d4178f60e075f099efe340c4d22b05ce4df013ef
[muen/linux.git] / samples / bpf / trace_event_user.c
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
30 static void print_ksym(__u64 addr)
31 {
32         struct ksym *sym;
33
34         if (!addr)
35                 return;
36         sym = ksym_search(addr);
37         if (!sym) {
38                 printf("ksym not found. Is kallsyms loaded?\n");
39                 return;
40         }
41
42         printf("%s;", sym->name);
43         if (!strcmp(sym->name, "sys_read"))
44                 sys_read_seen = true;
45         else if (!strcmp(sym->name, "sys_write"))
46                 sys_write_seen = true;
47 }
48
49 static void print_addr(__u64 addr)
50 {
51         if (!addr)
52                 return;
53         printf("%llx;", addr);
54 }
55
56 #define TASK_COMM_LEN 16
57
58 struct key_t {
59         char comm[TASK_COMM_LEN];
60         __u32 kernstack;
61         __u32 userstack;
62 };
63
64 static void print_stack(struct key_t *key, __u64 count)
65 {
66         __u64 ip[PERF_MAX_STACK_DEPTH] = {};
67         static bool warned;
68         int i;
69
70         printf("%3lld %s;", count, key->comm);
71         if (bpf_map_lookup_elem(map_fd[1], &key->kernstack, ip) != 0) {
72                 printf("---;");
73         } else {
74                 for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
75                         print_ksym(ip[i]);
76         }
77         printf("-;");
78         if (bpf_map_lookup_elem(map_fd[1], &key->userstack, ip) != 0) {
79                 printf("---;");
80         } else {
81                 for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
82                         print_addr(ip[i]);
83         }
84         if (count < 6)
85                 printf("\r");
86         else
87                 printf("\n");
88
89         if (key->kernstack == -EEXIST && !warned) {
90                 printf("stackmap collisions seen. Consider increasing size\n");
91                 warned = true;
92         } else if ((int)key->kernstack < 0 && (int)key->userstack < 0) {
93                 printf("err stackid %d %d\n", key->kernstack, key->userstack);
94         }
95 }
96
97 static void int_exit(int sig)
98 {
99         kill(0, SIGKILL);
100         exit(0);
101 }
102
103 static void print_stacks(void)
104 {
105         struct key_t key = {}, next_key;
106         __u64 value;
107         __u32 stackid = 0, next_id;
108         int fd = map_fd[0], stack_map = map_fd[1];
109
110         sys_read_seen = sys_write_seen = false;
111         while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
112                 bpf_map_lookup_elem(fd, &next_key, &value);
113                 print_stack(&next_key, value);
114                 bpf_map_delete_elem(fd, &next_key);
115                 key = next_key;
116         }
117         printf("\n");
118         if (!sys_read_seen || !sys_write_seen) {
119                 printf("BUG kernel stack doesn't contain sys_read() and sys_write()\n");
120                 int_exit(0);
121         }
122
123         /* clear stack map */
124         while (bpf_map_get_next_key(stack_map, &stackid, &next_id) == 0) {
125                 bpf_map_delete_elem(stack_map, &next_id);
126                 stackid = next_id;
127         }
128 }
129
130 static inline int generate_load(void)
131 {
132         if (system("dd if=/dev/zero of=/dev/null count=5000k status=none") < 0) {
133                 printf("failed to generate some load with dd: %s\n", strerror(errno));
134                 return -1;
135         }
136
137         return 0;
138 }
139
140 static void test_perf_event_all_cpu(struct perf_event_attr *attr)
141 {
142         int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
143         int *pmu_fd = malloc(nr_cpus * sizeof(int));
144         int i, error = 0;
145
146         /* system wide perf event, no need to inherit */
147         attr->inherit = 0;
148
149         /* open perf_event on all cpus */
150         for (i = 0; i < nr_cpus; i++) {
151                 pmu_fd[i] = sys_perf_event_open(attr, -1, i, -1, 0);
152                 if (pmu_fd[i] < 0) {
153                         printf("sys_perf_event_open failed\n");
154                         error = 1;
155                         goto all_cpu_err;
156                 }
157                 assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0);
158                 assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE) == 0);
159         }
160
161         if (generate_load() < 0) {
162                 error = 1;
163                 goto all_cpu_err;
164         }
165         print_stacks();
166 all_cpu_err:
167         for (i--; i >= 0; i--) {
168                 ioctl(pmu_fd[i], PERF_EVENT_IOC_DISABLE);
169                 close(pmu_fd[i]);
170         }
171         free(pmu_fd);
172         if (error)
173                 int_exit(0);
174 }
175
176 static void test_perf_event_task(struct perf_event_attr *attr)
177 {
178         int pmu_fd, error = 0;
179
180         /* per task perf event, enable inherit so the "dd ..." command can be traced properly.
181          * Enabling inherit will cause bpf_perf_prog_read_time helper failure.
182          */
183         attr->inherit = 1;
184
185         /* open task bound event */
186         pmu_fd = sys_perf_event_open(attr, 0, -1, -1, 0);
187         if (pmu_fd < 0) {
188                 printf("sys_perf_event_open failed\n");
189                 int_exit(0);
190         }
191         assert(ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0);
192         assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE) == 0);
193
194         if (generate_load() < 0) {
195                 error = 1;
196                 goto err;
197         }
198         print_stacks();
199 err:
200         ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE);
201         close(pmu_fd);
202         if (error)
203                 int_exit(0);
204 }
205
206 static void test_bpf_perf_event(void)
207 {
208         struct perf_event_attr attr_type_hw = {
209                 .sample_freq = SAMPLE_FREQ,
210                 .freq = 1,
211                 .type = PERF_TYPE_HARDWARE,
212                 .config = PERF_COUNT_HW_CPU_CYCLES,
213         };
214         struct perf_event_attr attr_type_sw = {
215                 .sample_freq = SAMPLE_FREQ,
216                 .freq = 1,
217                 .type = PERF_TYPE_SOFTWARE,
218                 .config = PERF_COUNT_SW_CPU_CLOCK,
219         };
220         struct perf_event_attr attr_hw_cache_l1d = {
221                 .sample_freq = SAMPLE_FREQ,
222                 .freq = 1,
223                 .type = PERF_TYPE_HW_CACHE,
224                 .config =
225                         PERF_COUNT_HW_CACHE_L1D |
226                         (PERF_COUNT_HW_CACHE_OP_READ << 8) |
227                         (PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
228         };
229         struct perf_event_attr attr_hw_cache_branch_miss = {
230                 .sample_freq = SAMPLE_FREQ,
231                 .freq = 1,
232                 .type = PERF_TYPE_HW_CACHE,
233                 .config =
234                         PERF_COUNT_HW_CACHE_BPU |
235                         (PERF_COUNT_HW_CACHE_OP_READ << 8) |
236                         (PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
237         };
238         struct perf_event_attr attr_type_raw = {
239                 .sample_freq = SAMPLE_FREQ,
240                 .freq = 1,
241                 .type = PERF_TYPE_RAW,
242                 /* Intel Instruction Retired */
243                 .config = 0xc0,
244         };
245         struct perf_event_attr attr_type_raw_lock_load = {
246                 .sample_freq = SAMPLE_FREQ,
247                 .freq = 1,
248                 .type = PERF_TYPE_RAW,
249                 /* Intel MEM_UOPS_RETIRED.LOCK_LOADS */
250                 .config = 0x21d0,
251                 /* Request to record lock address from PEBS */
252                 .sample_type = PERF_SAMPLE_ADDR,
253                 /* Record address value requires precise event */
254                 .precise_ip = 2,
255         };
256
257         printf("Test HW_CPU_CYCLES\n");
258         test_perf_event_all_cpu(&attr_type_hw);
259         test_perf_event_task(&attr_type_hw);
260
261         printf("Test SW_CPU_CLOCK\n");
262         test_perf_event_all_cpu(&attr_type_sw);
263         test_perf_event_task(&attr_type_sw);
264
265         printf("Test HW_CACHE_L1D\n");
266         test_perf_event_all_cpu(&attr_hw_cache_l1d);
267         test_perf_event_task(&attr_hw_cache_l1d);
268
269         printf("Test HW_CACHE_BPU\n");
270         test_perf_event_all_cpu(&attr_hw_cache_branch_miss);
271         test_perf_event_task(&attr_hw_cache_branch_miss);
272
273         printf("Test Instruction Retired\n");
274         test_perf_event_all_cpu(&attr_type_raw);
275         test_perf_event_task(&attr_type_raw);
276
277         printf("Test Lock Load\n");
278         test_perf_event_all_cpu(&attr_type_raw_lock_load);
279         test_perf_event_task(&attr_type_raw_lock_load);
280
281         printf("*** PASS ***\n");
282 }
283
284
285 int main(int argc, char **argv)
286 {
287         struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
288         char filename[256];
289
290         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
291         setrlimit(RLIMIT_MEMLOCK, &r);
292
293         signal(SIGINT, int_exit);
294         signal(SIGTERM, int_exit);
295
296         if (load_kallsyms()) {
297                 printf("failed to process /proc/kallsyms\n");
298                 return 1;
299         }
300
301         if (load_bpf_file(filename)) {
302                 printf("%s", bpf_log_buf);
303                 return 2;
304         }
305
306         if (fork() == 0) {
307                 read_trace_pipe();
308                 return 0;
309         }
310         test_bpf_perf_event();
311         int_exit(0);
312         return 0;
313 }