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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * builtin-ftrace.c
4 *
5 * Copyright (c) 2013 LG Electronics, Namhyung Kim <namhyung@kernel.org>
6 */
7
8#include "builtin.h"
9
10#include <errno.h>
11#include <unistd.h>
12#include <signal.h>
13#include <stdlib.h>
14#include <fcntl.h>
15#include <poll.h>
16#include <linux/capability.h>
17#include <linux/string.h>
18
19#include "debug.h"
20#include <subcmd/pager.h>
21#include <subcmd/parse-options.h>
22#include <api/fs/tracing_path.h>
23#include "evlist.h"
24#include "target.h"
25#include "cpumap.h"
26#include "thread_map.h"
27#include "util/cap.h"
28#include "util/config.h"
29
30#define DEFAULT_TRACER "function_graph"
31
32struct perf_ftrace {
33 struct evlist *evlist;
34 struct target target;
35 const char *tracer;
36 struct list_head filters;
37 struct list_head notrace;
38 struct list_head graph_funcs;
39 struct list_head nograph_funcs;
40 int graph_depth;
41};
42
43struct filter_entry {
44 struct list_head list;
45 char name[];
46};
47
48static bool done;
49
50static void sig_handler(int sig __maybe_unused)
51{
52 done = true;
53}
54
55/*
56 * perf_evlist__prepare_workload will send a SIGUSR1 if the fork fails, since
57 * we asked by setting its exec_error to the function below,
58 * ftrace__workload_exec_failed_signal.
59 *
60 * XXX We need to handle this more appropriately, emitting an error, etc.
61 */
62static void ftrace__workload_exec_failed_signal(int signo __maybe_unused,
63 siginfo_t *info __maybe_unused,
64 void *ucontext __maybe_unused)
65{
66 /* workload_exec_errno = info->si_value.sival_int; */
67 done = true;
68}
69
70static int __write_tracing_file(const char *name, const char *val, bool append)
71{
72 char *file;
73 int fd, ret = -1;
74 ssize_t size = strlen(val);
75 int flags = O_WRONLY;
76 char errbuf[512];
77 char *val_copy;
78
79 file = get_tracing_file(name);
80 if (!file) {
81 pr_debug("cannot get tracing file: %s\n", name);
82 return -1;
83 }
84
85 if (append)
86 flags |= O_APPEND;
87 else
88 flags |= O_TRUNC;
89
90 fd = open(file, flags);
91 if (fd < 0) {
92 pr_debug("cannot open tracing file: %s: %s\n",
93 name, str_error_r(errno, errbuf, sizeof(errbuf)));
94 goto out;
95 }
96
97 /*
98 * Copy the original value and append a '\n'. Without this,
99 * the kernel can hide possible errors.
100 */
101 val_copy = strdup(val);
102 if (!val_copy)
103 goto out_close;
104 val_copy[size] = '\n';
105
106 if (write(fd, val_copy, size + 1) == size + 1)
107 ret = 0;
108 else
109 pr_debug("write '%s' to tracing/%s failed: %s\n",
110 val, name, str_error_r(errno, errbuf, sizeof(errbuf)));
111
112 free(val_copy);
113out_close:
114 close(fd);
115out:
116 put_tracing_file(file);
117 return ret;
118}
119
120static int write_tracing_file(const char *name, const char *val)
121{
122 return __write_tracing_file(name, val, false);
123}
124
125static int append_tracing_file(const char *name, const char *val)
126{
127 return __write_tracing_file(name, val, true);
128}
129
130static int reset_tracing_cpu(void);
131static void reset_tracing_filters(void);
132
133static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
134{
135 if (write_tracing_file("tracing_on", "0") < 0)
136 return -1;
137
138 if (write_tracing_file("current_tracer", "nop") < 0)
139 return -1;
140
141 if (write_tracing_file("set_ftrace_pid", " ") < 0)
142 return -1;
143
144 if (reset_tracing_cpu() < 0)
145 return -1;
146
147 if (write_tracing_file("max_graph_depth", "0") < 0)
148 return -1;
149
150 reset_tracing_filters();
151 return 0;
152}
153
154static int set_tracing_pid(struct perf_ftrace *ftrace)
155{
156 int i;
157 char buf[16];
158
159 if (target__has_cpu(&ftrace->target))
160 return 0;
161
162 for (i = 0; i < perf_thread_map__nr(ftrace->evlist->core.threads); i++) {
163 scnprintf(buf, sizeof(buf), "%d",
164 ftrace->evlist->core.threads->map[i]);
165 if (append_tracing_file("set_ftrace_pid", buf) < 0)
166 return -1;
167 }
168 return 0;
169}
170
171static int set_tracing_cpumask(struct perf_cpu_map *cpumap)
172{
173 char *cpumask;
174 size_t mask_size;
175 int ret;
176 int last_cpu;
177
178 last_cpu = cpu_map__cpu(cpumap, cpumap->nr - 1);
179 mask_size = last_cpu / 4 + 2; /* one more byte for EOS */
180 mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */
181
182 cpumask = malloc(mask_size);
183 if (cpumask == NULL) {
184 pr_debug("failed to allocate cpu mask\n");
185 return -1;
186 }
187
188 cpu_map__snprint_mask(cpumap, cpumask, mask_size);
189
190 ret = write_tracing_file("tracing_cpumask", cpumask);
191
192 free(cpumask);
193 return ret;
194}
195
196static int set_tracing_cpu(struct perf_ftrace *ftrace)
197{
198 struct perf_cpu_map *cpumap = ftrace->evlist->core.cpus;
199
200 if (!target__has_cpu(&ftrace->target))
201 return 0;
202
203 return set_tracing_cpumask(cpumap);
204}
205
206static int reset_tracing_cpu(void)
207{
208 struct perf_cpu_map *cpumap = perf_cpu_map__new(NULL);
209 int ret;
210
211 ret = set_tracing_cpumask(cpumap);
212 perf_cpu_map__put(cpumap);
213 return ret;
214}
215
216static int __set_tracing_filter(const char *filter_file, struct list_head *funcs)
217{
218 struct filter_entry *pos;
219
220 list_for_each_entry(pos, funcs, list) {
221 if (append_tracing_file(filter_file, pos->name) < 0)
222 return -1;
223 }
224
225 return 0;
226}
227
228static int set_tracing_filters(struct perf_ftrace *ftrace)
229{
230 int ret;
231
232 ret = __set_tracing_filter("set_ftrace_filter", &ftrace->filters);
233 if (ret < 0)
234 return ret;
235
236 ret = __set_tracing_filter("set_ftrace_notrace", &ftrace->notrace);
237 if (ret < 0)
238 return ret;
239
240 ret = __set_tracing_filter("set_graph_function", &ftrace->graph_funcs);
241 if (ret < 0)
242 return ret;
243
244 /* old kernels do not have this filter */
245 __set_tracing_filter("set_graph_notrace", &ftrace->nograph_funcs);
246
247 return ret;
248}
249
250static void reset_tracing_filters(void)
251{
252 write_tracing_file("set_ftrace_filter", " ");
253 write_tracing_file("set_ftrace_notrace", " ");
254 write_tracing_file("set_graph_function", " ");
255 write_tracing_file("set_graph_notrace", " ");
256}
257
258static int set_tracing_depth(struct perf_ftrace *ftrace)
259{
260 char buf[16];
261
262 if (ftrace->graph_depth == 0)
263 return 0;
264
265 if (ftrace->graph_depth < 0) {
266 pr_err("invalid graph depth: %d\n", ftrace->graph_depth);
267 return -1;
268 }
269
270 snprintf(buf, sizeof(buf), "%d", ftrace->graph_depth);
271
272 if (write_tracing_file("max_graph_depth", buf) < 0)
273 return -1;
274
275 return 0;
276}
277
278static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
279{
280 char *trace_file;
281 int trace_fd;
282 char buf[4096];
283 struct pollfd pollfd = {
284 .events = POLLIN,
285 };
286
287 if (!perf_cap__capable(CAP_SYS_ADMIN)) {
288 pr_err("ftrace only works for %s!\n",
289#ifdef HAVE_LIBCAP_SUPPORT
290 "users with the SYS_ADMIN capability"
291#else
292 "root"
293#endif
294 );
295 return -1;
296 }
297
298 signal(SIGINT, sig_handler);
299 signal(SIGUSR1, sig_handler);
300 signal(SIGCHLD, sig_handler);
301 signal(SIGPIPE, sig_handler);
302
303 if (reset_tracing_files(ftrace) < 0) {
304 pr_err("failed to reset ftrace\n");
305 goto out;
306 }
307
308 /* reset ftrace buffer */
309 if (write_tracing_file("trace", "0") < 0)
310 goto out;
311
312 if (argc && perf_evlist__prepare_workload(ftrace->evlist,
313 &ftrace->target, argv, false,
314 ftrace__workload_exec_failed_signal) < 0) {
315 goto out;
316 }
317
318 if (set_tracing_pid(ftrace) < 0) {
319 pr_err("failed to set ftrace pid\n");
320 goto out_reset;
321 }
322
323 if (set_tracing_cpu(ftrace) < 0) {
324 pr_err("failed to set tracing cpumask\n");
325 goto out_reset;
326 }
327
328 if (set_tracing_filters(ftrace) < 0) {
329 pr_err("failed to set tracing filters\n");
330 goto out_reset;
331 }
332
333 if (set_tracing_depth(ftrace) < 0) {
334 pr_err("failed to set graph depth\n");
335 goto out_reset;
336 }
337
338 if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
339 pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
340 goto out_reset;
341 }
342
343 setup_pager();
344
345 trace_file = get_tracing_file("trace_pipe");
346 if (!trace_file) {
347 pr_err("failed to open trace_pipe\n");
348 goto out_reset;
349 }
350
351 trace_fd = open(trace_file, O_RDONLY);
352
353 put_tracing_file(trace_file);
354
355 if (trace_fd < 0) {
356 pr_err("failed to open trace_pipe\n");
357 goto out_reset;
358 }
359
360 fcntl(trace_fd, F_SETFL, O_NONBLOCK);
361 pollfd.fd = trace_fd;
362
363 if (write_tracing_file("tracing_on", "1") < 0) {
364 pr_err("can't enable tracing\n");
365 goto out_close_fd;
366 }
367
368 perf_evlist__start_workload(ftrace->evlist);
369
370 while (!done) {
371 if (poll(&pollfd, 1, -1) < 0)
372 break;
373
374 if (pollfd.revents & POLLIN) {
375 int n = read(trace_fd, buf, sizeof(buf));
376 if (n < 0)
377 break;
378 if (fwrite(buf, n, 1, stdout) != 1)
379 break;
380 }
381 }
382
383 write_tracing_file("tracing_on", "0");
384
385 /* read remaining buffer contents */
386 while (true) {
387 int n = read(trace_fd, buf, sizeof(buf));
388 if (n <= 0)
389 break;
390 if (fwrite(buf, n, 1, stdout) != 1)
391 break;
392 }
393
394out_close_fd:
395 close(trace_fd);
396out_reset:
397 reset_tracing_files(ftrace);
398out:
399 return done ? 0 : -1;
400}
401
402static int perf_ftrace_config(const char *var, const char *value, void *cb)
403{
404 struct perf_ftrace *ftrace = cb;
405
406 if (!strstarts(var, "ftrace."))
407 return 0;
408
409 if (strcmp(var, "ftrace.tracer"))
410 return -1;
411
412 if (!strcmp(value, "function_graph") ||
413 !strcmp(value, "function")) {
414 ftrace->tracer = value;
415 return 0;
416 }
417
418 pr_err("Please select \"function_graph\" (default) or \"function\"\n");
419 return -1;
420}
421
422static int parse_filter_func(const struct option *opt, const char *str,
423 int unset __maybe_unused)
424{
425 struct list_head *head = opt->value;
426 struct filter_entry *entry;
427
428 entry = malloc(sizeof(*entry) + strlen(str) + 1);
429 if (entry == NULL)
430 return -ENOMEM;
431
432 strcpy(entry->name, str);
433 list_add_tail(&entry->list, head);
434
435 return 0;
436}
437
438static void delete_filter_func(struct list_head *head)
439{
440 struct filter_entry *pos, *tmp;
441
442 list_for_each_entry_safe(pos, tmp, head, list) {
443 list_del_init(&pos->list);
444 free(pos);
445 }
446}
447
448int cmd_ftrace(int argc, const char **argv)
449{
450 int ret;
451 struct perf_ftrace ftrace = {
452 .tracer = DEFAULT_TRACER,
453 .target = { .uid = UINT_MAX, },
454 };
455 const char * const ftrace_usage[] = {
456 "perf ftrace [<options>] [<command>]",
457 "perf ftrace [<options>] -- <command> [<options>]",
458 NULL
459 };
460 const struct option ftrace_options[] = {
461 OPT_STRING('t', "tracer", &ftrace.tracer, "tracer",
462 "tracer to use: function_graph(default) or function"),
463 OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
464 "trace on existing process id"),
465 OPT_INCR('v', "verbose", &verbose,
466 "be more verbose"),
467 OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide,
468 "system-wide collection from all CPUs"),
469 OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu",
470 "list of cpus to monitor"),
471 OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func",
472 "trace given functions only", parse_filter_func),
473 OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func",
474 "do not trace given functions", parse_filter_func),
475 OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func",
476 "Set graph filter on given functions", parse_filter_func),
477 OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func",
478 "Set nograph filter on given functions", parse_filter_func),
479 OPT_INTEGER('D', "graph-depth", &ftrace.graph_depth,
480 "Max depth for function graph tracer"),
481 OPT_END()
482 };
483
484 INIT_LIST_HEAD(&ftrace.filters);
485 INIT_LIST_HEAD(&ftrace.notrace);
486 INIT_LIST_HEAD(&ftrace.graph_funcs);
487 INIT_LIST_HEAD(&ftrace.nograph_funcs);
488
489 ret = perf_config(perf_ftrace_config, &ftrace);
490 if (ret < 0)
491 return -1;
492
493 argc = parse_options(argc, argv, ftrace_options, ftrace_usage,
494 PARSE_OPT_STOP_AT_NON_OPTION);
495 if (!argc && target__none(&ftrace.target))
496 usage_with_options(ftrace_usage, ftrace_options);
497
498 ret = target__validate(&ftrace.target);
499 if (ret) {
500 char errbuf[512];
501
502 target__strerror(&ftrace.target, ret, errbuf, 512);
503 pr_err("%s\n", errbuf);
504 goto out_delete_filters;
505 }
506
507 ftrace.evlist = evlist__new();
508 if (ftrace.evlist == NULL) {
509 ret = -ENOMEM;
510 goto out_delete_filters;
511 }
512
513 ret = perf_evlist__create_maps(ftrace.evlist, &ftrace.target);
514 if (ret < 0)
515 goto out_delete_evlist;
516
517 ret = __cmd_ftrace(&ftrace, argc, argv);
518
519out_delete_evlist:
520 evlist__delete(ftrace.evlist);
521
522out_delete_filters:
523 delete_filter_func(&ftrace.filters);
524 delete_filter_func(&ftrace.notrace);
525 delete_filter_func(&ftrace.graph_funcs);
526 delete_filter_func(&ftrace.nograph_funcs);
527
528 return ret;
529}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * builtin-ftrace.c
4 *
5 * Copyright (c) 2013 LG Electronics, Namhyung Kim <namhyung@kernel.org>
6 * Copyright (c) 2020 Changbin Du <changbin.du@gmail.com>, significant enhancement.
7 */
8
9#include "builtin.h"
10
11#include <errno.h>
12#include <unistd.h>
13#include <signal.h>
14#include <stdlib.h>
15#include <fcntl.h>
16#include <poll.h>
17#include <linux/capability.h>
18#include <linux/string.h>
19
20#include "debug.h"
21#include <subcmd/pager.h>
22#include <subcmd/parse-options.h>
23#include <api/fs/tracing_path.h>
24#include "evlist.h"
25#include "target.h"
26#include "cpumap.h"
27#include "thread_map.h"
28#include "strfilter.h"
29#include "util/cap.h"
30#include "util/config.h"
31#include "util/units.h"
32#include "util/parse-sublevel-options.h"
33
34#define DEFAULT_TRACER "function_graph"
35
36struct perf_ftrace {
37 struct evlist *evlist;
38 struct target target;
39 const char *tracer;
40 struct list_head filters;
41 struct list_head notrace;
42 struct list_head graph_funcs;
43 struct list_head nograph_funcs;
44 int graph_depth;
45 unsigned long percpu_buffer_size;
46 bool inherit;
47 int func_stack_trace;
48 int func_irq_info;
49 int graph_nosleep_time;
50 int graph_noirqs;
51 int graph_verbose;
52 int graph_thresh;
53 unsigned int initial_delay;
54};
55
56struct filter_entry {
57 struct list_head list;
58 char name[];
59};
60
61static volatile int workload_exec_errno;
62static bool done;
63
64static void sig_handler(int sig __maybe_unused)
65{
66 done = true;
67}
68
69/*
70 * evlist__prepare_workload will send a SIGUSR1 if the fork fails, since
71 * we asked by setting its exec_error to the function below,
72 * ftrace__workload_exec_failed_signal.
73 *
74 * XXX We need to handle this more appropriately, emitting an error, etc.
75 */
76static void ftrace__workload_exec_failed_signal(int signo __maybe_unused,
77 siginfo_t *info __maybe_unused,
78 void *ucontext __maybe_unused)
79{
80 workload_exec_errno = info->si_value.sival_int;
81 done = true;
82}
83
84static int __write_tracing_file(const char *name, const char *val, bool append)
85{
86 char *file;
87 int fd, ret = -1;
88 ssize_t size = strlen(val);
89 int flags = O_WRONLY;
90 char errbuf[512];
91 char *val_copy;
92
93 file = get_tracing_file(name);
94 if (!file) {
95 pr_debug("cannot get tracing file: %s\n", name);
96 return -1;
97 }
98
99 if (append)
100 flags |= O_APPEND;
101 else
102 flags |= O_TRUNC;
103
104 fd = open(file, flags);
105 if (fd < 0) {
106 pr_debug("cannot open tracing file: %s: %s\n",
107 name, str_error_r(errno, errbuf, sizeof(errbuf)));
108 goto out;
109 }
110
111 /*
112 * Copy the original value and append a '\n'. Without this,
113 * the kernel can hide possible errors.
114 */
115 val_copy = strdup(val);
116 if (!val_copy)
117 goto out_close;
118 val_copy[size] = '\n';
119
120 if (write(fd, val_copy, size + 1) == size + 1)
121 ret = 0;
122 else
123 pr_debug("write '%s' to tracing/%s failed: %s\n",
124 val, name, str_error_r(errno, errbuf, sizeof(errbuf)));
125
126 free(val_copy);
127out_close:
128 close(fd);
129out:
130 put_tracing_file(file);
131 return ret;
132}
133
134static int write_tracing_file(const char *name, const char *val)
135{
136 return __write_tracing_file(name, val, false);
137}
138
139static int append_tracing_file(const char *name, const char *val)
140{
141 return __write_tracing_file(name, val, true);
142}
143
144static int read_tracing_file_to_stdout(const char *name)
145{
146 char buf[4096];
147 char *file;
148 int fd;
149 int ret = -1;
150
151 file = get_tracing_file(name);
152 if (!file) {
153 pr_debug("cannot get tracing file: %s\n", name);
154 return -1;
155 }
156
157 fd = open(file, O_RDONLY);
158 if (fd < 0) {
159 pr_debug("cannot open tracing file: %s: %s\n",
160 name, str_error_r(errno, buf, sizeof(buf)));
161 goto out;
162 }
163
164 /* read contents to stdout */
165 while (true) {
166 int n = read(fd, buf, sizeof(buf));
167 if (n == 0)
168 break;
169 else if (n < 0)
170 goto out_close;
171
172 if (fwrite(buf, n, 1, stdout) != 1)
173 goto out_close;
174 }
175 ret = 0;
176
177out_close:
178 close(fd);
179out:
180 put_tracing_file(file);
181 return ret;
182}
183
184static int read_tracing_file_by_line(const char *name,
185 void (*cb)(char *str, void *arg),
186 void *cb_arg)
187{
188 char *line = NULL;
189 size_t len = 0;
190 char *file;
191 FILE *fp;
192
193 file = get_tracing_file(name);
194 if (!file) {
195 pr_debug("cannot get tracing file: %s\n", name);
196 return -1;
197 }
198
199 fp = fopen(file, "r");
200 if (fp == NULL) {
201 pr_debug("cannot open tracing file: %s\n", name);
202 put_tracing_file(file);
203 return -1;
204 }
205
206 while (getline(&line, &len, fp) != -1) {
207 cb(line, cb_arg);
208 }
209
210 if (line)
211 free(line);
212
213 fclose(fp);
214 put_tracing_file(file);
215 return 0;
216}
217
218static int write_tracing_file_int(const char *name, int value)
219{
220 char buf[16];
221
222 snprintf(buf, sizeof(buf), "%d", value);
223 if (write_tracing_file(name, buf) < 0)
224 return -1;
225
226 return 0;
227}
228
229static int write_tracing_option_file(const char *name, const char *val)
230{
231 char *file;
232 int ret;
233
234 if (asprintf(&file, "options/%s", name) < 0)
235 return -1;
236
237 ret = __write_tracing_file(file, val, false);
238 free(file);
239 return ret;
240}
241
242static int reset_tracing_cpu(void);
243static void reset_tracing_filters(void);
244
245static void reset_tracing_options(struct perf_ftrace *ftrace __maybe_unused)
246{
247 write_tracing_option_file("function-fork", "0");
248 write_tracing_option_file("func_stack_trace", "0");
249 write_tracing_option_file("sleep-time", "1");
250 write_tracing_option_file("funcgraph-irqs", "1");
251 write_tracing_option_file("funcgraph-proc", "0");
252 write_tracing_option_file("funcgraph-abstime", "0");
253 write_tracing_option_file("latency-format", "0");
254 write_tracing_option_file("irq-info", "0");
255}
256
257static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
258{
259 if (write_tracing_file("tracing_on", "0") < 0)
260 return -1;
261
262 if (write_tracing_file("current_tracer", "nop") < 0)
263 return -1;
264
265 if (write_tracing_file("set_ftrace_pid", " ") < 0)
266 return -1;
267
268 if (reset_tracing_cpu() < 0)
269 return -1;
270
271 if (write_tracing_file("max_graph_depth", "0") < 0)
272 return -1;
273
274 if (write_tracing_file("tracing_thresh", "0") < 0)
275 return -1;
276
277 reset_tracing_filters();
278 reset_tracing_options(ftrace);
279 return 0;
280}
281
282static int set_tracing_pid(struct perf_ftrace *ftrace)
283{
284 int i;
285 char buf[16];
286
287 if (target__has_cpu(&ftrace->target))
288 return 0;
289
290 for (i = 0; i < perf_thread_map__nr(ftrace->evlist->core.threads); i++) {
291 scnprintf(buf, sizeof(buf), "%d",
292 perf_thread_map__pid(ftrace->evlist->core.threads, i));
293 if (append_tracing_file("set_ftrace_pid", buf) < 0)
294 return -1;
295 }
296 return 0;
297}
298
299static int set_tracing_cpumask(struct perf_cpu_map *cpumap)
300{
301 char *cpumask;
302 size_t mask_size;
303 int ret;
304 int last_cpu;
305
306 last_cpu = cpu_map__cpu(cpumap, cpumap->nr - 1);
307 mask_size = last_cpu / 4 + 2; /* one more byte for EOS */
308 mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */
309
310 cpumask = malloc(mask_size);
311 if (cpumask == NULL) {
312 pr_debug("failed to allocate cpu mask\n");
313 return -1;
314 }
315
316 cpu_map__snprint_mask(cpumap, cpumask, mask_size);
317
318 ret = write_tracing_file("tracing_cpumask", cpumask);
319
320 free(cpumask);
321 return ret;
322}
323
324static int set_tracing_cpu(struct perf_ftrace *ftrace)
325{
326 struct perf_cpu_map *cpumap = ftrace->evlist->core.cpus;
327
328 if (!target__has_cpu(&ftrace->target))
329 return 0;
330
331 return set_tracing_cpumask(cpumap);
332}
333
334static int set_tracing_func_stack_trace(struct perf_ftrace *ftrace)
335{
336 if (!ftrace->func_stack_trace)
337 return 0;
338
339 if (write_tracing_option_file("func_stack_trace", "1") < 0)
340 return -1;
341
342 return 0;
343}
344
345static int set_tracing_func_irqinfo(struct perf_ftrace *ftrace)
346{
347 if (!ftrace->func_irq_info)
348 return 0;
349
350 if (write_tracing_option_file("irq-info", "1") < 0)
351 return -1;
352
353 return 0;
354}
355
356static int reset_tracing_cpu(void)
357{
358 struct perf_cpu_map *cpumap = perf_cpu_map__new(NULL);
359 int ret;
360
361 ret = set_tracing_cpumask(cpumap);
362 perf_cpu_map__put(cpumap);
363 return ret;
364}
365
366static int __set_tracing_filter(const char *filter_file, struct list_head *funcs)
367{
368 struct filter_entry *pos;
369
370 list_for_each_entry(pos, funcs, list) {
371 if (append_tracing_file(filter_file, pos->name) < 0)
372 return -1;
373 }
374
375 return 0;
376}
377
378static int set_tracing_filters(struct perf_ftrace *ftrace)
379{
380 int ret;
381
382 ret = __set_tracing_filter("set_ftrace_filter", &ftrace->filters);
383 if (ret < 0)
384 return ret;
385
386 ret = __set_tracing_filter("set_ftrace_notrace", &ftrace->notrace);
387 if (ret < 0)
388 return ret;
389
390 ret = __set_tracing_filter("set_graph_function", &ftrace->graph_funcs);
391 if (ret < 0)
392 return ret;
393
394 /* old kernels do not have this filter */
395 __set_tracing_filter("set_graph_notrace", &ftrace->nograph_funcs);
396
397 return ret;
398}
399
400static void reset_tracing_filters(void)
401{
402 write_tracing_file("set_ftrace_filter", " ");
403 write_tracing_file("set_ftrace_notrace", " ");
404 write_tracing_file("set_graph_function", " ");
405 write_tracing_file("set_graph_notrace", " ");
406}
407
408static int set_tracing_depth(struct perf_ftrace *ftrace)
409{
410 if (ftrace->graph_depth == 0)
411 return 0;
412
413 if (ftrace->graph_depth < 0) {
414 pr_err("invalid graph depth: %d\n", ftrace->graph_depth);
415 return -1;
416 }
417
418 if (write_tracing_file_int("max_graph_depth", ftrace->graph_depth) < 0)
419 return -1;
420
421 return 0;
422}
423
424static int set_tracing_percpu_buffer_size(struct perf_ftrace *ftrace)
425{
426 int ret;
427
428 if (ftrace->percpu_buffer_size == 0)
429 return 0;
430
431 ret = write_tracing_file_int("buffer_size_kb",
432 ftrace->percpu_buffer_size / 1024);
433 if (ret < 0)
434 return ret;
435
436 return 0;
437}
438
439static int set_tracing_trace_inherit(struct perf_ftrace *ftrace)
440{
441 if (!ftrace->inherit)
442 return 0;
443
444 if (write_tracing_option_file("function-fork", "1") < 0)
445 return -1;
446
447 return 0;
448}
449
450static int set_tracing_sleep_time(struct perf_ftrace *ftrace)
451{
452 if (!ftrace->graph_nosleep_time)
453 return 0;
454
455 if (write_tracing_option_file("sleep-time", "0") < 0)
456 return -1;
457
458 return 0;
459}
460
461static int set_tracing_funcgraph_irqs(struct perf_ftrace *ftrace)
462{
463 if (!ftrace->graph_noirqs)
464 return 0;
465
466 if (write_tracing_option_file("funcgraph-irqs", "0") < 0)
467 return -1;
468
469 return 0;
470}
471
472static int set_tracing_funcgraph_verbose(struct perf_ftrace *ftrace)
473{
474 if (!ftrace->graph_verbose)
475 return 0;
476
477 if (write_tracing_option_file("funcgraph-proc", "1") < 0)
478 return -1;
479
480 if (write_tracing_option_file("funcgraph-abstime", "1") < 0)
481 return -1;
482
483 if (write_tracing_option_file("latency-format", "1") < 0)
484 return -1;
485
486 return 0;
487}
488
489static int set_tracing_thresh(struct perf_ftrace *ftrace)
490{
491 int ret;
492
493 if (ftrace->graph_thresh == 0)
494 return 0;
495
496 ret = write_tracing_file_int("tracing_thresh", ftrace->graph_thresh);
497 if (ret < 0)
498 return ret;
499
500 return 0;
501}
502
503static int set_tracing_options(struct perf_ftrace *ftrace)
504{
505 if (set_tracing_pid(ftrace) < 0) {
506 pr_err("failed to set ftrace pid\n");
507 return -1;
508 }
509
510 if (set_tracing_cpu(ftrace) < 0) {
511 pr_err("failed to set tracing cpumask\n");
512 return -1;
513 }
514
515 if (set_tracing_func_stack_trace(ftrace) < 0) {
516 pr_err("failed to set tracing option func_stack_trace\n");
517 return -1;
518 }
519
520 if (set_tracing_func_irqinfo(ftrace) < 0) {
521 pr_err("failed to set tracing option irq-info\n");
522 return -1;
523 }
524
525 if (set_tracing_filters(ftrace) < 0) {
526 pr_err("failed to set tracing filters\n");
527 return -1;
528 }
529
530 if (set_tracing_depth(ftrace) < 0) {
531 pr_err("failed to set graph depth\n");
532 return -1;
533 }
534
535 if (set_tracing_percpu_buffer_size(ftrace) < 0) {
536 pr_err("failed to set tracing per-cpu buffer size\n");
537 return -1;
538 }
539
540 if (set_tracing_trace_inherit(ftrace) < 0) {
541 pr_err("failed to set tracing option function-fork\n");
542 return -1;
543 }
544
545 if (set_tracing_sleep_time(ftrace) < 0) {
546 pr_err("failed to set tracing option sleep-time\n");
547 return -1;
548 }
549
550 if (set_tracing_funcgraph_irqs(ftrace) < 0) {
551 pr_err("failed to set tracing option funcgraph-irqs\n");
552 return -1;
553 }
554
555 if (set_tracing_funcgraph_verbose(ftrace) < 0) {
556 pr_err("failed to set tracing option funcgraph-proc/funcgraph-abstime\n");
557 return -1;
558 }
559
560 if (set_tracing_thresh(ftrace) < 0) {
561 pr_err("failed to set tracing thresh\n");
562 return -1;
563 }
564
565 return 0;
566}
567
568static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
569{
570 char *trace_file;
571 int trace_fd;
572 char buf[4096];
573 struct pollfd pollfd = {
574 .events = POLLIN,
575 };
576
577 if (!(perf_cap__capable(CAP_PERFMON) ||
578 perf_cap__capable(CAP_SYS_ADMIN))) {
579 pr_err("ftrace only works for %s!\n",
580#ifdef HAVE_LIBCAP_SUPPORT
581 "users with the CAP_PERFMON or CAP_SYS_ADMIN capability"
582#else
583 "root"
584#endif
585 );
586 return -1;
587 }
588
589 signal(SIGINT, sig_handler);
590 signal(SIGUSR1, sig_handler);
591 signal(SIGCHLD, sig_handler);
592 signal(SIGPIPE, sig_handler);
593
594 if (reset_tracing_files(ftrace) < 0) {
595 pr_err("failed to reset ftrace\n");
596 goto out;
597 }
598
599 /* reset ftrace buffer */
600 if (write_tracing_file("trace", "0") < 0)
601 goto out;
602
603 if (argc && evlist__prepare_workload(ftrace->evlist, &ftrace->target, argv, false,
604 ftrace__workload_exec_failed_signal) < 0) {
605 goto out;
606 }
607
608 if (set_tracing_options(ftrace) < 0)
609 goto out_reset;
610
611 if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
612 pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
613 goto out_reset;
614 }
615
616 setup_pager();
617
618 trace_file = get_tracing_file("trace_pipe");
619 if (!trace_file) {
620 pr_err("failed to open trace_pipe\n");
621 goto out_reset;
622 }
623
624 trace_fd = open(trace_file, O_RDONLY);
625
626 put_tracing_file(trace_file);
627
628 if (trace_fd < 0) {
629 pr_err("failed to open trace_pipe\n");
630 goto out_reset;
631 }
632
633 fcntl(trace_fd, F_SETFL, O_NONBLOCK);
634 pollfd.fd = trace_fd;
635
636 /* display column headers */
637 read_tracing_file_to_stdout("trace");
638
639 if (!ftrace->initial_delay) {
640 if (write_tracing_file("tracing_on", "1") < 0) {
641 pr_err("can't enable tracing\n");
642 goto out_close_fd;
643 }
644 }
645
646 evlist__start_workload(ftrace->evlist);
647
648 if (ftrace->initial_delay) {
649 usleep(ftrace->initial_delay * 1000);
650 if (write_tracing_file("tracing_on", "1") < 0) {
651 pr_err("can't enable tracing\n");
652 goto out_close_fd;
653 }
654 }
655
656 while (!done) {
657 if (poll(&pollfd, 1, -1) < 0)
658 break;
659
660 if (pollfd.revents & POLLIN) {
661 int n = read(trace_fd, buf, sizeof(buf));
662 if (n < 0)
663 break;
664 if (fwrite(buf, n, 1, stdout) != 1)
665 break;
666 }
667 }
668
669 write_tracing_file("tracing_on", "0");
670
671 if (workload_exec_errno) {
672 const char *emsg = str_error_r(workload_exec_errno, buf, sizeof(buf));
673 /* flush stdout first so below error msg appears at the end. */
674 fflush(stdout);
675 pr_err("workload failed: %s\n", emsg);
676 goto out_close_fd;
677 }
678
679 /* read remaining buffer contents */
680 while (true) {
681 int n = read(trace_fd, buf, sizeof(buf));
682 if (n <= 0)
683 break;
684 if (fwrite(buf, n, 1, stdout) != 1)
685 break;
686 }
687
688out_close_fd:
689 close(trace_fd);
690out_reset:
691 reset_tracing_files(ftrace);
692out:
693 return (done && !workload_exec_errno) ? 0 : -1;
694}
695
696static int perf_ftrace_config(const char *var, const char *value, void *cb)
697{
698 struct perf_ftrace *ftrace = cb;
699
700 if (!strstarts(var, "ftrace."))
701 return 0;
702
703 if (strcmp(var, "ftrace.tracer"))
704 return -1;
705
706 if (!strcmp(value, "function_graph") ||
707 !strcmp(value, "function")) {
708 ftrace->tracer = value;
709 return 0;
710 }
711
712 pr_err("Please select \"function_graph\" (default) or \"function\"\n");
713 return -1;
714}
715
716static void list_function_cb(char *str, void *arg)
717{
718 struct strfilter *filter = (struct strfilter *)arg;
719
720 if (strfilter__compare(filter, str))
721 printf("%s", str);
722}
723
724static int opt_list_avail_functions(const struct option *opt __maybe_unused,
725 const char *str, int unset)
726{
727 struct strfilter *filter;
728 const char *err = NULL;
729 int ret;
730
731 if (unset || !str)
732 return -1;
733
734 filter = strfilter__new(str, &err);
735 if (!filter)
736 return err ? -EINVAL : -ENOMEM;
737
738 ret = strfilter__or(filter, str, &err);
739 if (ret == -EINVAL) {
740 pr_err("Filter parse error at %td.\n", err - str + 1);
741 pr_err("Source: \"%s\"\n", str);
742 pr_err(" %*c\n", (int)(err - str + 1), '^');
743 strfilter__delete(filter);
744 return ret;
745 }
746
747 ret = read_tracing_file_by_line("available_filter_functions",
748 list_function_cb, filter);
749 strfilter__delete(filter);
750 if (ret < 0)
751 return ret;
752
753 exit(0);
754}
755
756static int parse_filter_func(const struct option *opt, const char *str,
757 int unset __maybe_unused)
758{
759 struct list_head *head = opt->value;
760 struct filter_entry *entry;
761
762 entry = malloc(sizeof(*entry) + strlen(str) + 1);
763 if (entry == NULL)
764 return -ENOMEM;
765
766 strcpy(entry->name, str);
767 list_add_tail(&entry->list, head);
768
769 return 0;
770}
771
772static void delete_filter_func(struct list_head *head)
773{
774 struct filter_entry *pos, *tmp;
775
776 list_for_each_entry_safe(pos, tmp, head, list) {
777 list_del_init(&pos->list);
778 free(pos);
779 }
780}
781
782static int parse_buffer_size(const struct option *opt,
783 const char *str, int unset)
784{
785 unsigned long *s = (unsigned long *)opt->value;
786 static struct parse_tag tags_size[] = {
787 { .tag = 'B', .mult = 1 },
788 { .tag = 'K', .mult = 1 << 10 },
789 { .tag = 'M', .mult = 1 << 20 },
790 { .tag = 'G', .mult = 1 << 30 },
791 { .tag = 0 },
792 };
793 unsigned long val;
794
795 if (unset) {
796 *s = 0;
797 return 0;
798 }
799
800 val = parse_tag_value(str, tags_size);
801 if (val != (unsigned long) -1) {
802 if (val < 1024) {
803 pr_err("buffer size too small, must larger than 1KB.");
804 return -1;
805 }
806 *s = val;
807 return 0;
808 }
809
810 return -1;
811}
812
813static int parse_func_tracer_opts(const struct option *opt,
814 const char *str, int unset)
815{
816 int ret;
817 struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value;
818 struct sublevel_option func_tracer_opts[] = {
819 { .name = "call-graph", .value_ptr = &ftrace->func_stack_trace },
820 { .name = "irq-info", .value_ptr = &ftrace->func_irq_info },
821 { .name = NULL, }
822 };
823
824 if (unset)
825 return 0;
826
827 ret = perf_parse_sublevel_options(str, func_tracer_opts);
828 if (ret)
829 return ret;
830
831 return 0;
832}
833
834static int parse_graph_tracer_opts(const struct option *opt,
835 const char *str, int unset)
836{
837 int ret;
838 struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value;
839 struct sublevel_option graph_tracer_opts[] = {
840 { .name = "nosleep-time", .value_ptr = &ftrace->graph_nosleep_time },
841 { .name = "noirqs", .value_ptr = &ftrace->graph_noirqs },
842 { .name = "verbose", .value_ptr = &ftrace->graph_verbose },
843 { .name = "thresh", .value_ptr = &ftrace->graph_thresh },
844 { .name = "depth", .value_ptr = &ftrace->graph_depth },
845 { .name = NULL, }
846 };
847
848 if (unset)
849 return 0;
850
851 ret = perf_parse_sublevel_options(str, graph_tracer_opts);
852 if (ret)
853 return ret;
854
855 return 0;
856}
857
858static void select_tracer(struct perf_ftrace *ftrace)
859{
860 bool graph = !list_empty(&ftrace->graph_funcs) ||
861 !list_empty(&ftrace->nograph_funcs);
862 bool func = !list_empty(&ftrace->filters) ||
863 !list_empty(&ftrace->notrace);
864
865 /* The function_graph has priority over function tracer. */
866 if (graph)
867 ftrace->tracer = "function_graph";
868 else if (func)
869 ftrace->tracer = "function";
870 /* Otherwise, the default tracer is used. */
871
872 pr_debug("%s tracer is used\n", ftrace->tracer);
873}
874
875int cmd_ftrace(int argc, const char **argv)
876{
877 int ret;
878 struct perf_ftrace ftrace = {
879 .tracer = DEFAULT_TRACER,
880 .target = { .uid = UINT_MAX, },
881 };
882 const char * const ftrace_usage[] = {
883 "perf ftrace [<options>] [<command>]",
884 "perf ftrace [<options>] -- <command> [<options>]",
885 NULL
886 };
887 const struct option ftrace_options[] = {
888 OPT_STRING('t', "tracer", &ftrace.tracer, "tracer",
889 "Tracer to use: function_graph(default) or function"),
890 OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",
891 "Show available functions to filter",
892 opt_list_avail_functions, "*"),
893 OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
894 "Trace on existing process id"),
895 /* TODO: Add short option -t after -t/--tracer can be removed. */
896 OPT_STRING(0, "tid", &ftrace.target.tid, "tid",
897 "Trace on existing thread id (exclusive to --pid)"),
898 OPT_INCR('v', "verbose", &verbose,
899 "Be more verbose"),
900 OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide,
901 "System-wide collection from all CPUs"),
902 OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu",
903 "List of cpus to monitor"),
904 OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func",
905 "Trace given functions using function tracer",
906 parse_filter_func),
907 OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func",
908 "Do not trace given functions", parse_filter_func),
909 OPT_CALLBACK(0, "func-opts", &ftrace, "options",
910 "Function tracer options, available options: call-graph,irq-info",
911 parse_func_tracer_opts),
912 OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func",
913 "Trace given functions using function_graph tracer",
914 parse_filter_func),
915 OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func",
916 "Set nograph filter on given functions", parse_filter_func),
917 OPT_CALLBACK(0, "graph-opts", &ftrace, "options",
918 "Graph tracer options, available options: nosleep-time,noirqs,verbose,thresh=<n>,depth=<n>",
919 parse_graph_tracer_opts),
920 OPT_CALLBACK('m', "buffer-size", &ftrace.percpu_buffer_size, "size",
921 "Size of per cpu buffer, needs to use a B, K, M or G suffix.", parse_buffer_size),
922 OPT_BOOLEAN(0, "inherit", &ftrace.inherit,
923 "Trace children processes"),
924 OPT_UINTEGER('D', "delay", &ftrace.initial_delay,
925 "Number of milliseconds to wait before starting tracing after program start"),
926 OPT_END()
927 };
928
929 INIT_LIST_HEAD(&ftrace.filters);
930 INIT_LIST_HEAD(&ftrace.notrace);
931 INIT_LIST_HEAD(&ftrace.graph_funcs);
932 INIT_LIST_HEAD(&ftrace.nograph_funcs);
933
934 ret = perf_config(perf_ftrace_config, &ftrace);
935 if (ret < 0)
936 return -1;
937
938 argc = parse_options(argc, argv, ftrace_options, ftrace_usage,
939 PARSE_OPT_STOP_AT_NON_OPTION);
940 if (!argc && target__none(&ftrace.target))
941 ftrace.target.system_wide = true;
942
943 select_tracer(&ftrace);
944
945 ret = target__validate(&ftrace.target);
946 if (ret) {
947 char errbuf[512];
948
949 target__strerror(&ftrace.target, ret, errbuf, 512);
950 pr_err("%s\n", errbuf);
951 goto out_delete_filters;
952 }
953
954 ftrace.evlist = evlist__new();
955 if (ftrace.evlist == NULL) {
956 ret = -ENOMEM;
957 goto out_delete_filters;
958 }
959
960 ret = evlist__create_maps(ftrace.evlist, &ftrace.target);
961 if (ret < 0)
962 goto out_delete_evlist;
963
964 ret = __cmd_ftrace(&ftrace, argc, argv);
965
966out_delete_evlist:
967 evlist__delete(ftrace.evlist);
968
969out_delete_filters:
970 delete_filter_func(&ftrace.filters);
971 delete_filter_func(&ftrace.notrace);
972 delete_filter_func(&ftrace.graph_funcs);
973 delete_filter_func(&ftrace.nograph_funcs);
974
975 return ret;
976}