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* net: sched: implement terse dump support in actVlad Buslov2020-05-154-9/+52
| | | | | | | | | | | | | Extend tcf_action_dump() with boolean argument 'terse' that is used to request terse-mode action dump. In terse mode only essential data needed to identify particular action (action kind, cookie, etc.) and its stats is put to resulting skb and everything else is omitted. Implement tcf_exts_terse_dump() helper in cls API that is intended to be used to request terse dump of all exts (actions) attached to the filter. Signed-off-by: Vlad Buslov <vladbu@mellanox.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: sched: introduce terse dump flagVlad Buslov2020-05-153-8/+41
| | | | | | | | | | | | | | | | Add new TCA_DUMP_FLAGS attribute and use it in cls API to request terse filter output from classifiers with TCA_DUMP_FLAGS_TERSE flag. This option is intended to be used to improve performance of TC filter dump when userland only needs to obtain stats and not the whole classifier/action data. Extend struct tcf_proto_ops with new terse_dump() callback that must be defined by supporting classifier implementations. Support of the options in specific classifiers and actions is implemented in following patches in the series. Signed-off-by: Vlad Buslov <vladbu@mellanox.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: core: recursively find netdev by device nodeTobias Waldekranz2020-05-151-5/+5
| | | | | | | | | | | | The assumption that a device node is associated either with the netdev's device, or the parent of that device, does not hold for all drivers. E.g. Freescale's DPAA has two layers of platform devices above the netdev. Instead, recursively walk up the tree from the netdev, allowing any parent to match against the sought after node. Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller2020-05-15139-544/+5253
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexei Starovoitov says: ==================== pull-request: bpf-next 2020-05-14 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Merged tag 'perf-for-bpf-2020-05-06' from tip tree that includes CAP_PERFMON. 2) support for narrow loads in bpf_sock_addr progs and additional helpers in cg-skb progs, from Andrey. 3) bpf benchmark runner, from Andrii. 4) arm and riscv JIT optimizations, from Luke. 5) bpf iterator infrastructure, from Yonghong. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| * Merge branch 'expand-cg_skb-helpers'Alexei Starovoitov2020-05-157-24/+386
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andrey Ignatov says: ==================== v2->v3: - better documentation for bpf_sk_cgroup_id in uapi (Yonghong Song) - save/restore errno in network helpers (Yonghong Song) - cleanup leftover after switching selftest to skeleton (Yonghong Song) - switch from map to skel->bss in selftest (Yonghong Song) v1->v2: - switch selftests to skeleton. This patch set allows a bunch of existing sk lookup and skb cgroup id helpers, and adds two new bpf_sk_{,ancestor_}cgroup_id helpers to be used in cgroup skb programs. It fills the gap to cover a use-case to apply intra-host cgroup-bpf network policy based on a source cgroup a packet comes from. For example, there can be multiple containers A, B, C running on a host. Every such container runs in its own cgroup that can have multiple sub-cgroups. But all these containers can share some IP addresses. At the same time container A wants to have a policy for a server S running in it so that only clients from this same container can connect to S, but not from other containers (such as B, C). Source IP address can't be used to decide whether to allow or deny a packet, but it looks reasonable to filter by cgroup id. The patch set allows to implement the following policy: * when an ingress packet comes to container's cgroup, lookup peer (client) socket this packet comes from; * having peer socket, get its cgroup id; * compare peer cgroup id with self cgroup id and allow packet only if they match, i.e. it comes from same cgroup; * the "sub-cgroup" part of the story can be addressed by getting not direct cgroup id of the peer socket, but ancestor cgroup id on specified level, similar to existing "ancestor" flavors of cgroup id helpers. A newly introduced selftest implements such a policy in its basic form to provide a better idea on the use-case. Patch 1 allows existing sk lookup helpers in cgroup skb. Patch 2 allows skb_ancestor_cgroup_id in cgrou skb. Patch 3 introduces two new helpers to get cgroup id of socket. Patch 4 extends network helpers to use them in the next patch. Patch 5 adds selftest / example of use-case. ==================== Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| | * selftests/bpf: Test for sk helpers in cgroup skbAndrey Ignatov2020-05-152-0/+192
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Test bpf_sk_lookup_tcp, bpf_sk_release, bpf_sk_cgroup_id and bpf_sk_ancestor_cgroup_id helpers from cgroup skb program. The test creates a testing cgroup, starts a TCPv6 server inside the cgroup and creates two client sockets: one inside testing cgroup and one outside. Then it attaches cgroup skb program to the cgroup that checks all TCP segments coming to the server and allows only those coming from the cgroup of the server. If a segment comes from a peer outside of the cgroup, it'll be dropped. Finally the test checks that client from inside testing cgroup can successfully connect to the server, but client outside the cgroup fails to connect by timeout. The main goal of the test is to check newly introduced bpf_sk_{,ancestor_}cgroup_id helpers. It also checks a couple of socket lookup helpers (tcp & release), but lookup helpers were introduced much earlier and covered by other tests. Here it's mostly checked that they can be called from cgroup skb. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/171f4c5d75e8ff4fe1c4e8c1c12288b5240a4549.1589486450.git.rdna@fb.com
| | * selftests/bpf: Add connect_fd_to_fd, connect_wait net helpersAndrey Ignatov2020-05-152-13/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add two new network helpers. connect_fd_to_fd connects an already created client socket fd to address of server fd. Sometimes it's useful to separate client socket creation and connecting this socket to a server, e.g. if client socket has to be created in a cgroup different from that of server cgroup. Additionally connect_to_fd is now implemented using connect_fd_to_fd, both helpers don't treat EINPROGRESS as an error and let caller decide how to proceed with it. connect_wait is a helper to work with non-blocking client sockets so that if connect_to_fd or connect_fd_to_fd returned -1 with errno == EINPROGRESS, caller can wait for connect to finish or for connection timeout. The helper returns -1 on error, 0 on timeout (1sec, hard-coded), and positive number on success. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/1403fab72300f379ca97ead4820ae43eac4414ef.1589486450.git.rdna@fb.com
| | * bpf: Introduce bpf_sk_{, ancestor_}cgroup_id helpersAndrey Ignatov2020-05-153-11/+121
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With having ability to lookup sockets in cgroup skb programs it becomes useful to access cgroup id of retrieved sockets so that policies can be implemented based on origin cgroup of such socket. For example, a container running in a cgroup can have cgroup skb ingress program that can lookup peer socket that is sending packets to a process inside the container and decide whether those packets should be allowed or denied based on cgroup id of the peer. More specifically such ingress program can implement intra-host policy "allow incoming packets only from this same container and not from any other container on same host" w/o relying on source IP addresses since quite often it can be the case that containers share same IP address on the host. Introduce two new helpers for this use-case: bpf_sk_cgroup_id() and bpf_sk_ancestor_cgroup_id(). These helpers are similar to existing bpf_skb_{,ancestor_}cgroup_id helpers with the only difference that sk is used to get cgroup id instead of skb, and share code with them. See documentation in UAPI for more details. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/f5884981249ce911f63e9b57ecd5d7d19154ff39.1589486450.git.rdna@fb.com
| | * bpf: Allow skb_ancestor_cgroup_id helper in cgroup skbAndrey Ignatov2020-05-151-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cgroup skb programs already can use bpf_skb_cgroup_id. Allow bpf_skb_ancestor_cgroup_id as well so that container policies can be implemented for a container that can have sub-cgroups dynamically created, but policies should still be implemented based on cgroup id of container itself not on an id of a sub-cgroup. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/8874194d6041eba190356453ea9f6071edf5f658.1589486450.git.rdna@fb.com
| | * bpf: Allow sk lookup helpers in cgroup skbAndrey Ignatov2020-05-151-0/+8
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently sk lookup helpers are allowed in tc, xdp, sk skb, and cgroup sock_addr programs. But they would be useful in cgroup skb as well so that for example cgroup skb ingress program can lookup a peer socket a packet comes from on same host and make a decision whether to allow or deny this packet based on the properties of that socket, e.g. cgroup that peer socket belongs to. Allow the following sk lookup helpers in cgroup skb: * bpf_sk_lookup_tcp; * bpf_sk_lookup_udp; * bpf_sk_release; * bpf_skc_lookup_tcp. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/f8c7ee280f1582b586629436d777b6db00597d63.1589486450.git.rdna@fb.com
| * selftest/bpf: Fix spelling mistake "SIGALARM" -> "SIGALRM"Colin Ian King2020-05-151-1/+1
| | | | | | | | | | | | | | | | | | There is a spelling mistake in an error message, fix it. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200514121529.259668-1-colin.king@canonical.com
| * bpf: Fix bpf_iter's task iterator logicAndrii Nakryiko2020-05-151-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | task_seq_get_next might stop prematurely if get_pid_task() fails to get task_struct. Failure to do so doesn't mean that there are no more tasks with higher pids. Procfs's iteration algorithm (see next_tgid in fs/proc/base.c) does a retry in such case. After this fix, instead of stopping prematurely after about 300 tasks on my server, bpf_iter program now returns >4000, which sounds much closer to reality. Fixes: eaaacd23910f ("bpf: Add task and task/file iterator targets") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200514055137.1564581-1-andriin@fb.com
| * selftests/bpf: Test narrow loads for bpf_sock_addr.user_portAndrey Ignatov2020-05-151-10/+28
| | | | | | | | | | | | | | | | | | | | Test 1,2,4-byte loads from bpf_sock_addr.user_port in sock_addr programs. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/e5c734a58cca4041ab30cb5471e644246f8cdb5a.1589420814.git.rdna@fb.com
| * bpf: Support narrow loads from bpf_sock_addr.user_portAndrey Ignatov2020-05-153-10/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | bpf_sock_addr.user_port supports only 4-byte load and it leads to ugly code in BPF programs, like: volatile __u32 user_port = ctx->user_port; __u16 port = bpf_ntohs(user_port); Since otherwise clang may optimize the load to be 2-byte and it's rejected by verifier. Add support for 1- and 2-byte loads same way as it's supported for other fields in bpf_sock_addr like user_ip4, msg_src_ip4, etc. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/c1e983f4c17573032601d0b2b1f9d1274f24bc16.1589420814.git.rdna@fb.com
| * samples/bpf: xdp_redirect_cpu: Set MAX_CPUS according to NR_CPUSLorenzo Bianconi2020-05-152-14/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | xdp_redirect_cpu is currently failing in bpf_prog_load_xattr() allocating cpu_map map if CONFIG_NR_CPUS is less than 64 since cpu_map_alloc() requires max_entries to be less than NR_CPUS. Set cpu_map max_entries according to NR_CPUS in xdp_redirect_cpu_kern.c and get currently running cpus in xdp_redirect_cpu_user.c Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/374472755001c260158c4e4b22f193bdd3c56fb7.1589300442.git.lorenzo@kernel.org
| * Merge branch 'bpf_iter-fixes'Alexei Starovoitov2020-05-1315-86/+183
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Yonghong Song says: ==================== Commit ae24345da54e ("bpf: Implement an interface to register bpf_iter targets") and its subsequent commits in the same patch set introduced bpf iterator, a way to run bpf program when iterating kernel data structures. This patch set addressed some followup issues. One big change is to allow target to pass ctx arg register types to verifier for verification purpose. Please see individual patch for details. Changelogs: v1 -> v2: . add "const" qualifier to struct bpf_iter_reg for bpf_iter_[un]reg_target, and this results in additional "const" qualifiers in some other places . drop the patch which will issue WARN_ONCE if seq_ops->show() returns a positive value. If this does happen, code review should spot this or author does know what he is doing. In the future, we do want to implement a mechanism to find out all registered targets so we will be aware of new additions. ==================== Acked-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| | * samples/bpf: Remove compiler warningsYonghong Song2020-05-133-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 5fbc220862fc ("tools/libpf: Add offsetof/container_of macro in bpf_helpers.h") added macros offsetof/container_of to bpf_helpers.h. Unfortunately, it caused compilation warnings below for a few samples/bpf programs: In file included from /data/users/yhs/work/net-next/samples/bpf/sockex2_kern.c:4: In file included from /data/users/yhs/work/net-next/include/uapi/linux/in.h:24: In file included from /data/users/yhs/work/net-next/include/linux/socket.h:8: In file included from /data/users/yhs/work/net-next/include/linux/uio.h:8: /data/users/yhs/work/net-next/include/linux/kernel.h:992:9: warning: 'container_of' macro redefined [-Wmacro-redefined] ^ /data/users/yhs/work/net-next/tools/lib/bpf/bpf_helpers.h:46:9: note: previous definition is here ^ 1 warning generated. CLANG-bpf samples/bpf/sockex3_kern.o In all these cases, bpf_helpers.h is included first, followed by other standard headers. The macro container_of is defined unconditionally in kernel.h, causing the compiler warning. The fix is to move bpf_helpers.h after standard headers. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200513180223.2949987-1-yhs@fb.com
| | * bpf: Enable bpf_iter targets registering ctx argument typesYonghong Song2020-05-1310-12/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit b121b341e598 ("bpf: Add PTR_TO_BTF_ID_OR_NULL support") adds a field btf_id_or_null_non0_off to bpf_prog->aux structure to indicate that the first ctx argument is PTR_TO_BTF_ID reg_type and all others are PTR_TO_BTF_ID_OR_NULL. This approach does not really scale if we have other different reg types in the future, e.g., a pointer to a buffer. This patch enables bpf_iter targets registering ctx argument reg types which may be different from the default one. For example, for pointers to structures, the default reg_type is PTR_TO_BTF_ID for tracing program. The target can register a particular pointer type as PTR_TO_BTF_ID_OR_NULL which can be used by the verifier to enforce accesses. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200513180221.2949882-1-yhs@fb.com
| | * bpf: Change func bpf_iter_unreg_target() signatureYonghong Song2020-05-133-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change func bpf_iter_unreg_target() parameter from target name to target reg_info, similar to bpf_iter_reg_target(). Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200513180220.2949737-1-yhs@fb.com
| | * bpf: net: Refactor bpf_iter target registrationYonghong Song2020-05-136-61/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently bpf_iter_reg_target takes parameters from target and allocates memory to save them. This is really not necessary, esp. in the future we may grow information passed from targets to bpf_iter manager. The patch refactors the code so target reg_info becomes static and bpf_iter manager can just take a reference to it. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200513180219.2949605-1-yhs@fb.com
| | * bpf: Add comments to interpret bpf_prog return valuesYonghong Song2020-05-131-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a short comment in bpf_iter_run_prog() function to explain how bpf_prog return value is converted to seq_ops->show() return value: bpf_prog return seq_ops()->show() return 0 0 1 -EAGAIN When show() return value is -EAGAIN, the current bpf_seq_read() will end. If the current seq_file buffer is empty, -EAGAIN will return to user space. Otherwise, the buffer will be copied to user space. In both cases, the next bpf_seq_read() call will try to show the same object which returned -EAGAIN previously. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200513180218.2949517-1-yhs@fb.com
| | * bpf: Change btf_iter func proto prefix to "bpf_iter_"Yonghong Song2020-05-132-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is to be consistent with tracing and lsm programs which have prefix "bpf_trace_" and "bpf_lsm_" respectively. Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200513180216.2949387-1-yhs@fb.com
| | * tools/bpf: selftests : Explain bpf_iter test failures with llvm 10.0.0Yonghong Song2020-05-131-0/+43
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 6879c042e105 ("tools/bpf: selftests: Add bpf_iter selftests") added self tests for bpf_iter feature. But two subtests ipv6_route and netlink needs llvm latest 10.x release branch or trunk due to a bug in llvm BPF backend. This patch added the file README.rst to document these two failures so people using llvm 10.0.0 can be aware of them. Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200513180215.2949237-1-yhs@fb.com
| * Merge branch 'benchmark-runner'Alexei Starovoitov2020-05-1316-66/+1162
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andrii Nakryiko says: ==================== Add generic benchmark runner framework which simplifies writing various performance benchmarks in a consistent fashion. This framework will be used in follow up patches to test performance of perf buffer and ring buffer as well. Patch #1 extracts parse_num_list to be re-used between test_progs and bench. Patch #2 adds generic runner implementation and atomic counter benchmarks to validate benchmark runner's behavior. Patch #3 implements test_overhead benchmark as part of bench runner. It also add fmod_ret BPF program type to a set of benchmarks. Patch #4 tests faster alternatives to set_task_comm() approach, tested in test_overhead, in search for minimal-overhead way to trigger BPF program execution from user-space on demand. v2->v3: - added --prod-affinity and --cons-affinity (Yonghong); - removed ringbuf-related options leftovers (Yonghong); - added more benchmarking results for test_overhead performance discrepancies; v1->v2: - moved benchmarks into benchs/ subdir (John); - added benchmark "suite" scripts (John); - few small clean ups, change defaults, etc. ==================== Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| | * selftest/bpf: Add BPF triggering benchmarkAndrii Nakryiko2020-05-135-1/+238
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is sometimes desirable to be able to trigger BPF program from user-space with minimal overhead. sys_enter would seem to be a good candidate, yet in a lot of cases there will be a lot of noise from syscalls triggered by other processes on the system. So while searching for low-overhead alternative, I've stumbled upon getpgid() syscall, which seems to be specific enough to not suffer from accidental syscall by other apps. This set of benchmarks compares tp, raw_tp w/ filtering by syscall ID, kprobe, fentry and fmod_ret with returning error (so that syscall would not be executed), to determine the lowest-overhead way. Here are results on my machine (using benchs/run_bench_trigger.sh script): base : 9.200 ± 0.319M/s tp : 6.690 ± 0.125M/s rawtp : 8.571 ± 0.214M/s kprobe : 6.431 ± 0.048M/s fentry : 8.955 ± 0.241M/s fmodret : 8.903 ± 0.135M/s So it seems like fmodret doesn't give much benefit for such lightweight syscall. Raw tracepoint is pretty decent despite additional filtering logic, but it will be called for any other syscall in the system, which rules it out. Fentry, though, seems to be adding the least amoung of overhead and achieves 97.3% of performance of baseline no-BPF-attached syscall. Using getpgid() seems to be preferable to set_task_comm() approach from test_overhead, as it's about 2.35x faster in a baseline performance. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200512192445.2351848-5-andriin@fb.com
| | * selftest/bpf: Fmod_ret prog and implement test_overhead as part of benchAndrii Nakryiko2020-05-136-2/+240
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add fmod_ret BPF program to existing test_overhead selftest. Also re-implement user-space benchmarking part into benchmark runner to compare results. Results with ./bench are consistently somewhat lower than test_overhead's, but relative performance of various types of BPF programs stay consisten (e.g., kretprobe is noticeably slower). This slowdown seems to be coming from the fact that test_overhead is single-threaded, while benchmark always spins off at least one thread for producer. This has been confirmed by hacking multi-threaded test_overhead variant and also single-threaded bench variant. Resutls are below. run_bench_rename.sh script from benchs/ subdirectory was used to produce results for ./bench. Single-threaded implementations =============================== /* bench: single-threaded, atomics */ base : 4.622 ± 0.049M/s kprobe : 3.673 ± 0.052M/s kretprobe : 2.625 ± 0.052M/s rawtp : 4.369 ± 0.089M/s fentry : 4.201 ± 0.558M/s fexit : 4.309 ± 0.148M/s fmodret : 4.314 ± 0.203M/s /* selftest: single-threaded, no atomics */ task_rename base 4555K events per sec task_rename kprobe 3643K events per sec task_rename kretprobe 2506K events per sec task_rename raw_tp 4303K events per sec task_rename fentry 4307K events per sec task_rename fexit 4010K events per sec task_rename fmod_ret 3984K events per sec Multi-threaded implementations ============================== /* bench: multi-threaded w/ atomics */ base : 3.910 ± 0.023M/s kprobe : 3.048 ± 0.037M/s kretprobe : 2.300 ± 0.015M/s rawtp : 3.687 ± 0.034M/s fentry : 3.740 ± 0.087M/s fexit : 3.510 ± 0.009M/s fmodret : 3.485 ± 0.050M/s /* selftest: multi-threaded w/ atomics */ task_rename base 3872K events per sec task_rename kprobe 3068K events per sec task_rename kretprobe 2350K events per sec task_rename raw_tp 3731K events per sec task_rename fentry 3639K events per sec task_rename fexit 3558K events per sec task_rename fmod_ret 3511K events per sec /* selftest: multi-threaded, no atomics */ task_rename base 3945K events per sec task_rename kprobe 3298K events per sec task_rename kretprobe 2451K events per sec task_rename raw_tp 3718K events per sec task_rename fentry 3782K events per sec task_rename fexit 3543K events per sec task_rename fmod_ret 3526K events per sec Note that the fact that ./bench benchmark always uses atomic increments for counting, while test_overhead doesn't, doesn't influence test results all that much. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200512192445.2351848-4-andriin@fb.com
| | * selftests/bpf: Add benchmark runner infrastructureAndrii Nakryiko2020-05-135-1/+608
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While working on BPF ringbuf implementation, testing, and benchmarking, I've developed a pretty generic and modular benchmark runner, which seems to be generically useful, as I've already used it for one more purpose (testing fastest way to trigger BPF program, to minimize overhead of in-kernel code). This patch adds generic part of benchmark runner and sets up Makefile for extending it with more sets of benchmarks. Benchmarker itself operates by spinning up specified number of producer and consumer threads, setting up interval timer sending SIGALARM signal to application once a second. Every second, current snapshot with hits/drops counters are collected and stored in an array. Drops are useful for producer/consumer benchmarks in which producer might overwhelm consumers. Once test finishes after given amount of warm-up and testing seconds, mean and stddev are calculated (ignoring warm-up results) and is printed out to stdout. This setup seems to give consistent and accurate results. To validate behavior, I added two atomic counting tests: global and local. For global one, all the producer threads are atomically incrementing same counter as fast as possible. This, of course, leads to huge drop of performance once there is more than one producer thread due to CPUs fighting for the same memory location. Local counting, on the other hand, maintains one counter per each producer thread, incremented independently. Once per second, all counters are read and added together to form final "counting throughput" measurement. As expected, such setup demonstrates linear scalability with number of producers (as long as there are enough physical CPU cores, of course). See example output below. Also, this setup can nicely demonstrate disastrous effects of false sharing, if care is not taken to take those per-producer counters apart into independent cache lines. Demo output shows global counter first with 1 producer, then with 4. Both total and per-producer performance significantly drop. The last run is local counter with 4 producers, demonstrating near-perfect scalability. $ ./bench -a -w1 -d2 -p1 count-global Setting up benchmark 'count-global'... Benchmark 'count-global' started. Iter 0 ( 24.822us): hits 148.179M/s (148.179M/prod), drops 0.000M/s Iter 1 ( 37.939us): hits 149.308M/s (149.308M/prod), drops 0.000M/s Iter 2 (-10.774us): hits 150.717M/s (150.717M/prod), drops 0.000M/s Iter 3 ( 3.807us): hits 151.435M/s (151.435M/prod), drops 0.000M/s Summary: hits 150.488 ± 1.079M/s (150.488M/prod), drops 0.000 ± 0.000M/s $ ./bench -a -w1 -d2 -p4 count-global Setting up benchmark 'count-global'... Benchmark 'count-global' started. Iter 0 ( 60.659us): hits 53.910M/s ( 13.477M/prod), drops 0.000M/s Iter 1 (-17.658us): hits 53.722M/s ( 13.431M/prod), drops 0.000M/s Iter 2 ( 5.865us): hits 53.495M/s ( 13.374M/prod), drops 0.000M/s Iter 3 ( 0.104us): hits 53.606M/s ( 13.402M/prod), drops 0.000M/s Summary: hits 53.608 ± 0.113M/s ( 13.402M/prod), drops 0.000 ± 0.000M/s $ ./bench -a -w1 -d2 -p4 count-local Setting up benchmark 'count-local'... Benchmark 'count-local' started. Iter 0 ( 23.388us): hits 640.450M/s (160.113M/prod), drops 0.000M/s Iter 1 ( 2.291us): hits 605.661M/s (151.415M/prod), drops 0.000M/s Iter 2 ( -6.415us): hits 607.092M/s (151.773M/prod), drops 0.000M/s Iter 3 ( -1.361us): hits 601.796M/s (150.449M/prod), drops 0.000M/s Summary: hits 604.849 ± 2.739M/s (151.212M/prod), drops 0.000 ± 0.000M/s Benchmark runner supports setting thread affinity for producer and consumer threads. You can use -a flag for default CPU selection scheme, where first consumer gets CPU #0, next one gets CPU #1, and so on. Then producer threads pick up next CPU and increment one-by-one as well. But user can also specify a set of CPUs independently for producers and consumers with --prod-affinity 1,2-10,15 and --cons-affinity <set-of-cpus>. The latter allows to force producers and consumers to share same set of CPUs, if necessary. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200512192445.2351848-3-andriin@fb.com
| | * selftests/bpf: Extract parse_num_list into generic testing_helpers.cAndrii Nakryiko2020-05-135-64/+78
| |/ | | | | | | | | | | | | | | | | | | | | Add testing_helpers.c, which will contain generic helpers for test runners and tests needing some common generic functionality, like parsing a set of numbers. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200512192445.2351848-2-andriin@fb.com
| * libbpf: Fix probe code to return EPERM if encounteredEelco Chaudron2020-05-131-7/+29
| | | | | | | | | | | | | | | | | | | | | | | | When the probe code was failing for any reason ENOTSUP was returned, even if this was due to not having enough lock space. This patch fixes this by returning EPERM to the user application, so it can respond and increase the RLIMIT_MEMLOCK size. Signed-off-by: Eelco Chaudron <echaudro@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/158927424896.2342.10402475603585742943.stgit@ebuild
| * selftests/bpf: Install generated test progsYauheni Kaliuta2020-05-131-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before commit 74b5a5968fe8 ("selftests/bpf: Replace test_progs and test_maps w/ general rule") selftests/bpf used generic install target from selftests/lib.mk to install generated bpf test progs by mentioning them in TEST_GEN_FILES variable. Take that functionality back. Fixes: 74b5a5968fe8 ("selftests/bpf: Replace test_progs and test_maps w/ general rule") Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200513021722.7787-1-yauheni.kaliuta@redhat.com
| * tools, bpf: Synchronise BPF UAPI header with toolsQuentin Monnet2020-05-111-50/+59
| | | | | | | | | | | | | | | | | | Synchronise the bpf.h header under tools, to report the fixes recently brought to the documentation for the BPF helpers. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200511161536.29853-5-quentin@isovalent.com
| * bpf: Minor fixes to BPF helpers documentationQuentin Monnet2020-05-112-50/+65
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Minor improvements to the documentation for BPF helpers: * Fix formatting for the description of "bpf_socket" for bpf_getsockopt() and bpf_setsockopt(), thus suppressing two warnings from rst2man about "Unexpected indentation". * Fix formatting for return values for bpf_sk_assign() and seq_file helpers. * Fix and harmonise formatting, in particular for function/struct names. * Remove blank lines before "Return:" sections. * Replace tabs found in the middle of text lines. * Fix typos. * Add a note to the footer (in Python script) about "bpftool feature probe", including for listing features available to unprivileged users, and add a reference to bpftool man page. Thanks to Florian for reporting two typos (duplicated words). Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200511161536.29853-4-quentin@isovalent.com
| * tools, bpftool: Minor fixes for documentationQuentin Monnet2020-05-1113-70/+116
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Bring minor improvements to bpftool documentation. Fix or harmonise formatting, update map types (including in interactive help), improve description for "map create", fix a build warning due to a missing line after the double-colon for the "bpftool prog profile" example, complete/harmonise/sort the list of related bpftool man pages in footers. v2: - Remove (instead of changing) mark-up on "value" in bpftool-map.rst, when it does not refer to something passed on the command line. - Fix an additional typo ("hexadeximal") in the same file. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200511161536.29853-3-quentin@isovalent.com
| * tools, bpftool: Poison and replace kernel integer typedefsQuentin Monnet2020-05-115-6/+9
| | | | | | | | | | | | | | | | | | | | | | | | Replace the use of kernel-only integer typedefs (u8, u32, etc.) by their user space counterpart (__u8, __u32, etc.). Similarly to what libbpf does, poison the typedefs to avoid introducing them again in the future. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200511161536.29853-2-quentin@isovalent.com
| * bpf, libbpf: Replace zero-length array with flexible-arrayGustavo A. R. Silva2020-05-114-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200507185057.GA13981@embeddedor
| * bpf, runqslower: include proper uapi/bpf.hSong Liu2020-05-101-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | runqslower doesn't specify include path for uapi/bpf.h. This causes the following warning: In file included from runqslower.c:10: .../tools/testing/selftests/bpf/tools/include/bpf/bpf.h:234:38: warning: 'enum bpf_stats_type' declared inside parameter list will not be visible outside of this definition or declaration 234 | LIBBPF_API int bpf_enable_stats(enum bpf_stats_type type); Fix this by adding -I tools/includ/uapi to the Makefile. Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Song Liu <songliubraving@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * Merge branch 'bpf_iter'Alexei Starovoitov2020-05-1043-14/+2664
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Yonghong Song says: ==================== Motivation: The current way to dump kernel data structures mostly: 1. /proc system 2. various specific tools like "ss" which requires kernel support. 3. drgn The dropback for the first two is that whenever you want to dump more, you need change the kernel. For example, Martin wants to dump socket local storage with "ss". Kernel change is needed for it to work ([1]). This is also the direct motivation for this work. drgn ([2]) solves this proble nicely and no kernel change is not needed. But since drgn is not able to verify the validity of a particular pointer value, it might present the wrong results in rare cases. In this patch set, we introduce bpf iterator. Initial kernel changes are still needed for interested kernel data, but a later data structure change will not require kernel changes any more. bpf program itself can adapt to new data structure changes. This will give certain flexibility with guaranteed correctness. In this patch set, kernel seq_ops is used to facilitate iterating through kernel data, similar to current /proc and many other lossless kernel dumping facilities. In the future, different iterators can be implemented to trade off losslessness for other criteria e.g. no repeated object visits, etc. User Interface: 1. Similar to prog/map/link, the iterator can be pinned into a path within a bpffs mount point. 2. The bpftool command can pin an iterator to a file bpftool iter pin <bpf_prog.o> <path> 3. Use `cat <path>` to dump the contents. Use `rm -f <path>` to remove the pinned iterator. 4. The anonymous iterator can be created as well. Please see patch #19 andd #20 for bpf programs and bpf iterator output examples. Note that certain iterators are namespace aware. For example, task and task_file targets only iterate through current pid namespace. ipv6_route and netlink will iterate through current net namespace. Please see individual patches for implementation details. Performance: The bpf iterator provides in-kernel aggregation abilities for kernel data. This can greatly improve performance compared to e.g., iterating all process directories under /proc. For example, I did an experiment on my VM with an application forking different number of tasks and each forked process opening various number of files. The following is the result with the latency with unit of microseconds: # of forked tasks # of open files # of bpf_prog calls # latency (us) 100 100 11503 7586 1000 1000 1013203 709513 10000 100 1130203 764519 The number of bpf_prog calls may be more than forked tasks multipled by open files since there are other tasks running on the system. The bpf program is a do-nothing program. One millions of bpf calls takes less than one second. Although the initial motivation is from Martin's sk_local_storage, this patch didn't implement tcp6 sockets and sk_local_storage. The /proc/net/tcp6 involves three types of sockets, timewait, request and tcp6 sockets. Some kind of type casting or other mechanism is needed to handle all these socket types in one bpf program. This will be addressed in future work. Currently, we do not support kernel data generated under module. This requires some BTF work. More work for more iterators, e.g., tcp, udp, bpf_map elements, etc. Changelog: v3 -> v4: - in bpf_seq_read(), if start() failed with an error, return that error to user space (Andrii) - in bpf_seq_printf(), if reading kernel memory failed for %s and %p{i,I}{4,6}, set buffer to empty string or address 0. Documented this behavior in uapi header (Andrii) - fix a few error handling issues for bpftool (Andrii) - A few other minor fixes and cosmetic changes. v2 -> v3: - add bpf_iter_unreg_target() to unregister a target, used in the error path of the __init functions. - handle err != 0 before handling overflow (Andrii) - reference count "task" for task_file target (Andrii) - remove some redundancy for bpf_map/task/task_file targets - add bpf_iter_unreg_target() in ip6_route_cleanup() - Handling "%%" format in bpf_seq_printf() (Andrii) - implement auto-attach for bpf_iter in libbpf (Andrii) - add macros offsetof and container_of in bpf_helpers.h (Andrii) - add tests for auto-attach and program-return-1 cases - some other minor fixes v1 -> v2: - removed target_feature, using callback functions instead - checking target to ensure program specified btf_id supported (Martin) - link_create change with new changes from Andrii - better handling of btf_iter vs. seq_file private data (Martin, Andrii) - implemented bpf_seq_read() (Andrii, Alexei) - percpu buffer for bpf_seq_printf() (Andrii) - better syntax for BPF_SEQ_PRINTF macro (Andrii) - bpftool fixes (Quentin) - a lot of other fixes RFC v2 -> v1: - rename bpfdump to bpf_iter - use bpffs instead of a new file system - use bpf_link to streamline and simplify iterator creation. References: [1]: https://lore.kernel.org/bpf/20200225230427.1976129-1-kafai@fb.com [2]: https://github.com/osandov/drgn ==================== Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| | * tools/bpf: selftests: Add bpf_iter selftestsYonghong Song2020-05-106-0/+509
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The added test includes the following subtests: - test verifier change for btf_id_or_null - test load/create_iter/read for ipv6_route/netlink/bpf_map/task/task_file - test anon bpf iterator - test anon bpf iterator reading one char at a time - test file bpf iterator - test overflow (single bpf program output not overflow) - test overflow (single bpf program output overflows) - test bpf prog returning 1 The ipv6_route tests the following verifier change - access fields in the variable length array of the structure. The netlink load tests the following verifier change - put a btf_id ptr value in a stack and accessible to tracing/iter programs. The anon bpf iterator also tests link auto attach through skeleton. $ test_progs -n 2 #2/1 btf_id_or_null:OK #2/2 ipv6_route:OK #2/3 netlink:OK #2/4 bpf_map:OK #2/5 task:OK #2/6 task_file:OK #2/7 anon:OK #2/8 anon-read-one-char:OK #2/9 file:OK #2/10 overflow:OK #2/11 overflow-e2big:OK #2/12 prog-ret-1:OK #2 bpf_iter:OK Summary: 1/12 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200509175923.2477637-1-yhs@fb.com
| | * tools/bpf: selftests: Add iter progs for bpf_map/task/task_fileYonghong Song2020-05-103-0/+79
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The implementation is arbitrary, just to show how the bpf programs can be written for bpf_map/task/task_file. They can be costomized for specific needs. For example, for bpf_map, the iterator prints out: $ cat /sys/fs/bpf/my_bpf_map id refcnt usercnt locked_vm 3 2 0 20 6 2 0 20 9 2 0 20 12 2 0 20 13 2 0 20 16 2 0 20 19 2 0 20 %%% END %%% For task, the iterator prints out: $ cat /sys/fs/bpf/my_task tgid gid 1 1 2 2 .... 1944 1944 1948 1948 1949 1949 1953 1953 === END === For task/file, the iterator prints out: $ cat /sys/fs/bpf/my_task_file tgid gid fd file 1 1 0 ffffffff95c97600 1 1 1 ffffffff95c97600 1 1 2 ffffffff95c97600 .... 1895 1895 255 ffffffff95c8fe00 1932 1932 0 ffffffff95c8fe00 1932 1932 1 ffffffff95c8fe00 1932 1932 2 ffffffff95c8fe00 1932 1932 3 ffffffff95c185c0 This is able to print out all open files (fd and file->f_op), so user can compare f_op against a particular kernel file operations to find what it is. For example, from /proc/kallsyms, we can find ffffffff95c185c0 r eventfd_fops so we will know tgid 1932 fd 3 is an eventfd file descriptor. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200509175922.2477576-1-yhs@fb.com
| | * tools/bpf: selftests: Add iterator programs for ipv6_route and netlinkYonghong Song2020-05-102-0/+128
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Two bpf programs are added in this patch for netlink and ipv6_route target. On my VM, I am able to achieve identical results compared to /proc/net/netlink and /proc/net/ipv6_route. $ cat /proc/net/netlink sk Eth Pid Groups Rmem Wmem Dump Locks Drops Inode 000000002c42d58b 0 0 00000000 0 0 0 2 0 7 00000000a4e8b5e1 0 1 00000551 0 0 0 2 0 18719 00000000e1b1c195 4 0 00000000 0 0 0 2 0 16422 000000007e6b29f9 6 0 00000000 0 0 0 2 0 16424 .... 00000000159a170d 15 1862 00000002 0 0 0 2 0 1886 000000009aca4bc9 15 3918224839 00000002 0 0 0 2 0 19076 00000000d0ab31d2 15 1 00000002 0 0 0 2 0 18683 000000008398fb08 16 0 00000000 0 0 0 2 0 27 $ cat /sys/fs/bpf/my_netlink sk Eth Pid Groups Rmem Wmem Dump Locks Drops Inode 000000002c42d58b 0 0 00000000 0 0 0 2 0 7 00000000a4e8b5e1 0 1 00000551 0 0 0 2 0 18719 00000000e1b1c195 4 0 00000000 0 0 0 2 0 16422 000000007e6b29f9 6 0 00000000 0 0 0 2 0 16424 .... 00000000159a170d 15 1862 00000002 0 0 0 2 0 1886 000000009aca4bc9 15 3918224839 00000002 0 0 0 2 0 19076 00000000d0ab31d2 15 1 00000002 0 0 0 2 0 18683 000000008398fb08 16 0 00000000 0 0 0 2 0 27 $ cat /proc/net/ipv6_route fe800000000000000000000000000000 40 00000000000000000000000000000000 00 00000000000000000000000000000000 00000100 00000001 00000000 00000001 eth0 00000000000000000000000000000000 00 00000000000000000000000000000000 00 00000000000000000000000000000000 ffffffff 00000001 00000000 00200200 lo 00000000000000000000000000000001 80 00000000000000000000000000000000 00 00000000000000000000000000000000 00000000 00000003 00000000 80200001 lo fe80000000000000c04b03fffe7827ce 80 00000000000000000000000000000000 00 00000000000000000000000000000000 00000000 00000002 00000000 80200001 eth0 ff000000000000000000000000000000 08 00000000000000000000000000000000 00 00000000000000000000000000000000 00000100 00000003 00000000 00000001 eth0 00000000000000000000000000000000 00 00000000000000000000000000000000 00 00000000000000000000000000000000 ffffffff 00000001 00000000 00200200 lo $ cat /sys/fs/bpf/my_ipv6_route fe800000000000000000000000000000 40 00000000000000000000000000000000 00 00000000000000000000000000000000 00000100 00000001 00000000 00000001 eth0 00000000000000000000000000000000 00 00000000000000000000000000000000 00 00000000000000000000000000000000 ffffffff 00000001 00000000 00200200 lo 00000000000000000000000000000001 80 00000000000000000000000000000000 00 00000000000000000000000000000000 00000000 00000003 00000000 80200001 lo fe80000000000000c04b03fffe7827ce 80 00000000000000000000000000000000 00 00000000000000000000000000000000 00000000 00000002 00000000 80200001 eth0 ff000000000000000000000000000000 08 00000000000000000000000000000000 00 00000000000000000000000000000000 00000100 00000003 00000000 00000001 eth0 00000000000000000000000000000000 00 00000000000000000000000000000000 00 00000000000000000000000000000000 ffffffff 00000001 00000000 00200200 lo Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200509175921.2477493-1-yhs@fb.com
| | * tools/bpftool: Add bpf_iter support for bptoolYonghong Song2020-05-106-1/+188
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, only one command is supported bpftool iter pin <bpf_prog.o> <path> It will pin the trace/iter bpf program in the object file <bpf_prog.o> to the <path> where <path> should be on a bpffs mount. For example, $ bpftool iter pin ./bpf_iter_ipv6_route.o \ /sys/fs/bpf/my_route User can then do a `cat` to print out the results: $ cat /sys/fs/bpf/my_route fe800000000000000000000000000000 40 00000000000000000000000000000000 ... 00000000000000000000000000000000 00 00000000000000000000000000000000 ... 00000000000000000000000000000001 80 00000000000000000000000000000000 ... fe800000000000008c0162fffebdfd57 80 00000000000000000000000000000000 ... ff000000000000000000000000000000 08 00000000000000000000000000000000 ... 00000000000000000000000000000000 00 00000000000000000000000000000000 ... The implementation for ipv6_route iterator is in one of subsequent patches. This patch also added BPF_LINK_TYPE_ITER to link query. In the future, we may add additional parameters to pin command by parameterizing the bpf iterator. For example, a map_id or pid may be added to let bpf program only traverses a single map or task, similar to kernel seq_file single_open(). We may also add introspection command for targets/iterators by leveraging the bpf_iter itself. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200509175920.2477247-1-yhs@fb.com
| | * tools/libpf: Add offsetof/container_of macro in bpf_helpers.hYonghong Song2020-05-101-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These two helpers will be used later in bpf_iter bpf program bpf_iter_netlink.c. Put them in bpf_helpers.h since they could be useful in other cases. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200509175919.2477104-1-yhs@fb.com
| | * tools/libbpf: Add bpf_iter supportYonghong Song2020-05-106-0/+91
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Two new libbpf APIs are added to support bpf_iter: - bpf_program__attach_iter Given a bpf program and additional parameters, which is none now, returns a bpf_link. - bpf_iter_create syscall level API to create a bpf iterator. The macro BPF_SEQ_PRINTF are also introduced. The format looks like: BPF_SEQ_PRINTF(seq, "task id %d\n", pid); This macro can help bpf program writers with nicer bpf_seq_printf syntax similar to the kernel one. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200509175917.2476936-1-yhs@fb.com
| | * bpf: Support variable length array in tracing programsYonghong Song2020-05-101-0/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In /proc/net/ipv6_route, we have struct fib6_info { struct fib6_table *fib6_table; ... struct fib6_nh fib6_nh[0]; } struct fib6_nh { struct fib_nh_common nh_common; struct rt6_info **rt6i_pcpu; struct rt6_exception_bucket *rt6i_exception_bucket; }; struct fib_nh_common { ... u8 nhc_gw_family; ... } The access: struct fib6_nh *fib6_nh = &rt->fib6_nh; ... fib6_nh->nh_common.nhc_gw_family ... This patch ensures such an access is handled properly. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200509175916.2476853-1-yhs@fb.com
| | * bpf: Handle spilled PTR_TO_BTF_ID properly when checking stack_boundaryYonghong Song2020-05-101-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This specifically to handle the case like below: // ptr below is a socket ptr identified by PTR_TO_BTF_ID u64 param[2] = { ptr, val }; bpf_seq_printf(seq, fmt, sizeof(fmt), param, sizeof(param)); In this case, the 16 bytes stack for "param" contains: 8 bytes for ptr with spilled PTR_TO_BTF_ID 8 bytes for val as STACK_MISC The current verifier will complain the ptr should not be visible to the helper. ... 16: (7b) *(u64 *)(r10 -64) = r2 18: (7b) *(u64 *)(r10 -56) = r1 19: (bf) r4 = r10 ; 20: (07) r4 += -64 ; BPF_SEQ_PRINTF(seq, fmt1, (long)s, s->sk_protocol); 21: (bf) r1 = r6 22: (18) r2 = 0xffffa8d00018605a 24: (b4) w3 = 10 25: (b4) w5 = 16 26: (85) call bpf_seq_printf#125 R0=inv(id=0) R1_w=ptr_seq_file(id=0,off=0,imm=0) R2_w=map_value(id=0,off=90,ks=4,vs=144,imm=0) R3_w=inv10 R4_w=fp-64 R5_w=inv16 R6=ptr_seq_file(id=0,off=0,imm=0) R7=ptr_netlink_sock(id=0,off=0,imm=0) R10=fp0 fp-56_w=mmmmmmmm fp-64_w=ptr_ last_idx 26 first_idx 13 regs=8 stack=0 before 25: (b4) w5 = 16 regs=8 stack=0 before 24: (b4) w3 = 10 invalid indirect read from stack off -64+0 size 16 Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200509175915.2476783-1-yhs@fb.com
| | * bpf: Add bpf_seq_printf and bpf_seq_write helpersYonghong Song2020-05-104-2/+292
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Two helpers bpf_seq_printf and bpf_seq_write, are added for writing data to the seq_file buffer. bpf_seq_printf supports common format string flag/width/type fields so at least I can get identical results for netlink and ipv6_route targets. For bpf_seq_printf and bpf_seq_write, return value -EOVERFLOW specifically indicates a write failure due to overflow, which means the object will be repeated in the next bpf invocation if object collection stays the same. Note that if the object collection is changed, depending how collection traversal is done, even if the object still in the collection, it may not be visited. For bpf_seq_printf, format %s, %p{i,I}{4,6} needs to read kernel memory. Reading kernel memory may fail in the following two cases: - invalid kernel address, or - valid kernel address but requiring a major fault If reading kernel memory failed, the %s string will be an empty string and %p{i,I}{4,6} will be all 0. Not returning error to bpf program is consistent with what bpf_trace_printk() does for now. bpf_seq_printf may return -EBUSY meaning that internal percpu buffer for memory copy of strings or other pointees is not available. Bpf program can return 1 to indicate it wants the same object to be repeated. Right now, this should not happen on no-RT kernels since migrate_disable(), which guards bpf prog call, calls preempt_disable(). Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200509175914.2476661-1-yhs@fb.com
| | * bpf: Add PTR_TO_BTF_ID_OR_NULL supportYonghong Song2020-05-103-5/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add bpf_reg_type PTR_TO_BTF_ID_OR_NULL support. For tracing/iter program, the bpf program context definition, e.g., for previous bpf_map target, looks like struct bpf_iter__bpf_map { struct bpf_iter_meta *meta; struct bpf_map *map; }; The kernel guarantees that meta is not NULL, but map pointer maybe NULL. The NULL map indicates that all objects have been traversed, so bpf program can take proper action, e.g., do final aggregation and/or send final report to user space. Add btf_id_or_null_non0_off to prog->aux structure, to indicate that if the context access offset is not 0, set to PTR_TO_BTF_ID_OR_NULL instead of PTR_TO_BTF_ID. This bit is set for tracing/iter program. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200509175912.2476576-1-yhs@fb.com
| | * bpf: Add task and task/file iterator targetsYonghong Song2020-05-102-1/+334
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Only the tasks belonging to "current" pid namespace are enumerated. For task/file target, the bpf program will have access to struct task_struct *task u32 fd struct file *file where fd/file is an open file for the task. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200509175911.2476407-1-yhs@fb.com
| | * net: bpf: Add netlink and ipv6_route bpf_iter targetsYonghong Song2020-05-105-4/+207
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch added netlink and ipv6_route targets, using the same seq_ops (except show() and minor changes for stop()) for /proc/net/{netlink,ipv6_route}. The net namespace for these targets are the current net namespace at file open stage, similar to /proc/net/{netlink,ipv6_route} reference counting the net namespace at seq_file open stage. Since module is not supported for now, ipv6_route is supported only if the IPV6 is built-in, i.e., not compiled as a module. The restriction can be lifted once module is properly supported for bpf_iter. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200509175910.2476329-1-yhs@fb.com
| | * bpf: Add bpf_map iteratorYonghong Song2020-05-104-1/+118
| | | | | | | | | | | | | | | | | | | | | | | | | | | Implement seq_file operations to traverse all bpf_maps. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200509175909.2476096-1-yhs@fb.com