Adding test that puts kprobe on bpf_fentry_test1 that calls bpf_kfunc_common_test kfunc, which has also kprobe on. The latter won't get triggered due to kprobe recursion check and kprobe missed counter is incremented. Acked-by: Hou Tao <houtao1@xxxxxxxxxx> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx> --- .../selftests/bpf/bpf_testmod/bpf_testmod.c | 5 ++ .../bpf/bpf_testmod/bpf_testmod_kfunc.h | 2 + .../testing/selftests/bpf/prog_tests/missed.c | 47 +++++++++++++++++++ .../selftests/bpf/progs/missed_kprobe.c | 30 ++++++++++++ 4 files changed, 84 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/missed.c create mode 100644 tools/testing/selftests/bpf/progs/missed_kprobe.c diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c index cefc5dd72573..a5e246f7b202 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c @@ -138,6 +138,10 @@ __bpf_kfunc void bpf_iter_testmod_seq_destroy(struct bpf_iter_testmod_seq *it) it->cnt = 0; } +__bpf_kfunc void bpf_kfunc_common_test(void) +{ +} + struct bpf_testmod_btf_type_tag_1 { int a; }; @@ -343,6 +347,7 @@ BTF_SET8_START(bpf_testmod_common_kfunc_ids) BTF_ID_FLAGS(func, bpf_iter_testmod_seq_new, KF_ITER_NEW) BTF_ID_FLAGS(func, bpf_iter_testmod_seq_next, KF_ITER_NEXT | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_iter_testmod_seq_destroy, KF_ITER_DESTROY) +BTF_ID_FLAGS(func, bpf_kfunc_common_test) BTF_SET8_END(bpf_testmod_common_kfunc_ids) static const struct btf_kfunc_id_set bpf_testmod_common_kfunc_set = { diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h index f5c5b1375c24..7c664dd61059 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h @@ -104,4 +104,6 @@ void bpf_kfunc_call_test_fail1(struct prog_test_fail1 *p); void bpf_kfunc_call_test_fail2(struct prog_test_fail2 *p); void bpf_kfunc_call_test_fail3(struct prog_test_fail3 *p); void bpf_kfunc_call_test_mem_len_fail1(void *mem, int len); + +void bpf_kfunc_common_test(void) __ksym; #endif /* _BPF_TESTMOD_KFUNC_H */ diff --git a/tools/testing/selftests/bpf/prog_tests/missed.c b/tools/testing/selftests/bpf/prog_tests/missed.c new file mode 100644 index 000000000000..fc674258c81f --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/missed.c @@ -0,0 +1,47 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <test_progs.h> +#include "missed_kprobe.skel.h" + +/* + * Putting kprobe on bpf_fentry_test1 that calls bpf_kfunc_common_test + * kfunc, which has also kprobe on. The latter won't get triggered due + * to kprobe recursion check and kprobe missed counter is incremented. + */ +static void test_missed_perf_kprobe(void) +{ + LIBBPF_OPTS(bpf_test_run_opts, topts); + struct bpf_link_info info = {}; + struct missed_kprobe *skel; + __u32 len = sizeof(info); + int err, prog_fd; + + skel = missed_kprobe__open_and_load(); + if (!ASSERT_OK_PTR(skel, "missed_kprobe__open_and_load")) + goto cleanup; + + err = missed_kprobe__attach(skel); + if (!ASSERT_OK(err, "missed_kprobe__attach")) + goto cleanup; + + prog_fd = bpf_program__fd(skel->progs.trigger); + err = bpf_prog_test_run_opts(prog_fd, &topts); + ASSERT_OK(err, "test_run"); + ASSERT_EQ(topts.retval, 0, "test_run"); + + err = bpf_link_get_info_by_fd(bpf_link__fd(skel->links.test2), &info, &len); + if (!ASSERT_OK(err, "bpf_link_get_info_by_fd")) + goto cleanup; + + ASSERT_EQ(info.type, BPF_LINK_TYPE_PERF_EVENT, "info.type"); + ASSERT_EQ(info.perf_event.type, BPF_PERF_EVENT_KPROBE, "info.perf_event.type"); + ASSERT_EQ(info.perf_event.kprobe.missed, 1, "info.perf_event.kprobe.missed"); + +cleanup: + missed_kprobe__destroy(skel); +} + +void serial_test_missed(void) +{ + if (test__start_subtest("perf_kprobe")) + test_missed_perf_kprobe(); +} diff --git a/tools/testing/selftests/bpf/progs/missed_kprobe.c b/tools/testing/selftests/bpf/progs/missed_kprobe.c new file mode 100644 index 000000000000..7f9ef701f5de --- /dev/null +++ b/tools/testing/selftests/bpf/progs/missed_kprobe.c @@ -0,0 +1,30 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> +#include "../bpf_testmod/bpf_testmod_kfunc.h" + +char _license[] SEC("license") = "GPL"; + +/* + * No tests in here, just to trigger 'bpf_fentry_test*' + * through tracing test_run + */ +SEC("fentry/bpf_modify_return_test") +int BPF_PROG(trigger) +{ + return 0; +} + +SEC("kprobe/bpf_fentry_test1") +int test1(struct pt_regs *ctx) +{ + bpf_kfunc_common_test(); + return 0; +} + +SEC("kprobe/bpf_kfunc_common_test") +int test2(struct pt_regs *ctx) +{ + return 0; +} -- 2.41.0