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-rw-r--r--include/linux/bpf.h10
-rw-r--r--include/uapi/linux/bpf.h15
-rw-r--r--kernel/bpf/bpf_iter.c58
-rw-r--r--kernel/bpf/map_iter.c37
-rw-r--r--kernel/bpf/syscall.c2
-rw-r--r--net/core/bpf_sk_storage.c37
6 files changed, 102 insertions, 57 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index cef4ef0d2b4e..55f694b63164 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1214,15 +1214,17 @@ struct bpf_iter_aux_info {
struct bpf_map *map;
};
-typedef int (*bpf_iter_check_target_t)(struct bpf_prog *prog,
- struct bpf_iter_aux_info *aux);
+typedef int (*bpf_iter_attach_target_t)(struct bpf_prog *prog,
+ union bpf_iter_link_info *linfo,
+ struct bpf_iter_aux_info *aux);
+typedef void (*bpf_iter_detach_target_t)(struct bpf_iter_aux_info *aux);
#define BPF_ITER_CTX_ARG_MAX 2
struct bpf_iter_reg {
const char *target;
- bpf_iter_check_target_t check_target;
+ bpf_iter_attach_target_t attach_target;
+ bpf_iter_detach_target_t detach_target;
u32 ctx_arg_info_size;
- enum bpf_iter_link_info req_linfo;
struct bpf_ctx_arg_aux ctx_arg_info[BPF_ITER_CTX_ARG_MAX];
const struct bpf_iter_seq_info *seq_info;
};
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index b134e679e9db..0480f893facd 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -81,6 +81,12 @@ struct bpf_cgroup_storage_key {
__u32 attach_type; /* program attach type */
};
+union bpf_iter_link_info {
+ struct {
+ __u32 map_fd;
+ } map;
+};
+
/* BPF syscall commands, see bpf(2) man-page for details. */
enum bpf_cmd {
BPF_MAP_CREATE,
@@ -249,13 +255,6 @@ enum bpf_link_type {
MAX_BPF_LINK_TYPE,
};
-enum bpf_iter_link_info {
- BPF_ITER_LINK_UNSPEC = 0,
- BPF_ITER_LINK_MAP_FD = 1,
-
- MAX_BPF_ITER_LINK_INFO,
-};
-
/* cgroup-bpf attach flags used in BPF_PROG_ATTACH command
*
* NONE(default): No further bpf programs allowed in the subtree.
@@ -623,6 +622,8 @@ union bpf_attr {
};
__u32 attach_type; /* attach type */
__u32 flags; /* extra flags */
+ __aligned_u64 iter_info; /* extra bpf_iter_link_info */
+ __u32 iter_info_len; /* iter_info length */
} link_create;
struct { /* struct used by BPF_LINK_UPDATE command */
diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c
index 363b9cafc2d8..b6715964b685 100644
--- a/kernel/bpf/bpf_iter.c
+++ b/kernel/bpf/bpf_iter.c
@@ -338,8 +338,8 @@ static void bpf_iter_link_release(struct bpf_link *link)
struct bpf_iter_link *iter_link =
container_of(link, struct bpf_iter_link, link);
- if (iter_link->aux.map)
- bpf_map_put_with_uref(iter_link->aux.map);
+ if (iter_link->tinfo->reg_info->detach_target)
+ iter_link->tinfo->reg_info->detach_target(&iter_link->aux);
}
static void bpf_iter_link_dealloc(struct bpf_link *link)
@@ -390,15 +390,35 @@ bool bpf_link_is_iter(struct bpf_link *link)
int bpf_iter_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
{
+ union bpf_iter_link_info __user *ulinfo;
struct bpf_link_primer link_primer;
struct bpf_iter_target_info *tinfo;
- struct bpf_iter_aux_info aux = {};
+ union bpf_iter_link_info linfo;
struct bpf_iter_link *link;
- u32 prog_btf_id, target_fd;
+ u32 prog_btf_id, linfo_len;
bool existed = false;
- struct bpf_map *map;
int err;
+ if (attr->link_create.target_fd || attr->link_create.flags)
+ return -EINVAL;
+
+ memset(&linfo, 0, sizeof(union bpf_iter_link_info));
+
+ ulinfo = u64_to_user_ptr(attr->link_create.iter_info);
+ linfo_len = attr->link_create.iter_info_len;
+ if (!ulinfo ^ !linfo_len)
+ return -EINVAL;
+
+ if (ulinfo) {
+ err = bpf_check_uarg_tail_zero(ulinfo, sizeof(linfo),
+ linfo_len);
+ if (err)
+ return err;
+ linfo_len = min_t(u32, linfo_len, sizeof(linfo));
+ if (copy_from_user(&linfo, ulinfo, linfo_len))
+ return -EFAULT;
+ }
+
prog_btf_id = prog->aux->attach_btf_id;
mutex_lock(&targets_mutex);
list_for_each_entry(tinfo, &targets, list) {
@@ -411,13 +431,6 @@ int bpf_iter_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
if (!existed)
return -ENOENT;
- /* Make sure user supplied flags are target expected. */
- target_fd = attr->link_create.target_fd;
- if (attr->link_create.flags != tinfo->reg_info->req_linfo)
- return -EINVAL;
- if (!attr->link_create.flags && target_fd)
- return -EINVAL;
-
link = kzalloc(sizeof(*link), GFP_USER | __GFP_NOWARN);
if (!link)
return -ENOMEM;
@@ -431,28 +444,15 @@ int bpf_iter_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
return err;
}
- if (tinfo->reg_info->req_linfo == BPF_ITER_LINK_MAP_FD) {
- map = bpf_map_get_with_uref(target_fd);
- if (IS_ERR(map)) {
- err = PTR_ERR(map);
- goto cleanup_link;
- }
-
- aux.map = map;
- err = tinfo->reg_info->check_target(prog, &aux);
+ if (tinfo->reg_info->attach_target) {
+ err = tinfo->reg_info->attach_target(prog, &linfo, &link->aux);
if (err) {
- bpf_map_put_with_uref(map);
- goto cleanup_link;
+ bpf_link_cleanup(&link_primer);
+ return err;
}
-
- link->aux.map = map;
}
return bpf_link_settle(&link_primer);
-
-cleanup_link:
- bpf_link_cleanup(&link_primer);
- return err;
}
static void init_seq_meta(struct bpf_iter_priv_data *priv_data,
diff --git a/kernel/bpf/map_iter.c b/kernel/bpf/map_iter.c
index fbe1f557cb88..af86048e5afd 100644
--- a/kernel/bpf/map_iter.c
+++ b/kernel/bpf/map_iter.c
@@ -98,12 +98,21 @@ static struct bpf_iter_reg bpf_map_reg_info = {
.seq_info = &bpf_map_seq_info,
};
-static int bpf_iter_check_map(struct bpf_prog *prog,
- struct bpf_iter_aux_info *aux)
+static int bpf_iter_attach_map(struct bpf_prog *prog,
+ union bpf_iter_link_info *linfo,
+ struct bpf_iter_aux_info *aux)
{
u32 key_acc_size, value_acc_size, key_size, value_size;
- struct bpf_map *map = aux->map;
+ struct bpf_map *map;
bool is_percpu = false;
+ int err = -EINVAL;
+
+ if (!linfo->map.map_fd)
+ return -EBADF;
+
+ map = bpf_map_get_with_uref(linfo->map.map_fd);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
@@ -112,7 +121,7 @@ static int bpf_iter_check_map(struct bpf_prog *prog,
else if (map->map_type != BPF_MAP_TYPE_HASH &&
map->map_type != BPF_MAP_TYPE_LRU_HASH &&
map->map_type != BPF_MAP_TYPE_ARRAY)
- return -EINVAL;
+ goto put_map;
key_acc_size = prog->aux->max_rdonly_access;
value_acc_size = prog->aux->max_rdwr_access;
@@ -122,10 +131,22 @@ static int bpf_iter_check_map(struct bpf_prog *prog,
else
value_size = round_up(map->value_size, 8) * num_possible_cpus();
- if (key_acc_size > key_size || value_acc_size > value_size)
- return -EACCES;
+ if (key_acc_size > key_size || value_acc_size > value_size) {
+ err = -EACCES;
+ goto put_map;
+ }
+ aux->map = map;
return 0;
+
+put_map:
+ bpf_map_put_with_uref(map);
+ return err;
+}
+
+static void bpf_iter_detach_map(struct bpf_iter_aux_info *aux)
+{
+ bpf_map_put_with_uref(aux->map);
}
DEFINE_BPF_ITER_FUNC(bpf_map_elem, struct bpf_iter_meta *meta,
@@ -133,8 +154,8 @@ DEFINE_BPF_ITER_FUNC(bpf_map_elem, struct bpf_iter_meta *meta,
static const struct bpf_iter_reg bpf_map_elem_reg_info = {
.target = "bpf_map_elem",
- .check_target = bpf_iter_check_map,
- .req_linfo = BPF_ITER_LINK_MAP_FD,
+ .attach_target = bpf_iter_attach_map,
+ .detach_target = bpf_iter_detach_map,
.ctx_arg_info_size = 2,
.ctx_arg_info = {
{ offsetof(struct bpf_iter__bpf_map_elem, key),
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 2f343ce15747..86299a292214 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -3883,7 +3883,7 @@ static int tracing_bpf_link_attach(const union bpf_attr *attr, struct bpf_prog *
return -EINVAL;
}
-#define BPF_LINK_CREATE_LAST_FIELD link_create.flags
+#define BPF_LINK_CREATE_LAST_FIELD link_create.iter_info_len
static int link_create(union bpf_attr *attr)
{
enum bpf_prog_type ptype;
diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
index d3377c90a291..b988f48153a4 100644
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c
@@ -1384,18 +1384,39 @@ static int bpf_iter_init_sk_storage_map(void *priv_data,
return 0;
}
-static int bpf_iter_check_map(struct bpf_prog *prog,
- struct bpf_iter_aux_info *aux)
+static int bpf_iter_attach_map(struct bpf_prog *prog,
+ union bpf_iter_link_info *linfo,
+ struct bpf_iter_aux_info *aux)
{
- struct bpf_map *map = aux->map;
+ struct bpf_map *map;
+ int err = -EINVAL;
+
+ if (!linfo->map.map_fd)
+ return -EBADF;
+
+ map = bpf_map_get_with_uref(linfo->map.map_fd);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
if (map->map_type != BPF_MAP_TYPE_SK_STORAGE)
- return -EINVAL;
+ goto put_map;
- if (prog->aux->max_rdonly_access > map->value_size)
- return -EACCES;
+ if (prog->aux->max_rdonly_access > map->value_size) {
+ err = -EACCES;
+ goto put_map;
+ }
+ aux->map = map;
return 0;
+
+put_map:
+ bpf_map_put_with_uref(map);
+ return err;
+}
+
+static void bpf_iter_detach_map(struct bpf_iter_aux_info *aux)
+{
+ bpf_map_put_with_uref(aux->map);
}
static const struct seq_operations bpf_sk_storage_map_seq_ops = {
@@ -1414,8 +1435,8 @@ static const struct bpf_iter_seq_info iter_seq_info = {
static struct bpf_iter_reg bpf_sk_storage_map_reg_info = {
.target = "bpf_sk_storage_map",
- .check_target = bpf_iter_check_map,
- .req_linfo = BPF_ITER_LINK_MAP_FD,
+ .attach_target = bpf_iter_attach_map,
+ .detach_target = bpf_iter_detach_map,
.ctx_arg_info_size = 2,
.ctx_arg_info = {
{ offsetof(struct bpf_iter__bpf_sk_storage_map, sk),