treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206
[muen/linux.git] / samples / bpf / trace_event_user.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2016 Facebook
3  */
4 #include <stdio.h>
5 #include <unistd.h>
6 #include <stdlib.h>
7 #include <stdbool.h>
8 #include <string.h>
9 #include <fcntl.h>
10 #include <poll.h>
11 #include <sys/ioctl.h>
12 #include <linux/perf_event.h>
13 #include <linux/bpf.h>
14 #include <signal.h>
15 #include <assert.h>
16 #include <errno.h>
17 #include <sys/resource.h>
18 #include "libbpf.h"
19 #include "bpf_load.h"
20 #include "perf-sys.h"
21 #include "trace_helpers.h"
22
23 #define SAMPLE_FREQ 50
24
25 static bool sys_read_seen, sys_write_seen;
26
27 static void print_ksym(__u64 addr)
28 {
29         struct ksym *sym;
30
31         if (!addr)
32                 return;
33         sym = ksym_search(addr);
34         if (!sym) {
35                 printf("ksym not found. Is kallsyms loaded?\n");
36                 return;
37         }
38
39         printf("%s;", sym->name);
40         if (!strcmp(sym->name, "sys_read"))
41                 sys_read_seen = true;
42         else if (!strcmp(sym->name, "sys_write"))
43                 sys_write_seen = true;
44 }
45
46 static void print_addr(__u64 addr)
47 {
48         if (!addr)
49                 return;
50         printf("%llx;", addr);
51 }
52
53 #define TASK_COMM_LEN 16
54
55 struct key_t {
56         char comm[TASK_COMM_LEN];
57         __u32 kernstack;
58         __u32 userstack;
59 };
60
61 static void print_stack(struct key_t *key, __u64 count)
62 {
63         __u64 ip[PERF_MAX_STACK_DEPTH] = {};
64         static bool warned;
65         int i;
66
67         printf("%3lld %s;", count, key->comm);
68         if (bpf_map_lookup_elem(map_fd[1], &key->kernstack, ip) != 0) {
69                 printf("---;");
70         } else {
71                 for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
72                         print_ksym(ip[i]);
73         }
74         printf("-;");
75         if (bpf_map_lookup_elem(map_fd[1], &key->userstack, ip) != 0) {
76                 printf("---;");
77         } else {
78                 for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
79                         print_addr(ip[i]);
80         }
81         if (count < 6)
82                 printf("\r");
83         else
84                 printf("\n");
85
86         if (key->kernstack == -EEXIST && !warned) {
87                 printf("stackmap collisions seen. Consider increasing size\n");
88                 warned = true;
89         } else if ((int)key->kernstack < 0 && (int)key->userstack < 0) {
90                 printf("err stackid %d %d\n", key->kernstack, key->userstack);
91         }
92 }
93
94 static void int_exit(int sig)
95 {
96         kill(0, SIGKILL);
97         exit(0);
98 }
99
100 static void print_stacks(void)
101 {
102         struct key_t key = {}, next_key;
103         __u64 value;
104         __u32 stackid = 0, next_id;
105         int fd = map_fd[0], stack_map = map_fd[1];
106
107         sys_read_seen = sys_write_seen = false;
108         while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
109                 bpf_map_lookup_elem(fd, &next_key, &value);
110                 print_stack(&next_key, value);
111                 bpf_map_delete_elem(fd, &next_key);
112                 key = next_key;
113         }
114         printf("\n");
115         if (!sys_read_seen || !sys_write_seen) {
116                 printf("BUG kernel stack doesn't contain sys_read() and sys_write()\n");
117                 int_exit(0);
118         }
119
120         /* clear stack map */
121         while (bpf_map_get_next_key(stack_map, &stackid, &next_id) == 0) {
122                 bpf_map_delete_elem(stack_map, &next_id);
123                 stackid = next_id;
124         }
125 }
126
127 static inline int generate_load(void)
128 {
129         if (system("dd if=/dev/zero of=/dev/null count=5000k status=none") < 0) {
130                 printf("failed to generate some load with dd: %s\n", strerror(errno));
131                 return -1;
132         }
133
134         return 0;
135 }
136
137 static void test_perf_event_all_cpu(struct perf_event_attr *attr)
138 {
139         int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
140         int *pmu_fd = malloc(nr_cpus * sizeof(int));
141         int i, error = 0;
142
143         /* system wide perf event, no need to inherit */
144         attr->inherit = 0;
145
146         /* open perf_event on all cpus */
147         for (i = 0; i < nr_cpus; i++) {
148                 pmu_fd[i] = sys_perf_event_open(attr, -1, i, -1, 0);
149                 if (pmu_fd[i] < 0) {
150                         printf("sys_perf_event_open failed\n");
151                         error = 1;
152                         goto all_cpu_err;
153                 }
154                 assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0);
155                 assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE) == 0);
156         }
157
158         if (generate_load() < 0) {
159                 error = 1;
160                 goto all_cpu_err;
161         }
162         print_stacks();
163 all_cpu_err:
164         for (i--; i >= 0; i--) {
165                 ioctl(pmu_fd[i], PERF_EVENT_IOC_DISABLE);
166                 close(pmu_fd[i]);
167         }
168         free(pmu_fd);
169         if (error)
170                 int_exit(0);
171 }
172
173 static void test_perf_event_task(struct perf_event_attr *attr)
174 {
175         int pmu_fd, error = 0;
176
177         /* per task perf event, enable inherit so the "dd ..." command can be traced properly.
178          * Enabling inherit will cause bpf_perf_prog_read_time helper failure.
179          */
180         attr->inherit = 1;
181
182         /* open task bound event */
183         pmu_fd = sys_perf_event_open(attr, 0, -1, -1, 0);
184         if (pmu_fd < 0) {
185                 printf("sys_perf_event_open failed\n");
186                 int_exit(0);
187         }
188         assert(ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0);
189         assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE) == 0);
190
191         if (generate_load() < 0) {
192                 error = 1;
193                 goto err;
194         }
195         print_stacks();
196 err:
197         ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE);
198         close(pmu_fd);
199         if (error)
200                 int_exit(0);
201 }
202
203 static void test_bpf_perf_event(void)
204 {
205         struct perf_event_attr attr_type_hw = {
206                 .sample_freq = SAMPLE_FREQ,
207                 .freq = 1,
208                 .type = PERF_TYPE_HARDWARE,
209                 .config = PERF_COUNT_HW_CPU_CYCLES,
210         };
211         struct perf_event_attr attr_type_sw = {
212                 .sample_freq = SAMPLE_FREQ,
213                 .freq = 1,
214                 .type = PERF_TYPE_SOFTWARE,
215                 .config = PERF_COUNT_SW_CPU_CLOCK,
216         };
217         struct perf_event_attr attr_hw_cache_l1d = {
218                 .sample_freq = SAMPLE_FREQ,
219                 .freq = 1,
220                 .type = PERF_TYPE_HW_CACHE,
221                 .config =
222                         PERF_COUNT_HW_CACHE_L1D |
223                         (PERF_COUNT_HW_CACHE_OP_READ << 8) |
224                         (PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
225         };
226         struct perf_event_attr attr_hw_cache_branch_miss = {
227                 .sample_freq = SAMPLE_FREQ,
228                 .freq = 1,
229                 .type = PERF_TYPE_HW_CACHE,
230                 .config =
231                         PERF_COUNT_HW_CACHE_BPU |
232                         (PERF_COUNT_HW_CACHE_OP_READ << 8) |
233                         (PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
234         };
235         struct perf_event_attr attr_type_raw = {
236                 .sample_freq = SAMPLE_FREQ,
237                 .freq = 1,
238                 .type = PERF_TYPE_RAW,
239                 /* Intel Instruction Retired */
240                 .config = 0xc0,
241         };
242         struct perf_event_attr attr_type_raw_lock_load = {
243                 .sample_freq = SAMPLE_FREQ,
244                 .freq = 1,
245                 .type = PERF_TYPE_RAW,
246                 /* Intel MEM_UOPS_RETIRED.LOCK_LOADS */
247                 .config = 0x21d0,
248                 /* Request to record lock address from PEBS */
249                 .sample_type = PERF_SAMPLE_ADDR,
250                 /* Record address value requires precise event */
251                 .precise_ip = 2,
252         };
253
254         printf("Test HW_CPU_CYCLES\n");
255         test_perf_event_all_cpu(&attr_type_hw);
256         test_perf_event_task(&attr_type_hw);
257
258         printf("Test SW_CPU_CLOCK\n");
259         test_perf_event_all_cpu(&attr_type_sw);
260         test_perf_event_task(&attr_type_sw);
261
262         printf("Test HW_CACHE_L1D\n");
263         test_perf_event_all_cpu(&attr_hw_cache_l1d);
264         test_perf_event_task(&attr_hw_cache_l1d);
265
266         printf("Test HW_CACHE_BPU\n");
267         test_perf_event_all_cpu(&attr_hw_cache_branch_miss);
268         test_perf_event_task(&attr_hw_cache_branch_miss);
269
270         printf("Test Instruction Retired\n");
271         test_perf_event_all_cpu(&attr_type_raw);
272         test_perf_event_task(&attr_type_raw);
273
274         printf("Test Lock Load\n");
275         test_perf_event_all_cpu(&attr_type_raw_lock_load);
276         test_perf_event_task(&attr_type_raw_lock_load);
277
278         printf("*** PASS ***\n");
279 }
280
281
282 int main(int argc, char **argv)
283 {
284         struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
285         char filename[256];
286
287         snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
288         setrlimit(RLIMIT_MEMLOCK, &r);
289
290         signal(SIGINT, int_exit);
291         signal(SIGTERM, int_exit);
292
293         if (load_kallsyms()) {
294                 printf("failed to process /proc/kallsyms\n");
295                 return 1;
296         }
297
298         if (load_bpf_file(filename)) {
299                 printf("%s", bpf_log_buf);
300                 return 2;
301         }
302
303         if (fork() == 0) {
304                 read_trace_pipe();
305                 return 0;
306         }
307         test_bpf_perf_event();
308         int_exit(0);
309         return 0;
310 }