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TOMOYO Linux Cross Reference
Linux/tools/perf/builtin-ftrace.c

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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  * 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 
 35 struct 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 
 56 struct filter_entry {
 57         struct list_head        list;
 58         char                    name[];
 59 };
 60 
 61 static volatile int workload_exec_errno;
 62 static bool done;
 63 
 64 static 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  */
 76 static 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 
 84 static 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);
127 out_close:
128         close(fd);
129 out:
130         put_tracing_file(file);
131         return ret;
132 }
133 
134 static int write_tracing_file(const char *name, const char *val)
135 {
136         return __write_tracing_file(name, val, false);
137 }
138 
139 static int append_tracing_file(const char *name, const char *val)
140 {
141         return __write_tracing_file(name, val, true);
142 }
143 
144 static 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 
177 out_close:
178         close(fd);
179 out:
180         put_tracing_file(file);
181         return ret;
182 }
183 
184 static 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 
195 static 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 
208 static int reset_tracing_cpu(void);
209 static void reset_tracing_filters(void);
210 
211 static void reset_tracing_options(struct perf_ftrace *ftrace __maybe_unused)
212 {
213         write_tracing_option_file("function-fork", "");
214         write_tracing_option_file("func_stack_trace", "");
215         write_tracing_option_file("sleep-time", "1");
216         write_tracing_option_file("funcgraph-irqs", "1");
217         write_tracing_option_file("funcgraph-proc", "");
218         write_tracing_option_file("funcgraph-abstime", "");
219         write_tracing_option_file("latency-format", "");
220         write_tracing_option_file("irq-info", "");
221 }
222 
223 static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
224 {
225         if (write_tracing_file("tracing_on", "") < 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)
238                 return -1;
239 
240         if (write_tracing_file("tracing_thresh", "") < 0)
241                 return -1;
242 
243         reset_tracing_filters();
244         reset_tracing_options(ftrace);
245         return 0;
246 }
247 
248 static 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 
265 static 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 
290 static 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 
300 static 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 
311 static 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 
322 static 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 
332 static 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 
344 static 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 
366 static 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 
374 static 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 
390 static 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 
405 static 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 
416 static 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)
422                 return -1;
423 
424         return 0;
425 }
426 
427 static 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)
433                 return -1;
434 
435         return 0;
436 }
437 
438 static 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 
455 static 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 
469 static 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 
534 static 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)
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", "");
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 
658 out_close_fd:
659         close(trace_fd);
660 out_reset:
661         reset_tracing_files(ftrace);
662 out:
663         return (done && !workload_exec_errno) ? 0 : -1;
664 }
665 
666 static 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 
686 static 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 
702 static 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 
712 static 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 
743 static 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 
764 static 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 
788 static 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 
805 int 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 
895 out_delete_evlist:
896         evlist__delete(ftrace.evlist);
897 
898 out_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 }
906 

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