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Commit | Line | Data |
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1c6bec5b | 1 | // SPDX-License-Identifier: GPL-2.0-only |
d01f4e8d NK |
2 | /* |
3 | * builtin-ftrace.c | |
4 | * | |
5 | * Copyright (c) 2013 LG Electronics, Namhyung Kim <namhyung@kernel.org> | |
d01f4e8d NK |
6 | */ |
7 | ||
8 | #include "builtin.h" | |
9 | #include "perf.h" | |
10 | ||
a43783ae | 11 | #include <errno.h> |
d01f4e8d NK |
12 | #include <unistd.h> |
13 | #include <signal.h> | |
a9af6be5 | 14 | #include <fcntl.h> |
4208735d | 15 | #include <poll.h> |
d01f4e8d NK |
16 | |
17 | #include "debug.h" | |
18 | #include <subcmd/parse-options.h> | |
20a9ed28 | 19 | #include <api/fs/tracing_path.h> |
d01f4e8d NK |
20 | #include "evlist.h" |
21 | #include "target.h" | |
dc231032 | 22 | #include "cpumap.h" |
d01f4e8d | 23 | #include "thread_map.h" |
b05d1093 | 24 | #include "util/config.h" |
d01f4e8d NK |
25 | |
26 | ||
27 | #define DEFAULT_TRACER "function_graph" | |
28 | ||
29 | struct perf_ftrace { | |
78b83e8b NK |
30 | struct perf_evlist *evlist; |
31 | struct target target; | |
32 | const char *tracer; | |
33 | struct list_head filters; | |
34 | struct list_head notrace; | |
35 | struct list_head graph_funcs; | |
36 | struct list_head nograph_funcs; | |
1096c35a | 37 | int graph_depth; |
78b83e8b NK |
38 | }; |
39 | ||
40 | struct filter_entry { | |
41 | struct list_head list; | |
42 | char name[]; | |
d01f4e8d NK |
43 | }; |
44 | ||
45 | static bool done; | |
46 | ||
47 | static void sig_handler(int sig __maybe_unused) | |
48 | { | |
49 | done = true; | |
50 | } | |
51 | ||
52 | /* | |
53 | * perf_evlist__prepare_workload will send a SIGUSR1 if the fork fails, since | |
54 | * we asked by setting its exec_error to the function below, | |
55 | * ftrace__workload_exec_failed_signal. | |
56 | * | |
57 | * XXX We need to handle this more appropriately, emitting an error, etc. | |
58 | */ | |
59 | static void ftrace__workload_exec_failed_signal(int signo __maybe_unused, | |
60 | siginfo_t *info __maybe_unused, | |
61 | void *ucontext __maybe_unused) | |
62 | { | |
63 | /* workload_exec_errno = info->si_value.sival_int; */ | |
64 | done = true; | |
65 | } | |
66 | ||
a9af6be5 | 67 | static int __write_tracing_file(const char *name, const char *val, bool append) |
d01f4e8d NK |
68 | { |
69 | char *file; | |
70 | int fd, ret = -1; | |
71 | ssize_t size = strlen(val); | |
a9af6be5 | 72 | int flags = O_WRONLY; |
e7bd9ba2 | 73 | char errbuf[512]; |
63cd02d8 | 74 | char *val_copy; |
d01f4e8d NK |
75 | |
76 | file = get_tracing_file(name); | |
77 | if (!file) { | |
78 | pr_debug("cannot get tracing file: %s\n", name); | |
79 | return -1; | |
80 | } | |
81 | ||
a9af6be5 NK |
82 | if (append) |
83 | flags |= O_APPEND; | |
84 | else | |
85 | flags |= O_TRUNC; | |
86 | ||
87 | fd = open(file, flags); | |
d01f4e8d | 88 | if (fd < 0) { |
e7bd9ba2 NK |
89 | pr_debug("cannot open tracing file: %s: %s\n", |
90 | name, str_error_r(errno, errbuf, sizeof(errbuf))); | |
d01f4e8d NK |
91 | goto out; |
92 | } | |
93 | ||
63cd02d8 CD |
94 | /* |
95 | * Copy the original value and append a '\n'. Without this, | |
96 | * the kernel can hide possible errors. | |
97 | */ | |
98 | val_copy = strdup(val); | |
99 | if (!val_copy) | |
100 | goto out_close; | |
101 | val_copy[size] = '\n'; | |
102 | ||
103 | if (write(fd, val_copy, size + 1) == size + 1) | |
d01f4e8d NK |
104 | ret = 0; |
105 | else | |
e7bd9ba2 NK |
106 | pr_debug("write '%s' to tracing/%s failed: %s\n", |
107 | val, name, str_error_r(errno, errbuf, sizeof(errbuf))); | |
d01f4e8d | 108 | |
63cd02d8 CD |
109 | free(val_copy); |
110 | out_close: | |
d01f4e8d NK |
111 | close(fd); |
112 | out: | |
113 | put_tracing_file(file); | |
114 | return ret; | |
115 | } | |
116 | ||
a9af6be5 NK |
117 | static int write_tracing_file(const char *name, const char *val) |
118 | { | |
119 | return __write_tracing_file(name, val, false); | |
120 | } | |
121 | ||
122 | static int append_tracing_file(const char *name, const char *val) | |
123 | { | |
124 | return __write_tracing_file(name, val, true); | |
125 | } | |
126 | ||
dc231032 | 127 | static int reset_tracing_cpu(void); |
78b83e8b | 128 | static void reset_tracing_filters(void); |
dc231032 | 129 | |
d01f4e8d NK |
130 | static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused) |
131 | { | |
132 | if (write_tracing_file("tracing_on", "0") < 0) | |
133 | return -1; | |
134 | ||
135 | if (write_tracing_file("current_tracer", "nop") < 0) | |
136 | return -1; | |
137 | ||
138 | if (write_tracing_file("set_ftrace_pid", " ") < 0) | |
139 | return -1; | |
140 | ||
dc231032 NK |
141 | if (reset_tracing_cpu() < 0) |
142 | return -1; | |
143 | ||
1096c35a NK |
144 | if (write_tracing_file("max_graph_depth", "0") < 0) |
145 | return -1; | |
146 | ||
78b83e8b | 147 | reset_tracing_filters(); |
d01f4e8d NK |
148 | return 0; |
149 | } | |
150 | ||
a9af6be5 NK |
151 | static int set_tracing_pid(struct perf_ftrace *ftrace) |
152 | { | |
153 | int i; | |
154 | char buf[16]; | |
155 | ||
156 | if (target__has_cpu(&ftrace->target)) | |
157 | return 0; | |
158 | ||
159 | for (i = 0; i < thread_map__nr(ftrace->evlist->threads); i++) { | |
160 | scnprintf(buf, sizeof(buf), "%d", | |
161 | ftrace->evlist->threads->map[i]); | |
162 | if (append_tracing_file("set_ftrace_pid", buf) < 0) | |
163 | return -1; | |
164 | } | |
165 | return 0; | |
166 | } | |
167 | ||
f854839b | 168 | static int set_tracing_cpumask(struct perf_cpu_map *cpumap) |
dc231032 NK |
169 | { |
170 | char *cpumask; | |
171 | size_t mask_size; | |
172 | int ret; | |
173 | int last_cpu; | |
174 | ||
175 | last_cpu = cpu_map__cpu(cpumap, cpumap->nr - 1); | |
176 | mask_size = (last_cpu + 3) / 4 + 1; | |
177 | mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */ | |
178 | ||
179 | cpumask = malloc(mask_size); | |
180 | if (cpumask == NULL) { | |
181 | pr_debug("failed to allocate cpu mask\n"); | |
182 | return -1; | |
183 | } | |
184 | ||
185 | cpu_map__snprint_mask(cpumap, cpumask, mask_size); | |
186 | ||
187 | ret = write_tracing_file("tracing_cpumask", cpumask); | |
188 | ||
189 | free(cpumask); | |
190 | return ret; | |
191 | } | |
192 | ||
193 | static int set_tracing_cpu(struct perf_ftrace *ftrace) | |
194 | { | |
f854839b | 195 | struct perf_cpu_map *cpumap = ftrace->evlist->cpus; |
dc231032 NK |
196 | |
197 | if (!target__has_cpu(&ftrace->target)) | |
198 | return 0; | |
199 | ||
200 | return set_tracing_cpumask(cpumap); | |
201 | } | |
202 | ||
203 | static int reset_tracing_cpu(void) | |
204 | { | |
f854839b | 205 | struct perf_cpu_map *cpumap = cpu_map__new(NULL); |
dc231032 NK |
206 | int ret; |
207 | ||
208 | ret = set_tracing_cpumask(cpumap); | |
209 | cpu_map__put(cpumap); | |
210 | return ret; | |
211 | } | |
212 | ||
78b83e8b NK |
213 | static int __set_tracing_filter(const char *filter_file, struct list_head *funcs) |
214 | { | |
215 | struct filter_entry *pos; | |
216 | ||
217 | list_for_each_entry(pos, funcs, list) { | |
218 | if (append_tracing_file(filter_file, pos->name) < 0) | |
219 | return -1; | |
220 | } | |
221 | ||
222 | return 0; | |
223 | } | |
224 | ||
225 | static int set_tracing_filters(struct perf_ftrace *ftrace) | |
226 | { | |
227 | int ret; | |
228 | ||
229 | ret = __set_tracing_filter("set_ftrace_filter", &ftrace->filters); | |
230 | if (ret < 0) | |
231 | return ret; | |
232 | ||
233 | ret = __set_tracing_filter("set_ftrace_notrace", &ftrace->notrace); | |
234 | if (ret < 0) | |
235 | return ret; | |
236 | ||
237 | ret = __set_tracing_filter("set_graph_function", &ftrace->graph_funcs); | |
238 | if (ret < 0) | |
239 | return ret; | |
240 | ||
241 | /* old kernels do not have this filter */ | |
242 | __set_tracing_filter("set_graph_notrace", &ftrace->nograph_funcs); | |
243 | ||
244 | return ret; | |
245 | } | |
246 | ||
247 | static void reset_tracing_filters(void) | |
248 | { | |
249 | write_tracing_file("set_ftrace_filter", " "); | |
250 | write_tracing_file("set_ftrace_notrace", " "); | |
251 | write_tracing_file("set_graph_function", " "); | |
252 | write_tracing_file("set_graph_notrace", " "); | |
253 | } | |
254 | ||
1096c35a NK |
255 | static int set_tracing_depth(struct perf_ftrace *ftrace) |
256 | { | |
257 | char buf[16]; | |
258 | ||
259 | if (ftrace->graph_depth == 0) | |
260 | return 0; | |
261 | ||
262 | if (ftrace->graph_depth < 0) { | |
263 | pr_err("invalid graph depth: %d\n", ftrace->graph_depth); | |
264 | return -1; | |
265 | } | |
266 | ||
267 | snprintf(buf, sizeof(buf), "%d", ftrace->graph_depth); | |
268 | ||
269 | if (write_tracing_file("max_graph_depth", buf) < 0) | |
270 | return -1; | |
271 | ||
272 | return 0; | |
273 | } | |
274 | ||
d01f4e8d NK |
275 | static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) |
276 | { | |
277 | char *trace_file; | |
278 | int trace_fd; | |
d01f4e8d NK |
279 | char buf[4096]; |
280 | struct pollfd pollfd = { | |
281 | .events = POLLIN, | |
282 | }; | |
283 | ||
284 | if (geteuid() != 0) { | |
285 | pr_err("ftrace only works for root!\n"); | |
286 | return -1; | |
287 | } | |
288 | ||
d01f4e8d NK |
289 | signal(SIGINT, sig_handler); |
290 | signal(SIGUSR1, sig_handler); | |
291 | signal(SIGCHLD, sig_handler); | |
58335964 | 292 | signal(SIGPIPE, sig_handler); |
d01f4e8d | 293 | |
63cd02d8 CD |
294 | if (reset_tracing_files(ftrace) < 0) { |
295 | pr_err("failed to reset ftrace\n"); | |
a9af6be5 | 296 | goto out; |
63cd02d8 | 297 | } |
d01f4e8d NK |
298 | |
299 | /* reset ftrace buffer */ | |
300 | if (write_tracing_file("trace", "0") < 0) | |
301 | goto out; | |
302 | ||
a9af6be5 NK |
303 | if (argc && perf_evlist__prepare_workload(ftrace->evlist, |
304 | &ftrace->target, argv, false, | |
305 | ftrace__workload_exec_failed_signal) < 0) { | |
d01f4e8d NK |
306 | goto out; |
307 | } | |
308 | ||
a9af6be5 NK |
309 | if (set_tracing_pid(ftrace) < 0) { |
310 | pr_err("failed to set ftrace pid\n"); | |
311 | goto out_reset; | |
d01f4e8d NK |
312 | } |
313 | ||
dc231032 NK |
314 | if (set_tracing_cpu(ftrace) < 0) { |
315 | pr_err("failed to set tracing cpumask\n"); | |
316 | goto out_reset; | |
317 | } | |
318 | ||
78b83e8b NK |
319 | if (set_tracing_filters(ftrace) < 0) { |
320 | pr_err("failed to set tracing filters\n"); | |
321 | goto out_reset; | |
322 | } | |
323 | ||
1096c35a NK |
324 | if (set_tracing_depth(ftrace) < 0) { |
325 | pr_err("failed to set graph depth\n"); | |
326 | goto out_reset; | |
327 | } | |
328 | ||
a9af6be5 NK |
329 | if (write_tracing_file("current_tracer", ftrace->tracer) < 0) { |
330 | pr_err("failed to set current_tracer to %s\n", ftrace->tracer); | |
331 | goto out_reset; | |
d01f4e8d NK |
332 | } |
333 | ||
29681bc5 NK |
334 | setup_pager(); |
335 | ||
d01f4e8d NK |
336 | trace_file = get_tracing_file("trace_pipe"); |
337 | if (!trace_file) { | |
338 | pr_err("failed to open trace_pipe\n"); | |
a9af6be5 | 339 | goto out_reset; |
d01f4e8d NK |
340 | } |
341 | ||
342 | trace_fd = open(trace_file, O_RDONLY); | |
343 | ||
344 | put_tracing_file(trace_file); | |
345 | ||
346 | if (trace_fd < 0) { | |
347 | pr_err("failed to open trace_pipe\n"); | |
a9af6be5 | 348 | goto out_reset; |
d01f4e8d NK |
349 | } |
350 | ||
351 | fcntl(trace_fd, F_SETFL, O_NONBLOCK); | |
352 | pollfd.fd = trace_fd; | |
353 | ||
354 | if (write_tracing_file("tracing_on", "1") < 0) { | |
355 | pr_err("can't enable tracing\n"); | |
356 | goto out_close_fd; | |
357 | } | |
358 | ||
359 | perf_evlist__start_workload(ftrace->evlist); | |
360 | ||
361 | while (!done) { | |
362 | if (poll(&pollfd, 1, -1) < 0) | |
363 | break; | |
364 | ||
365 | if (pollfd.revents & POLLIN) { | |
366 | int n = read(trace_fd, buf, sizeof(buf)); | |
367 | if (n < 0) | |
368 | break; | |
369 | if (fwrite(buf, n, 1, stdout) != 1) | |
370 | break; | |
371 | } | |
372 | } | |
373 | ||
374 | write_tracing_file("tracing_on", "0"); | |
375 | ||
376 | /* read remaining buffer contents */ | |
377 | while (true) { | |
378 | int n = read(trace_fd, buf, sizeof(buf)); | |
379 | if (n <= 0) | |
380 | break; | |
381 | if (fwrite(buf, n, 1, stdout) != 1) | |
382 | break; | |
383 | } | |
384 | ||
385 | out_close_fd: | |
386 | close(trace_fd); | |
a9af6be5 | 387 | out_reset: |
d01f4e8d | 388 | reset_tracing_files(ftrace); |
a9af6be5 | 389 | out: |
d01f4e8d NK |
390 | return done ? 0 : -1; |
391 | } | |
392 | ||
b05d1093 TS |
393 | static int perf_ftrace_config(const char *var, const char *value, void *cb) |
394 | { | |
395 | struct perf_ftrace *ftrace = cb; | |
396 | ||
8e99b6d4 | 397 | if (!strstarts(var, "ftrace.")) |
b05d1093 TS |
398 | return 0; |
399 | ||
400 | if (strcmp(var, "ftrace.tracer")) | |
401 | return -1; | |
402 | ||
403 | if (!strcmp(value, "function_graph") || | |
404 | !strcmp(value, "function")) { | |
405 | ftrace->tracer = value; | |
406 | return 0; | |
407 | } | |
408 | ||
409 | pr_err("Please select \"function_graph\" (default) or \"function\"\n"); | |
410 | return -1; | |
411 | } | |
412 | ||
78b83e8b NK |
413 | static int parse_filter_func(const struct option *opt, const char *str, |
414 | int unset __maybe_unused) | |
415 | { | |
416 | struct list_head *head = opt->value; | |
417 | struct filter_entry *entry; | |
418 | ||
419 | entry = malloc(sizeof(*entry) + strlen(str) + 1); | |
420 | if (entry == NULL) | |
421 | return -ENOMEM; | |
422 | ||
423 | strcpy(entry->name, str); | |
424 | list_add_tail(&entry->list, head); | |
425 | ||
426 | return 0; | |
427 | } | |
428 | ||
429 | static void delete_filter_func(struct list_head *head) | |
430 | { | |
431 | struct filter_entry *pos, *tmp; | |
432 | ||
433 | list_for_each_entry_safe(pos, tmp, head, list) { | |
e56fbc9d | 434 | list_del_init(&pos->list); |
78b83e8b NK |
435 | free(pos); |
436 | } | |
437 | } | |
438 | ||
b0ad8ea6 | 439 | int cmd_ftrace(int argc, const char **argv) |
d01f4e8d NK |
440 | { |
441 | int ret; | |
442 | struct perf_ftrace ftrace = { | |
bf062bd2 | 443 | .tracer = DEFAULT_TRACER, |
d01f4e8d NK |
444 | .target = { .uid = UINT_MAX, }, |
445 | }; | |
446 | const char * const ftrace_usage[] = { | |
a9af6be5 | 447 | "perf ftrace [<options>] [<command>]", |
d01f4e8d NK |
448 | "perf ftrace [<options>] -- <command> [<options>]", |
449 | NULL | |
450 | }; | |
451 | const struct option ftrace_options[] = { | |
452 | OPT_STRING('t', "tracer", &ftrace.tracer, "tracer", | |
ec347870 | 453 | "tracer to use: function_graph(default) or function"), |
a9af6be5 NK |
454 | OPT_STRING('p', "pid", &ftrace.target.pid, "pid", |
455 | "trace on existing process id"), | |
d01f4e8d NK |
456 | OPT_INCR('v', "verbose", &verbose, |
457 | "be more verbose"), | |
dc231032 NK |
458 | OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide, |
459 | "system-wide collection from all CPUs"), | |
460 | OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu", | |
461 | "list of cpus to monitor"), | |
78b83e8b NK |
462 | OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func", |
463 | "trace given functions only", parse_filter_func), | |
464 | OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func", | |
465 | "do not trace given functions", parse_filter_func), | |
466 | OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func", | |
467 | "Set graph filter on given functions", parse_filter_func), | |
468 | OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func", | |
469 | "Set nograph filter on given functions", parse_filter_func), | |
1096c35a NK |
470 | OPT_INTEGER('D', "graph-depth", &ftrace.graph_depth, |
471 | "Max depth for function graph tracer"), | |
d01f4e8d NK |
472 | OPT_END() |
473 | }; | |
474 | ||
78b83e8b NK |
475 | INIT_LIST_HEAD(&ftrace.filters); |
476 | INIT_LIST_HEAD(&ftrace.notrace); | |
477 | INIT_LIST_HEAD(&ftrace.graph_funcs); | |
478 | INIT_LIST_HEAD(&ftrace.nograph_funcs); | |
479 | ||
b05d1093 TS |
480 | ret = perf_config(perf_ftrace_config, &ftrace); |
481 | if (ret < 0) | |
482 | return -1; | |
483 | ||
d01f4e8d NK |
484 | argc = parse_options(argc, argv, ftrace_options, ftrace_usage, |
485 | PARSE_OPT_STOP_AT_NON_OPTION); | |
a9af6be5 | 486 | if (!argc && target__none(&ftrace.target)) |
d01f4e8d NK |
487 | usage_with_options(ftrace_usage, ftrace_options); |
488 | ||
a9af6be5 NK |
489 | ret = target__validate(&ftrace.target); |
490 | if (ret) { | |
491 | char errbuf[512]; | |
492 | ||
493 | target__strerror(&ftrace.target, ret, errbuf, 512); | |
494 | pr_err("%s\n", errbuf); | |
78b83e8b | 495 | goto out_delete_filters; |
a9af6be5 NK |
496 | } |
497 | ||
d01f4e8d | 498 | ftrace.evlist = perf_evlist__new(); |
78b83e8b NK |
499 | if (ftrace.evlist == NULL) { |
500 | ret = -ENOMEM; | |
501 | goto out_delete_filters; | |
502 | } | |
d01f4e8d NK |
503 | |
504 | ret = perf_evlist__create_maps(ftrace.evlist, &ftrace.target); | |
505 | if (ret < 0) | |
506 | goto out_delete_evlist; | |
507 | ||
d01f4e8d NK |
508 | ret = __cmd_ftrace(&ftrace, argc, argv); |
509 | ||
510 | out_delete_evlist: | |
511 | perf_evlist__delete(ftrace.evlist); | |
512 | ||
78b83e8b NK |
513 | out_delete_filters: |
514 | delete_filter_func(&ftrace.filters); | |
515 | delete_filter_func(&ftrace.notrace); | |
516 | delete_filter_func(&ftrace.graph_funcs); | |
517 | delete_filter_func(&ftrace.nograph_funcs); | |
518 | ||
d01f4e8d NK |
519 | return ret; |
520 | } |