1 /* Copyright (c) 2016 Facebook
3 * This program is free software; you can redistribute it and/or
4 * modify it under the terms of version 2 of the GNU General Public
5 * License as published by the Free Software Foundation.
14 #include <sys/ioctl.h>
15 #include <linux/perf_event.h>
16 #include <linux/bpf.h>
20 #include <sys/resource.h>
25 #define SAMPLE_FREQ 50
27 static bool sys_read_seen, sys_write_seen;
29 static void print_ksym(__u64 addr)
35 sym = ksym_search(addr);
36 printf("%s;", sym->name);
37 if (!strcmp(sym->name, "sys_read"))
39 else if (!strcmp(sym->name, "sys_write"))
40 sys_write_seen = true;
43 static void print_addr(__u64 addr)
47 printf("%llx;", addr);
50 #define TASK_COMM_LEN 16
53 char comm[TASK_COMM_LEN];
58 static void print_stack(struct key_t *key, __u64 count)
60 __u64 ip[PERF_MAX_STACK_DEPTH] = {};
64 printf("%3lld %s;", count, key->comm);
65 if (bpf_map_lookup_elem(map_fd[1], &key->kernstack, ip) != 0) {
68 for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
72 if (bpf_map_lookup_elem(map_fd[1], &key->userstack, ip) != 0) {
75 for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
80 if (key->kernstack == -EEXIST && !warned) {
81 printf("stackmap collisions seen. Consider increasing size\n");
83 } else if ((int)key->kernstack < 0 && (int)key->userstack < 0) {
84 printf("err stackid %d %d\n", key->kernstack, key->userstack);
88 static void int_exit(int sig)
94 static void print_stacks(void)
96 struct key_t key = {}, next_key;
98 __u32 stackid = 0, next_id;
99 int fd = map_fd[0], stack_map = map_fd[1];
101 sys_read_seen = sys_write_seen = false;
102 while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
103 bpf_map_lookup_elem(fd, &next_key, &value);
104 print_stack(&next_key, value);
105 bpf_map_delete_elem(fd, &next_key);
109 if (!sys_read_seen || !sys_write_seen) {
110 printf("BUG kernel stack doesn't contain sys_read() and sys_write()\n");
114 /* clear stack map */
115 while (bpf_map_get_next_key(stack_map, &stackid, &next_id) == 0) {
116 bpf_map_delete_elem(stack_map, &next_id);
121 static void test_perf_event_all_cpu(struct perf_event_attr *attr)
123 int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
124 int *pmu_fd = malloc(nr_cpus * sizeof(int));
127 /* open perf_event on all cpus */
128 for (i = 0; i < nr_cpus; i++) {
129 pmu_fd[i] = sys_perf_event_open(attr, -1, i, -1, 0);
131 printf("sys_perf_event_open failed\n");
134 assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0);
135 assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE, 0) == 0);
137 system("dd if=/dev/zero of=/dev/null count=5000k");
140 for (i--; i >= 0; i--)
145 static void test_perf_event_task(struct perf_event_attr *attr)
149 /* open task bound event */
150 pmu_fd = sys_perf_event_open(attr, 0, -1, -1, 0);
152 printf("sys_perf_event_open failed\n");
155 assert(ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0);
156 assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0);
157 system("dd if=/dev/zero of=/dev/null count=5000k");
162 static void test_bpf_perf_event(void)
164 struct perf_event_attr attr_type_hw = {
165 .sample_freq = SAMPLE_FREQ,
167 .type = PERF_TYPE_HARDWARE,
168 .config = PERF_COUNT_HW_CPU_CYCLES,
171 struct perf_event_attr attr_type_sw = {
172 .sample_freq = SAMPLE_FREQ,
174 .type = PERF_TYPE_SOFTWARE,
175 .config = PERF_COUNT_SW_CPU_CLOCK,
179 test_perf_event_all_cpu(&attr_type_hw);
180 test_perf_event_task(&attr_type_hw);
181 test_perf_event_all_cpu(&attr_type_sw);
182 test_perf_event_task(&attr_type_sw);
186 int main(int argc, char **argv)
188 struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
191 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
192 setrlimit(RLIMIT_MEMLOCK, &r);
194 signal(SIGINT, int_exit);
196 if (load_kallsyms()) {
197 printf("failed to process /proc/kallsyms\n");
201 if (load_bpf_file(filename)) {
202 printf("%s", bpf_log_buf);
210 test_bpf_perf_event();