1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <stdio.h>
3 #include <unistd.h>
4 #include <stdlib.h>
5 #include <stdbool.h>
6 #include <string.h>
7 #include <fcntl.h>
8 #include <poll.h>
9 #include <linux/perf_event.h>
10 #include <linux/bpf.h>
11 #include <errno.h>
12 #include <assert.h>
13 #include <sys/syscall.h>
14 #include <sys/ioctl.h>
15 #include <sys/mman.h>
16 #include <time.h>
17 #include <signal.h>
18 #include <libbpf.h>
19 #include "bpf_load.h"
20 #include "perf-sys.h"
21 #include "trace_helpers.h"
22 
23 static int pmu_fd;
24 
25 static __u64 time_get_ns(void)
26 {
27 	struct timespec ts;
28 
29 	clock_gettime(CLOCK_MONOTONIC, &ts);
30 	return ts.tv_sec * 1000000000ull + ts.tv_nsec;
31 }
32 
33 static __u64 start_time;
34 
35 #define MAX_CNT 100000ll
36 
37 static int print_bpf_output(void *data, int size)
38 {
39 	static __u64 cnt;
40 	struct {
41 		__u64 pid;
42 		__u64 cookie;
43 	} *e = data;
44 
45 	if (e->cookie != 0x12345678) {
46 		printf("BUG pid %llx cookie %llx sized %d\n",
47 		       e->pid, e->cookie, size);
48 		return LIBBPF_PERF_EVENT_ERROR;
49 	}
50 
51 	cnt++;
52 
53 	if (cnt == MAX_CNT) {
54 		printf("recv %lld events per sec\n",
55 		       MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
56 		return LIBBPF_PERF_EVENT_DONE;
57 	}
58 
59 	return LIBBPF_PERF_EVENT_CONT;
60 }
61 
62 static void test_bpf_perf_event(void)
63 {
64 	struct perf_event_attr attr = {
65 		.sample_type = PERF_SAMPLE_RAW,
66 		.type = PERF_TYPE_SOFTWARE,
67 		.config = PERF_COUNT_SW_BPF_OUTPUT,
68 	};
69 	int key = 0;
70 
71 	pmu_fd = sys_perf_event_open(&attr, -1/*pid*/, 0/*cpu*/, -1/*group_fd*/, 0);
72 
73 	assert(pmu_fd >= 0);
74 	assert(bpf_map_update_elem(map_fd[0], &key, &pmu_fd, BPF_ANY) == 0);
75 	ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
76 }
77 
78 int main(int argc, char **argv)
79 {
80 	char filename[256];
81 	FILE *f;
82 	int ret;
83 
84 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
85 
86 	if (load_bpf_file(filename)) {
87 		printf("%s", bpf_log_buf);
88 		return 1;
89 	}
90 
91 	test_bpf_perf_event();
92 
93 	if (perf_event_mmap(pmu_fd) < 0)
94 		return 1;
95 
96 	f = popen("taskset 1 dd if=/dev/zero of=/dev/null", "r");
97 	(void) f;
98 
99 	start_time = time_get_ns();
100 	ret = perf_event_poller(pmu_fd, print_bpf_output);
101 	kill(0, SIGINT);
102 	return ret;
103 }
104