xref: /linux/samples/bpf/tracex6_user.c (revision f3539c12d8196ce0a1993364d30b3a18908470d1)
1 #include <stdio.h>
2 #include <unistd.h>
3 #include <stdlib.h>
4 #include <stdbool.h>
5 #include <string.h>
6 #include <fcntl.h>
7 #include <poll.h>
8 #include <sys/ioctl.h>
9 #include <linux/perf_event.h>
10 #include <linux/bpf.h>
11 #include "libbpf.h"
12 #include "bpf_load.h"
13 
14 #define SAMPLE_PERIOD  0x7fffffffffffffffULL
15 
16 static void test_bpf_perf_event(void)
17 {
18 	int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
19 	int *pmu_fd = malloc(nr_cpus * sizeof(int));
20 	int status, i;
21 
22 	struct perf_event_attr attr_insn_pmu = {
23 		.freq = 0,
24 		.sample_period = SAMPLE_PERIOD,
25 		.inherit = 0,
26 		.type = PERF_TYPE_HARDWARE,
27 		.read_format = 0,
28 		.sample_type = 0,
29 		.config = 0,/* PMU: cycles */
30 	};
31 
32 	for (i = 0; i < nr_cpus; i++) {
33 		pmu_fd[i] = perf_event_open(&attr_insn_pmu, -1/*pid*/, i/*cpu*/, -1/*group_fd*/, 0);
34 		if (pmu_fd[i] < 0) {
35 			printf("event syscall failed\n");
36 			goto exit;
37 		}
38 
39 		bpf_update_elem(map_fd[0], &i, &pmu_fd[i], BPF_ANY);
40 		ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE, 0);
41 	}
42 
43 	status = system("ls > /dev/null");
44 	if (status)
45 		goto exit;
46 	status = system("sleep 2");
47 	if (status)
48 		goto exit;
49 
50 exit:
51 	for (i = 0; i < nr_cpus; i++)
52 		close(pmu_fd[i]);
53 	close(map_fd[0]);
54 	free(pmu_fd);
55 }
56 
57 int main(int argc, char **argv)
58 {
59 	char filename[256];
60 
61 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
62 
63 	if (load_bpf_file(filename)) {
64 		printf("%s", bpf_log_buf);
65 		return 1;
66 	}
67 
68 	test_bpf_perf_event();
69 	read_trace_pipe();
70 
71 	return 0;
72 }
73