tools/perf/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 "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", "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
 223 static 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
 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") < 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") < 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") < 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
 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 }