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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 "util/cap.h"
29#include "util/config.h"
30#include "util/units.h"
31#include "util/parse-sublevel-options.h"
32
33#define DEFAULT_TRACER "function_graph"
34
35struct perf_ftrace {
36 struct evlist *evlist;
37 struct target target;
38 const char *tracer;
39 bool list_avail_functions;
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 * perf_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 write_tracing_file_int(const char *name, int value)
185{
186 char buf[16];
187
188 snprintf(buf, sizeof(buf), "%d", value);
189 if (write_tracing_file(name, buf) < 0)
190 return -1;
191
192 return 0;
193}
194
195static int write_tracing_option_file(const char *name, const char *val)
196{
197 char *file;
198 int ret;
199
200 if (asprintf(&file, "options/%s", name) < 0)
201 return -1;
202
203 ret = __write_tracing_file(file, val, false);
204 free(file);
205 return ret;
206}
207
208static int reset_tracing_cpu(void);
209static void reset_tracing_filters(void);
210
211static void reset_tracing_options(struct perf_ftrace *ftrace __maybe_unused)
212{
213 write_tracing_option_file("function-fork", "0");
214 write_tracing_option_file("func_stack_trace", "0");
215 write_tracing_option_file("sleep-time", "1");
216 write_tracing_option_file("funcgraph-irqs", "1");
217 write_tracing_option_file("funcgraph-proc", "0");
218 write_tracing_option_file("funcgraph-abstime", "0");
219 write_tracing_option_file("latency-format", "0");
220 write_tracing_option_file("irq-info", "0");
221}
222
223static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
224{
225 if (write_tracing_file("tracing_on", "0") < 0)
226 return -1;
227
228 if (write_tracing_file("current_tracer", "nop") < 0)
229 return -1;
230
231 if (write_tracing_file("set_ftrace_pid", " ") < 0)
232 return -1;
233
234 if (reset_tracing_cpu() < 0)
235 return -1;
236
237 if (write_tracing_file("max_graph_depth", "0") < 0)
238 return -1;
239
240 if (write_tracing_file("tracing_thresh", "0") < 0)
241 return -1;
242
243 reset_tracing_filters();
244 reset_tracing_options(ftrace);
245 return 0;
246}
247
248static int set_tracing_pid(struct perf_ftrace *ftrace)
249{
250 int i;
251 char buf[16];
252
253 if (target__has_cpu(&ftrace->target))
254 return 0;
255
256 for (i = 0; i < perf_thread_map__nr(ftrace->evlist->core.threads); i++) {
257 scnprintf(buf, sizeof(buf), "%d",
258 ftrace->evlist->core.threads->map[i]);
259 if (append_tracing_file("set_ftrace_pid", buf) < 0)
260 return -1;
261 }
262 return 0;
263}
264
265static int set_tracing_cpumask(struct perf_cpu_map *cpumap)
266{
267 char *cpumask;
268 size_t mask_size;
269 int ret;
270 int last_cpu;
271
272 last_cpu = cpu_map__cpu(cpumap, cpumap->nr - 1);
273 mask_size = last_cpu / 4 + 2; /* one more byte for EOS */
274 mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */
275
276 cpumask = malloc(mask_size);
277 if (cpumask == NULL) {
278 pr_debug("failed to allocate cpu mask\n");
279 return -1;
280 }
281
282 cpu_map__snprint_mask(cpumap, cpumask, mask_size);
283
284 ret = write_tracing_file("tracing_cpumask", cpumask);
285
286 free(cpumask);
287 return ret;
288}
289
290static int set_tracing_cpu(struct perf_ftrace *ftrace)
291{
292 struct perf_cpu_map *cpumap = ftrace->evlist->core.cpus;
293
294 if (!target__has_cpu(&ftrace->target))
295 return 0;
296
297 return set_tracing_cpumask(cpumap);
298}
299
300static int set_tracing_func_stack_trace(struct perf_ftrace *ftrace)
301{
302 if (!ftrace->func_stack_trace)
303 return 0;
304
305 if (write_tracing_option_file("func_stack_trace", "1") < 0)
306 return -1;
307
308 return 0;
309}
310
311static int set_tracing_func_irqinfo(struct perf_ftrace *ftrace)
312{
313 if (!ftrace->func_irq_info)
314 return 0;
315
316 if (write_tracing_option_file("irq-info", "1") < 0)
317 return -1;
318
319 return 0;
320}
321
322static int reset_tracing_cpu(void)
323{
324 struct perf_cpu_map *cpumap = perf_cpu_map__new(NULL);
325 int ret;
326
327 ret = set_tracing_cpumask(cpumap);
328 perf_cpu_map__put(cpumap);
329 return ret;
330}
331
332static int __set_tracing_filter(const char *filter_file, struct list_head *funcs)
333{
334 struct filter_entry *pos;
335
336 list_for_each_entry(pos, funcs, list) {
337 if (append_tracing_file(filter_file, pos->name) < 0)
338 return -1;
339 }
340
341 return 0;
342}
343
344static int set_tracing_filters(struct perf_ftrace *ftrace)
345{
346 int ret;
347
348 ret = __set_tracing_filter("set_ftrace_filter", &ftrace->filters);
349 if (ret < 0)
350 return ret;
351
352 ret = __set_tracing_filter("set_ftrace_notrace", &ftrace->notrace);
353 if (ret < 0)
354 return ret;
355
356 ret = __set_tracing_filter("set_graph_function", &ftrace->graph_funcs);
357 if (ret < 0)
358 return ret;
359
360 /* old kernels do not have this filter */
361 __set_tracing_filter("set_graph_notrace", &ftrace->nograph_funcs);
362
363 return ret;
364}
365
366static void reset_tracing_filters(void)
367{
368 write_tracing_file("set_ftrace_filter", " ");
369 write_tracing_file("set_ftrace_notrace", " ");
370 write_tracing_file("set_graph_function", " ");
371 write_tracing_file("set_graph_notrace", " ");
372}
373
374static int set_tracing_depth(struct perf_ftrace *ftrace)
375{
376 if (ftrace->graph_depth == 0)
377 return 0;
378
379 if (ftrace->graph_depth < 0) {
380 pr_err("invalid graph depth: %d\n", ftrace->graph_depth);
381 return -1;
382 }
383
384 if (write_tracing_file_int("max_graph_depth", ftrace->graph_depth) < 0)
385 return -1;
386
387 return 0;
388}
389
390static int set_tracing_percpu_buffer_size(struct perf_ftrace *ftrace)
391{
392 int ret;
393
394 if (ftrace->percpu_buffer_size == 0)
395 return 0;
396
397 ret = write_tracing_file_int("buffer_size_kb",
398 ftrace->percpu_buffer_size / 1024);
399 if (ret < 0)
400 return ret;
401
402 return 0;
403}
404
405static int set_tracing_trace_inherit(struct perf_ftrace *ftrace)
406{
407 if (!ftrace->inherit)
408 return 0;
409
410 if (write_tracing_option_file("function-fork", "1") < 0)
411 return -1;
412
413 return 0;
414}
415
416static int set_tracing_sleep_time(struct perf_ftrace *ftrace)
417{
418 if (!ftrace->graph_nosleep_time)
419 return 0;
420
421 if (write_tracing_option_file("sleep-time", "0") < 0)
422 return -1;
423
424 return 0;
425}
426
427static int set_tracing_funcgraph_irqs(struct perf_ftrace *ftrace)
428{
429 if (!ftrace->graph_noirqs)
430 return 0;
431
432 if (write_tracing_option_file("funcgraph-irqs", "0") < 0)
433 return -1;
434
435 return 0;
436}
437
438static int set_tracing_funcgraph_verbose(struct perf_ftrace *ftrace)
439{
440 if (!ftrace->graph_verbose)
441 return 0;
442
443 if (write_tracing_option_file("funcgraph-proc", "1") < 0)
444 return -1;
445
446 if (write_tracing_option_file("funcgraph-abstime", "1") < 0)
447 return -1;
448
449 if (write_tracing_option_file("latency-format", "1") < 0)
450 return -1;
451
452 return 0;
453}
454
455static int set_tracing_thresh(struct perf_ftrace *ftrace)
456{
457 int ret;
458
459 if (ftrace->graph_thresh == 0)
460 return 0;
461
462 ret = write_tracing_file_int("tracing_thresh", ftrace->graph_thresh);
463 if (ret < 0)
464 return ret;
465
466 return 0;
467}
468
469static int set_tracing_options(struct perf_ftrace *ftrace)
470{
471 if (set_tracing_pid(ftrace) < 0) {
472 pr_err("failed to set ftrace pid\n");
473 return -1;
474 }
475
476 if (set_tracing_cpu(ftrace) < 0) {
477 pr_err("failed to set tracing cpumask\n");
478 return -1;
479 }
480
481 if (set_tracing_func_stack_trace(ftrace) < 0) {
482 pr_err("failed to set tracing option func_stack_trace\n");
483 return -1;
484 }
485
486 if (set_tracing_func_irqinfo(ftrace) < 0) {
487 pr_err("failed to set tracing option irq-info\n");
488 return -1;
489 }
490
491 if (set_tracing_filters(ftrace) < 0) {
492 pr_err("failed to set tracing filters\n");
493 return -1;
494 }
495
496 if (set_tracing_depth(ftrace) < 0) {
497 pr_err("failed to set graph depth\n");
498 return -1;
499 }
500
501 if (set_tracing_percpu_buffer_size(ftrace) < 0) {
502 pr_err("failed to set tracing per-cpu buffer size\n");
503 return -1;
504 }
505
506 if (set_tracing_trace_inherit(ftrace) < 0) {
507 pr_err("failed to set tracing option function-fork\n");
508 return -1;
509 }
510
511 if (set_tracing_sleep_time(ftrace) < 0) {
512 pr_err("failed to set tracing option sleep-time\n");
513 return -1;
514 }
515
516 if (set_tracing_funcgraph_irqs(ftrace) < 0) {
517 pr_err("failed to set tracing option funcgraph-irqs\n");
518 return -1;
519 }
520
521 if (set_tracing_funcgraph_verbose(ftrace) < 0) {
522 pr_err("failed to set tracing option funcgraph-proc/funcgraph-abstime\n");
523 return -1;
524 }
525
526 if (set_tracing_thresh(ftrace) < 0) {
527 pr_err("failed to set tracing thresh\n");
528 return -1;
529 }
530
531 return 0;
532}
533
534static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
535{
536 char *trace_file;
537 int trace_fd;
538 char buf[4096];
539 struct pollfd pollfd = {
540 .events = POLLIN,
541 };
542
543 if (!(perf_cap__capable(CAP_PERFMON) ||
544 perf_cap__capable(CAP_SYS_ADMIN))) {
545 pr_err("ftrace only works for %s!\n",
546#ifdef HAVE_LIBCAP_SUPPORT
547 "users with the CAP_PERFMON or CAP_SYS_ADMIN capability"
548#else
549 "root"
550#endif
551 );
552 return -1;
553 }
554
555 signal(SIGINT, sig_handler);
556 signal(SIGUSR1, sig_handler);
557 signal(SIGCHLD, sig_handler);
558 signal(SIGPIPE, sig_handler);
559
560 if (ftrace->list_avail_functions)
561 return read_tracing_file_to_stdout("available_filter_functions");
562
563 if (reset_tracing_files(ftrace) < 0) {
564 pr_err("failed to reset ftrace\n");
565 goto out;
566 }
567
568 /* reset ftrace buffer */
569 if (write_tracing_file("trace", "0") < 0)
570 goto out;
571
572 if (argc && perf_evlist__prepare_workload(ftrace->evlist,
573 &ftrace->target, argv, false,
574 ftrace__workload_exec_failed_signal) < 0) {
575 goto out;
576 }
577
578 if (set_tracing_options(ftrace) < 0)
579 goto out_reset;
580
581 if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
582 pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
583 goto out_reset;
584 }
585
586 setup_pager();
587
588 trace_file = get_tracing_file("trace_pipe");
589 if (!trace_file) {
590 pr_err("failed to open trace_pipe\n");
591 goto out_reset;
592 }
593
594 trace_fd = open(trace_file, O_RDONLY);
595
596 put_tracing_file(trace_file);
597
598 if (trace_fd < 0) {
599 pr_err("failed to open trace_pipe\n");
600 goto out_reset;
601 }
602
603 fcntl(trace_fd, F_SETFL, O_NONBLOCK);
604 pollfd.fd = trace_fd;
605
606 /* display column headers */
607 read_tracing_file_to_stdout("trace");
608
609 if (!ftrace->initial_delay) {
610 if (write_tracing_file("tracing_on", "1") < 0) {
611 pr_err("can't enable tracing\n");
612 goto out_close_fd;
613 }
614 }
615
616 perf_evlist__start_workload(ftrace->evlist);
617
618 if (ftrace->initial_delay) {
619 usleep(ftrace->initial_delay * 1000);
620 if (write_tracing_file("tracing_on", "1") < 0) {
621 pr_err("can't enable tracing\n");
622 goto out_close_fd;
623 }
624 }
625
626 while (!done) {
627 if (poll(&pollfd, 1, -1) < 0)
628 break;
629
630 if (pollfd.revents & POLLIN) {
631 int n = read(trace_fd, buf, sizeof(buf));
632 if (n < 0)
633 break;
634 if (fwrite(buf, n, 1, stdout) != 1)
635 break;
636 }
637 }
638
639 write_tracing_file("tracing_on", "0");
640
641 if (workload_exec_errno) {
642 const char *emsg = str_error_r(workload_exec_errno, buf, sizeof(buf));
643 /* flush stdout first so below error msg appears at the end. */
644 fflush(stdout);
645 pr_err("workload failed: %s\n", emsg);
646 goto out_close_fd;
647 }
648
649 /* read remaining buffer contents */
650 while (true) {
651 int n = read(trace_fd, buf, sizeof(buf));
652 if (n <= 0)
653 break;
654 if (fwrite(buf, n, 1, stdout) != 1)
655 break;
656 }
657
658out_close_fd:
659 close(trace_fd);
660out_reset:
661 reset_tracing_files(ftrace);
662out:
663 return (done && !workload_exec_errno) ? 0 : -1;
664}
665
666static int perf_ftrace_config(const char *var, const char *value, void *cb)
667{
668 struct perf_ftrace *ftrace = cb;
669
670 if (!strstarts(var, "ftrace."))
671 return 0;
672
673 if (strcmp(var, "ftrace.tracer"))
674 return -1;
675
676 if (!strcmp(value, "function_graph") ||
677 !strcmp(value, "function")) {
678 ftrace->tracer = value;
679 return 0;
680 }
681
682 pr_err("Please select \"function_graph\" (default) or \"function\"\n");
683 return -1;
684}
685
686static int parse_filter_func(const struct option *opt, const char *str,
687 int unset __maybe_unused)
688{
689 struct list_head *head = opt->value;
690 struct filter_entry *entry;
691
692 entry = malloc(sizeof(*entry) + strlen(str) + 1);
693 if (entry == NULL)
694 return -ENOMEM;
695
696 strcpy(entry->name, str);
697 list_add_tail(&entry->list, head);
698
699 return 0;
700}
701
702static void delete_filter_func(struct list_head *head)
703{
704 struct filter_entry *pos, *tmp;
705
706 list_for_each_entry_safe(pos, tmp, head, list) {
707 list_del_init(&pos->list);
708 free(pos);
709 }
710}
711
712static int parse_buffer_size(const struct option *opt,
713 const char *str, int unset)
714{
715 unsigned long *s = (unsigned long *)opt->value;
716 static struct parse_tag tags_size[] = {
717 { .tag = 'B', .mult = 1 },
718 { .tag = 'K', .mult = 1 << 10 },
719 { .tag = 'M', .mult = 1 << 20 },
720 { .tag = 'G', .mult = 1 << 30 },
721 { .tag = 0 },
722 };
723 unsigned long val;
724
725 if (unset) {
726 *s = 0;
727 return 0;
728 }
729
730 val = parse_tag_value(str, tags_size);
731 if (val != (unsigned long) -1) {
732 if (val < 1024) {
733 pr_err("buffer size too small, must larger than 1KB.");
734 return -1;
735 }
736 *s = val;
737 return 0;
738 }
739
740 return -1;
741}
742
743static int parse_func_tracer_opts(const struct option *opt,
744 const char *str, int unset)
745{
746 int ret;
747 struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value;
748 struct sublevel_option func_tracer_opts[] = {
749 { .name = "call-graph", .value_ptr = &ftrace->func_stack_trace },
750 { .name = "irq-info", .value_ptr = &ftrace->func_irq_info },
751 { .name = NULL, }
752 };
753
754 if (unset)
755 return 0;
756
757 ret = perf_parse_sublevel_options(str, func_tracer_opts);
758 if (ret)
759 return ret;
760
761 return 0;
762}
763
764static int parse_graph_tracer_opts(const struct option *opt,
765 const char *str, int unset)
766{
767 int ret;
768 struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value;
769 struct sublevel_option graph_tracer_opts[] = {
770 { .name = "nosleep-time", .value_ptr = &ftrace->graph_nosleep_time },
771 { .name = "noirqs", .value_ptr = &ftrace->graph_noirqs },
772 { .name = "verbose", .value_ptr = &ftrace->graph_verbose },
773 { .name = "thresh", .value_ptr = &ftrace->graph_thresh },
774 { .name = "depth", .value_ptr = &ftrace->graph_depth },
775 { .name = NULL, }
776 };
777
778 if (unset)
779 return 0;
780
781 ret = perf_parse_sublevel_options(str, graph_tracer_opts);
782 if (ret)
783 return ret;
784
785 return 0;
786}
787
788static void select_tracer(struct perf_ftrace *ftrace)
789{
790 bool graph = !list_empty(&ftrace->graph_funcs) ||
791 !list_empty(&ftrace->nograph_funcs);
792 bool func = !list_empty(&ftrace->filters) ||
793 !list_empty(&ftrace->notrace);
794
795 /* The function_graph has priority over function tracer. */
796 if (graph)
797 ftrace->tracer = "function_graph";
798 else if (func)
799 ftrace->tracer = "function";
800 /* Otherwise, the default tracer is used. */
801
802 pr_debug("%s tracer is used\n", ftrace->tracer);
803}
804
805int cmd_ftrace(int argc, const char **argv)
806{
807 int ret;
808 struct perf_ftrace ftrace = {
809 .tracer = DEFAULT_TRACER,
810 .target = { .uid = UINT_MAX, },
811 };
812 const char * const ftrace_usage[] = {
813 "perf ftrace [<options>] [<command>]",
814 "perf ftrace [<options>] -- <command> [<options>]",
815 NULL
816 };
817 const struct option ftrace_options[] = {
818 OPT_STRING('t', "tracer", &ftrace.tracer, "tracer",
819 "Tracer to use: function_graph(default) or function"),
820 OPT_BOOLEAN('F', "funcs", &ftrace.list_avail_functions,
821 "Show available functions to filter"),
822 OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
823 "Trace on existing process id"),
824 /* TODO: Add short option -t after -t/--tracer can be removed. */
825 OPT_STRING(0, "tid", &ftrace.target.tid, "tid",
826 "Trace on existing thread id (exclusive to --pid)"),
827 OPT_INCR('v', "verbose", &verbose,
828 "Be more verbose"),
829 OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide,
830 "System-wide collection from all CPUs"),
831 OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu",
832 "List of cpus to monitor"),
833 OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func",
834 "Trace given functions using function tracer",
835 parse_filter_func),
836 OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func",
837 "Do not trace given functions", parse_filter_func),
838 OPT_CALLBACK(0, "func-opts", &ftrace, "options",
839 "Function tracer options, available options: call-graph,irq-info",
840 parse_func_tracer_opts),
841 OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func",
842 "Trace given functions using function_graph tracer",
843 parse_filter_func),
844 OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func",
845 "Set nograph filter on given functions", parse_filter_func),
846 OPT_CALLBACK(0, "graph-opts", &ftrace, "options",
847 "Graph tracer options, available options: nosleep-time,noirqs,verbose,thresh=<n>,depth=<n>",
848 parse_graph_tracer_opts),
849 OPT_CALLBACK('m', "buffer-size", &ftrace.percpu_buffer_size, "size",
850 "Size of per cpu buffer, needs to use a B, K, M or G suffix.", parse_buffer_size),
851 OPT_BOOLEAN(0, "inherit", &ftrace.inherit,
852 "Trace children processes"),
853 OPT_UINTEGER('D', "delay", &ftrace.initial_delay,
854 "Number of milliseconds to wait before starting tracing after program start"),
855 OPT_END()
856 };
857
858 INIT_LIST_HEAD(&ftrace.filters);
859 INIT_LIST_HEAD(&ftrace.notrace);
860 INIT_LIST_HEAD(&ftrace.graph_funcs);
861 INIT_LIST_HEAD(&ftrace.nograph_funcs);
862
863 ret = perf_config(perf_ftrace_config, &ftrace);
864 if (ret < 0)
865 return -1;
866
867 argc = parse_options(argc, argv, ftrace_options, ftrace_usage,
868 PARSE_OPT_STOP_AT_NON_OPTION);
869 if (!argc && target__none(&ftrace.target))
870 ftrace.target.system_wide = true;
871
872 select_tracer(&ftrace);
873
874 ret = target__validate(&ftrace.target);
875 if (ret) {
876 char errbuf[512];
877
878 target__strerror(&ftrace.target, ret, errbuf, 512);
879 pr_err("%s\n", errbuf);
880 goto out_delete_filters;
881 }
882
883 ftrace.evlist = evlist__new();
884 if (ftrace.evlist == NULL) {
885 ret = -ENOMEM;
886 goto out_delete_filters;
887 }
888
889 ret = perf_evlist__create_maps(ftrace.evlist, &ftrace.target);
890 if (ret < 0)
891 goto out_delete_evlist;
892
893 ret = __cmd_ftrace(&ftrace, argc, argv);
894
895out_delete_evlist:
896 evlist__delete(ftrace.evlist);
897
898out_delete_filters:
899 delete_filter_func(&ftrace.filters);
900 delete_filter_func(&ftrace.notrace);
901 delete_filter_func(&ftrace.graph_funcs);
902 delete_filter_func(&ftrace.nograph_funcs);
903
904 return ret;
905}