out +again in a second or later revision, it is also required to add a +version number (``v2``, ``v3``, ...) into the subject prefix:: - git format-patch --subject-prefix='PATCH net-next v2' start..finish + git format-patch --subject-prefix='PATCH net-next v2' start..finish - When changes have been requested to the patch series, always send the - whole patch series again with the feedback incorporated (never send - individual diffs on top of the old series). +When changes have been requested to the patch series, always send the +whole patch series again with the feedback incorporated (never send +individual diffs on top of the old series). Q: What does it mean when a patch gets applied to bpf or bpf-next tree? - +----------------------------------------------------------------------- A: It means that the patch looks good for mainline inclusion from - a BPF point of view. - - Be aware that this is not a final verdict that the patch will - automatically get accepted into net or net-next trees eventually: - - On the netdev kernel mailing list reviews can come in at any point - in time. If discussions around a patch conclude that they cannot - get included as-is, we will either apply a follow-up fix or drop - them from the trees entirely. Therefore, we also reserve to rebase - the trees when deemed necessary. After all, the purpose of the tree - is to i) accumulate and stage BPF patches for integration into trees - like net and net-next, and ii) run extensive BPF test suite and - workloads on the patches before they make their way any further. - - Once the BPF pull request was accepted by David S. Miller, then - the patches end up in net or net-next tree, respectively, and - make their way from there further into mainline. Again, see the - netdev FAQ for additional information e.g. on how often they are - merged to mainline. +a BPF point of view. -Q: How long do I need to wait for feedback on my BPF patches? +Be aware that this is not a final verdict that the patch will +automatically get accepted into net or net-next trees eventually: + +On the netdev kernel mailing list reviews can come in at any point +in time. If discussions around a patch conclude that they cannot +get included as-is, we will either apply a follow-up fix or drop +them from the trees entirely. Therefore, we also reserve to rebase +the trees when deemed necessary. After all, the purpose of the tree +is to: + +i) accumulate and stage BPF patches for integration into trees + like net and net-next, and +ii) run extensive BPF test suite and + workloads on the patches before they make their way any further. + +Once the BPF pull request was accepted by David S. Miller, then +the patches end up in net or net-next tree, respectively, and +make their way from there further into mainline. Again, see the +`netdev FAQ`_ for additional information e.g. on how often they are +merged to mainline. + +Q: How long do I need to wait for feedback on my BPF patches? +------------------------------------------------------------- A: We try to keep the latency low. The usual time to feedback will - be around 2 or 3 business days. It may vary depending on the - complexity of changes and current patch load. +be around 2 or 3 business days. It may vary depending on the +complexity of changes and current patch load. -Q: How often do you send pull requests to major kernel trees like - net or net-next? +Q: How often do you send pull requests to major kernel trees like net or net-next? +---------------------------------------------------------------------------------- A: Pull requests will be sent out rather often in order to not - accumulate too many patches in bpf or bpf-next. +accumulate too many patches in bpf or bpf-next. - As a rule of thumb, expect pull requests for each tree regularly - at the end of the week. In some cases pull requests could additionally - come also in the middle of the week depending on the current patch - load or urgency. +As a rule of thumb, expect pull requests for each tree regularly +at the end of the week. In some cases pull requests could additionally +come also in the middle of the week depending on the current patch +load or urgency. Q: Are patches applied to bpf-next when the merge window is open? - +----------------------------------------------------------------- A: For the time when the merge window is open, bpf-next will not be - processed. This is roughly analogous to net-next patch processing, - so feel free to read up on the netdev FAQ about further details. +processed. This is roughly analogous to net-next patch processing, +so feel free to read up on the `netdev FAQ`_ about further details. - During those two weeks of merge window, we might ask you to resend - your patch series once bpf-next is open again. Once Linus released - a v*-rc1 after the merge window, we continue processing of bpf-next. +During those two weeks of merge window, we might ask you to resend +your patch series once bpf-next is open again. Once Linus released +a ``v*-rc1`` after the merge window, we continue processing of bpf-next. - For non-subscribers to kernel mailing lists, there is also a status - page run by David S. Miller on net-next that provides guidance: +For non-subscribers to kernel mailing lists, there is also a status +page run by David S. Miller on net-next that provides guidance: - http://vger.kernel.org/~davem/net-next.html + http://vger.kernel.org/~davem/net-next.html +Q: Verifier changes and test cases +---------------------------------- Q: I made a BPF verifier change, do I need to add test cases for - BPF kernel selftests? +BPF kernel selftests_? A: If the patch has changes to the behavior of the verifier, then yes, - it is absolutely necessary to add test cases to the BPF kernel - selftests suite. If they are not present and we think they are - needed, then we might ask for them before accepting any changes. - - In particular, test_verifier.c is tracking a high number of BPF test - cases, including a lot of corner cases that LLVM BPF back end may - generate out of the restricted C code. Thus, adding test cases is - absolutely crucial to make sure future changes do not accidentally - affect prior use-cases. Thus, treat those test cases as: verifier - behavior that is not tracked in test_verifier.c could potentially - be subject to change. - -Q: When should I add code to samples/bpf/ and when to BPF kernel - selftests? - -A: In general, we prefer additions to BPF kernel selftests rather than - samples/bpf/. The rationale is very simple: kernel selftests are - regularly run by various bots to test for kernel regressions. - - The more test cases we add to BPF selftests, the better the coverage - and the less likely it is that those could accidentally break. It is - not that BPF kernel selftests cannot demo how a specific feature can - be used. - - That said, samples/bpf/ may be a good place for people to get started, - so it might be advisable that simple demos of features could go into - samples/bpf/, but advanced functional and corner-case testing rather - into kernel selftests. - - If your sample looks like a test case, then go for BPF kernel selftests - instead! +it is absolutely necessary to add test cases to the BPF kernel +selftests_ suite. If they are not present and we think they are +needed, then we might ask for them before accepting any changes. + +In particular, test_verifier.c is tracking a high number of BPF test +cases, including a lot of corner cases that LLVM BPF back end may +generate out of the restricted C code. Thus, adding test cases is +absolutely crucial to make sure future changes do not accidentally +affect prior use-cases. Thus, treat those test cases as: verifier +behavior that is not tracked in test_verifier.c could potentially +be subject to change. + +Q: samples/bpf preference vs selftests? +--------------------------------------- +Q: When should I add code to `samples/bpf/`_ and when to BPF kernel +selftests_ ? + +A: In general, we prefer additions to BPF kernel selftests_ rather than +`samples/bpf/`_. The rationale is very simple: kernel selftests are +regularly run by various bots to test for kernel regressions. + +The more test cases we add to BPF selftests, the better the coverage +and the less likely it is that those could accidentally break. It is +not that BPF kernel selftests cannot demo how a specific feature can +be used. + +That said, `samples/bpf/`_ may be a good place for people to get started, +so it might be advisable that simple demos of features could go into +`samples/bpf/`_, but advanced functional and corner-case testing rather +into kernel selftests. + +If your sample looks like a test case, then go for BPF kernel selftests +instead! Q: When should I add code to the bpftool? - +----------------------------------------- A: The main purpose of bpftool (under tools/bpf/bpftool/) is to provide - a central user space tool for debugging and introspection of BPF programs - and maps that are active in the kernel. If UAPI changes related to BPF - enable for dumping additional information of programs or maps, then - bpftool should be extended as well to support dumping them. +a central user space tool for debugging and introspection of BPF programs +and maps that are active in the kernel. If UAPI changes related to BPF +enable for dumping additional information of programs or maps, then +bpftool should be extended as well to support dumping them. Q: When should I add code to iproute2's BPF loader? - -A: For UAPI changes related to the XDP or tc layer (e.g. cls_bpf), the - convention is that those control-path related changes are added to - iproute2's BPF loader as well from user space side. This is not only - useful to have UAPI changes properly designed to be usable, but also - to make those changes available to a wider user base of major - downstream distributions. +--------------------------------------------------- +A: For UAPI changes related to the XDP or tc layer (e.g. ``cls_bpf``), +the convention is that those control-path related changes are added to +iproute2's BPF loader as well from user space side. This is not only +useful to have UAPI changes properly designed to be usable, but also +to make those changes available to a wider user base of major +downstream distributions. Q: Do you accept patches as well for iproute2's BPF loader? - +----------------------------------------------------------- A: Patches for the iproute2's BPF loader have to be sent to: - netdev@vger.kernel.org + netdev@vger.kernel.org - While those patches are not processed by the BPF kernel maintainers, - please keep them in Cc as well, so they can be reviewed. +While those patches are not processed by the BPF kernel maintainers, +please keep them in Cc as well, so they can be reviewed. - The official git repository for iproute2 is run by Stephen Hemminger - and can be found at: +The official git repository for iproute2 is run by Stephen Hemminger +and can be found at: - https://git.kernel.org/pub/scm/linux/kernel/git/shemminger/iproute2.git/ + https://git.kernel.org/pub/scm/linux/kernel/git/shemminger/iproute2.git/ - The patches need to have a subject prefix of '[PATCH iproute2 master]' - or '[PATCH iproute2 net-next]'. 'master' or 'net-next' describes the - target branch where the patch should be applied to. Meaning, if kernel - changes went into the net-next kernel tree, then the related iproute2 - changes need to go into the iproute2 net-next branch, otherwise they - can be targeted at master branch. The iproute2 net-next branch will get - merged into the master branch after the current iproute2 version from - master has been released. +The patches need to have a subject prefix of '``[PATCH iproute2 +master]``' or '``[PATCH iproute2 net-next]``'. '``master``' or +'``net-next``' describes the target branch where the patch should be +applied to. Meaning, if kernel changes went into the net-next kernel +tree, then the related iproute2 changes need to go into the iproute2 +net-next branch, otherwise they can be targeted at master branch. The +iproute2 net-next branch will get merged into the master branch after +the current iproute2 version from master has been released. - Like BPF, the patches end up in patchwork under the netdev project and - are delegated to 'shemminger' for further processing: +Like BPF, the patches end up in patchwork under the netdev project and +are delegated to 'shemminger' for further processing: - http://patchwork.ozlabs.org/project/netdev/list/?delegate=389 + http://patchwork.ozlabs.org/project/netdev/list/?delegate=389 Q: What is the minimum requirement before I submit my BPF patches? - +------------------------------------------------------------------ A: When submitting patches, always take the time and properly test your - patches *prior* to submission. Never rush them! If maintainers find - that your patches have not been properly tested, it is a good way to - get them grumpy. Testing patch submissions is a hard requirement! - - Note, fixes that go to bpf tree *must* have a Fixes: tag included. The - same applies to fixes that target bpf-next, where the affected commit - is in net-next (or in some cases bpf-next). The Fixes: tag is crucial - in order to identify follow-up commits and tremendously helps for people - having to do backporting, so it is a must have! - - We also don't accept patches with an empty commit message. Take your - time and properly write up a high quality commit message, it is - essential! - - Think about it this way: other developers looking at your code a month - from now need to understand *why* a certain change has been done that - way, and whether there have been flaws in the analysis or assumptions - that the original author did. Thus providing a proper rationale and - describing the use-case for the changes is a must. - - Patch submissions with >1 patch must have a cover letter which includes - a high level description of the series. This high level summary will - then be placed into the merge commit by the BPF maintainers such that - it is also accessible from the git log for future reference. - +patches *prior* to submission. Never rush them! If maintainers find +that your patches have not been properly tested, it is a good way to +get them grumpy. Testing patch submissions is a hard requirement! + +Note, fixes that go to bpf tree *must* have a ``Fixes:`` tag included. +The same applies to fixes that target bpf-next, where the affected +commit is in net-next (or in some cases bpf-next). The ``Fixes:`` tag is +crucial in order to identify follow-up commits and tremendously helps +for people having to do backporting, so it is a must have! + +We also don't accept patches with an empty commit message. Take your +time and properly write up a high quality commit message, it is +essential! + +Think about it this way: other developers looking at your code a month +from now need to understand *why* a certain change has been done that +way, and whether there have been flaws in the analysis or assumptions +that the original author did. Thus providing a proper rationale and +describing the use-case for the changes is a must. + +Patch submissions with >1 patch must have a cover letter which includes +a high level description of the series. This high level summary will +then be placed into the merge commit by the BPF maintainers such that +it is also accessible from the git log for future reference. + +Q: Features changing BPF JIT and/or LLVM +---------------------------------------- Q: What do I need to consider when adding a new instruction or feature - that would require BPF JIT and/or LLVM integration as well? +that would require BPF JIT and/or LLVM integration as well? A: We try hard to keep all BPF JITs up to date such that the same user - experience can be guaranteed when running BPF programs on different - architectures without having the program punt to the less efficient - interpreter in case the in-kernel BPF JIT is enabled. +experience can be guaranteed when running BPF programs on different +architectures without having the program punt to the less efficient +interpreter in case the in-kernel BPF JIT is enabled. - If you are unable to implement or test the required JIT changes for - certain architectures, please work together with the related BPF JIT - developers in order to get the feature implemented in a timely manner. - Please refer to the git log (arch/*/net/) to locate the necessary - people for helping out. +If you are unable to implement or test the required JIT changes for +certain architectures, please work together with the related BPF JIT +developers in order to get the feature implemented in a timely manner. +Please refer to the git log (``arch/*/net/``) to locate the necessary +people for helping out. - Also always make sure to add BPF test cases (e.g. test_bpf.c and - test_verifier.c) for new instructions, so that they can receive - broad test coverage and help run-time testing the various BPF JITs. +Also always make sure to add BPF test cases (e.g. test_bpf.c and +test_verifier.c) for new instructions, so that they can receive +broad test coverage and help run-time testing the various BPF JITs. - In case of new BPF instructions, once the changes have been accepted - into the Linux kernel, please implement support into LLVM's BPF back - end. See LLVM section below for further information. +In case of new BPF instructions, once the changes have been accepted +into the Linux kernel, please implement support into LLVM's BPF back +end. See LLVM_ section below for further information. -Stable submission: ------------------- +Stable submission +================= Q: I need a specific BPF commit in stable kernels. What should I do? - +-------------------------------------------------------------------- A: In case you need a specific fix in stable kernels, first check whether - the commit has already been applied in the related linux-*.y branches: +the commit has already been applied in the related ``linux-*.y`` branches: - https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/ + https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/ - If not the case, then drop an email to the BPF maintainers with the - netdev kernel mailing list in Cc and ask for the fix to be queued up: +If not the case, then drop an email to the BPF maintainers with the +netdev kernel mailing list in Cc and ask for the fix to be queued up: - netdev@vger.kernel.org + netdev@vger.kernel.org - The process in general is the same as on netdev itself, see also the - netdev FAQ document. +The process in general is the same as on netdev itself, see also the +`netdev FAQ`_ document. Q: Do you also backport to kernels not currently maintained as stable? - +---------------------------------------------------------------------- A: No. If you need a specific BPF commit in kernels that are currently not - maintained by the stable maintainers, then you are on your own. +maintained by the stable maintainers, then you are on your own. - The current stable and longterm stable kernels are all listed here: +The current stable and longterm stable kernels are all listed here: - https://www.kernel.org/ + https://www.kernel.org/ -Q: The BPF patch I am about to submit needs to go to stable as well. What - should I do? +Q: The BPF patch I am about to submit needs to go to stable as well +------------------------------------------------------------------- +What should I do? A: The same rules apply as with netdev patch submissions in general, see - netdev FAQ under: +`netdev FAQ`_ under: - Documentation/networking/netdev-FAQ.txt + `Documentation/networking/netdev-FAQ.txt`_ - Never add "Cc: stable@vger.kernel.org" to the patch description, but - ask the BPF maintainers to queue the patches instead. This can be done - with a note, for example, under the "---" part of the patch which does - not go into the git log. Alternatively, this can be done as a simple - request by mail instead. +Never add "``Cc: stable@vger.kernel.org``" to the patch description, but +ask the BPF maintainers to queue the patches instead. This can be done +with a note, for example, under the ``---`` part of the patch which does +not go into the git log. Alternatively, this can be done as a simple +request by mail instead. +Q: Queue stable patches +----------------------- Q: Where do I find currently queued BPF patches that will be submitted - to stable? +to stable? A: Once patches that fix critical bugs got applied into the bpf tree, they - are queued up for stable submission under: +are queued up for stable submission under: - http://patchwork.ozlabs.org/bundle/bpf/stable/?state=* + http://patchwork.ozlabs.org/bundle/bpf/stable/?state=* - They will be on hold there at minimum until the related commit made its - way into the mainline kernel tree. +They will be on hold there at minimum until the related commit made its +way into the mainline kernel tree. - After having been under broader exposure, the queued patches will be - submitted by the BPF maintainers to the stable maintainers. +After having been under broader exposure, the queued patches will be +submitted by the BPF maintainers to the stable maintainers. -Testing patches: ----------------- +Testing patches +=============== Q: Which BPF kernel selftests version should I run my kernel against? +--------------------------------------------------------------------- +A: If you run a kernel ``xyz``, then always run the BPF kernel selftests +from that kernel ``xyz`` as well. Do not expect that the BPF selftest +from the latest mainline tree will pass all the time. -A: If you run a kernel xyz, then always run the BPF kernel selftests from - that kernel xyz as well. Do not expect that the BPF selftest from the - latest mainline tree will pass all the time. - - In particular, test_bpf.c and test_verifier.c have a large number of - test cases and are constantly updated with new BPF test sequences, or - existing ones are adapted to verifier changes e.g. due to verifier - becoming smarter and being able to better track certain things. +In particular, test_bpf.c and test_verifier.c have a large number of +test cases and are constantly updated with new BPF test sequences, or +existing ones are adapted to verifier changes e.g. due to verifier +becoming smarter and being able to better track certain things. -LLVM: ------ +LLVM +==== Q: Where do I find LLVM with BPF support? - +----------------------------------------- A: The BPF back end for LLVM is upstream in LLVM since version 3.7.1. - All major distributions these days ship LLVM with BPF back end enabled, - so for the majority of use-cases it is not required to compile LLVM by - hand anymore, just install the distribution provided package. +All major distributions these days ship LLVM with BPF back end enabled, +so for the majority of use-cases it is not required to compile LLVM by +hand anymore, just install the distribution provided package. - LLVM's static compiler lists the supported targets through 'llc --version', - make sure BPF targets are listed. Example: +LLVM's static compiler lists the supported targets through +``llc --version``, make sure BPF targets are listed. Example:: $ llc --version LLVM (http://llvm.org/): @@ -434,18 +456,18 @@ A: The BPF back end for LLVM is upstream in LLVM since version 3.7.1. x86 - 32-bit X86: Pentium-Pro and above x86-64 - 64-bit X86: EM64T and AMD64 - For developers in order to utilize the latest features added to LLVM's - BPF back end, it is advisable to run the latest LLVM releases. Support - for new BPF kernel features such as additions to the BPF instruction - set are often developed together. +For developers in order to utilize the latest features added to LLVM's +BPF back end, it is advisable to run the latest LLVM releases. Support +for new BPF kernel features such as additions to the BPF instruction +set are often developed together. - All LLVM releases can be found at: http://releases.llvm.org/ +All LLVM releases can be found at: http://releases.llvm.org/ Q: Got it, so how do I build LLVM manually anyway? - +-------------------------------------------------- A: You need cmake and gcc-c++ as build requisites for LLVM. Once you have - that set up, proceed with building the latest LLVM and clang version - from the git repositories: +that set up, proceed with building the latest LLVM and clang version +from the git repositories:: $ git clone http://llvm.org/git/llvm.git $ cd llvm/tools @@ -457,44 +479,51 @@ A: You need cmake and gcc-c++ as build requisites for LLVM. Once you have -DLLVM_BUILD_RUNTIME=OFF $ make -j $(getconf _NPROCESSORS_ONLN) - The built binaries can then be found in the build/bin/ directory, where - you can point the PATH variable to. +The built binaries can then be found in the build/bin/ directory, where +you can point the PATH variable to. +Q: Reporting LLVM BPF issues +---------------------------- Q: Should I notify BPF kernel maintainers about issues in LLVM's BPF code - generation back end or about LLVM generated code that the verifier - refuses to accept? +generation back end or about LLVM generated code that the verifier +refuses to accept? + +A: Yes, please do! -A: Yes, please do! LLVM's BPF back end is a key piece of the whole BPF - infrastructure and it ties deeply into verification of programs from the - kernel side. Therefore, any issues on either side need to be investigated - and fixed whenever necessary. +LLVM's BPF back end is a key piece of the whole BPF +infrastructure and it ties deeply into verification of programs from the +kernel side. Therefore, any issues on either side need to be investigated +and fixed whenever necessary. - Therefore, please make sure to bring them up at netdev kernel mailing - list and Cc BPF maintainers for LLVM and kernel bits: +Therefore, please make sure to bring them up at netdev kernel mailing +list and Cc BPF maintainers for LLVM and kernel bits: - Yonghong Song - Alexei Starovoitov - Daniel Borkmann +* Yonghong Song +* Alexei Starovoitov +* Daniel Borkmann - LLVM also has an issue tracker where BPF related bugs can be found: +LLVM also has an issue tracker where BPF related bugs can be found: - https://bugs.llvm.org/buglist.cgi?quicksearch=bpf + https://bugs.llvm.org/buglist.cgi?quicksearch=bpf - However, it is better to reach out through mailing lists with having - maintainers in Cc. +However, it is better to reach out through mailing lists with having +maintainers in Cc. +Q: New BPF instruction for kernel and LLVM +------------------------------------------ Q: I have added a new BPF instruction to the kernel, how can I integrate - it into LLVM? +it into LLVM? -A: LLVM has a -mcpu selector for the BPF back end in order to allow the - selection of BPF instruction set extensions. By default the 'generic' - processor target is used, which is the base instruction set (v1) of BPF. +A: LLVM has a ``-mcpu`` selector for the BPF back end in order to allow +the selection of BPF instruction set extensions. By default the +``generic`` processor target is used, which is the base instruction set +(v1) of BPF. - LLVM has an option to select -mcpu=probe where it will probe the host - kernel for supported BPF instruction set extensions and selects the - optimal set automatically. +LLVM has an option to select ``-mcpu=probe`` where it will probe the host +kernel for supported BPF instruction set extensions and selects the +optimal set automatically. - For cross-compilation, a specific version can be select manually as well. +For cross-compilation, a specific version can be select manually as well :: $ llc -march bpf -mcpu=help Available CPUs for this target: @@ -505,66 +534,78 @@ A: LLVM has a -mcpu selector for the BPF back end in order to allow the v2 - Select the v2 processor. [...] - Newly added BPF instructions to the Linux kernel need to follow the same - scheme, bump the instruction set version and implement probing for the - extensions such that -mcpu=probe users can benefit from the optimization - transparently when upgrading their kernels. +Newly added BPF instructions to the Linux kernel need to follow the same +scheme, bump the instruction set version and implement probing for the +extensions such that ``-mcpu=probe`` users can benefit from the +optimization transparently when upgrading their kernels. - If you are unable to implement support for the newly added BPF instruction - please reach out to BPF developers for help. +If you are unable to implement support for the newly added BPF instruction +please reach out to BPF developers for help. - By the way, the BPF kernel selftests run with -mcpu=probe for better - test coverage. +By the way, the BPF kernel selftests run with ``-mcpu=probe`` for better +test coverage. -Q: In some cases clang flag "-target bpf" is used but in other cases the - default clang target, which matches the underlying architecture, is used. - What is the difference and when I should use which? +Q: clang flag for target bpf? +----------------------------- +Q: In some cases clang flag ``-target bpf`` is used but in other cases the +default clang target, which matches the underlying architecture, is used. +What is the difference and when I should use which? A: Although LLVM IR generation and optimization try to stay architecture - independent, "-target " still has some impact on generated code: - - - BPF program may recursively include header file(s) with file scope - inline assembly codes. The default target can handle this well, - while bpf target may fail if bpf backend assembler does not - understand these assembly codes, which is true in most cases. - - - When compiled without -g, additional elf sections, e.g., - .eh_frame and .rela.eh_frame, may be present in the object file - with default target, but not with bpf target. - - - The default target may turn a C switch statement into a switch table - lookup and jump operation. Since the switch table is placed - in the global readonly section, the bpf program will fail to load. - The bpf target does not support switch table optimization. - The clang option "-fno-jump-tables" can be used to disable - switch table generation. - - - For clang -target bpf, it is guaranteed that pointer or long / - unsigned long types will always have a width of 64 bit, no matter - whether underlying clang binary or default target (or kernel) is - 32 bit. However, when native clang target is used, then it will - compile these types based on the underlying architecture's conventions, - meaning in case of 32 bit architecture, pointer or long / unsigned - long types e.g. in BPF context structure will have width of 32 bit - while the BPF LLVM back end still operates in 64 bit. The native - target is mostly needed in tracing for the case of walking pt_regs - or other kernel structures where CPU's register width matters. - Otherwise, clang -target bpf is generally recommended. - - You should use default target when: - - - Your program includes a header file, e.g., ptrace.h, which eventually - pulls in some header files containing file scope host assembly codes. - - You can add "-fno-jump-tables" to work around the switch table issue. - - Otherwise, you can use bpf target. Additionally, you _must_ use bpf target - when: - - - Your program uses data structures with pointer or long / unsigned long - types that interface with BPF helpers or context data structures. Access - into these structures is verified by the BPF verifier and may result - in verification failures if the native architecture is not aligned with - the BPF architecture, e.g. 64-bit. An example of this is - BPF_PROG_TYPE_SK_MSG require '-target bpf' +independent, ``-target `` still has some impact on generated code: + +- BPF program may recursively include header file(s) with file scope + inline assembly codes. The default target can handle this well, + while ``bpf`` target may fail if bpf backend assembler does not + understand these assembly codes, which is true in most cases. + +- When compiled without ``-g``, additional elf sections, e.g., + .eh_frame and .rela.eh_frame, may be present in the object file + with default target, but not with ``bpf`` target. + +- The default target may turn a C switch statement into a switch table + lookup and jump operation. Since the switch table is placed + in the global readonly section, the bpf program will fail to load. + The bpf target does not support switch table optimization. + The clang option ``-fno-jump-tables`` can be used to disable + switch table generation. + +- For clang ``-target bpf``, it is guaranteed that pointer or long / + unsigned long types will always have a width of 64 bit, no matter + whether underlying clang binary or default target (or kernel) is + 32 bit. However, when native clang target is used, then it will + compile these types based on the underlying architecture's conventions, + meaning in case of 32 bit architecture, pointer or long / unsigned + long types e.g. in BPF context structure will have width of 32 bit + while the BPF LLVM back end still operates in 64 bit. The native + target is mostly needed in tracing for the case of walking ``pt_regs`` + or other kernel structures where CPU's register width matters. + Otherwise, ``clang -target bpf`` is generally recommended. + +You should use default target when: + +- Your program includes a header file, e.g., ptrace.h, which eventually + pulls in some header files containing file scope host assembly codes. + +- You can add ``-fno-jump-tables`` to work around the switch table issue. + +Otherwise, you can use ``bpf`` target. Additionally, you *must* use bpf target +when: + +- Your program uses data structures with pointer or long / unsigned long + types that interface with BPF helpers or context data structures. Access + into these structures is verified by the BPF verifier and may result + in verification failures if the native architecture is not aligned with + the BPF architecture, e.g. 64-bit. An example of this is + BPF_PROG_TYPE_SK_MSG require ``-target bpf`` + + +.. Links +.. _Documentation/process/: https://www.kernel.org/doc/html/latest/process/ +.. _MAINTAINERS: ../../MAINTAINERS +.. _Documentation/networking/netdev-FAQ.txt: ../networking/netdev-FAQ.txt +.. _netdev FAQ: ../networking/netdev-FAQ.txt +.. _samples/bpf/: ../../samples/bpf/ +.. _selftests: ../../tools/testing/selftests/bpf/ Happy BPF hacking! -- cgit v1.2.3 From b7a27c3aafa252d1e416c223cb97c123de4ed28a Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Mon, 14 May 2018 15:42:32 +0200 Subject: bpf, doc: howto use/run the BPF selftests I always forget howto run the BPF selftests. Thus, lets add that info to the QA document. Documentation was based on Cilium's documentation: http://cilium.readthedocs.io/en/latest/bpf/#verifying-the-setup Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov --- Documentation/bpf/bpf_devel_QA.rst | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/Documentation/bpf/bpf_devel_QA.rst b/Documentation/bpf/bpf_devel_QA.rst index 2254bdeae990..0e7c1d946e83 100644 --- a/Documentation/bpf/bpf_devel_QA.rst +++ b/Documentation/bpf/bpf_devel_QA.rst @@ -417,6 +417,33 @@ submitted by the BPF maintainers to the stable maintainers. Testing patches =============== +Q: How to run BPF selftests +--------------------------- +A: After you have booted into the newly compiled kernel, navigate to +the BPF selftests_ suite in order to test BPF functionality (current +working directory points to the root of the cloned git tree):: + + $ cd tools/testing/selftests/bpf/ + $ make + +To run the verifier tests:: + + $ sudo ./test_verifier + +The verifier tests print out all the current checks being +performed. The summary at the end of running all tests will dump +information of test successes and failures:: + + Summary: 418 PASSED, 0 FAILED + +In order to run through all BPF selftests, the following command is +needed:: + + $ sudo make run_tests + +See the kernels selftest `Documentation/dev-tools/kselftest.rst`_ +document for further documentation. + Q: Which BPF kernel selftests version should I run my kernel against? --------------------------------------------------------------------- A: If you run a kernel ``xyz``, then always run the BPF kernel selftests @@ -607,5 +634,7 @@ when: .. _netdev FAQ: ../networking/netdev-FAQ.txt .. _samples/bpf/: ../../samples/bpf/ .. _selftests: ../../tools/testing/selftests/bpf/ +.. _Documentation/dev-tools/kselftest.rst: + https://www.kernel.org/doc/html/latest/dev-tools/kselftest.html Happy BPF hacking! -- cgit v1.2.3 From f2467c2dbc019548052f3a64dc1efd01c0ae27aa Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Mon, 14 May 2018 17:11:29 -0700 Subject: selftests/bpf: make sure build-id is on --build-id may not be a default linker config. Make sure it's used when linking urandom_read test program. Otherwise test_stacktrace_build_id[_nmi] tests will be failling. Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 438d4f93875b..133ebc68cbe4 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -19,7 +19,7 @@ all: $(TEST_CUSTOM_PROGS) $(TEST_CUSTOM_PROGS): urandom_read urandom_read: urandom_read.c - $(CC) -o $(TEST_CUSTOM_PROGS) -static $< + $(CC) -o $(TEST_CUSTOM_PROGS) -static $< -Wl,--build-id # Order correspond to 'make run_tests' order TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs \ -- cgit v1.2.3 From e5cd3abcb31a48d4ea91bd32f0618802ca5f3592 Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Mon, 14 May 2018 10:00:16 -0700 Subject: bpf: sockmap, refactor sockmap routines to work with hashmap This patch only refactors the existing sockmap code. This will allow much of the psock initialization code path and bpf helper codes to work for both sockmap bpf map types that are backed by an array, the currently supported type, and the new hash backed bpf map type sockhash. Most the fallout comes from three changes, - Pushing bpf programs into an independent structure so we can use it from the htab struct in the next patch. - Generalizing helpers to use void *key instead of the hardcoded u32. - Instead of passing map/key through the metadata we now do the lookup inline. This avoids storing the key in the metadata which will be useful when keys can be longer than 4 bytes. We rename the sk pointers to sk_redir at this point as well to avoid any confusion between the current sk pointer and the redirect pointer sk_redir. Signed-off-by: John Fastabend Acked-by: David S. Miller Signed-off-by: Daniel Borkmann --- include/linux/filter.h | 3 +- include/net/tcp.h | 3 +- kernel/bpf/sockmap.c | 148 +++++++++++++++++++++++++++++-------------------- net/core/filter.c | 31 +++-------- 4 files changed, 98 insertions(+), 87 deletions(-) diff --git a/include/linux/filter.h b/include/linux/filter.h index da7e16523128..9dbcb9d55921 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -515,9 +515,8 @@ struct sk_msg_buff { int sg_end; struct scatterlist sg_data[MAX_SKB_FRAGS]; bool sg_copy[MAX_SKB_FRAGS]; - __u32 key; __u32 flags; - struct bpf_map *map; + struct sock *sk_redir; struct sk_buff *skb; struct list_head list; }; diff --git a/include/net/tcp.h b/include/net/tcp.h index cf803fe0fb86..059287374ba0 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -814,9 +814,8 @@ struct tcp_skb_cb { #endif } header; /* For incoming skbs */ struct { - __u32 key; __u32 flags; - struct bpf_map *map; + struct sock *sk_redir; void *data_end; } bpf; }; diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c index 098eca568c2b..beab9ec9b023 100644 --- a/kernel/bpf/sockmap.c +++ b/kernel/bpf/sockmap.c @@ -48,14 +48,18 @@ #define SOCK_CREATE_FLAG_MASK \ (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY) -struct bpf_stab { - struct bpf_map map; - struct sock **sock_map; +struct bpf_sock_progs { struct bpf_prog *bpf_tx_msg; struct bpf_prog *bpf_parse; struct bpf_prog *bpf_verdict; }; +struct bpf_stab { + struct bpf_map map; + struct sock **sock_map; + struct bpf_sock_progs progs; +}; + enum smap_psock_state { SMAP_TX_RUNNING, }; @@ -461,7 +465,7 @@ static int free_curr_sg(struct sock *sk, struct sk_msg_buff *md) static int bpf_map_msg_verdict(int _rc, struct sk_msg_buff *md) { return ((_rc == SK_PASS) ? - (md->map ? __SK_REDIRECT : __SK_PASS) : + (md->sk_redir ? __SK_REDIRECT : __SK_PASS) : __SK_DROP); } @@ -1092,7 +1096,7 @@ static int smap_verdict_func(struct smap_psock *psock, struct sk_buff *skb) * when we orphan the skb so that we don't have the possibility * to reference a stale map. */ - TCP_SKB_CB(skb)->bpf.map = NULL; + TCP_SKB_CB(skb)->bpf.sk_redir = NULL; skb->sk = psock->sock; bpf_compute_data_pointers(skb); preempt_disable(); @@ -1102,7 +1106,7 @@ static int smap_verdict_func(struct smap_psock *psock, struct sk_buff *skb) /* Moving return codes from UAPI namespace into internal namespace */ return rc == SK_PASS ? - (TCP_SKB_CB(skb)->bpf.map ? __SK_REDIRECT : __SK_PASS) : + (TCP_SKB_CB(skb)->bpf.sk_redir ? __SK_REDIRECT : __SK_PASS) : __SK_DROP; } @@ -1372,7 +1376,6 @@ static int smap_init_sock(struct smap_psock *psock, } static void smap_init_progs(struct smap_psock *psock, - struct bpf_stab *stab, struct bpf_prog *verdict, struct bpf_prog *parse) { @@ -1450,14 +1453,13 @@ static void smap_gc_work(struct work_struct *w) kfree(psock); } -static struct smap_psock *smap_init_psock(struct sock *sock, - struct bpf_stab *stab) +static struct smap_psock *smap_init_psock(struct sock *sock, int node) { struct smap_psock *psock; psock = kzalloc_node(sizeof(struct smap_psock), GFP_ATOMIC | __GFP_NOWARN, - stab->map.numa_node); + node); if (!psock) return ERR_PTR(-ENOMEM); @@ -1662,40 +1664,26 @@ out: * - sock_map must use READ_ONCE and (cmp)xchg operations * - BPF verdict/parse programs must use READ_ONCE and xchg operations */ -static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, - struct bpf_map *map, - void *key, u64 flags) + +static int __sock_map_ctx_update_elem(struct bpf_map *map, + struct bpf_sock_progs *progs, + struct sock *sock, + struct sock **map_link, + void *key) { - struct bpf_stab *stab = container_of(map, struct bpf_stab, map); - struct smap_psock_map_entry *e = NULL; struct bpf_prog *verdict, *parse, *tx_msg; - struct sock *osock, *sock; + struct smap_psock_map_entry *e = NULL; struct smap_psock *psock; - u32 i = *(u32 *)key; bool new = false; int err; - if (unlikely(flags > BPF_EXIST)) - return -EINVAL; - - if (unlikely(i >= stab->map.max_entries)) - return -E2BIG; - - sock = READ_ONCE(stab->sock_map[i]); - if (flags == BPF_EXIST && !sock) - return -ENOENT; - else if (flags == BPF_NOEXIST && sock) - return -EEXIST; - - sock = skops->sk; - /* 1. If sock map has BPF programs those will be inherited by the * sock being added. If the sock is already attached to BPF programs * this results in an error. */ - verdict = READ_ONCE(stab->bpf_verdict); - parse = READ_ONCE(stab->bpf_parse); - tx_msg = READ_ONCE(stab->bpf_tx_msg); + verdict = READ_ONCE(progs->bpf_verdict); + parse = READ_ONCE(progs->bpf_parse); + tx_msg = READ_ONCE(progs->bpf_tx_msg); if (parse && verdict) { /* bpf prog refcnt may be zero if a concurrent attach operation @@ -1703,11 +1691,11 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, * we increment the refcnt. If this is the case abort with an * error. */ - verdict = bpf_prog_inc_not_zero(stab->bpf_verdict); + verdict = bpf_prog_inc_not_zero(progs->bpf_verdict); if (IS_ERR(verdict)) return PTR_ERR(verdict); - parse = bpf_prog_inc_not_zero(stab->bpf_parse); + parse = bpf_prog_inc_not_zero(progs->bpf_parse); if (IS_ERR(parse)) { bpf_prog_put(verdict); return PTR_ERR(parse); @@ -1715,7 +1703,7 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, } if (tx_msg) { - tx_msg = bpf_prog_inc_not_zero(stab->bpf_tx_msg); + tx_msg = bpf_prog_inc_not_zero(progs->bpf_tx_msg); if (IS_ERR(tx_msg)) { if (verdict) bpf_prog_put(verdict); @@ -1748,7 +1736,7 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, goto out_progs; } } else { - psock = smap_init_psock(sock, stab); + psock = smap_init_psock(sock, map->numa_node); if (IS_ERR(psock)) { err = PTR_ERR(psock); goto out_progs; @@ -1763,7 +1751,6 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, err = -ENOMEM; goto out_progs; } - e->entry = &stab->sock_map[i]; /* 3. At this point we have a reference to a valid psock that is * running. Attach any BPF programs needed. @@ -1780,7 +1767,7 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, err = smap_init_sock(psock, sock); if (err) goto out_free; - smap_init_progs(psock, stab, verdict, parse); + smap_init_progs(psock, verdict, parse); smap_start_sock(psock, sock); } @@ -1789,19 +1776,12 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, * it with. Because we can only have a single set of programs if * old_sock has a strp we can stop it. */ - list_add_tail(&e->list, &psock->maps); - write_unlock_bh(&sock->sk_callback_lock); - - osock = xchg(&stab->sock_map[i], sock); - if (osock) { - struct smap_psock *opsock = smap_psock_sk(osock); - - write_lock_bh(&osock->sk_callback_lock); - smap_list_remove(opsock, &stab->sock_map[i]); - smap_release_sock(opsock, osock); - write_unlock_bh(&osock->sk_callback_lock); + if (map_link) { + e->entry = map_link; + list_add_tail(&e->list, &psock->maps); } - return 0; + write_unlock_bh(&sock->sk_callback_lock); + return err; out_free: smap_release_sock(psock, sock); out_progs: @@ -1816,23 +1796,69 @@ out_progs: return err; } -int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type) +static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, + struct bpf_map *map, + void *key, u64 flags) { struct bpf_stab *stab = container_of(map, struct bpf_stab, map); + struct bpf_sock_progs *progs = &stab->progs; + struct sock *osock, *sock; + u32 i = *(u32 *)key; + int err; + + if (unlikely(flags > BPF_EXIST)) + return -EINVAL; + + if (unlikely(i >= stab->map.max_entries)) + return -E2BIG; + + sock = READ_ONCE(stab->sock_map[i]); + if (flags == BPF_EXIST && !sock) + return -ENOENT; + else if (flags == BPF_NOEXIST && sock) + return -EEXIST; + + sock = skops->sk; + err = __sock_map_ctx_update_elem(map, progs, sock, &stab->sock_map[i], + key); + if (err) + goto out; + + osock = xchg(&stab->sock_map[i], sock); + if (osock) { + struct smap_psock *opsock = smap_psock_sk(osock); + + write_lock_bh(&osock->sk_callback_lock); + smap_list_remove(opsock, &stab->sock_map[i]); + smap_release_sock(opsock, osock); + write_unlock_bh(&osock->sk_callback_lock); + } +out: + return 0; +} + +int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type) +{ + struct bpf_sock_progs *progs; struct bpf_prog *orig; - if (unlikely(map->map_type != BPF_MAP_TYPE_SOCKMAP)) + if (map->map_type == BPF_MAP_TYPE_SOCKMAP) { + struct bpf_stab *stab = container_of(map, struct bpf_stab, map); + + progs = &stab->progs; + } else { return -EINVAL; + } switch (type) { case BPF_SK_MSG_VERDICT: - orig = xchg(&stab->bpf_tx_msg, prog); + orig = xchg(&progs->bpf_tx_msg, prog); break; case BPF_SK_SKB_STREAM_PARSER: - orig = xchg(&stab->bpf_parse, prog); + orig = xchg(&progs->bpf_parse, prog); break; case BPF_SK_SKB_STREAM_VERDICT: - orig = xchg(&stab->bpf_verdict, prog); + orig = xchg(&progs->bpf_verdict, prog); break; default: return -EOPNOTSUPP; @@ -1881,16 +1907,18 @@ static int sock_map_update_elem(struct bpf_map *map, static void sock_map_release(struct bpf_map *map) { struct bpf_stab *stab = container_of(map, struct bpf_stab, map); + struct bpf_sock_progs *progs; struct bpf_prog *orig; - orig = xchg(&stab->bpf_parse, NULL); + progs = &stab->progs; + orig = xchg(&progs->bpf_parse, NULL); if (orig) bpf_prog_put(orig); - orig = xchg(&stab->bpf_verdict, NULL); + orig = xchg(&progs->bpf_verdict, NULL); if (orig) bpf_prog_put(orig); - orig = xchg(&stab->bpf_tx_msg, NULL); + orig = xchg(&progs->bpf_tx_msg, NULL); if (orig) bpf_prog_put(orig); } diff --git a/net/core/filter.c b/net/core/filter.c index ca60d2872da4..61a3ed6bac25 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2083,9 +2083,10 @@ BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb, if (unlikely(flags & ~(BPF_F_INGRESS))) return SK_DROP; - tcb->bpf.key = key; tcb->bpf.flags = flags; - tcb->bpf.map = map; + tcb->bpf.sk_redir = __sock_map_lookup_elem(map, key); + if (!tcb->bpf.sk_redir) + return SK_DROP; return SK_PASS; } @@ -2093,16 +2094,8 @@ BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb, struct sock *do_sk_redirect_map(struct sk_buff *skb) { struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); - struct sock *sk = NULL; - - if (tcb->bpf.map) { - sk = __sock_map_lookup_elem(tcb->bpf.map, tcb->bpf.key); - tcb->bpf.key = 0; - tcb->bpf.map = NULL; - } - - return sk; + return tcb->bpf.sk_redir; } static const struct bpf_func_proto bpf_sk_redirect_map_proto = { @@ -2122,25 +2115,17 @@ BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg_buff *, msg, if (unlikely(flags & ~(BPF_F_INGRESS))) return SK_DROP; - msg->key = key; msg->flags = flags; - msg->map = map; + msg->sk_redir = __sock_map_lookup_elem(map, key); + if (!msg->sk_redir) + return SK_DROP; return SK_PASS; } struct sock *do_msg_redirect_map(struct sk_msg_buff *msg) { - struct sock *sk = NULL; - - if (msg->map) { - sk = __sock_map_lookup_elem(msg->map, msg->key); - - msg->key = 0; - msg->map = NULL; - } - - return sk; + return msg->sk_redir; } static const struct bpf_func_proto bpf_msg_redirect_map_proto = { -- cgit v1.2.3 From 81110384441a59cff47430f20f049e69b98c17f4 Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Mon, 14 May 2018 10:00:17 -0700 Subject: bpf: sockmap, add hash map support Sockmap is currently backed by an array and enforces keys to be four bytes. This works well for many use cases and was originally modeled after devmap which also uses four bytes keys. However, this has become limiting in larger use cases where a hash would be more appropriate. For example users may want to use the 5-tuple of the socket as the lookup key. To support this add hash support. Signed-off-by: John Fastabend Acked-by: David S. Miller Signed-off-by: Daniel Borkmann --- include/linux/bpf.h | 8 + include/linux/bpf_types.h | 1 + include/uapi/linux/bpf.h | 54 ++++- kernel/bpf/core.c | 1 + kernel/bpf/sockmap.c | 494 ++++++++++++++++++++++++++++++++++++++++++++-- kernel/bpf/verifier.c | 14 +- net/core/filter.c | 58 ++++++ 7 files changed, 611 insertions(+), 19 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index a38e474bf7ee..ed0122b45b63 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -668,6 +668,7 @@ static inline void bpf_map_offload_map_free(struct bpf_map *map) #if defined(CONFIG_STREAM_PARSER) && defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_INET) struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key); +struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key); int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type); #else static inline struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key) @@ -675,6 +676,12 @@ static inline struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key) return NULL; } +static inline struct sock *__sock_hash_lookup_elem(struct bpf_map *map, + void *key) +{ + return NULL; +} + static inline int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type) @@ -724,6 +731,7 @@ extern const struct bpf_func_proto bpf_get_current_comm_proto; extern const struct bpf_func_proto bpf_get_stackid_proto; extern const struct bpf_func_proto bpf_get_stack_proto; extern const struct bpf_func_proto bpf_sock_map_update_proto; +extern const struct bpf_func_proto bpf_sock_hash_update_proto; /* Shared helpers among cBPF and eBPF. */ void bpf_user_rnd_init_once(void); diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h index d7df1b323082..b67f8793de0d 100644 --- a/include/linux/bpf_types.h +++ b/include/linux/bpf_types.h @@ -47,6 +47,7 @@ BPF_MAP_TYPE(BPF_MAP_TYPE_HASH_OF_MAPS, htab_of_maps_map_ops) BPF_MAP_TYPE(BPF_MAP_TYPE_DEVMAP, dev_map_ops) #if defined(CONFIG_STREAM_PARSER) && defined(CONFIG_INET) BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKMAP, sock_map_ops) +BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKHASH, sock_hash_ops) #endif BPF_MAP_TYPE(BPF_MAP_TYPE_CPUMAP, cpu_map_ops) #if defined(CONFIG_XDP_SOCKETS) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 02e4112510f8..d94d333a8225 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -118,6 +118,7 @@ enum bpf_map_type { BPF_MAP_TYPE_SOCKMAP, BPF_MAP_TYPE_CPUMAP, BPF_MAP_TYPE_XSKMAP, + BPF_MAP_TYPE_SOCKHASH, }; enum bpf_prog_type { @@ -1828,7 +1829,6 @@ union bpf_attr { * Return * 0 on success, or a negative error in case of failure. * - * * int bpf_fib_lookup(void *ctx, struct bpf_fib_lookup *params, int plen, u32 flags) * Description * Do FIB lookup in kernel tables using parameters in *params*. @@ -1855,6 +1855,53 @@ union bpf_attr { * Egress device index on success, 0 if packet needs to continue * up the stack for further processing or a negative error in case * of failure. + * + * int bpf_sock_hash_update(struct bpf_sock_ops_kern *skops, struct bpf_map *map, void *key, u64 flags) + * Description + * Add an entry to, or update a sockhash *map* referencing sockets. + * The *skops* is used as a new value for the entry associated to + * *key*. *flags* is one of: + * + * **BPF_NOEXIST** + * The entry for *key* must not exist in the map. + * **BPF_EXIST** + * The entry for *key* must already exist in the map. + * **BPF_ANY** + * No condition on the existence of the entry for *key*. + * + * If the *map* has eBPF programs (parser and verdict), those will + * be inherited by the socket being added. If the socket is + * already attached to eBPF programs, this results in an error. + * Return + * 0 on success, or a negative error in case of failure. + * + * int bpf_msg_redirect_hash(struct sk_msg_buff *msg, struct bpf_map *map, void *key, u64 flags) + * Description + * This helper is used in programs implementing policies at the + * socket level. If the message *msg* is allowed to pass (i.e. if + * the verdict eBPF program returns **SK_PASS**), redirect it to + * the socket referenced by *map* (of type + * **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and + * egress interfaces can be used for redirection. The + * **BPF_F_INGRESS** value in *flags* is used to make the + * distinction (ingress path is selected if the flag is present, + * egress path otherwise). This is the only flag supported for now. + * Return + * **SK_PASS** on success, or **SK_DROP** on error. + * + * int bpf_sk_redirect_hash(struct sk_buff *skb, struct bpf_map *map, void *key, u64 flags) + * Description + * This helper is used in programs implementing policies at the + * skb socket level. If the sk_buff *skb* is allowed to pass (i.e. + * if the verdeict eBPF program returns **SK_PASS**), redirect it + * to the socket referenced by *map* (of type + * **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and + * egress interfaces can be used for redirection. The + * **BPF_F_INGRESS** value in *flags* is used to make the + * distinction (ingress path is selected if the flag is present, + * egress otherwise). This is the only flag supported for now. + * Return + * **SK_PASS** on success, or **SK_DROP** on error. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -1926,7 +1973,10 @@ union bpf_attr { FN(skb_get_xfrm_state), \ FN(get_stack), \ FN(skb_load_bytes_relative), \ - FN(fib_lookup), + FN(fib_lookup), \ + FN(sock_hash_update), \ + FN(msg_redirect_hash), \ + FN(sk_redirect_hash), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index d0d7d9462368..2194c6a9df42 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -1707,6 +1707,7 @@ const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak; const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; const struct bpf_func_proto bpf_get_current_comm_proto __weak; const struct bpf_func_proto bpf_sock_map_update_proto __weak; +const struct bpf_func_proto bpf_sock_hash_update_proto __weak; const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) { diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c index beab9ec9b023..56879c9fd3a4 100644 --- a/kernel/bpf/sockmap.c +++ b/kernel/bpf/sockmap.c @@ -60,6 +60,28 @@ struct bpf_stab { struct bpf_sock_progs progs; }; +struct bucket { + struct hlist_head head; + raw_spinlock_t lock; +}; + +struct bpf_htab { + struct bpf_map map; + struct bucket *buckets; + atomic_t count; + u32 n_buckets; + u32 elem_size; + struct bpf_sock_progs progs; +}; + +struct htab_elem { + struct rcu_head rcu; + struct hlist_node hash_node; + u32 hash; + struct sock *sk; + char key[0]; +}; + enum smap_psock_state { SMAP_TX_RUNNING, }; @@ -67,6 +89,8 @@ enum smap_psock_state { struct smap_psock_map_entry { struct list_head list; struct sock **entry; + struct htab_elem *hash_link; + struct bpf_htab *htab; }; struct smap_psock { @@ -195,6 +219,12 @@ out: rcu_read_unlock(); } +static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l) +{ + atomic_dec(&htab->count); + kfree_rcu(l, rcu); +} + static void bpf_tcp_close(struct sock *sk, long timeout) { void (*close_fun)(struct sock *sk, long timeout); @@ -231,10 +261,16 @@ static void bpf_tcp_close(struct sock *sk, long timeout) } list_for_each_entry_safe(e, tmp, &psock->maps, list) { - osk = cmpxchg(e->entry, sk, NULL); - if (osk == sk) { - list_del(&e->list); - smap_release_sock(psock, sk); + if (e->entry) { + osk = cmpxchg(e->entry, sk, NULL); + if (osk == sk) { + list_del(&e->list); + smap_release_sock(psock, sk); + } + } else { + hlist_del_rcu(&e->hash_link->hash_node); + smap_release_sock(psock, e->hash_link->sk); + free_htab_elem(e->htab, e->hash_link); } } write_unlock_bh(&sk->sk_callback_lock); @@ -1527,12 +1563,14 @@ free_stab: return ERR_PTR(err); } -static void smap_list_remove(struct smap_psock *psock, struct sock **entry) +static void smap_list_remove(struct smap_psock *psock, + struct sock **entry, + struct htab_elem *hash_link) { struct smap_psock_map_entry *e, *tmp; list_for_each_entry_safe(e, tmp, &psock->maps, list) { - if (e->entry == entry) { + if (e->entry == entry || e->hash_link == hash_link) { list_del(&e->list); break; } @@ -1570,7 +1608,7 @@ static void sock_map_free(struct bpf_map *map) * to be null and queued for garbage collection. */ if (likely(psock)) { - smap_list_remove(psock, &stab->sock_map[i]); + smap_list_remove(psock, &stab->sock_map[i], NULL); smap_release_sock(psock, sock); } write_unlock_bh(&sock->sk_callback_lock); @@ -1629,7 +1667,7 @@ static int sock_map_delete_elem(struct bpf_map *map, void *key) if (psock->bpf_parse) smap_stop_sock(psock, sock); - smap_list_remove(psock, &stab->sock_map[k]); + smap_list_remove(psock, &stab->sock_map[k], NULL); smap_release_sock(psock, sock); out: write_unlock_bh(&sock->sk_callback_lock); @@ -1746,10 +1784,12 @@ static int __sock_map_ctx_update_elem(struct bpf_map *map, new = true; } - e = kzalloc(sizeof(*e), GFP_ATOMIC | __GFP_NOWARN); - if (!e) { - err = -ENOMEM; - goto out_progs; + if (map_link) { + e = kzalloc(sizeof(*e), GFP_ATOMIC | __GFP_NOWARN); + if (!e) { + err = -ENOMEM; + goto out_progs; + } } /* 3. At this point we have a reference to a valid psock that is @@ -1783,6 +1823,7 @@ static int __sock_map_ctx_update_elem(struct bpf_map *map, write_unlock_bh(&sock->sk_callback_lock); return err; out_free: + kfree(e); smap_release_sock(psock, sock); out_progs: if (verdict) @@ -1829,7 +1870,7 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, struct smap_psock *opsock = smap_psock_sk(osock); write_lock_bh(&osock->sk_callback_lock); - smap_list_remove(opsock, &stab->sock_map[i]); + smap_list_remove(opsock, &stab->sock_map[i], NULL); smap_release_sock(opsock, osock); write_unlock_bh(&osock->sk_callback_lock); } @@ -1846,6 +1887,10 @@ int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type) struct bpf_stab *stab = container_of(map, struct bpf_stab, map); progs = &stab->progs; + } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH) { + struct bpf_htab *htab = container_of(map, struct bpf_htab, map); + + progs = &htab->progs; } else { return -EINVAL; } @@ -1906,11 +1951,19 @@ static int sock_map_update_elem(struct bpf_map *map, static void sock_map_release(struct bpf_map *map) { - struct bpf_stab *stab = container_of(map, struct bpf_stab, map); struct bpf_sock_progs *progs; struct bpf_prog *orig; - progs = &stab->progs; + if (map->map_type == BPF_MAP_TYPE_SOCKMAP) { + struct bpf_stab *stab = container_of(map, struct bpf_stab, map); + + progs = &stab->progs; + } else { + struct bpf_htab *htab = container_of(map, struct bpf_htab, map); + + progs = &htab->progs; + } + orig = xchg(&progs->bpf_parse, NULL); if (orig) bpf_prog_put(orig); @@ -1923,6 +1976,390 @@ static void sock_map_release(struct bpf_map *map) bpf_prog_put(orig); } +static struct bpf_map *sock_hash_alloc(union bpf_attr *attr) +{ + struct bpf_htab *htab; + int i, err; + u64 cost; + + if (!capable(CAP_NET_ADMIN)) + return ERR_PTR(-EPERM); + + /* check sanity of attributes */ + if (attr->max_entries == 0 || attr->value_size != 4 || + attr->map_flags & ~SOCK_CREATE_FLAG_MASK) + return ERR_PTR(-EINVAL); + + err = bpf_tcp_ulp_register(); + if (err && err != -EEXIST) + return ERR_PTR(err); + + htab = kzalloc(sizeof(*htab), GFP_USER); + if (!htab) + return ERR_PTR(-ENOMEM); + + bpf_map_init_from_attr(&htab->map, attr); + + htab->n_buckets = roundup_pow_of_two(htab->map.max_entries); + htab->elem_size = sizeof(struct htab_elem) + + round_up(htab->map.key_size, 8); + err = -EINVAL; + if (htab->n_buckets == 0 || + htab->n_buckets > U32_MAX / sizeof(struct bucket)) + goto free_htab; + + cost = (u64) htab->n_buckets * sizeof(struct bucket) + + (u64) htab->elem_size * htab->map.max_entries; + + if (cost >= U32_MAX - PAGE_SIZE) + goto free_htab; + + htab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT; + err = bpf_map_precharge_memlock(htab->map.pages); + if (err) + goto free_htab; + + err = -ENOMEM; + htab->buckets = bpf_map_area_alloc( + htab->n_buckets * sizeof(struct bucket), + htab->map.numa_node); + if (!htab->buckets) + goto free_htab; + + for (i = 0; i < htab->n_buckets; i++) { + INIT_HLIST_HEAD(&htab->buckets[i].head); + raw_spin_lock_init(&htab->buckets[i].lock); + } + + return &htab->map; +free_htab: + kfree(htab); + return ERR_PTR(err); +} + +static inline struct bucket *__select_bucket(struct bpf_htab *htab, u32 hash) +{ + return &htab->buckets[hash & (htab->n_buckets - 1)]; +} + +static inline struct hlist_head *select_bucket(struct bpf_htab *htab, u32 hash) +{ + return &__select_bucket(htab, hash)->head; +} + +static void sock_hash_free(struct bpf_map *map) +{ + struct bpf_htab *htab = container_of(map, struct bpf_htab, map); + int i; + + synchronize_rcu(); + + /* At this point no update, lookup or delete operations can happen. + * However, be aware we can still get a socket state event updates, + * and data ready callabacks that reference the psock from sk_user_data + * Also psock worker threads are still in-flight. So smap_release_sock + * will only free the psock after cancel_sync on the worker threads + * and a grace period expire to ensure psock is really safe to remove. + */ + rcu_read_lock(); + for (i = 0; i < htab->n_buckets; i++) { + struct hlist_head *head = select_bucket(htab, i); + struct hlist_node *n; + struct htab_elem *l; + + hlist_for_each_entry_safe(l, n, head, hash_node) { + struct sock *sock = l->sk; + struct smap_psock *psock; + + hlist_del_rcu(&l->hash_node); + write_lock_bh(&sock->sk_callback_lock); + psock = smap_psock_sk(sock); + /* This check handles a racing sock event that can get + * the sk_callback_lock before this case but after xchg + * causing the refcnt to hit zero and sock user data + * (psock) to be null and queued for garbage collection. + */ + if (likely(psock)) { + smap_list_remove(psock, NULL, l); + smap_release_sock(psock, sock); + } + write_unlock_bh(&sock->sk_callback_lock); + kfree(l); + } + } + rcu_read_unlock(); + bpf_map_area_free(htab->buckets); + kfree(htab); +} + +static struct htab_elem *alloc_sock_hash_elem(struct bpf_htab *htab, + void *key, u32 key_size, u32 hash, + struct sock *sk, + struct htab_elem *old_elem) +{ + struct htab_elem *l_new; + + if (atomic_inc_return(&htab->count) > htab->map.max_entries) { + if (!old_elem) { + atomic_dec(&htab->count); + return ERR_PTR(-E2BIG); + } + } + l_new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN, + htab->map.numa_node); + if (!l_new) + return ERR_PTR(-ENOMEM); + + memcpy(l_new->key, key, key_size); + l_new->sk = sk; + l_new->hash = hash; + return l_new; +} + +static struct htab_elem *lookup_elem_raw(struct hlist_head *head, + u32 hash, void *key, u32 key_size) +{ + struct htab_elem *l; + + hlist_for_each_entry_rcu(l, head, hash_node) { + if (l->hash == hash && !memcmp(&l->key, key, key_size)) + return l; + } + + return NULL; +} + +static inline u32 htab_map_hash(const void *key, u32 key_len) +{ + return jhash(key, key_len, 0); +} + +static int sock_hash_get_next_key(struct bpf_map *map, + void *key, void *next_key) +{ + struct bpf_htab *htab = container_of(map, struct bpf_htab, map); + struct htab_elem *l, *next_l; + struct hlist_head *h; + u32 hash, key_size; + int i = 0; + + WARN_ON_ONCE(!rcu_read_lock_held()); + + key_size = map->key_size; + if (!key) + goto find_first_elem; + hash = htab_map_hash(key, key_size); + h = select_bucket(htab, hash); + + l = lookup_elem_raw(h, hash, key, key_size); + if (!l) + goto find_first_elem; + next_l = hlist_entry_safe( + rcu_dereference_raw(hlist_next_rcu(&l->hash_node)), + struct htab_elem, hash_node); + if (next_l) { + memcpy(next_key, next_l->key, key_size); + return 0; + } + + /* no more elements in this hash list, go to the next bucket */ + i = hash & (htab->n_buckets - 1); + i++; + +find_first_elem: + /* iterate over buckets */ + for (; i < htab->n_buckets; i++) { + h = select_bucket(htab, i); + + /* pick first element in the bucket */ + next_l = hlist_entry_safe( + rcu_dereference_raw(hlist_first_rcu(h)), + struct htab_elem, hash_node); + if (next_l) { + /* if it's not empty, just return it */ + memcpy(next_key, next_l->key, key_size); + return 0; + } + } + + /* iterated over all buckets and all elements */ + return -ENOENT; +} + +static int sock_hash_ctx_update_elem(struct bpf_sock_ops_kern *skops, + struct bpf_map *map, + void *key, u64 map_flags) +{ + struct bpf_htab *htab = container_of(map, struct bpf_htab, map); + struct bpf_sock_progs *progs = &htab->progs; + struct htab_elem *l_new = NULL, *l_old; + struct smap_psock_map_entry *e = NULL; + struct hlist_head *head; + struct smap_psock *psock; + u32 key_size, hash; + struct sock *sock; + struct bucket *b; + int err; + + sock = skops->sk; + + if (sock->sk_type != SOCK_STREAM || + sock->sk_protocol != IPPROTO_TCP) + return -EOPNOTSUPP; + + if (unlikely(map_flags > BPF_EXIST)) + return -EINVAL; + + e = kzalloc(sizeof(*e), GFP_ATOMIC | __GFP_NOWARN); + if (!e) + return -ENOMEM; + + WARN_ON_ONCE(!rcu_read_lock_held()); + key_size = map->key_size; + hash = htab_map_hash(key, key_size); + b = __select_bucket(htab, hash); + head = &b->head; + + err = __sock_map_ctx_update_elem(map, progs, sock, NULL, key); + if (err) + goto err; + + /* bpf_map_update_elem() can be called in_irq() */ + raw_spin_lock_bh(&b->lock); + l_old = lookup_elem_raw(head, hash, key, key_size); + if (l_old && map_flags == BPF_NOEXIST) { + err = -EEXIST; + goto bucket_err; + } + if (!l_old && map_flags == BPF_EXIST) { + err = -ENOENT; + goto bucket_err; + } + + l_new = alloc_sock_hash_elem(htab, key, key_size, hash, sock, l_old); + if (IS_ERR(l_new)) { + err = PTR_ERR(l_new); + goto bucket_err; + } + + psock = smap_psock_sk(sock); + if (unlikely(!psock)) { + err = -EINVAL; + goto bucket_err; + } + + e->hash_link = l_new; + e->htab = container_of(map, struct bpf_htab, map); + list_add_tail(&e->list, &psock->maps); + + /* add new element to the head of the list, so that + * concurrent search will find it before old elem + */ + hlist_add_head_rcu(&l_new->hash_node, head); + if (l_old) { + psock = smap_psock_sk(l_old->sk); + + hlist_del_rcu(&l_old->hash_node); + smap_list_remove(psock, NULL, l_old); + smap_release_sock(psock, l_old->sk); + free_htab_elem(htab, l_old); + } + raw_spin_unlock_bh(&b->lock); + return 0; +bucket_err: + raw_spin_unlock_bh(&b->lock); +err: + kfree(e); + psock = smap_psock_sk(sock); + if (psock) + smap_release_sock(psock, sock); + return err; +} + +static int sock_hash_update_elem(struct bpf_map *map, + void *key, void *value, u64 flags) +{ + struct bpf_sock_ops_kern skops; + u32 fd = *(u32 *)value; + struct socket *socket; + int err; + + socket = sockfd_lookup(fd, &err); + if (!socket) + return err; + + skops.sk = socket->sk; + if (!skops.sk) { + fput(socket->file); + return -EINVAL; + } + + err = sock_hash_ctx_update_elem(&skops, map, key, flags); + fput(socket->file); + return err; +} + +static int sock_hash_delete_elem(struct bpf_map *map, void *key) +{ + struct bpf_htab *htab = container_of(map, struct bpf_htab, map); + struct hlist_head *head; + struct bucket *b; + struct htab_elem *l; + u32 hash, key_size; + int ret = -ENOENT; + + key_size = map->key_size; + hash = htab_map_hash(key, key_size); + b = __select_bucket(htab, hash); + head = &b->head; + + raw_spin_lock_bh(&b->lock); + l = lookup_elem_raw(head, hash, key, key_size); + if (l) { + struct sock *sock = l->sk; + struct smap_psock *psock; + + hlist_del_rcu(&l->hash_node); + write_lock_bh(&sock->sk_callback_lock); + psock = smap_psock_sk(sock); + /* This check handles a racing sock event that can get the + * sk_callback_lock before this case but after xchg happens + * causing the refcnt to hit zero and sock user data (psock) + * to be null and queued for garbage collection. + */ + if (likely(psock)) { + smap_list_remove(psock, NULL, l); + smap_release_sock(psock, sock); + } + write_unlock_bh(&sock->sk_callback_lock); + free_htab_elem(htab, l); + ret = 0; + } + raw_spin_unlock_bh(&b->lock); + return ret; +} + +struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key) +{ + struct bpf_htab *htab = container_of(map, struct bpf_htab, map); + struct hlist_head *head; + struct htab_elem *l; + u32 key_size, hash; + struct bucket *b; + struct sock *sk; + + key_size = map->key_size; + hash = htab_map_hash(key, key_size); + b = __select_bucket(htab, hash); + head = &b->head; + + raw_spin_lock_bh(&b->lock); + l = lookup_elem_raw(head, hash, key, key_size); + sk = l ? l->sk : NULL; + raw_spin_unlock_bh(&b->lock); + return sk; +} + const struct bpf_map_ops sock_map_ops = { .map_alloc = sock_map_alloc, .map_free = sock_map_free, @@ -1933,6 +2370,15 @@ const struct bpf_map_ops sock_map_ops = { .map_release_uref = sock_map_release, }; +const struct bpf_map_ops sock_hash_ops = { + .map_alloc = sock_hash_alloc, + .map_free = sock_hash_free, + .map_lookup_elem = sock_map_lookup, + .map_get_next_key = sock_hash_get_next_key, + .map_update_elem = sock_hash_update_elem, + .map_delete_elem = sock_hash_delete_elem, +}; + BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, bpf_sock, struct bpf_map *, map, void *, key, u64, flags) { @@ -1950,3 +2396,21 @@ const struct bpf_func_proto bpf_sock_map_update_proto = { .arg3_type = ARG_PTR_TO_MAP_KEY, .arg4_type = ARG_ANYTHING, }; + +BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, bpf_sock, + struct bpf_map *, map, void *, key, u64, flags) +{ + WARN_ON_ONCE(!rcu_read_lock_held()); + return sock_hash_ctx_update_elem(bpf_sock, map, key, flags); +} + +const struct bpf_func_proto bpf_sock_hash_update_proto = { + .func = bpf_sock_hash_update, + .gpl_only = false, + .pkt_access = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_CONST_MAP_PTR, + .arg3_type = ARG_PTR_TO_MAP_KEY, + .arg4_type = ARG_ANYTHING, +}; diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index d92d9c37affd..a9e4b1372da6 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -2093,6 +2093,13 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, func_id != BPF_FUNC_msg_redirect_map) goto error; break; + case BPF_MAP_TYPE_SOCKHASH: + if (func_id != BPF_FUNC_sk_redirect_hash && + func_id != BPF_FUNC_sock_hash_update && + func_id != BPF_FUNC_map_delete_elem && + func_id != BPF_FUNC_msg_redirect_hash) + goto error; + break; default: break; } @@ -2130,11 +2137,14 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, break; case BPF_FUNC_sk_redirect_map: case BPF_FUNC_msg_redirect_map: + case BPF_FUNC_sock_map_update: if (map->map_type != BPF_MAP_TYPE_SOCKMAP) goto error; break; - case BPF_FUNC_sock_map_update: - if (map->map_type != BPF_MAP_TYPE_SOCKMAP) + case BPF_FUNC_sk_redirect_hash: + case BPF_FUNC_msg_redirect_hash: + case BPF_FUNC_sock_hash_update: + if (map->map_type != BPF_MAP_TYPE_SOCKHASH) goto error; break; default: diff --git a/net/core/filter.c b/net/core/filter.c index 61a3ed6bac25..6d0d1560bd70 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2074,6 +2074,33 @@ static const struct bpf_func_proto bpf_redirect_proto = { .arg2_type = ARG_ANYTHING, }; +BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb, + struct bpf_map *, map, void *, key, u64, flags) +{ + struct tcp_skb_cb *tcb = TCP_SKB_CB(skb); + + /* If user passes invalid input drop the packet. */ + if (unlikely(flags & ~(BPF_F_INGRESS))) + return SK_DROP; + + tcb->bpf.flags = flags; + tcb->bpf.sk_redir = __sock_hash_lookup_elem(map, key); + if (!tcb->bpf.sk_redir) + return SK_DROP; + + return SK_PASS; +} + +static const struct bpf_func_proto bpf_sk_redirect_hash_proto = { + .func = bpf_sk_redirect_hash, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_CONST_MAP_PTR, + .arg3_type = ARG_PTR_TO_MAP_KEY, + .arg4_type = ARG_ANYTHING, +}; + BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb, struct bpf_map *, map, u32, key, u64, flags) { @@ -2108,6 +2135,31 @@ static const struct bpf_func_proto bpf_sk_redirect_map_proto = { .arg4_type = ARG_ANYTHING, }; +BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg_buff *, msg, + struct bpf_map *, map, void *, key, u64, flags) +{ + /* If user passes invalid input drop the packet. */ + if (unlikely(flags & ~(BPF_F_INGRESS))) + return SK_DROP; + + msg->flags = flags; + msg->sk_redir = __sock_hash_lookup_elem(map, key); + if (!msg->sk_redir) + return SK_DROP; + + return SK_PASS; +} + +static const struct bpf_func_proto bpf_msg_redirect_hash_proto = { + .func = bpf_msg_redirect_hash, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_CONST_MAP_PTR, + .arg3_type = ARG_PTR_TO_MAP_KEY, + .arg4_type = ARG_ANYTHING, +}; + BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg_buff *, msg, struct bpf_map *, map, u32, key, u64, flags) { @@ -4502,6 +4554,8 @@ sock_ops_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_sock_ops_cb_flags_set_proto; case BPF_FUNC_sock_map_update: return &bpf_sock_map_update_proto; + case BPF_FUNC_sock_hash_update: + return &bpf_sock_hash_update_proto; default: return bpf_base_func_proto(func_id); } @@ -4513,6 +4567,8 @@ sk_msg_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) switch (func_id) { case BPF_FUNC_msg_redirect_map: return &bpf_msg_redirect_map_proto; + case BPF_FUNC_msg_redirect_hash: + return &bpf_msg_redirect_hash_proto; case BPF_FUNC_msg_apply_bytes: return &bpf_msg_apply_bytes_proto; case BPF_FUNC_msg_cork_bytes: @@ -4544,6 +4600,8 @@ sk_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_get_socket_uid_proto; case BPF_FUNC_sk_redirect_map: return &bpf_sk_redirect_map_proto; + case BPF_FUNC_sk_redirect_hash: + return &bpf_sk_redirect_hash_proto; default: return bpf_base_func_proto(func_id); } -- cgit v1.2.3 From b8b394faa92418521829bbd4ae9cb22fb6c504ed Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Mon, 14 May 2018 10:00:18 -0700 Subject: bpf: selftest additions for SOCKHASH This runs existing SOCKMAP tests with SOCKHASH map type. To do this we push programs into include file and build two BPF programs. One for SOCKHASH and one for SOCKMAP. We then run the entire test suite with each type. Signed-off-by: John Fastabend Acked-by: David S. Miller Signed-off-by: Daniel Borkmann --- tools/include/uapi/linux/bpf.h | 54 +++- tools/testing/selftests/bpf/Makefile | 2 +- tools/testing/selftests/bpf/bpf_helpers.h | 8 + tools/testing/selftests/bpf/test_sockhash_kern.c | 5 + tools/testing/selftests/bpf/test_sockmap.c | 27 +- tools/testing/selftests/bpf/test_sockmap_kern.c | 343 +-------------------- tools/testing/selftests/bpf/test_sockmap_kern.h | 363 +++++++++++++++++++++++ 7 files changed, 453 insertions(+), 349 deletions(-) create mode 100644 tools/testing/selftests/bpf/test_sockhash_kern.c create mode 100644 tools/testing/selftests/bpf/test_sockmap_kern.h diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 02e4112510f8..d94d333a8225 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -118,6 +118,7 @@ enum bpf_map_type { BPF_MAP_TYPE_SOCKMAP, BPF_MAP_TYPE_CPUMAP, BPF_MAP_TYPE_XSKMAP, + BPF_MAP_TYPE_SOCKHASH, }; enum bpf_prog_type { @@ -1828,7 +1829,6 @@ union bpf_attr { * Return * 0 on success, or a negative error in case of failure. * - * * int bpf_fib_lookup(void *ctx, struct bpf_fib_lookup *params, int plen, u32 flags) * Description * Do FIB lookup in kernel tables using parameters in *params*. @@ -1855,6 +1855,53 @@ union bpf_attr { * Egress device index on success, 0 if packet needs to continue * up the stack for further processing or a negative error in case * of failure. + * + * int bpf_sock_hash_update(struct bpf_sock_ops_kern *skops, struct bpf_map *map, void *key, u64 flags) + * Description + * Add an entry to, or update a sockhash *map* referencing sockets. + * The *skops* is used as a new value for the entry associated to + * *key*. *flags* is one of: + * + * **BPF_NOEXIST** + * The entry for *key* must not exist in the map. + * **BPF_EXIST** + * The entry for *key* must already exist in the map. + * **BPF_ANY** + * No condition on the existence of the entry for *key*. + * + * If the *map* has eBPF programs (parser and verdict), those will + * be inherited by the socket being added. If the socket is + * already attached to eBPF programs, this results in an error. + * Return + * 0 on success, or a negative error in case of failure. + * + * int bpf_msg_redirect_hash(struct sk_msg_buff *msg, struct bpf_map *map, void *key, u64 flags) + * Description + * This helper is used in programs implementing policies at the + * socket level. If the message *msg* is allowed to pass (i.e. if + * the verdict eBPF program returns **SK_PASS**), redirect it to + * the socket referenced by *map* (of type + * **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and + * egress interfaces can be used for redirection. The + * **BPF_F_INGRESS** value in *flags* is used to make the + * distinction (ingress path is selected if the flag is present, + * egress path otherwise). This is the only flag supported for now. + * Return + * **SK_PASS** on success, or **SK_DROP** on error. + * + * int bpf_sk_redirect_hash(struct sk_buff *skb, struct bpf_map *map, void *key, u64 flags) + * Description + * This helper is used in programs implementing policies at the + * skb socket level. If the sk_buff *skb* is allowed to pass (i.e. + * if the verdeict eBPF program returns **SK_PASS**), redirect it + * to the socket referenced by *map* (of type + * **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and + * egress interfaces can be used for redirection. The + * **BPF_F_INGRESS** value in *flags* is used to make the + * distinction (ingress path is selected if the flag is present, + * egress otherwise). This is the only flag supported for now. + * Return + * **SK_PASS** on success, or **SK_DROP** on error. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -1926,7 +1973,10 @@ union bpf_attr { FN(skb_get_xfrm_state), \ FN(get_stack), \ FN(skb_load_bytes_relative), \ - FN(fib_lookup), + FN(fib_lookup), \ + FN(sock_hash_update), \ + FN(msg_redirect_hash), \ + FN(sk_redirect_hash), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 133ebc68cbe4..1eb0fa2aba92 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -33,7 +33,7 @@ TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test sample_map_ret0.o test_tcpbpf_kern.o test_stacktrace_build_id.o \ sockmap_tcp_msg_prog.o connect4_prog.o connect6_prog.o test_adjust_tail.o \ test_btf_haskv.o test_btf_nokv.o test_sockmap_kern.o test_tunnel_kern.o \ - test_get_stack_rawtp.o + test_get_stack_rawtp.o test_sockmap_kern.o test_sockhash_kern.o # Order correspond to 'make run_tests' order TEST_PROGS := test_kmod.sh \ diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h index 2375d06c706b..8f143dfb3700 100644 --- a/tools/testing/selftests/bpf/bpf_helpers.h +++ b/tools/testing/selftests/bpf/bpf_helpers.h @@ -75,9 +75,14 @@ static int (*bpf_sock_ops_cb_flags_set)(void *ctx, int flags) = (void *) BPF_FUNC_sock_ops_cb_flags_set; static int (*bpf_sk_redirect_map)(void *ctx, void *map, int key, int flags) = (void *) BPF_FUNC_sk_redirect_map; +static int (*bpf_sk_redirect_hash)(void *ctx, void *map, void *key, int flags) = + (void *) BPF_FUNC_sk_redirect_hash; static int (*bpf_sock_map_update)(void *map, void *key, void *value, unsigned long long flags) = (void *) BPF_FUNC_sock_map_update; +static int (*bpf_sock_hash_update)(void *map, void *key, void *value, + unsigned long long flags) = + (void *) BPF_FUNC_sock_hash_update; static int (*bpf_perf_event_read_value)(void *map, unsigned long long flags, void *buf, unsigned int buf_size) = (void *) BPF_FUNC_perf_event_read_value; @@ -88,6 +93,9 @@ static int (*bpf_override_return)(void *ctx, unsigned long rc) = (void *) BPF_FUNC_override_return; static int (*bpf_msg_redirect_map)(void *ctx, void *map, int key, int flags) = (void *) BPF_FUNC_msg_redirect_map; +static int (*bpf_msg_redirect_hash)(void *ctx, + void *map, void *key, int flags) = + (void *) BPF_FUNC_msg_redirect_hash; static int (*bpf_msg_apply_bytes)(void *ctx, int len) = (void *) BPF_FUNC_msg_apply_bytes; static int (*bpf_msg_cork_bytes)(void *ctx, int len) = diff --git a/tools/testing/selftests/bpf/test_sockhash_kern.c b/tools/testing/selftests/bpf/test_sockhash_kern.c new file mode 100644 index 000000000000..e6755916442a --- /dev/null +++ b/tools/testing/selftests/bpf/test_sockhash_kern.c @@ -0,0 +1,5 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2018 Covalent IO, Inc. http://covalent.io +#undef SOCKMAP +#define TEST_MAP_TYPE BPF_MAP_TYPE_SOCKHASH +#include "./test_sockmap_kern.h" diff --git a/tools/testing/selftests/bpf/test_sockmap.c b/tools/testing/selftests/bpf/test_sockmap.c index 29c022d23f4e..eb17fae458e6 100644 --- a/tools/testing/selftests/bpf/test_sockmap.c +++ b/tools/testing/selftests/bpf/test_sockmap.c @@ -47,7 +47,8 @@ static void running_handler(int a); #define S1_PORT 10000 #define S2_PORT 10001 -#define BPF_FILENAME "test_sockmap_kern.o" +#define BPF_SOCKMAP_FILENAME "test_sockmap_kern.o" +#define BPF_SOCKHASH_FILENAME "test_sockhash_kern.o" #define CG_PATH "/sockmap" /* global sockets */ @@ -1260,9 +1261,8 @@ int prog_type[] = { BPF_PROG_TYPE_SK_MSG, }; -static int populate_progs(void) +static int populate_progs(char *bpf_file) { - char *bpf_file = BPF_FILENAME; struct bpf_program *prog; struct bpf_object *obj; int i = 0; @@ -1306,11 +1306,11 @@ static int populate_progs(void) return 0; } -static int test_suite(void) +static int __test_suite(char *bpf_file) { int cg_fd, err; - err = populate_progs(); + err = populate_progs(bpf_file); if (err < 0) { fprintf(stderr, "ERROR: (%i) load bpf failed\n", err); return err; @@ -1347,17 +1347,30 @@ static int test_suite(void) out: printf("Summary: %i PASSED %i FAILED\n", passed, failed); + cleanup_cgroup_environment(); close(cg_fd); return err; } +static int test_suite(void) +{ + int err; + + err = __test_suite(BPF_SOCKMAP_FILENAME); + if (err) + goto out; + err = __test_suite(BPF_SOCKHASH_FILENAME); +out: + return err; +} + int main(int argc, char **argv) { struct rlimit r = {10 * 1024 * 1024, RLIM_INFINITY}; int iov_count = 1, length = 1024, rate = 1; struct sockmap_options options = {0}; int opt, longindex, err, cg_fd = 0; - char *bpf_file = BPF_FILENAME; + char *bpf_file = BPF_SOCKMAP_FILENAME; int test = PING_PONG; if (setrlimit(RLIMIT_MEMLOCK, &r)) { @@ -1438,7 +1451,7 @@ int main(int argc, char **argv) return -1; } - err = populate_progs(); + err = populate_progs(bpf_file); if (err) { fprintf(stderr, "populate program: (%s) %s\n", bpf_file, strerror(errno)); diff --git a/tools/testing/selftests/bpf/test_sockmap_kern.c b/tools/testing/selftests/bpf/test_sockmap_kern.c index 33de97e2b6b6..677b2ed1cc1e 100644 --- a/tools/testing/selftests/bpf/test_sockmap_kern.c +++ b/tools/testing/selftests/bpf/test_sockmap_kern.c @@ -1,340 +1,5 @@ // SPDX-License-Identifier: GPL-2.0 -// Copyright (c) 2017-2018 Covalent IO, Inc. http://covalent.io -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include "bpf_helpers.h" -#include "bpf_endian.h" - -/* Sockmap sample program connects a client and a backend together - * using cgroups. - * - * client:X <---> frontend:80 client:X <---> backend:80 - * - * For simplicity we hard code values here and bind 1:1. The hard - * coded values are part of the setup in sockmap.sh script that - * is associated with this BPF program. - * - * The bpf_printk is verbose and prints information as connections - * are established and verdicts are decided. - */ - -#define bpf_printk(fmt, ...) \ -({ \ - char ____fmt[] = fmt; \ - bpf_trace_printk(____fmt, sizeof(____fmt), \ - ##__VA_ARGS__); \ -}) - -struct bpf_map_def SEC("maps") sock_map = { - .type = BPF_MAP_TYPE_SOCKMAP, - .key_size = sizeof(int), - .value_size = sizeof(int), - .max_entries = 20, -}; - -struct bpf_map_def SEC("maps") sock_map_txmsg = { - .type = BPF_MAP_TYPE_SOCKMAP, - .key_size = sizeof(int), - .value_size = sizeof(int), - .max_entries = 20, -}; - -struct bpf_map_def SEC("maps") sock_map_redir = { - .type = BPF_MAP_TYPE_SOCKMAP, - .key_size = sizeof(int), - .value_size = sizeof(int), - .max_entries = 20, -}; - -struct bpf_map_def SEC("maps") sock_apply_bytes = { - .type = BPF_MAP_TYPE_ARRAY, - .key_size = sizeof(int), - .value_size = sizeof(int), - .max_entries = 1 -}; - -struct bpf_map_def SEC("maps") sock_cork_bytes = { - .type = BPF_MAP_TYPE_ARRAY, - .key_size = sizeof(int), - .value_size = sizeof(int), - .max_entries = 1 -}; - -struct bpf_map_def SEC("maps") sock_pull_bytes = { - .type = BPF_MAP_TYPE_ARRAY, - .key_size = sizeof(int), - .value_size = sizeof(int), - .max_entries = 2 -}; - -struct bpf_map_def SEC("maps") sock_redir_flags = { - .type = BPF_MAP_TYPE_ARRAY, - .key_size = sizeof(int), - .value_size = sizeof(int), - .max_entries = 1 -}; - -struct bpf_map_def SEC("maps") sock_skb_opts = { - .type = BPF_MAP_TYPE_ARRAY, - .key_size = sizeof(int), - .value_size = sizeof(int), - .max_entries = 1 -}; - -SEC("sk_skb1") -int bpf_prog1(struct __sk_buff *skb) -{ - return skb->len; -} - -SEC("sk_skb2") -int bpf_prog2(struct __sk_buff *skb) -{ - __u32 lport = skb->local_port; - __u32 rport = skb->remote_port; - int len, *f, ret, zero = 0; - __u64 flags = 0; - - if (lport == 10000) - ret = 10; - else - ret = 1; - - len = (__u32)skb->data_end - (__u32)skb->data; - f = bpf_map_lookup_elem(&sock_skb_opts, &zero); - if (f && *f) { - ret = 3; - flags = *f; - } - - bpf_printk("sk_skb2: redirect(%iB) flags=%i\n", - len, flags); - return bpf_sk_redirect_map(skb, &sock_map, ret, flags); -} - -SEC("sockops") -int bpf_sockmap(struct bpf_sock_ops *skops) -{ - __u32 lport, rport; - int op, err = 0, index, key, ret; - - - op = (int) skops->op; - - switch (op) { - case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB: - lport = skops->local_port; - rport = skops->remote_port; - - if (lport == 10000) { - ret = 1; - err = bpf_sock_map_update(skops, &sock_map, &ret, - BPF_NOEXIST); - bpf_printk("passive(%i -> %i) map ctx update err: %d\n", - lport, bpf_ntohl(rport), err); - } - break; - case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB: - lport = skops->local_port; - rport = skops->remote_port; - - if (bpf_ntohl(rport) == 10001) { - ret = 10; - err = bpf_sock_map_update(skops, &sock_map, &ret, - BPF_NOEXIST); - bpf_printk("active(%i -> %i) map ctx update err: %d\n", - lport, bpf_ntohl(rport), err); - } - break; - default: - break; - } - - return 0; -} - -SEC("sk_msg1") -int bpf_prog4(struct sk_msg_md *msg) -{ - int *bytes, zero = 0, one = 1; - int *start, *end; - - bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero); - if (bytes) - bpf_msg_apply_bytes(msg, *bytes); - bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero); - if (bytes) - bpf_msg_cork_bytes(msg, *bytes); - start = bpf_map_lookup_elem(&sock_pull_bytes, &zero); - end = bpf_map_lookup_elem(&sock_pull_bytes, &one); - if (start && end) - bpf_msg_pull_data(msg, *start, *end, 0); - return SK_PASS; -} - -SEC("sk_msg2") -int bpf_prog5(struct sk_msg_md *msg) -{ - int err1 = -1, err2 = -1, zero = 0, one = 1; - int *bytes, *start, *end, len1, len2; - - bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero); - if (bytes) - err1 = bpf_msg_apply_bytes(msg, *bytes); - bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero); - if (bytes) - err2 = bpf_msg_cork_bytes(msg, *bytes); - len1 = (__u64)msg->data_end - (__u64)msg->data; - start = bpf_map_lookup_elem(&sock_pull_bytes, &zero); - end = bpf_map_lookup_elem(&sock_pull_bytes, &one); - if (start && end) { - int err; - - bpf_printk("sk_msg2: pull(%i:%i)\n", - start ? *start : 0, end ? *end : 0); - err = bpf_msg_pull_data(msg, *start, *end, 0); - if (err) - bpf_printk("sk_msg2: pull_data err %i\n", - err); - len2 = (__u64)msg->data_end - (__u64)msg->data; - bpf_printk("sk_msg2: length update %i->%i\n", - len1, len2); - } - bpf_printk("sk_msg2: data length %i err1 %i err2 %i\n", - len1, err1, err2); - return SK_PASS; -} - -SEC("sk_msg3") -int bpf_prog6(struct sk_msg_md *msg) -{ - int *bytes, zero = 0, one = 1, key = 0; - int *start, *end, *f; - __u64 flags = 0; - - bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero); - if (bytes) - bpf_msg_apply_bytes(msg, *bytes); - bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero); - if (bytes) - bpf_msg_cork_bytes(msg, *bytes); - start = bpf_map_lookup_elem(&sock_pull_bytes, &zero); - end = bpf_map_lookup_elem(&sock_pull_bytes, &one); - if (start && end) - bpf_msg_pull_data(msg, *start, *end, 0); - f = bpf_map_lookup_elem(&sock_redir_flags, &zero); - if (f && *f) { - key = 2; - flags = *f; - } - return bpf_msg_redirect_map(msg, &sock_map_redir, key, flags); -} - -SEC("sk_msg4") -int bpf_prog7(struct sk_msg_md *msg) -{ - int err1 = 0, err2 = 0, zero = 0, one = 1, key = 0; - int *f, *bytes, *start, *end, len1, len2; - __u64 flags = 0; - - int err; - bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero); - if (bytes) - err1 = bpf_msg_apply_bytes(msg, *bytes); - bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero); - if (bytes) - err2 = bpf_msg_cork_bytes(msg, *bytes); - len1 = (__u64)msg->data_end - (__u64)msg->data; - start = bpf_map_lookup_elem(&sock_pull_bytes, &zero); - end = bpf_map_lookup_elem(&sock_pull_bytes, &one); - if (start && end) { - - bpf_printk("sk_msg2: pull(%i:%i)\n", - start ? *start : 0, end ? *end : 0); - err = bpf_msg_pull_data(msg, *start, *end, 0); - if (err) - bpf_printk("sk_msg2: pull_data err %i\n", - err); - len2 = (__u64)msg->data_end - (__u64)msg->data; - bpf_printk("sk_msg2: length update %i->%i\n", - len1, len2); - } - f = bpf_map_lookup_elem(&sock_redir_flags, &zero); - if (f && *f) { - key = 2; - flags = *f; - } - bpf_printk("sk_msg3: redirect(%iB) flags=%i err=%i\n", - len1, flags, err1 ? err1 : err2); - err = bpf_msg_redirect_map(msg, &sock_map_redir, key, flags); - bpf_printk("sk_msg3: err %i\n", err); - return err; -} - -SEC("sk_msg5") -int bpf_prog8(struct sk_msg_md *msg) -{ - void *data_end = (void *)(long) msg->data_end; - void *data = (void *)(long) msg->data; - int ret = 0, *bytes, zero = 0; - - bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero); - if (bytes) { - ret = bpf_msg_apply_bytes(msg, *bytes); - if (ret) - return SK_DROP; - } else { - return SK_DROP; - } - return SK_PASS; -} -SEC("sk_msg6") -int bpf_prog9(struct sk_msg_md *msg) -{ - void *data_end = (void *)(long) msg->data_end; - void *data = (void *)(long) msg->data; - int ret = 0, *bytes, zero = 0; - - bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero); - if (bytes) { - if (((__u64)data_end - (__u64)data) >= *bytes) - return SK_PASS; - ret = bpf_msg_cork_bytes(msg, *bytes); - if (ret) - return SK_DROP; - } - return SK_PASS; -} - -SEC("sk_msg7") -int bpf_prog10(struct sk_msg_md *msg) -{ - int *bytes, zero = 0, one = 1; - int *start, *end; - - bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero); - if (bytes) - bpf_msg_apply_bytes(msg, *bytes); - bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero); - if (bytes) - bpf_msg_cork_bytes(msg, *bytes); - start = bpf_map_lookup_elem(&sock_pull_bytes, &zero); - end = bpf_map_lookup_elem(&sock_pull_bytes, &one); - if (start && end) - bpf_msg_pull_data(msg, *start, *end, 0); - - return SK_DROP; -} - -int _version SEC("version") = 1; -char _license[] SEC("license") = "GPL"; +// Copyright (c) 2018 Covalent IO, Inc. http://covalent.io +#define SOCKMAP +#define TEST_MAP_TYPE BPF_MAP_TYPE_SOCKMAP +#include "./test_sockmap_kern.h" diff --git a/tools/testing/selftests/bpf/test_sockmap_kern.h b/tools/testing/selftests/bpf/test_sockmap_kern.h new file mode 100644 index 000000000000..8e8e41780bb9 --- /dev/null +++ b/tools/testing/selftests/bpf/test_sockmap_kern.h @@ -0,0 +1,363 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (c) 2017-2018 Covalent IO, Inc. http://covalent.io */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "bpf_helpers.h" +#include "bpf_endian.h" + +/* Sockmap sample program connects a client and a backend together + * using cgroups. + * + * client:X <---> frontend:80 client:X <---> backend:80 + * + * For simplicity we hard code values here and bind 1:1. The hard + * coded values are part of the setup in sockmap.sh script that + * is associated with this BPF program. + * + * The bpf_printk is verbose and prints information as connections + * are established and verdicts are decided. + */ + +#define bpf_printk(fmt, ...) \ +({ \ + char ____fmt[] = fmt; \ + bpf_trace_printk(____fmt, sizeof(____fmt), \ + ##__VA_ARGS__); \ +}) + +struct bpf_map_def SEC("maps") sock_map = { + .type = TEST_MAP_TYPE, + .key_size = sizeof(int), + .value_size = sizeof(int), + .max_entries = 20, +}; + +struct bpf_map_def SEC("maps") sock_map_txmsg = { + .type = TEST_MAP_TYPE, + .key_size = sizeof(int), + .value_size = sizeof(int), + .max_entries = 20, +}; + +struct bpf_map_def SEC("maps") sock_map_redir = { + .type = TEST_MAP_TYPE, + .key_size = sizeof(int), + .value_size = sizeof(int), + .max_entries = 20, +}; + +struct bpf_map_def SEC("maps") sock_apply_bytes = { + .type = BPF_MAP_TYPE_ARRAY, + .key_size = sizeof(int), + .value_size = sizeof(int), + .max_entries = 1 +}; + +struct bpf_map_def SEC("maps") sock_cork_bytes = { + .type = BPF_MAP_TYPE_ARRAY, + .key_size = sizeof(int), + .value_size = sizeof(int), + .max_entries = 1 +}; + +struct bpf_map_def SEC("maps") sock_pull_bytes = { + .type = BPF_MAP_TYPE_ARRAY, + .key_size = sizeof(int), + .value_size = sizeof(int), + .max_entries = 2 +}; + +struct bpf_map_def SEC("maps") sock_redir_flags = { + .type = BPF_MAP_TYPE_ARRAY, + .key_size = sizeof(int), + .value_size = sizeof(int), + .max_entries = 1 +}; + +struct bpf_map_def SEC("maps") sock_skb_opts = { + .type = BPF_MAP_TYPE_ARRAY, + .key_size = sizeof(int), + .value_size = sizeof(int), + .max_entries = 1 +}; + +SEC("sk_skb1") +int bpf_prog1(struct __sk_buff *skb) +{ + return skb->len; +} + +SEC("sk_skb2") +int bpf_prog2(struct __sk_buff *skb) +{ + __u32 lport = skb->local_port; + __u32 rport = skb->remote_port; + int len, *f, ret, zero = 0; + __u64 flags = 0; + + if (lport == 10000) + ret = 10; + else + ret = 1; + + len = (__u32)skb->data_end - (__u32)skb->data; + f = bpf_map_lookup_elem(&sock_skb_opts, &zero); + if (f && *f) { + ret = 3; + flags = *f; + } + + bpf_printk("sk_skb2: redirect(%iB) flags=%i\n", + len, flags); +#ifdef SOCKMAP + return bpf_sk_redirect_map(skb, &sock_map, ret, flags); +#else + return bpf_sk_redirect_hash(skb, &sock_map, &ret, flags); +#endif + +} + +SEC("sockops") +int bpf_sockmap(struct bpf_sock_ops *skops) +{ + __u32 lport, rport; + int op, err = 0, index, key, ret; + + + op = (int) skops->op; + + switch (op) { + case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB: + lport = skops->local_port; + rport = skops->remote_port; + + if (lport == 10000) { + ret = 1; +#ifdef SOCKMAP + err = bpf_sock_map_update(skops, &sock_map, &ret, + BPF_NOEXIST); +#else + err = bpf_sock_hash_update(skops, &sock_map, &ret, + BPF_NOEXIST); +#endif + bpf_printk("passive(%i -> %i) map ctx update err: %d\n", + lport, bpf_ntohl(rport), err); + } + break; + case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB: + lport = skops->local_port; + rport = skops->remote_port; + + if (bpf_ntohl(rport) == 10001) { + ret = 10; +#ifdef SOCKMAP + err = bpf_sock_map_update(skops, &sock_map, &ret, + BPF_NOEXIST); +#else + err = bpf_sock_hash_update(skops, &sock_map, &ret, + BPF_NOEXIST); +#endif + bpf_printk("active(%i -> %i) map ctx update err: %d\n", + lport, bpf_ntohl(rport), err); + } + break; + default: + break; + } + + return 0; +} + +SEC("sk_msg1") +int bpf_prog4(struct sk_msg_md *msg) +{ + int *bytes, zero = 0, one = 1; + int *start, *end; + + bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero); + if (bytes) + bpf_msg_apply_bytes(msg, *bytes); + bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero); + if (bytes) + bpf_msg_cork_bytes(msg, *bytes); + start = bpf_map_lookup_elem(&sock_pull_bytes, &zero); + end = bpf_map_lookup_elem(&sock_pull_bytes, &one); + if (start && end) + bpf_msg_pull_data(msg, *start, *end, 0); + return SK_PASS; +} + +SEC("sk_msg2") +int bpf_prog5(struct sk_msg_md *msg) +{ + int err1 = -1, err2 = -1, zero = 0, one = 1; + int *bytes, *start, *end, len1, len2; + + bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero); + if (bytes) + err1 = bpf_msg_apply_bytes(msg, *bytes); + bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero); + if (bytes) + err2 = bpf_msg_cork_bytes(msg, *bytes); + len1 = (__u64)msg->data_end - (__u64)msg->data; + start = bpf_map_lookup_elem(&sock_pull_bytes, &zero); + end = bpf_map_lookup_elem(&sock_pull_bytes, &one); + if (start && end) { + int err; + + bpf_printk("sk_msg2: pull(%i:%i)\n", + start ? *start : 0, end ? *end : 0); + err = bpf_msg_pull_data(msg, *start, *end, 0); + if (err) + bpf_printk("sk_msg2: pull_data err %i\n", + err); + len2 = (__u64)msg->data_end - (__u64)msg->data; + bpf_printk("sk_msg2: length update %i->%i\n", + len1, len2); + } + bpf_printk("sk_msg2: data length %i err1 %i err2 %i\n", + len1, err1, err2); + return SK_PASS; +} + +SEC("sk_msg3") +int bpf_prog6(struct sk_msg_md *msg) +{ + int *bytes, zero = 0, one = 1, key = 0; + int *start, *end, *f; + __u64 flags = 0; + + bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero); + if (bytes) + bpf_msg_apply_bytes(msg, *bytes); + bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero); + if (bytes) + bpf_msg_cork_bytes(msg, *bytes); + start = bpf_map_lookup_elem(&sock_pull_bytes, &zero); + end = bpf_map_lookup_elem(&sock_pull_bytes, &one); + if (start && end) + bpf_msg_pull_data(msg, *start, *end, 0); + f = bpf_map_lookup_elem(&sock_redir_flags, &zero); + if (f && *f) { + key = 2; + flags = *f; + } +#ifdef SOCKMAP + return bpf_msg_redirect_map(msg, &sock_map_redir, key, flags); +#else + return bpf_msg_redirect_hash(msg, &sock_map_redir, &key, flags); +#endif +} + +SEC("sk_msg4") +int bpf_prog7(struct sk_msg_md *msg) +{ + int err1 = 0, err2 = 0, zero = 0, one = 1, key = 0; + int *f, *bytes, *start, *end, len1, len2; + __u64 flags = 0; + + int err; + bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero); + if (bytes) + err1 = bpf_msg_apply_bytes(msg, *bytes); + bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero); + if (bytes) + err2 = bpf_msg_cork_bytes(msg, *bytes); + len1 = (__u64)msg->data_end - (__u64)msg->data; + start = bpf_map_lookup_elem(&sock_pull_bytes, &zero); + end = bpf_map_lookup_elem(&sock_pull_bytes, &one); + if (start && end) { + + bpf_printk("sk_msg2: pull(%i:%i)\n", + start ? *start : 0, end ? *end : 0); + err = bpf_msg_pull_data(msg, *start, *end, 0); + if (err) + bpf_printk("sk_msg2: pull_data err %i\n", + err); + len2 = (__u64)msg->data_end - (__u64)msg->data; + bpf_printk("sk_msg2: length update %i->%i\n", + len1, len2); + } + f = bpf_map_lookup_elem(&sock_redir_flags, &zero); + if (f && *f) { + key = 2; + flags = *f; + } + bpf_printk("sk_msg3: redirect(%iB) flags=%i err=%i\n", + len1, flags, err1 ? err1 : err2); +#ifdef SOCKMAP + err = bpf_msg_redirect_map(msg, &sock_map_redir, key, flags); +#else + err = bpf_msg_redirect_hash(msg, &sock_map_redir, &key, flags); +#endif + bpf_printk("sk_msg3: err %i\n", err); + return err; +} + +SEC("sk_msg5") +int bpf_prog8(struct sk_msg_md *msg) +{ + void *data_end = (void *)(long) msg->data_end; + void *data = (void *)(long) msg->data; + int ret = 0, *bytes, zero = 0; + + bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero); + if (bytes) { + ret = bpf_msg_apply_bytes(msg, *bytes); + if (ret) + return SK_DROP; + } else { + return SK_DROP; + } + return SK_PASS; +} +SEC("sk_msg6") +int bpf_prog9(struct sk_msg_md *msg) +{ + void *data_end = (void *)(long) msg->data_end; + void *data = (void *)(long) msg->data; + int ret = 0, *bytes, zero = 0; + + bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero); + if (bytes) { + if (((__u64)data_end - (__u64)data) >= *bytes) + return SK_PASS; + ret = bpf_msg_cork_bytes(msg, *bytes); + if (ret) + return SK_DROP; + } + return SK_PASS; +} + +SEC("sk_msg7") +int bpf_prog10(struct sk_msg_md *msg) +{ + int *bytes, zero = 0, one = 1; + int *start, *end; + + bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero); + if (bytes) + bpf_msg_apply_bytes(msg, *bytes); + bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero); + if (bytes) + bpf_msg_cork_bytes(msg, *bytes); + start = bpf_map_lookup_elem(&sock_pull_bytes, &zero); + end = bpf_map_lookup_elem(&sock_pull_bytes, &one); + if (start && end) + bpf_msg_pull_data(msg, *start, *end, 0); + + return SK_DROP; +} + +int _version SEC("version") = 1; +char _license[] SEC("license") = "GPL"; -- cgit v1.2.3 From 62c52d1fddb5ef201e3a25d7bd1b79fcb0ca42b8 Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Mon, 14 May 2018 10:00:19 -0700 Subject: bpf: bpftool, support for sockhash This adds the SOCKHASH map type to bpftools so that we get correct pretty printing. Signed-off-by: John Fastabend Acked-by: David S. Miller Signed-off-by: Daniel Borkmann --- tools/bpf/bpftool/map.c | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index af6766e956ba..097b1a5e046b 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -66,6 +66,7 @@ static const char * const map_type_name[] = { [BPF_MAP_TYPE_DEVMAP] = "devmap", [BPF_MAP_TYPE_SOCKMAP] = "sockmap", [BPF_MAP_TYPE_CPUMAP] = "cpumap", + [BPF_MAP_TYPE_SOCKHASH] = "sockhash", }; static bool map_is_per_cpu(__u32 type) -- cgit v1.2.3 From 44edef77bd92730e1520b07f5ae2c9f4628738a8 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Tue, 15 May 2018 16:20:52 -0700 Subject: samples/bpf: Decrement ttl in fib forwarding example Only consider forwarding packets if ttl in received packet is > 1 and decrement ttl before handing off to bpf_redirect_map. Signed-off-by: David Ahern Acked-by: Yonghong Song Signed-off-by: Daniel Borkmann --- samples/bpf/xdp_fwd_kern.c | 39 +++++++++++++++++++++++++++++++-------- 1 file changed, 31 insertions(+), 8 deletions(-) diff --git a/samples/bpf/xdp_fwd_kern.c b/samples/bpf/xdp_fwd_kern.c index cdf4fc383cc9..4a6be0f87505 100644 --- a/samples/bpf/xdp_fwd_kern.c +++ b/samples/bpf/xdp_fwd_kern.c @@ -30,12 +30,24 @@ struct bpf_map_def SEC("maps") tx_port = { .max_entries = 64, }; +/* from include/net/ip.h */ +static __always_inline int ip_decrease_ttl(struct iphdr *iph) +{ + u32 check = (__force u32)iph->check; + + check += (__force u32)htons(0x0100); + iph->check = (__force __sum16)(check + (check >= 0xFFFF)); + return --iph->ttl; +} + static __always_inline int xdp_fwd_flags(struct xdp_md *ctx, u32 flags) { void *data_end = (void *)(long)ctx->data_end; void *data = (void *)(long)ctx->data; struct bpf_fib_lookup fib_params; struct ethhdr *eth = data; + struct ipv6hdr *ip6h; + struct iphdr *iph; int out_index; u16 h_proto; u64 nh_off; @@ -48,11 +60,14 @@ static __always_inline int xdp_fwd_flags(struct xdp_md *ctx, u32 flags) h_proto = eth->h_proto; if (h_proto == htons(ETH_P_IP)) { - struct iphdr *iph = data + nh_off; + iph = data + nh_off; if (iph + 1 > data_end) return XDP_DROP; + if (iph->ttl <= 1) + return XDP_PASS; + fib_params.family = AF_INET; fib_params.tos = iph->tos; fib_params.l4_protocol = iph->protocol; @@ -64,19 +79,22 @@ static __always_inline int xdp_fwd_flags(struct xdp_md *ctx, u32 flags) } else if (h_proto == htons(ETH_P_IPV6)) { struct in6_addr *src = (struct in6_addr *) fib_params.ipv6_src; struct in6_addr *dst = (struct in6_addr *) fib_params.ipv6_dst; - struct ipv6hdr *iph = data + nh_off; - if (iph + 1 > data_end) + ip6h = data + nh_off; + if (ip6h + 1 > data_end) return XDP_DROP; + if (ip6h->hop_limit <= 1) + return XDP_PASS; + fib_params.family = AF_INET6; - fib_params.flowlabel = *(__be32 *)iph & IPV6_FLOWINFO_MASK; - fib_params.l4_protocol = iph->nexthdr; + fib_params.flowlabel = *(__be32 *)ip6h & IPV6_FLOWINFO_MASK; + fib_params.l4_protocol = ip6h->nexthdr; fib_params.sport = 0; fib_params.dport = 0; - fib_params.tot_len = ntohs(iph->payload_len); - *src = iph->saddr; - *dst = iph->daddr; + fib_params.tot_len = ntohs(ip6h->payload_len); + *src = ip6h->saddr; + *dst = ip6h->daddr; } else { return XDP_PASS; } @@ -92,6 +110,11 @@ static __always_inline int xdp_fwd_flags(struct xdp_md *ctx, u32 flags) * forwarding packets are dropped. */ if (out_index > 0) { + if (h_proto == htons(ETH_P_IP)) + ip_decrease_ttl(iph); + else if (h_proto == htons(ETH_P_IPV6)) + ip6h->hop_limit--; + memcpy(eth->h_dest, fib_params.dmac, ETH_ALEN); memcpy(eth->h_source, fib_params.smac, ETH_ALEN); return bpf_redirect_map(&tx_port, out_index, 0); -- cgit v1.2.3 From be2d04d11fd33bd46622f94619aae1596d9f9303 Mon Sep 17 00:00:00 2001 From: Mathieu Malaterre Date: Wed, 16 May 2018 22:27:41 +0200 Subject: bpf: add __printf verification to bpf_verifier_vlog MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit __printf is useful to verify format and arguments. ‘bpf_verifier_vlog’ function is used twice in verifier.c in both cases the caller function already uses the __printf gcc attribute. Remove the following warning, triggered with W=1: kernel/bpf/verifier.c:176:2: warning: function might be possible candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format] Signed-off-by: Mathieu Malaterre Signed-off-by: Daniel Borkmann --- include/linux/bpf_verifier.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 8f70dc181e23..c286813deaeb 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -200,8 +200,8 @@ struct bpf_verifier_env { u32 subprog_cnt; }; -void bpf_verifier_vlog(struct bpf_verifier_log *log, const char *fmt, - va_list args); +__printf(2, 0) void bpf_verifier_vlog(struct bpf_verifier_log *log, + const char *fmt, va_list args); __printf(2, 3) void bpf_verifier_log_write(struct bpf_verifier_env *env, const char *fmt, ...); -- cgit v1.2.3 From f0307a7ed17fa8925321a4f58f5ca56eeedd4fa3 Mon Sep 17 00:00:00 2001 From: David Beckett Date: Wed, 16 May 2018 14:02:49 -0700 Subject: libbpf: add ifindex to enable offload support BPF programs currently can only be offloaded using iproute2. This patch will allow programs to be offloaded using libbpf calls. Signed-off-by: David Beckett Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- tools/lib/bpf/bpf.c | 2 ++ tools/lib/bpf/bpf.h | 2 ++ tools/lib/bpf/libbpf.c | 18 +++++++++++++++--- tools/lib/bpf/libbpf.h | 1 + 4 files changed, 20 insertions(+), 3 deletions(-) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index a3a8fb2ac697..6a8a00097fd8 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -91,6 +91,7 @@ int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr) attr.btf_fd = create_attr->btf_fd; attr.btf_key_id = create_attr->btf_key_id; attr.btf_value_id = create_attr->btf_value_id; + attr.map_ifindex = create_attr->map_ifindex; return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); } @@ -201,6 +202,7 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, attr.log_size = 0; attr.log_level = 0; attr.kern_version = load_attr->kern_version; + attr.prog_ifindex = load_attr->prog_ifindex; memcpy(attr.prog_name, load_attr->name, min(name_len, BPF_OBJ_NAME_LEN - 1)); diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index fb3a146d92ff..15bff7728cf1 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -38,6 +38,7 @@ struct bpf_create_map_attr { __u32 btf_fd; __u32 btf_key_id; __u32 btf_value_id; + __u32 map_ifindex; }; int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr); @@ -64,6 +65,7 @@ struct bpf_load_program_attr { size_t insns_cnt; const char *license; __u32 kern_version; + __u32 prog_ifindex; }; /* Recommend log buffer size */ diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index df54c4c9e48a..3dbe217bf23e 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -178,6 +178,7 @@ struct bpf_program { /* Index in elf obj file, for relocation use. */ int idx; char *name; + int prog_ifindex; char *section_name; struct bpf_insn *insns; size_t insns_cnt, main_prog_cnt; @@ -213,6 +214,7 @@ struct bpf_map { int fd; char *name; size_t offset; + int map_ifindex; struct bpf_map_def def; uint32_t btf_key_id; uint32_t btf_value_id; @@ -1091,6 +1093,7 @@ bpf_object__create_maps(struct bpf_object *obj) int *pfd = &map->fd; create_attr.name = map->name; + create_attr.map_ifindex = map->map_ifindex; create_attr.map_type = def->type; create_attr.map_flags = def->map_flags; create_attr.key_size = def->key_size; @@ -1273,7 +1276,7 @@ static int bpf_object__collect_reloc(struct bpf_object *obj) static int load_program(enum bpf_prog_type type, enum bpf_attach_type expected_attach_type, const char *name, struct bpf_insn *insns, int insns_cnt, - char *license, u32 kern_version, int *pfd) + char *license, u32 kern_version, int *pfd, int prog_ifindex) { struct bpf_load_program_attr load_attr; char *log_buf; @@ -1287,6 +1290,7 @@ load_program(enum bpf_prog_type type, enum bpf_attach_type expected_attach_type, load_attr.insns_cnt = insns_cnt; load_attr.license = license; load_attr.kern_version = kern_version; + load_attr.prog_ifindex = prog_ifindex; if (!load_attr.insns || !load_attr.insns_cnt) return -EINVAL; @@ -1368,7 +1372,8 @@ bpf_program__load(struct bpf_program *prog, } err = load_program(prog->type, prog->expected_attach_type, prog->name, prog->insns, prog->insns_cnt, - license, kern_version, &fd); + license, kern_version, &fd, + prog->prog_ifindex); if (!err) prog->instances.fds[0] = fd; goto out; @@ -1399,7 +1404,8 @@ bpf_program__load(struct bpf_program *prog, err = load_program(prog->type, prog->expected_attach_type, prog->name, result.new_insn_ptr, result.new_insn_cnt, - license, kern_version, &fd); + license, kern_version, &fd, + prog->prog_ifindex); if (err) { pr_warning("Loading the %dth instance of program '%s' failed\n", @@ -2188,6 +2194,7 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, enum bpf_attach_type expected_attach_type; enum bpf_prog_type prog_type; struct bpf_object *obj; + struct bpf_map *map; int section_idx; int err; @@ -2207,6 +2214,7 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, * section name. */ prog_type = attr->prog_type; + prog->prog_ifindex = attr->ifindex; expected_attach_type = attr->expected_attach_type; if (prog_type == BPF_PROG_TYPE_UNSPEC) { section_idx = bpf_program__identify_section(prog); @@ -2227,6 +2235,10 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, first_prog = prog; } + bpf_map__for_each(map, obj) { + map->map_ifindex = attr->ifindex; + } + if (!first_prog) { pr_warning("object file doesn't contain bpf program\n"); bpf_object__close(obj); diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 4574b9563278..cd3fd8d782c7 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -259,6 +259,7 @@ struct bpf_prog_load_attr { const char *file; enum bpf_prog_type prog_type; enum bpf_attach_type expected_attach_type; + int ifindex; }; int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, -- cgit v1.2.3 From 683d2ac3904c74a625ea62d7fcc6c1efd84be087 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Wed, 16 May 2018 14:06:26 -0700 Subject: bpf: fix sock hashmap kmalloc warning syzbot reported a kernel warning below: WARNING: CPU: 0 PID: 4499 at mm/slab_common.c:996 kmalloc_slab+0x56/0x70 mm/slab_common.c:996 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 4499 Comm: syz-executor050 Not tainted 4.17.0-rc3+ #9 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b9/0x294 lib/dump_stack.c:113 panic+0x22f/0x4de kernel/panic.c:184 __warn.cold.8+0x163/0x1b3 kernel/panic.c:536 report_bug+0x252/0x2d0 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] do_error_trap+0x1de/0x490 arch/x86/kernel/traps.c:296 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992 RIP: 0010:kmalloc_slab+0x56/0x70 mm/slab_common.c:996 RSP: 0018:ffff8801d907fc58 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8801aeecb280 RCX: ffffffff8185ebd7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000ffffffe1 RBP: ffff8801d907fc58 R08: ffff8801adb5e1c0 R09: ffffed0035a84700 R10: ffffed0035a84700 R11: ffff8801ad423803 R12: ffff8801aeecb280 R13: 00000000fffffff4 R14: ffff8801ad891a00 R15: 00000000014200c0 __do_kmalloc mm/slab.c:3713 [inline] __kmalloc+0x25/0x760 mm/slab.c:3727 kmalloc include/linux/slab.h:517 [inline] map_get_next_key+0x24a/0x640 kernel/bpf/syscall.c:858 __do_sys_bpf kernel/bpf/syscall.c:2131 [inline] __se_sys_bpf kernel/bpf/syscall.c:2096 [inline] __x64_sys_bpf+0x354/0x4f0 kernel/bpf/syscall.c:2096 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe The test case is against sock hashmap with a key size 0xffffffe1. Such a large key size will cause the below code in function sock_hash_alloc() overflowing and produces a smaller elem_size, hence map creation will be successful. htab->elem_size = sizeof(struct htab_elem) + round_up(htab->map.key_size, 8); Later, when map_get_next_key is called and kernel tries to allocate the key unsuccessfully, it will issue the above warning. Similar to hashtab, ensure the key size is at most MAX_BPF_STACK for a successful map creation. Fixes: 81110384441a ("bpf: sockmap, add hash map support") Reported-by: syzbot+e4566d29080e7f3460ff@syzkaller.appspotmail.com Signed-off-by: Yonghong Song Acked-by: John Fastabend Signed-off-by: Daniel Borkmann --- kernel/bpf/sockmap.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c index 56879c9fd3a4..79f5e8988889 100644 --- a/kernel/bpf/sockmap.c +++ b/kernel/bpf/sockmap.c @@ -1990,6 +1990,12 @@ static struct bpf_map *sock_hash_alloc(union bpf_attr *attr) attr->map_flags & ~SOCK_CREATE_FLAG_MASK) return ERR_PTR(-EINVAL); + if (attr->key_size > MAX_BPF_STACK) + /* eBPF programs initialize keys on stack, so they cannot be + * larger than max stack size + */ + return ERR_PTR(-E2BIG); + err = bpf_tcp_ulp_register(); if (err && err != -EEXIST) return ERR_PTR(err); -- cgit v1.2.3 From e23afe5e7cba89cd0744c5218eda1b3553455c17 Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Wed, 16 May 2018 16:38:14 -0700 Subject: bpf: sockmap, on update propagate errors back to userspace When an error happens in the update sockmap element logic also pass the err up to the user. Fixes: e5cd3abcb31a ("bpf: sockmap, refactor sockmap routines to work with hashmap") Signed-off-by: John Fastabend Signed-off-by: Daniel Borkmann --- kernel/bpf/sockmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c index 79f5e8988889..c6de1393df63 100644 --- a/kernel/bpf/sockmap.c +++ b/kernel/bpf/sockmap.c @@ -1875,7 +1875,7 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops, write_unlock_bh(&osock->sk_callback_lock); } out: - return 0; + return err; } int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type) -- cgit v1.2.3