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author | Jakub Kicinski <kuba@kernel.org> | 2024-01-06 06:15:32 +0300 |
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committer | Jakub Kicinski <kuba@kernel.org> | 2024-01-06 06:15:32 +0300 |
commit | 8158a50f9058ce882a6a020c41cef6bae2c3eae3 (patch) | |
tree | 7b0eef570ee9a02971813e074afa674a54e8e403 /tools/testing/selftests/bpf/prog_tests/recursive_attach.c | |
parent | 795fd9342c628839ac9c3f3133d063ce2e577ea7 (diff) | |
parent | 5fe4ee6ae187523f710f1b93024437a073d88b17 (diff) | |
download | linux-8158a50f9058ce882a6a020c41cef6bae2c3eae3.tar.xz |
Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:
====================
pull-request: bpf-next 2024-01-05
We've added 40 non-merge commits during the last 2 day(s) which contain
a total of 73 files changed, 1526 insertions(+), 951 deletions(-).
The main changes are:
1) Fix a memory leak when streaming AF_UNIX sockets were inserted
into multiple sockmap slots/maps, from John Fastabend.
2) Fix gotol in s390 BPF JIT with large offsets, from Ilya Leoshkevich.
3) Fix reattachment branch in bpf_tracing_prog_attach() and reject
the request if there is no valid attach_btf, from Jiri Olsa.
4) Remove deprecated bpfilter kernel leftovers given the project
is developed in user space (https://github.com/facebook/bpfilter),
from Quentin Deslandes.
5) Relax tracing BPF program recursive attach rules given right now
it is not possible to create tracing program call cycles,
from Dmitrii Dolgov.
6) Fix excessive memory consumption for the bpf_global_percpu_ma
for systems with a large number of CPUs, from Yonghong Song.
7) Small x86 BPF JIT cleanup to reuse emit_nops instead of open-coding
memcpy of x86_nops, from Leon Hwang.
8) Follow-up for libbpf to support __arg_ctx global function argument tag
semantics to complement the merged kernel side, from Andrii Nakryiko.
9) Introduce "volatile compare" macros for BPF selftests in order
to make the latter more robust against compiler optimization,
from Alexei Starovoitov.
10) Small simplification in verifier's size checking of helper accesses
along with additional selftests, from Andrei Matei.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (40 commits)
selftests/bpf: Test re-attachment fix for bpf_tracing_prog_attach
bpf: Fix re-attachment branch in bpf_tracing_prog_attach
selftests/bpf: Add test for recursive attachment of tracing progs
bpf: Relax tracing prog recursive attach rules
bpf, x86: Use emit_nops to replace memcpy x86_nops
selftests/bpf: Test gotol with large offsets
selftests/bpf: Double the size of test_loader log
s390/bpf: Fix gotol with large offsets
bpfilter: remove bpfilter
bpf: Remove unnecessary cpu == 0 check in memalloc
selftests/bpf: add __arg_ctx BTF rewrite test
selftests/bpf: add arg:ctx cases to test_global_funcs tests
libbpf: implement __arg_ctx fallback logic
libbpf: move BTF loading step after relocation step
libbpf: move exception callbacks assignment logic into relocation step
libbpf: use stable map placeholder FDs
libbpf: don't rely on map->fd as an indicator of map being created
libbpf: use explicit map reuse flag to skip map creation steps
libbpf: make uniform use of btf__fd() accessor inside libbpf
selftests/bpf: Add a selftest with > 512-byte percpu allocation size
...
====================
Link: https://lore.kernel.org/r/20240105170105.21070-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/recursive_attach.c')
-rw-r--r-- | tools/testing/selftests/bpf/prog_tests/recursive_attach.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/recursive_attach.c b/tools/testing/selftests/bpf/prog_tests/recursive_attach.c new file mode 100644 index 000000000000..8100509e561b --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/recursive_attach.c @@ -0,0 +1,151 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2023 Red Hat, Inc. */ +#include <test_progs.h> +#include "fentry_recursive.skel.h" +#include "fentry_recursive_target.skel.h" +#include <bpf/btf.h> +#include "bpf/libbpf_internal.h" + +/* Test recursive attachment of tracing progs with more than one nesting level + * is not possible. Create a chain of attachment, verify that the last prog + * will fail. Depending on the arguments, following cases are tested: + * + * - Recursive loading of tracing progs, without attaching (attach = false, + * detach = false). The chain looks like this: + * load target + * load fentry1 -> target + * load fentry2 -> fentry1 (fail) + * + * - Recursive attach of tracing progs (attach = true, detach = false). The + * chain looks like this: + * load target + * load fentry1 -> target + * attach fentry1 -> target + * load fentry2 -> fentry1 (fail) + * + * - Recursive attach and detach of tracing progs (attach = true, detach = + * true). This validates that attach_tracing_prog flag will be set throughout + * the whole lifecycle of an fentry prog, independently from whether it's + * detached. The chain looks like this: + * load target + * load fentry1 -> target + * attach fentry1 -> target + * detach fentry1 + * load fentry2 -> fentry1 (fail) + */ +static void test_recursive_fentry_chain(bool attach, bool detach) +{ + struct fentry_recursive_target *target_skel = NULL; + struct fentry_recursive *tracing_chain[2] = {}; + struct bpf_program *prog; + int prev_fd, err; + + target_skel = fentry_recursive_target__open_and_load(); + if (!ASSERT_OK_PTR(target_skel, "fentry_recursive_target__open_and_load")) + return; + + /* Create an attachment chain with two fentry progs */ + for (int i = 0; i < 2; i++) { + tracing_chain[i] = fentry_recursive__open(); + if (!ASSERT_OK_PTR(tracing_chain[i], "fentry_recursive__open")) + goto close_prog; + + /* The first prog in the chain is going to be attached to the target + * fentry program, the second one to the previous in the chain. + */ + prog = tracing_chain[i]->progs.recursive_attach; + if (i == 0) { + prev_fd = bpf_program__fd(target_skel->progs.test1); + err = bpf_program__set_attach_target(prog, prev_fd, "test1"); + } else { + prev_fd = bpf_program__fd(tracing_chain[i-1]->progs.recursive_attach); + err = bpf_program__set_attach_target(prog, prev_fd, "recursive_attach"); + } + + if (!ASSERT_OK(err, "bpf_program__set_attach_target")) + goto close_prog; + + err = fentry_recursive__load(tracing_chain[i]); + /* The first attach should succeed, the second fail */ + if (i == 0) { + if (!ASSERT_OK(err, "fentry_recursive__load")) + goto close_prog; + + if (attach) { + err = fentry_recursive__attach(tracing_chain[i]); + if (!ASSERT_OK(err, "fentry_recursive__attach")) + goto close_prog; + } + + if (detach) { + /* Flag attach_tracing_prog should still be set, preventing + * attachment of the following prog. + */ + fentry_recursive__detach(tracing_chain[i]); + } + } else { + if (!ASSERT_ERR(err, "fentry_recursive__load")) + goto close_prog; + } + } + +close_prog: + fentry_recursive_target__destroy(target_skel); + for (int i = 0; i < 2; i++) { + fentry_recursive__destroy(tracing_chain[i]); + } +} + +void test_recursive_fentry(void) +{ + if (test__start_subtest("attach")) + test_recursive_fentry_chain(true, false); + if (test__start_subtest("load")) + test_recursive_fentry_chain(false, false); + if (test__start_subtest("detach")) + test_recursive_fentry_chain(true, true); +} + +/* Test that a tracing prog reattachment (when we land in + * "prog->aux->dst_trampoline and tgt_prog is NULL" branch in + * bpf_tracing_prog_attach) does not lead to a crash due to missing attach_btf + */ +void test_fentry_attach_btf_presence(void) +{ + struct fentry_recursive_target *target_skel = NULL; + struct fentry_recursive *tracing_skel = NULL; + struct bpf_program *prog; + int err, link_fd, tgt_prog_fd; + + target_skel = fentry_recursive_target__open_and_load(); + if (!ASSERT_OK_PTR(target_skel, "fentry_recursive_target__open_and_load")) + goto close_prog; + + tracing_skel = fentry_recursive__open(); + if (!ASSERT_OK_PTR(tracing_skel, "fentry_recursive__open")) + goto close_prog; + + prog = tracing_skel->progs.recursive_attach; + tgt_prog_fd = bpf_program__fd(target_skel->progs.fentry_target); + err = bpf_program__set_attach_target(prog, tgt_prog_fd, "fentry_target"); + if (!ASSERT_OK(err, "bpf_program__set_attach_target")) + goto close_prog; + + err = fentry_recursive__load(tracing_skel); + if (!ASSERT_OK(err, "fentry_recursive__load")) + goto close_prog; + + tgt_prog_fd = bpf_program__fd(tracing_skel->progs.recursive_attach); + link_fd = bpf_link_create(tgt_prog_fd, 0, BPF_TRACE_FENTRY, NULL); + if (!ASSERT_GE(link_fd, 0, "link_fd")) + goto close_prog; + + fentry_recursive__detach(tracing_skel); + + err = fentry_recursive__attach(tracing_skel); + ASSERT_ERR(err, "fentry_recursive__attach"); + +close_prog: + fentry_recursive_target__destroy(target_skel); + fentry_recursive__destroy(tracing_skel); +} |