1 /* Copyright (c) 2016 Facebook
2 *
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.
6 */
7 #include <stdio.h>
8 #include <unistd.h>
9 #include <stdlib.h>
10 #include <stdbool.h>
11 #include <string.h>
12 #include <fcntl.h>
13 #include <poll.h>
14 #include <sys/ioctl.h>
15 #include <linux/perf_event.h>
16 #include <linux/bpf.h>
17 #include <signal.h>
18 #include <assert.h>
19 #include <errno.h>
20 #include <sys/resource.h>
21 #include "libbpf.h"
22 #include "bpf_load.h"
23 #include "perf-sys.h"
24 #include "trace_helpers.h"
25
26 #define SAMPLE_FREQ 50
27
28 static bool sys_read_seen, sys_write_seen;
29
print_ksym(__u64 addr)30 static void print_ksym(__u64 addr)
31 {
32 struct ksym *sym;
33
34 if (!addr)
35 return;
36 sym = ksym_search(addr);
37 printf("%s;", sym->name);
38 if (!strcmp(sym->name, "sys_read"))
39 sys_read_seen = true;
40 else if (!strcmp(sym->name, "sys_write"))
41 sys_write_seen = true;
42 }
43
print_addr(__u64 addr)44 static void print_addr(__u64 addr)
45 {
46 if (!addr)
47 return;
48 printf("%llx;", addr);
49 }
50
51 #define TASK_COMM_LEN 16
52
53 struct key_t {
54 char comm[TASK_COMM_LEN];
55 __u32 kernstack;
56 __u32 userstack;
57 };
58
print_stack(struct key_t * key,__u64 count)59 static void print_stack(struct key_t *key, __u64 count)
60 {
61 __u64 ip[PERF_MAX_STACK_DEPTH] = {};
62 static bool warned;
63 int i;
64
65 printf("%3lld %s;", count, key->comm);
66 if (bpf_map_lookup_elem(map_fd[1], &key->kernstack, ip) != 0) {
67 printf("---;");
68 } else {
69 for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
70 print_ksym(ip[i]);
71 }
72 printf("-;");
73 if (bpf_map_lookup_elem(map_fd[1], &key->userstack, ip) != 0) {
74 printf("---;");
75 } else {
76 for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
77 print_addr(ip[i]);
78 }
79 if (count < 6)
80 printf("\r");
81 else
82 printf("\n");
83
84 if (key->kernstack == -EEXIST && !warned) {
85 printf("stackmap collisions seen. Consider increasing size\n");
86 warned = true;
87 } else if ((int)key->kernstack < 0 && (int)key->userstack < 0) {
88 printf("err stackid %d %d\n", key->kernstack, key->userstack);
89 }
90 }
91
int_exit(int sig)92 static void int_exit(int sig)
93 {
94 kill(0, SIGKILL);
95 exit(0);
96 }
97
print_stacks(void)98 static void print_stacks(void)
99 {
100 struct key_t key = {}, next_key;
101 __u64 value;
102 __u32 stackid = 0, next_id;
103 int fd = map_fd[0], stack_map = map_fd[1];
104
105 sys_read_seen = sys_write_seen = false;
106 while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
107 bpf_map_lookup_elem(fd, &next_key, &value);
108 print_stack(&next_key, value);
109 bpf_map_delete_elem(fd, &next_key);
110 key = next_key;
111 }
112 printf("\n");
113 if (!sys_read_seen || !sys_write_seen) {
114 printf("BUG kernel stack doesn't contain sys_read() and sys_write()\n");
115 int_exit(0);
116 }
117
118 /* clear stack map */
119 while (bpf_map_get_next_key(stack_map, &stackid, &next_id) == 0) {
120 bpf_map_delete_elem(stack_map, &next_id);
121 stackid = next_id;
122 }
123 }
124
generate_load(void)125 static inline int generate_load(void)
126 {
127 if (system("dd if=/dev/zero of=/dev/null count=5000k status=none") < 0) {
128 printf("failed to generate some load with dd: %s\n", strerror(errno));
129 return -1;
130 }
131
132 return 0;
133 }
134
test_perf_event_all_cpu(struct perf_event_attr * attr)135 static void test_perf_event_all_cpu(struct perf_event_attr *attr)
136 {
137 int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
138 int *pmu_fd = malloc(nr_cpus * sizeof(int));
139 int i, error = 0;
140
141 /* system wide perf event, no need to inherit */
142 attr->inherit = 0;
143
144 /* open perf_event on all cpus */
145 for (i = 0; i < nr_cpus; i++) {
146 pmu_fd[i] = sys_perf_event_open(attr, -1, i, -1, 0);
147 if (pmu_fd[i] < 0) {
148 printf("sys_perf_event_open failed\n");
149 error = 1;
150 goto all_cpu_err;
151 }
152 assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0);
153 assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE) == 0);
154 }
155
156 if (generate_load() < 0) {
157 error = 1;
158 goto all_cpu_err;
159 }
160 print_stacks();
161 all_cpu_err:
162 for (i--; i >= 0; i--) {
163 ioctl(pmu_fd[i], PERF_EVENT_IOC_DISABLE);
164 close(pmu_fd[i]);
165 }
166 free(pmu_fd);
167 if (error)
168 int_exit(0);
169 }
170
test_perf_event_task(struct perf_event_attr * attr)171 static void test_perf_event_task(struct perf_event_attr *attr)
172 {
173 int pmu_fd, error = 0;
174
175 /* per task perf event, enable inherit so the "dd ..." command can be traced properly.
176 * Enabling inherit will cause bpf_perf_prog_read_time helper failure.
177 */
178 attr->inherit = 1;
179
180 /* open task bound event */
181 pmu_fd = sys_perf_event_open(attr, 0, -1, -1, 0);
182 if (pmu_fd < 0) {
183 printf("sys_perf_event_open failed\n");
184 int_exit(0);
185 }
186 assert(ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0);
187 assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE) == 0);
188
189 if (generate_load() < 0) {
190 error = 1;
191 goto err;
192 }
193 print_stacks();
194 err:
195 ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE);
196 close(pmu_fd);
197 if (error)
198 int_exit(0);
199 }
200
test_bpf_perf_event(void)201 static void test_bpf_perf_event(void)
202 {
203 struct perf_event_attr attr_type_hw = {
204 .sample_freq = SAMPLE_FREQ,
205 .freq = 1,
206 .type = PERF_TYPE_HARDWARE,
207 .config = PERF_COUNT_HW_CPU_CYCLES,
208 };
209 struct perf_event_attr attr_type_sw = {
210 .sample_freq = SAMPLE_FREQ,
211 .freq = 1,
212 .type = PERF_TYPE_SOFTWARE,
213 .config = PERF_COUNT_SW_CPU_CLOCK,
214 };
215 struct perf_event_attr attr_hw_cache_l1d = {
216 .sample_freq = SAMPLE_FREQ,
217 .freq = 1,
218 .type = PERF_TYPE_HW_CACHE,
219 .config =
220 PERF_COUNT_HW_CACHE_L1D |
221 (PERF_COUNT_HW_CACHE_OP_READ << 8) |
222 (PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
223 };
224 struct perf_event_attr attr_hw_cache_branch_miss = {
225 .sample_freq = SAMPLE_FREQ,
226 .freq = 1,
227 .type = PERF_TYPE_HW_CACHE,
228 .config =
229 PERF_COUNT_HW_CACHE_BPU |
230 (PERF_COUNT_HW_CACHE_OP_READ << 8) |
231 (PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
232 };
233 struct perf_event_attr attr_type_raw = {
234 .sample_freq = SAMPLE_FREQ,
235 .freq = 1,
236 .type = PERF_TYPE_RAW,
237 /* Intel Instruction Retired */
238 .config = 0xc0,
239 };
240 struct perf_event_attr attr_type_raw_lock_load = {
241 .sample_freq = SAMPLE_FREQ,
242 .freq = 1,
243 .type = PERF_TYPE_RAW,
244 /* Intel MEM_UOPS_RETIRED.LOCK_LOADS */
245 .config = 0x21d0,
246 /* Request to record lock address from PEBS */
247 .sample_type = PERF_SAMPLE_ADDR,
248 /* Record address value requires precise event */
249 .precise_ip = 2,
250 };
251
252 printf("Test HW_CPU_CYCLES\n");
253 test_perf_event_all_cpu(&attr_type_hw);
254 test_perf_event_task(&attr_type_hw);
255
256 printf("Test SW_CPU_CLOCK\n");
257 test_perf_event_all_cpu(&attr_type_sw);
258 test_perf_event_task(&attr_type_sw);
259
260 printf("Test HW_CACHE_L1D\n");
261 test_perf_event_all_cpu(&attr_hw_cache_l1d);
262 test_perf_event_task(&attr_hw_cache_l1d);
263
264 printf("Test HW_CACHE_BPU\n");
265 test_perf_event_all_cpu(&attr_hw_cache_branch_miss);
266 test_perf_event_task(&attr_hw_cache_branch_miss);
267
268 printf("Test Instruction Retired\n");
269 test_perf_event_all_cpu(&attr_type_raw);
270 test_perf_event_task(&attr_type_raw);
271
272 printf("Test Lock Load\n");
273 test_perf_event_all_cpu(&attr_type_raw_lock_load);
274 test_perf_event_task(&attr_type_raw_lock_load);
275
276 printf("*** PASS ***\n");
277 }
278
279
main(int argc,char ** argv)280 int main(int argc, char **argv)
281 {
282 struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
283 char filename[256];
284
285 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
286 setrlimit(RLIMIT_MEMLOCK, &r);
287
288 signal(SIGINT, int_exit);
289 signal(SIGTERM, int_exit);
290
291 if (load_kallsyms()) {
292 printf("failed to process /proc/kallsyms\n");
293 return 1;
294 }
295
296 if (load_bpf_file(filename)) {
297 printf("%s", bpf_log_buf);
298 return 2;
299 }
300
301 if (fork() == 0) {
302 read_trace_pipe();
303 return 0;
304 }
305 test_bpf_perf_event();
306 int_exit(0);
307 return 0;
308 }
309
