From 7f18fabdaaffb9ec735e362829bdcddfc94338c8 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Tue, 7 Jul 2020 18:53:18 -0700 Subject: [PATCH] selftests/bpf: Switch perf_buffer test to tracepoint and skeleton [upstream commit 6984cbc6dfa280687367b9660d8c830518239851] Switch perf_buffer test to use skeleton to avoid use of bpf_prog_load() and make test a bit more succinct. Also switch BPF program to use tracepoint instead of kprobe, as that allows to support older kernels, which had tracepoint support before kprobe support in the form that libbpf expects (i.e., libbpf expects /sys/bus/event_source/devices/kprobe/type, which doesn't always exist on old kernels). Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20200708015318.3827358-7-andriin@fb.com --- .../selftests/bpf/prog_tests/perf_buffer.c | 42 ++++++------------- .../selftests/bpf/progs/test_perf_buffer.c | 4 +- 2 files changed, 14 insertions(+), 32 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/perf_buffer.c b/tools/testing/selftests/bpf/prog_tests/perf_buffer.c index cf6c87936..ff6ae3619 100644 --- a/tools/testing/selftests/bpf/prog_tests/perf_buffer.c +++ b/tools/testing/selftests/bpf/prog_tests/perf_buffer.c @@ -4,6 +4,7 @@ #include #include #include +#include "test_perf_buffer.skel.h" #include "libbpf_internal.h" static void on_sample(void *ctx, int cpu, void *data, __u32 size) @@ -20,16 +21,11 @@ static void on_sample(void *ctx, int cpu, void *data, __u32 size) void test_perf_buffer(void) { - int err, prog_fd, on_len, nr_on_cpus = 0, nr_cpus, i, duration = 0; - const char *prog_name = "kprobe/sys_nanosleep"; - const char *file = "./test_perf_buffer.o"; + int err, on_len, nr_on_cpus = 0, nr_cpus, i, duration = 0; struct perf_buffer_opts pb_opts = {}; - struct bpf_map *perf_buf_map; + struct test_perf_buffer *skel; cpu_set_t cpu_set, cpu_seen; - struct bpf_program *prog; - struct bpf_object *obj; struct perf_buffer *pb; - struct bpf_link *link; bool *online; nr_cpus = libbpf_num_possible_cpus(); @@ -46,33 +42,21 @@ void test_perf_buffer(void) nr_on_cpus++; /* load program */ - err = bpf_prog_load(file, BPF_PROG_TYPE_KPROBE, &obj, &prog_fd); - if (CHECK(err, "obj_load", "err %d errno %d\n", err, errno)) { - obj = NULL; - goto out_close; - } - - prog = bpf_object__find_program_by_title(obj, prog_name); - if (CHECK(!prog, "find_probe", "prog '%s' not found\n", prog_name)) + skel = test_perf_buffer__open_and_load(); + if (CHECK(!skel, "skel_load", "skeleton open/load failed\n")) goto out_close; - /* load map */ - perf_buf_map = bpf_object__find_map_by_name(obj, "perf_buf_map"); - if (CHECK(!perf_buf_map, "find_perf_buf_map", "not found\n")) - goto out_close; - - /* attach kprobe */ - link = bpf_program__attach_kprobe(prog, false /* retprobe */, - SYS_NANOSLEEP_KPROBE_NAME); - if (CHECK(IS_ERR(link), "attach_kprobe", "err %ld\n", PTR_ERR(link))) + /* attach probe */ + err = test_perf_buffer__attach(skel); + if (CHECK(err, "attach_kprobe", "err %d\n", err)) goto out_close; /* set up perf buffer */ pb_opts.sample_cb = on_sample; pb_opts.ctx = &cpu_seen; - pb = perf_buffer__new(bpf_map__fd(perf_buf_map), 1, &pb_opts); + pb = perf_buffer__new(bpf_map__fd(skel->maps.perf_buf_map), 1, &pb_opts); if (CHECK(IS_ERR(pb), "perf_buf__new", "err %ld\n", PTR_ERR(pb))) - goto out_detach; + goto out_close; /* trigger kprobe on every CPU */ CPU_ZERO(&cpu_seen); @@ -89,7 +73,7 @@ void test_perf_buffer(void) &cpu_set); if (err && CHECK(err, "set_affinity", "cpu #%d, err %d\n", i, err)) - goto out_detach; + goto out_close; usleep(1); } @@ -105,9 +89,7 @@ void test_perf_buffer(void) out_free_pb: perf_buffer__free(pb); -out_detach: - bpf_link__destroy(link); out_close: - bpf_object__close(obj); + test_perf_buffer__destroy(skel); free(online); } diff --git a/tools/testing/selftests/bpf/progs/test_perf_buffer.c b/tools/testing/selftests/bpf/progs/test_perf_buffer.c index 876c27deb..ac0b5072d 100644 --- a/tools/testing/selftests/bpf/progs/test_perf_buffer.c +++ b/tools/testing/selftests/bpf/progs/test_perf_buffer.c @@ -11,8 +11,8 @@ struct { __uint(value_size, sizeof(int)); } perf_buf_map SEC(".maps"); -SEC("kprobe/sys_nanosleep") -int handle_sys_nanosleep_entry(struct pt_regs *ctx) +SEC("tp/raw_syscalls/sys_enter") +int handle_sys_enter(void *ctx) { int cpu = bpf_get_smp_processor_id();