1 // SPDX-License-Identifier: GPL-2.0
5 #include <sys/socket.h>
6 #include <test_progs.h>
7 #include "bpf/libbpf_internal.h"
9 static void on_sample(void *ctx, int cpu, void *data, __u32 size)
11 int cpu_data = *(int *)data, duration = 0;
12 cpu_set_t *cpu_seen = ctx;
15 CHECK(cpu_data != cpu, "check_cpu_data",
16 "cpu_data %d != cpu %d\n", cpu_data, cpu);
18 CPU_SET(cpu, cpu_seen);
21 void test_perf_buffer(void)
23 int err, prog_fd, on_len, nr_on_cpus = 0, nr_cpus, i, duration = 0;
24 const char *prog_name = "kprobe/sys_nanosleep";
25 const char *file = "./test_perf_buffer.o";
26 struct perf_buffer_opts pb_opts = {};
27 struct bpf_map *perf_buf_map;
28 cpu_set_t cpu_set, cpu_seen;
29 struct bpf_program *prog;
30 struct bpf_object *obj;
31 struct perf_buffer *pb;
32 struct bpf_link *link;
35 nr_cpus = libbpf_num_possible_cpus();
36 if (CHECK(nr_cpus < 0, "nr_cpus", "err %d\n", nr_cpus))
39 err = parse_cpu_mask_file("/sys/devices/system/cpu/online",
41 if (CHECK(err, "nr_on_cpus", "err %d\n", err))
44 for (i = 0; i < on_len; i++)
49 err = bpf_prog_load(file, BPF_PROG_TYPE_KPROBE, &obj, &prog_fd);
50 if (CHECK(err, "obj_load", "err %d errno %d\n", err, errno)) {
55 prog = bpf_object__find_program_by_title(obj, prog_name);
56 if (CHECK(!prog, "find_probe", "prog '%s' not found\n", prog_name))
60 perf_buf_map = bpf_object__find_map_by_name(obj, "perf_buf_map");
61 if (CHECK(!perf_buf_map, "find_perf_buf_map", "not found\n"))
65 link = bpf_program__attach_kprobe(prog, false /* retprobe */,
66 SYS_NANOSLEEP_KPROBE_NAME);
67 if (CHECK(IS_ERR(link), "attach_kprobe", "err %ld\n", PTR_ERR(link)))
70 /* set up perf buffer */
71 pb_opts.sample_cb = on_sample;
72 pb_opts.ctx = &cpu_seen;
73 pb = perf_buffer__new(bpf_map__fd(perf_buf_map), 1, &pb_opts);
74 if (CHECK(IS_ERR(pb), "perf_buf__new", "err %ld\n", PTR_ERR(pb)))
77 /* trigger kprobe on every CPU */
79 for (i = 0; i < nr_cpus; i++) {
80 if (i >= on_len || !online[i]) {
81 printf("skipping offline CPU #%d\n", i);
88 err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set),
90 if (err && CHECK(err, "set_affinity", "cpu #%d, err %d\n",
97 /* read perf buffer */
98 err = perf_buffer__poll(pb, 100);
99 if (CHECK(err < 0, "perf_buffer__poll", "err %d\n", err))
102 if (CHECK(CPU_COUNT(&cpu_seen) != nr_on_cpus, "seen_cpu_cnt",
103 "expect %d, seen %d\n", nr_on_cpus, CPU_COUNT(&cpu_seen)))
107 perf_buffer__free(pb);
109 bpf_link__destroy(link);
111 bpf_object__close(obj);