eecc70fc3b1992a0256f7cd36abb5713dda0f5a7
[releases.git] / builtin-ftrace.c
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
36 struct 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
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 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
218 static 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
229 static 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
242 static int reset_tracing_cpu(void);
243 static void reset_tracing_filters(void);
244
245 static 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
257 static 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
282 static 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
299 static 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
324 static 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
334 static 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
345 static 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
356 static 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
366 static 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
378 static 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
400 static 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
408 static 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
424 static 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
439 static 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
450 static 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
461 static 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
472 static 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
489 static 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
503 static 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
568 static 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 && perf_evlist__prepare_workload(ftrace->evlist,
604                                 &ftrace->target, argv, false,
605                                 ftrace__workload_exec_failed_signal) < 0) {
606                 goto out;
607         }
608
609         if (set_tracing_options(ftrace) < 0)
610                 goto out_reset;
611
612         if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
613                 pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
614                 goto out_reset;
615         }
616
617         setup_pager();
618
619         trace_file = get_tracing_file("trace_pipe");
620         if (!trace_file) {
621                 pr_err("failed to open trace_pipe\n");
622                 goto out_reset;
623         }
624
625         trace_fd = open(trace_file, O_RDONLY);
626
627         put_tracing_file(trace_file);
628
629         if (trace_fd < 0) {
630                 pr_err("failed to open trace_pipe\n");
631                 goto out_reset;
632         }
633
634         fcntl(trace_fd, F_SETFL, O_NONBLOCK);
635         pollfd.fd = trace_fd;
636
637         /* display column headers */
638         read_tracing_file_to_stdout("trace");
639
640         if (!ftrace->initial_delay) {
641                 if (write_tracing_file("tracing_on", "1") < 0) {
642                         pr_err("can't enable tracing\n");
643                         goto out_close_fd;
644                 }
645         }
646
647         perf_evlist__start_workload(ftrace->evlist);
648
649         if (ftrace->initial_delay) {
650                 usleep(ftrace->initial_delay * 1000);
651                 if (write_tracing_file("tracing_on", "1") < 0) {
652                         pr_err("can't enable tracing\n");
653                         goto out_close_fd;
654                 }
655         }
656
657         while (!done) {
658                 if (poll(&pollfd, 1, -1) < 0)
659                         break;
660
661                 if (pollfd.revents & POLLIN) {
662                         int n = read(trace_fd, buf, sizeof(buf));
663                         if (n < 0)
664                                 break;
665                         if (fwrite(buf, n, 1, stdout) != 1)
666                                 break;
667                 }
668         }
669
670         write_tracing_file("tracing_on", "0");
671
672         if (workload_exec_errno) {
673                 const char *emsg = str_error_r(workload_exec_errno, buf, sizeof(buf));
674                 /* flush stdout first so below error msg appears at the end. */
675                 fflush(stdout);
676                 pr_err("workload failed: %s\n", emsg);
677                 goto out_close_fd;
678         }
679
680         /* read remaining buffer contents */
681         while (true) {
682                 int n = read(trace_fd, buf, sizeof(buf));
683                 if (n <= 0)
684                         break;
685                 if (fwrite(buf, n, 1, stdout) != 1)
686                         break;
687         }
688
689 out_close_fd:
690         close(trace_fd);
691 out_reset:
692         reset_tracing_files(ftrace);
693 out:
694         return (done && !workload_exec_errno) ? 0 : -1;
695 }
696
697 static int perf_ftrace_config(const char *var, const char *value, void *cb)
698 {
699         struct perf_ftrace *ftrace = cb;
700
701         if (!strstarts(var, "ftrace."))
702                 return 0;
703
704         if (strcmp(var, "ftrace.tracer"))
705                 return -1;
706
707         if (!strcmp(value, "function_graph") ||
708             !strcmp(value, "function")) {
709                 ftrace->tracer = value;
710                 return 0;
711         }
712
713         pr_err("Please select \"function_graph\" (default) or \"function\"\n");
714         return -1;
715 }
716
717 static void list_function_cb(char *str, void *arg)
718 {
719         struct strfilter *filter = (struct strfilter *)arg;
720
721         if (strfilter__compare(filter, str))
722                 printf("%s", str);
723 }
724
725 static int opt_list_avail_functions(const struct option *opt __maybe_unused,
726                                     const char *str, int unset)
727 {
728         struct strfilter *filter;
729         const char *err = NULL;
730         int ret;
731
732         if (unset || !str)
733                 return -1;
734
735         filter = strfilter__new(str, &err);
736         if (!filter)
737                 return err ? -EINVAL : -ENOMEM;
738
739         ret = strfilter__or(filter, str, &err);
740         if (ret == -EINVAL) {
741                 pr_err("Filter parse error at %td.\n", err - str + 1);
742                 pr_err("Source: \"%s\"\n", str);
743                 pr_err("         %*c\n", (int)(err - str + 1), '^');
744                 strfilter__delete(filter);
745                 return ret;
746         }
747
748         ret = read_tracing_file_by_line("available_filter_functions",
749                                         list_function_cb, filter);
750         strfilter__delete(filter);
751         if (ret < 0)
752                 return ret;
753
754         exit(0);
755 }
756
757 static int parse_filter_func(const struct option *opt, const char *str,
758                              int unset __maybe_unused)
759 {
760         struct list_head *head = opt->value;
761         struct filter_entry *entry;
762
763         entry = malloc(sizeof(*entry) + strlen(str) + 1);
764         if (entry == NULL)
765                 return -ENOMEM;
766
767         strcpy(entry->name, str);
768         list_add_tail(&entry->list, head);
769
770         return 0;
771 }
772
773 static void delete_filter_func(struct list_head *head)
774 {
775         struct filter_entry *pos, *tmp;
776
777         list_for_each_entry_safe(pos, tmp, head, list) {
778                 list_del_init(&pos->list);
779                 free(pos);
780         }
781 }
782
783 static int parse_buffer_size(const struct option *opt,
784                              const char *str, int unset)
785 {
786         unsigned long *s = (unsigned long *)opt->value;
787         static struct parse_tag tags_size[] = {
788                 { .tag  = 'B', .mult = 1       },
789                 { .tag  = 'K', .mult = 1 << 10 },
790                 { .tag  = 'M', .mult = 1 << 20 },
791                 { .tag  = 'G', .mult = 1 << 30 },
792                 { .tag  = 0 },
793         };
794         unsigned long val;
795
796         if (unset) {
797                 *s = 0;
798                 return 0;
799         }
800
801         val = parse_tag_value(str, tags_size);
802         if (val != (unsigned long) -1) {
803                 if (val < 1024) {
804                         pr_err("buffer size too small, must larger than 1KB.");
805                         return -1;
806                 }
807                 *s = val;
808                 return 0;
809         }
810
811         return -1;
812 }
813
814 static int parse_func_tracer_opts(const struct option *opt,
815                                   const char *str, int unset)
816 {
817         int ret;
818         struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value;
819         struct sublevel_option func_tracer_opts[] = {
820                 { .name = "call-graph", .value_ptr = &ftrace->func_stack_trace },
821                 { .name = "irq-info",   .value_ptr = &ftrace->func_irq_info },
822                 { .name = NULL, }
823         };
824
825         if (unset)
826                 return 0;
827
828         ret = perf_parse_sublevel_options(str, func_tracer_opts);
829         if (ret)
830                 return ret;
831
832         return 0;
833 }
834
835 static int parse_graph_tracer_opts(const struct option *opt,
836                                   const char *str, int unset)
837 {
838         int ret;
839         struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value;
840         struct sublevel_option graph_tracer_opts[] = {
841                 { .name = "nosleep-time",       .value_ptr = &ftrace->graph_nosleep_time },
842                 { .name = "noirqs",             .value_ptr = &ftrace->graph_noirqs },
843                 { .name = "verbose",            .value_ptr = &ftrace->graph_verbose },
844                 { .name = "thresh",             .value_ptr = &ftrace->graph_thresh },
845                 { .name = "depth",              .value_ptr = &ftrace->graph_depth },
846                 { .name = NULL, }
847         };
848
849         if (unset)
850                 return 0;
851
852         ret = perf_parse_sublevel_options(str, graph_tracer_opts);
853         if (ret)
854                 return ret;
855
856         return 0;
857 }
858
859 static void select_tracer(struct perf_ftrace *ftrace)
860 {
861         bool graph = !list_empty(&ftrace->graph_funcs) ||
862                      !list_empty(&ftrace->nograph_funcs);
863         bool func = !list_empty(&ftrace->filters) ||
864                     !list_empty(&ftrace->notrace);
865
866         /* The function_graph has priority over function tracer. */
867         if (graph)
868                 ftrace->tracer = "function_graph";
869         else if (func)
870                 ftrace->tracer = "function";
871         /* Otherwise, the default tracer is used. */
872
873         pr_debug("%s tracer is used\n", ftrace->tracer);
874 }
875
876 int cmd_ftrace(int argc, const char **argv)
877 {
878         int ret;
879         struct perf_ftrace ftrace = {
880                 .tracer = DEFAULT_TRACER,
881                 .target = { .uid = UINT_MAX, },
882         };
883         const char * const ftrace_usage[] = {
884                 "perf ftrace [<options>] [<command>]",
885                 "perf ftrace [<options>] -- <command> [<options>]",
886                 NULL
887         };
888         const struct option ftrace_options[] = {
889         OPT_STRING('t', "tracer", &ftrace.tracer, "tracer",
890                    "Tracer to use: function_graph(default) or function"),
891         OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",
892                              "Show available functions to filter",
893                              opt_list_avail_functions, "*"),
894         OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
895                    "Trace on existing process id"),
896         /* TODO: Add short option -t after -t/--tracer can be removed. */
897         OPT_STRING(0, "tid", &ftrace.target.tid, "tid",
898                    "Trace on existing thread id (exclusive to --pid)"),
899         OPT_INCR('v', "verbose", &verbose,
900                  "Be more verbose"),
901         OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide,
902                     "System-wide collection from all CPUs"),
903         OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu",
904                     "List of cpus to monitor"),
905         OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func",
906                      "Trace given functions using function tracer",
907                      parse_filter_func),
908         OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func",
909                      "Do not trace given functions", parse_filter_func),
910         OPT_CALLBACK(0, "func-opts", &ftrace, "options",
911                      "Function tracer options, available options: call-graph,irq-info",
912                      parse_func_tracer_opts),
913         OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func",
914                      "Trace given functions using function_graph tracer",
915                      parse_filter_func),
916         OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func",
917                      "Set nograph filter on given functions", parse_filter_func),
918         OPT_CALLBACK(0, "graph-opts", &ftrace, "options",
919                      "Graph tracer options, available options: nosleep-time,noirqs,verbose,thresh=<n>,depth=<n>",
920                      parse_graph_tracer_opts),
921         OPT_CALLBACK('m', "buffer-size", &ftrace.percpu_buffer_size, "size",
922                      "Size of per cpu buffer, needs to use a B, K, M or G suffix.", parse_buffer_size),
923         OPT_BOOLEAN(0, "inherit", &ftrace.inherit,
924                     "Trace children processes"),
925         OPT_UINTEGER('D', "delay", &ftrace.initial_delay,
926                      "Number of milliseconds to wait before starting tracing after program start"),
927         OPT_END()
928         };
929
930         INIT_LIST_HEAD(&ftrace.filters);
931         INIT_LIST_HEAD(&ftrace.notrace);
932         INIT_LIST_HEAD(&ftrace.graph_funcs);
933         INIT_LIST_HEAD(&ftrace.nograph_funcs);
934
935         ret = perf_config(perf_ftrace_config, &ftrace);
936         if (ret < 0)
937                 return -1;
938
939         argc = parse_options(argc, argv, ftrace_options, ftrace_usage,
940                             PARSE_OPT_STOP_AT_NON_OPTION);
941         if (!argc && target__none(&ftrace.target))
942                 ftrace.target.system_wide = true;
943
944         select_tracer(&ftrace);
945
946         ret = target__validate(&ftrace.target);
947         if (ret) {
948                 char errbuf[512];
949
950                 target__strerror(&ftrace.target, ret, errbuf, 512);
951                 pr_err("%s\n", errbuf);
952                 goto out_delete_filters;
953         }
954
955         ftrace.evlist = evlist__new();
956         if (ftrace.evlist == NULL) {
957                 ret = -ENOMEM;
958                 goto out_delete_filters;
959         }
960
961         ret = perf_evlist__create_maps(ftrace.evlist, &ftrace.target);
962         if (ret < 0)
963                 goto out_delete_evlist;
964
965         ret = __cmd_ftrace(&ftrace, argc, argv);
966
967 out_delete_evlist:
968         evlist__delete(ftrace.evlist);
969
970 out_delete_filters:
971         delete_filter_func(&ftrace.filters);
972         delete_filter_func(&ftrace.notrace);
973         delete_filter_func(&ftrace.graph_funcs);
974         delete_filter_func(&ftrace.nograph_funcs);
975
976         return ret;
977 }