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 <[email protected]>
   6  * Copyright (c) 2020  Changbin Du <[email protected]>, 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 <inttypes.h>
  17 #include <math.h>
  18 #include <poll.h>
  19 #include <ctype.h>
  20 #include <linux/capability.h>
  21 #include <linux/string.h>
  22
  23 #include "debug.h"
  24 #include <subcmd/pager.h>
  25 #include <subcmd/parse-options.h>
  26 #include <api/io.h>
  27 #include <api/fs/tracing_path.h>
  28 #include "evlist.h"
  29 #include "target.h"
  30 #include "cpumap.h"
  31 #include "hashmap.h"
  32 #include "thread_map.h"
  33 #include "strfilter.h"
  34 #include "util/cap.h"
  35 #include "util/config.h"
  36 #include "util/ftrace.h"
  37 #include "util/stat.h"
  38 #include "util/units.h"
  39 #include "util/parse-sublevel-options.h"
  40
  41 #define DEFAULT_TRACER  "function_graph"
  42
  43 static volatile sig_atomic_t workload_exec_errno;
  44 static volatile sig_atomic_t done;
  45
  46 static void sig_handler(int sig __maybe_unused)
  47 {
  48         done = true;
  49 }
  50
  51 /*
  52  * evlist__prepare_workload will send a SIGUSR1 if the fork fails, since
  53  * we asked by setting its exec_error to the function below,
  54  * ftrace__workload_exec_failed_signal.
  55  *
  56  * XXX We need to handle this more appropriately, emitting an error, etc.
  57  */
  58 static void ftrace__workload_exec_failed_signal(int signo __maybe_unused,
  59                                                 siginfo_t *info __maybe_unused,
  60                                                 void *ucontext __maybe_unused)
  61 {
  62         workload_exec_errno = info->si_value.sival_int;
  63         done = true;
  64 }
  65
  66 static bool check_ftrace_capable(void)
  67 {
  68         bool used_root;
  69
  70         if (perf_cap__capable(CAP_PERFMON, &used_root))
  71                 return true;
  72
  73         if (!used_root && perf_cap__capable(CAP_SYS_ADMIN, &used_root))
  74                 return true;
  75
  76         pr_err("ftrace only works for %s!\n",
  77                 used_root ? "root"
  78                           : "users with the CAP_PERFMON or CAP_SYS_ADMIN capability"
  79                 );
  80         return false;
  81 }
  82
  83 static bool is_ftrace_supported(void)
  84 {
  85         char *file;
  86         bool supported = false;
  87
  88         file = get_tracing_file("set_ftrace_pid");
  89         if (!file) {
  90                 pr_debug("cannot get tracing file set_ftrace_pid\n");
  91                 return false;
  92         }
  93
  94         if (!access(file, F_OK))
  95                 supported = true;
  96
  97         put_tracing_file(file);
  98         return supported;
  99 }
 100
 101 static int __write_tracing_file(const char *name, const char *val, bool append)
 102 {
 103         char *file;
 104         int fd, ret = -1;
 105         ssize_t size = strlen(val);
 106         int flags = O_WRONLY;
 107         char errbuf[512];
 108         char *val_copy;
 109
 110         file = get_tracing_file(name);
 111         if (!file) {
 112                 pr_debug("cannot get tracing file: %s\n", name);
 113                 return -1;
 114         }
 115
 116         if (append)
 117                 flags |= O_APPEND;
 118         else
 119                 flags |= O_TRUNC;
 120
 121         fd = open(file, flags);
 122         if (fd < 0) {
 123                 pr_debug("cannot open tracing file: %s: %s\n",
 124                          name, str_error_r(errno, errbuf, sizeof(errbuf)));
 125                 goto out;
 126         }
 127
 128         /*
 129          * Copy the original value and append a '\n'. Without this,
 130          * the kernel can hide possible errors.
 131          */
 132         val_copy = strdup(val);
 133         if (!val_copy)
 134                 goto out_close;
 135         val_copy[size] = '\n';
 136
 137         if (write(fd, val_copy, size + 1) == size + 1)
 138                 ret = 0;
 139         else
 140                 pr_debug("write '%s' to tracing/%s failed: %s\n",
 141                          val, name, str_error_r(errno, errbuf, sizeof(errbuf)));
 142
 143         free(val_copy);
 144 out_close:
 145         close(fd);
 146 out:
 147         put_tracing_file(file);
 148         return ret;
 149 }
 150
 151 static int write_tracing_file(const char *name, const char *val)
 152 {
 153         return __write_tracing_file(name, val, false);
 154 }
 155
 156 static int append_tracing_file(const char *name, const char *val)
 157 {
 158         return __write_tracing_file(name, val, true);
 159 }
 160
 161 static int read_tracing_file_to_stdout(const char *name)
 162 {
 163         char buf[4096];
 164         char *file;
 165         int fd;
 166         int ret = -1;
 167
 168         file = get_tracing_file(name);
 169         if (!file) {
 170                 pr_debug("cannot get tracing file: %s\n", name);
 171                 return -1;
 172         }
 173
 174         fd = open(file, O_RDONLY);
 175         if (fd < 0) {
 176                 pr_debug("cannot open tracing file: %s: %s\n",
 177                          name, str_error_r(errno, buf, sizeof(buf)));
 178                 goto out;
 179         }
 180
 181         /* read contents to stdout */
 182         while (true) {
 183                 int n = read(fd, buf, sizeof(buf));
 184                 if (n == 0)
 185                         break;
 186                 else if (n < 0)
 187                         goto out_close;
 188
 189                 if (fwrite(buf, n, 1, stdout) != 1)
 190                         goto out_close;
 191         }
 192         ret = 0;
 193
 194 out_close:
 195         close(fd);
 196 out:
 197         put_tracing_file(file);
 198         return ret;
 199 }
 200
 201 static int read_tracing_file_by_line(const char *name,
 202                                      void (*cb)(char *str, void *arg),
 203                                      void *cb_arg)
 204 {
 205         char *line = NULL;
 206         size_t len = 0;
 207         char *file;
 208         FILE *fp;
 209
 210         file = get_tracing_file(name);
 211         if (!file) {
 212                 pr_debug("cannot get tracing file: %s\n", name);
 213                 return -1;
 214         }
 215
 216         fp = fopen(file, "r");
 217         if (fp == NULL) {
 218                 pr_debug("cannot open tracing file: %s\n", name);
 219                 put_tracing_file(file);
 220                 return -1;
 221         }
 222
 223         while (getline(&line, &len, fp) != -1) {
 224                 cb(line, cb_arg);
 225         }
 226
 227         if (line)
 228                 free(line);
 229
 230         fclose(fp);
 231         put_tracing_file(file);
 232         return 0;
 233 }
 234
 235 static int write_tracing_file_int(const char *name, int value)
 236 {
 237         char buf[16];
 238
 239         snprintf(buf, sizeof(buf), "%d", value);
 240         if (write_tracing_file(name, buf) < 0)
 241                 return -1;
 242
 243         return 0;
 244 }
 245
 246 static int write_tracing_option_file(const char *name, const char *val)
 247 {
 248         char *file;
 249         int ret;
 250
 251         if (asprintf(&file, "options/%s", name) < 0)
 252                 return -1;
 253
 254         ret = __write_tracing_file(file, val, false);
 255         free(file);
 256         return ret;
 257 }
 258
 259 static int reset_tracing_cpu(void);
 260 static void reset_tracing_filters(void);
 261
 262 static void reset_tracing_options(struct perf_ftrace *ftrace __maybe_unused)
 263 {
 264         write_tracing_option_file("function-fork", "0");
 265         write_tracing_option_file("func_stack_trace", "0");
 266         write_tracing_option_file("sleep-time", "1");
 267         write_tracing_option_file("funcgraph-irqs", "1");
 268         write_tracing_option_file("funcgraph-proc", "0");
 269         write_tracing_option_file("funcgraph-abstime", "0");
 270         write_tracing_option_file("funcgraph-tail", "0");
 271         write_tracing_option_file("latency-format", "0");
 272         write_tracing_option_file("irq-info", "0");
 273 }
 274
 275 static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
 276 {
 277         if (write_tracing_file("tracing_on", "0") < 0)
 278                 return -1;
 279
 280         if (write_tracing_file("current_tracer", "nop") < 0)
 281                 return -1;
 282
 283         if (write_tracing_file("set_ftrace_pid", " ") < 0)
 284                 return -1;
 285
 286         if (reset_tracing_cpu() < 0)
 287                 return -1;
 288
 289         if (write_tracing_file("max_graph_depth", "0") < 0)
 290                 return -1;
 291
 292         if (write_tracing_file("tracing_thresh", "0") < 0)
 293                 return -1;
 294
 295         reset_tracing_filters();
 296         reset_tracing_options(ftrace);
 297         return 0;
 298 }
 299
 300 static int set_tracing_pid(struct perf_ftrace *ftrace)
 301 {
 302         int i;
 303         char buf[16];
 304
 305         if (target__has_cpu(&ftrace->target))
 306                 return 0;
 307
 308         for (i = 0; i < perf_thread_map__nr(ftrace->evlist->core.threads); i++) {
 309                 scnprintf(buf, sizeof(buf), "%d",
 310                           perf_thread_map__pid(ftrace->evlist->core.threads, i));
 311                 if (append_tracing_file("set_ftrace_pid", buf) < 0)
 312                         return -1;
 313         }
 314         return 0;
 315 }
 316
 317 static int set_tracing_cpumask(struct perf_cpu_map *cpumap)
 318 {
 319         char *cpumask;
 320         size_t mask_size;
 321         int ret;
 322         int last_cpu;
 323
 324         last_cpu = perf_cpu_map__cpu(cpumap, perf_cpu_map__nr(cpumap) - 1).cpu;
 325         mask_size = last_cpu / 4 + 2; /* one more byte for EOS */
 326         mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */
 327
 328         cpumask = malloc(mask_size);
 329         if (cpumask == NULL) {
 330                 pr_debug("failed to allocate cpu mask\n");
 331                 return -1;
 332         }
 333
 334         cpu_map__snprint_mask(cpumap, cpumask, mask_size);
 335
 336         ret = write_tracing_file("tracing_cpumask", cpumask);
 337
 338         free(cpumask);
 339         return ret;
 340 }
 341
 342 static int set_tracing_cpu(struct perf_ftrace *ftrace)
 343 {
 344         struct perf_cpu_map *cpumap = ftrace->evlist->core.user_requested_cpus;
 345
 346         if (!target__has_cpu(&ftrace->target))
 347                 return 0;
 348
 349         return set_tracing_cpumask(cpumap);
 350 }
 351
 352 static int set_tracing_func_stack_trace(struct perf_ftrace *ftrace)
 353 {
 354         if (!ftrace->func_stack_trace)
 355                 return 0;
 356
 357         if (write_tracing_option_file("func_stack_trace", "1") < 0)
 358                 return -1;
 359
 360         return 0;
 361 }
 362
 363 static int set_tracing_func_irqinfo(struct perf_ftrace *ftrace)
 364 {
 365         if (!ftrace->func_irq_info)
 366                 return 0;
 367
 368         if (write_tracing_option_file("irq-info", "1") < 0)
 369                 return -1;
 370
 371         return 0;
 372 }
 373
 374 static int reset_tracing_cpu(void)
 375 {
 376         struct perf_cpu_map *cpumap = perf_cpu_map__new_online_cpus();
 377         int ret;
 378
 379         ret = set_tracing_cpumask(cpumap);
 380         perf_cpu_map__put(cpumap);
 381         return ret;
 382 }
 383
 384 static int __set_tracing_filter(const char *filter_file, struct list_head *funcs)
 385 {
 386         struct filter_entry *pos;
 387
 388         list_for_each_entry(pos, funcs, list) {
 389                 if (append_tracing_file(filter_file, pos->name) < 0)
 390                         return -1;
 391         }
 392
 393         return 0;
 394 }
 395
 396 static int set_tracing_filters(struct perf_ftrace *ftrace)
 397 {
 398         int ret;
 399
 400         ret = __set_tracing_filter("set_ftrace_filter", &ftrace->filters);
 401         if (ret < 0)
 402                 return ret;
 403
 404         ret = __set_tracing_filter("set_ftrace_notrace", &ftrace->notrace);
 405         if (ret < 0)
 406                 return ret;
 407
 408         ret = __set_tracing_filter("set_graph_function", &ftrace->graph_funcs);
 409         if (ret < 0)
 410                 return ret;
 411
 412         /* old kernels do not have this filter */
 413         __set_tracing_filter("set_graph_notrace", &ftrace->nograph_funcs);
 414
 415         return ret;
 416 }
 417
 418 static void reset_tracing_filters(void)
 419 {
 420         write_tracing_file("set_ftrace_filter", " ");
 421         write_tracing_file("set_ftrace_notrace", " ");
 422         write_tracing_file("set_graph_function", " ");
 423         write_tracing_file("set_graph_notrace", " ");
 424 }
 425
 426 static int set_tracing_depth(struct perf_ftrace *ftrace)
 427 {
 428         if (ftrace->graph_depth == 0)
 429                 return 0;
 430
 431         if (ftrace->graph_depth < 0) {
 432                 pr_err("invalid graph depth: %d\n", ftrace->graph_depth);
 433                 return -1;
 434         }
 435
 436         if (write_tracing_file_int("max_graph_depth", ftrace->graph_depth) < 0)
 437                 return -1;
 438
 439         return 0;
 440 }
 441
 442 static int set_tracing_percpu_buffer_size(struct perf_ftrace *ftrace)
 443 {
 444         int ret;
 445
 446         if (ftrace->percpu_buffer_size == 0)
 447                 return 0;
 448
 449         ret = write_tracing_file_int("buffer_size_kb",
 450                                      ftrace->percpu_buffer_size / 1024);
 451         if (ret < 0)
 452                 return ret;
 453
 454         return 0;
 455 }
 456
 457 static int set_tracing_trace_inherit(struct perf_ftrace *ftrace)
 458 {
 459         if (!ftrace->inherit)
 460                 return 0;
 461
 462         if (write_tracing_option_file("function-fork", "1") < 0)
 463                 return -1;
 464
 465         return 0;
 466 }
 467
 468 static int set_tracing_sleep_time(struct perf_ftrace *ftrace)
 469 {
 470         if (!ftrace->graph_nosleep_time)
 471                 return 0;
 472
 473         if (write_tracing_option_file("sleep-time", "0") < 0)
 474                 return -1;
 475
 476         return 0;
 477 }
 478
 479 static int set_tracing_funcgraph_irqs(struct perf_ftrace *ftrace)
 480 {
 481         if (!ftrace->graph_noirqs)
 482                 return 0;
 483
 484         if (write_tracing_option_file("funcgraph-irqs", "0") < 0)
 485                 return -1;
 486
 487         return 0;
 488 }
 489
 490 static int set_tracing_funcgraph_verbose(struct perf_ftrace *ftrace)
 491 {
 492         if (!ftrace->graph_verbose)
 493                 return 0;
 494
 495         if (write_tracing_option_file("funcgraph-proc", "1") < 0)
 496                 return -1;
 497
 498         if (write_tracing_option_file("funcgraph-abstime", "1") < 0)
 499                 return -1;
 500
 501         if (write_tracing_option_file("latency-format", "1") < 0)
 502                 return -1;
 503
 504         return 0;
 505 }
 506
 507 static int set_tracing_funcgraph_tail(struct perf_ftrace *ftrace)
 508 {
 509         if (!ftrace->graph_tail)
 510                 return 0;
 511
 512         if (write_tracing_option_file("funcgraph-tail", "1") < 0)
 513                 return -1;
 514
 515         return 0;
 516 }
 517
 518 static int set_tracing_thresh(struct perf_ftrace *ftrace)
 519 {
 520         int ret;
 521
 522         if (ftrace->graph_thresh == 0)
 523                 return 0;
 524
 525         ret = write_tracing_file_int("tracing_thresh", ftrace->graph_thresh);
 526         if (ret < 0)
 527                 return ret;
 528
 529         return 0;
 530 }
 531
 532 static int set_tracing_options(struct perf_ftrace *ftrace)
 533 {
 534         if (set_tracing_pid(ftrace) < 0) {
 535                 pr_err("failed to set ftrace pid\n");
 536                 return -1;
 537         }
 538
 539         if (set_tracing_cpu(ftrace) < 0) {
 540                 pr_err("failed to set tracing cpumask\n");
 541                 return -1;
 542         }
 543
 544         if (set_tracing_func_stack_trace(ftrace) < 0) {
 545                 pr_err("failed to set tracing option func_stack_trace\n");
 546                 return -1;
 547         }
 548
 549         if (set_tracing_func_irqinfo(ftrace) < 0) {
 550                 pr_err("failed to set tracing option irq-info\n");
 551                 return -1;
 552         }
 553
 554         if (set_tracing_filters(ftrace) < 0) {
 555                 pr_err("failed to set tracing filters\n");
 556                 return -1;
 557         }
 558
 559         if (set_tracing_depth(ftrace) < 0) {
 560                 pr_err("failed to set graph depth\n");
 561                 return -1;
 562         }
 563
 564         if (set_tracing_percpu_buffer_size(ftrace) < 0) {
 565                 pr_err("failed to set tracing per-cpu buffer size\n");
 566                 return -1;
 567         }
 568
 569         if (set_tracing_trace_inherit(ftrace) < 0) {
 570                 pr_err("failed to set tracing option function-fork\n");
 571                 return -1;
 572         }
 573
 574         if (set_tracing_sleep_time(ftrace) < 0) {
 575                 pr_err("failed to set tracing option sleep-time\n");
 576                 return -1;
 577         }
 578
 579         if (set_tracing_funcgraph_irqs(ftrace) < 0) {
 580                 pr_err("failed to set tracing option funcgraph-irqs\n");
 581                 return -1;
 582         }
 583
 584         if (set_tracing_funcgraph_verbose(ftrace) < 0) {
 585                 pr_err("failed to set tracing option funcgraph-proc/funcgraph-abstime\n");
 586                 return -1;
 587         }
 588
 589         if (set_tracing_thresh(ftrace) < 0) {
 590                 pr_err("failed to set tracing thresh\n");
 591                 return -1;
 592         }
 593
 594         if (set_tracing_funcgraph_tail(ftrace) < 0) {
 595                 pr_err("failed to set tracing option funcgraph-tail\n");
 596                 return -1;
 597         }
 598
 599         return 0;
 600 }
 601
 602 static void select_tracer(struct perf_ftrace *ftrace)
 603 {
 604         bool graph = !list_empty(&ftrace->graph_funcs) ||
 605                      !list_empty(&ftrace->nograph_funcs);
 606         bool func = !list_empty(&ftrace->filters) ||
 607                     !list_empty(&ftrace->notrace);
 608
 609         /* The function_graph has priority over function tracer. */
 610         if (graph)
 611                 ftrace->tracer = "function_graph";
 612         else if (func)
 613                 ftrace->tracer = "function";
 614         /* Otherwise, the default tracer is used. */
 615
 616         pr_debug("%s tracer is used\n", ftrace->tracer);
 617 }
 618
 619 static int __cmd_ftrace(struct perf_ftrace *ftrace)
 620 {
 621         char *trace_file;
 622         int trace_fd;
 623         char buf[4096];
 624         struct pollfd pollfd = {
 625                 .events = POLLIN,
 626         };
 627
 628         select_tracer(ftrace);
 629
 630         if (reset_tracing_files(ftrace) < 0) {
 631                 pr_err("failed to reset ftrace\n");
 632                 goto out;
 633         }
 634
 635         /* reset ftrace buffer */
 636         if (write_tracing_file("trace", "0") < 0)
 637                 goto out;
 638
 639         if (set_tracing_options(ftrace) < 0)
 640                 goto out_reset;
 641
 642         if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
 643                 pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
 644                 goto out_reset;
 645         }
 646
 647         setup_pager();
 648
 649         trace_file = get_tracing_file("trace_pipe");
 650         if (!trace_file) {
 651                 pr_err("failed to open trace_pipe\n");
 652                 goto out_reset;
 653         }
 654
 655         trace_fd = open(trace_file, O_RDONLY);
 656
 657         put_tracing_file(trace_file);
 658
 659         if (trace_fd < 0) {
 660                 pr_err("failed to open trace_pipe\n");
 661                 goto out_reset;
 662         }
 663
 664         fcntl(trace_fd, F_SETFL, O_NONBLOCK);
 665         pollfd.fd = trace_fd;
 666
 667         /* display column headers */
 668         read_tracing_file_to_stdout("trace");
 669
 670         if (!ftrace->target.initial_delay) {
 671                 if (write_tracing_file("tracing_on", "1") < 0) {
 672                         pr_err("can't enable tracing\n");
 673                         goto out_close_fd;
 674                 }
 675         }
 676
 677         evlist__start_workload(ftrace->evlist);
 678
 679         if (ftrace->target.initial_delay > 0) {
 680                 usleep(ftrace->target.initial_delay * 1000);
 681                 if (write_tracing_file("tracing_on", "1") < 0) {
 682                         pr_err("can't enable tracing\n");
 683                         goto out_close_fd;
 684                 }
 685         }
 686
 687         while (!done) {
 688                 if (poll(&pollfd, 1, -1) < 0)
 689                         break;
 690
 691                 if (pollfd.revents & POLLIN) {
 692                         int n = read(trace_fd, buf, sizeof(buf));
 693                         if (n < 0)
 694                                 break;
 695                         if (fwrite(buf, n, 1, stdout) != 1)
 696                                 break;
 697                         /* flush output since stdout is in full buffering mode due to pager */
 698                         fflush(stdout);
 699                 }
 700         }
 701
 702         write_tracing_file("tracing_on", "0");
 703
 704         if (workload_exec_errno) {
 705                 const char *emsg = str_error_r(workload_exec_errno, buf, sizeof(buf));
 706                 /* flush stdout first so below error msg appears at the end. */
 707                 fflush(stdout);
 708                 pr_err("workload failed: %s\n", emsg);
 709                 goto out_close_fd;
 710         }
 711
 712         /* read remaining buffer contents */
 713         while (true) {
 714                 int n = read(trace_fd, buf, sizeof(buf));
 715                 if (n <= 0)
 716                         break;
 717                 if (fwrite(buf, n, 1, stdout) != 1)
 718                         break;
 719         }
 720
 721 out_close_fd:
 722         close(trace_fd);
 723 out_reset:
 724         reset_tracing_files(ftrace);
 725 out:
 726         return (done && !workload_exec_errno) ? 0 : -1;
 727 }
 728
 729 static void make_histogram(int buckets[], char *buf, size_t len, char *linebuf,
 730                            bool use_nsec)
 731 {
 732         char *p, *q;
 733         char *unit;
 734         double num;
 735         int i;
 736
 737         /* ensure NUL termination */
 738         buf[len] = '\0';
 739
 740         /* handle data line by line */
 741         for (p = buf; (q = strchr(p, '\n')) != NULL; p = q + 1) {
 742                 *q = '\0';
 743                 /* move it to the line buffer */
 744                 strcat(linebuf, p);
 745
 746                 /*
 747                  * parse trace output to get function duration like in
 748                  *
 749                  * # tracer: function_graph
 750                  * #
 751                  * # CPU  DURATION                  FUNCTION CALLS
 752                  * # |     |   |                     |   |   |   |
 753                  *  1) + 10.291 us   |  do_filp_open();
 754                  *  1)   4.889 us    |  do_filp_open();
 755                  *  1)   6.086 us    |  do_filp_open();
 756                  *
 757                  */
 758                 if (linebuf[0] == '#')
 759                         goto next;
 760
 761                 /* ignore CPU */
 762                 p = strchr(linebuf, ')');
 763                 if (p == NULL)
 764                         p = linebuf;
 765
 766                 while (*p && !isdigit(*p) && (*p != '|'))
 767                         p++;
 768
 769                 /* no duration */
 770                 if (*p == '\0' || *p == '|')
 771                         goto next;
 772
 773                 num = strtod(p, &unit);
 774                 if (!unit || strncmp(unit, " us", 3))
 775                         goto next;
 776
 777                 if (use_nsec)
 778                         num *= 1000;
 779
 780                 i = log2(num);
 781                 if (i < 0)
 782                         i = 0;
 783                 if (i >= NUM_BUCKET)
 784                         i = NUM_BUCKET - 1;
 785
 786                 buckets[i]++;
 787
 788 next:
 789                 /* empty the line buffer for the next output  */
 790                 linebuf[0] = '\0';
 791         }
 792
 793         /* preserve any remaining output (before newline) */
 794         strcat(linebuf, p);
 795 }
 796
 797 static void display_histogram(int buckets[], bool use_nsec)
 798 {
 799         int i;
 800         int total = 0;
 801         int bar_total = 46;  /* to fit in 80 column */
 802         char bar[] = "###############################################";
 803         int bar_len;
 804
 805         for (i = 0; i < NUM_BUCKET; i++)
 806                 total += buckets[i];
 807
 808         if (total == 0) {
 809                 printf("No data found\n");
 810                 return;
 811         }
 812
 813         printf("# %14s | %10s | %-*s |\n",
 814                "  DURATION    ", "COUNT", bar_total, "GRAPH");
 815
 816         bar_len = buckets[0] * bar_total / total;
 817         printf("  %4d - %-4d %s | %10d | %.*s%*s |\n",
 818                0, 1, use_nsec ? "ns" : "us", buckets[0], bar_len, bar, bar_total - bar_len, "");
 819
 820         for (i = 1; i < NUM_BUCKET - 1; i++) {
 821                 int start = (1 << (i - 1));
 822                 int stop = 1 << i;
 823                 const char *unit = use_nsec ? "ns" : "us";
 824
 825                 if (start >= 1024) {
 826                         start >>= 10;
 827                         stop >>= 10;
 828                         unit = use_nsec ? "us" : "ms";
 829                 }
 830                 bar_len = buckets[i] * bar_total / total;
 831                 printf("  %4d - %-4d %s | %10d | %.*s%*s |\n",
 832                        start, stop, unit, buckets[i], bar_len, bar,
 833                        bar_total - bar_len, "");
 834         }
 835
 836         bar_len = buckets[NUM_BUCKET - 1] * bar_total / total;
 837         printf("  %4d - %-4s %s | %10d | %.*s%*s |\n",
 838                1, "...", use_nsec ? "ms" : " s", buckets[NUM_BUCKET - 1],
 839                bar_len, bar, bar_total - bar_len, "");
 840
 841 }
 842
 843 static int prepare_func_latency(struct perf_ftrace *ftrace)
 844 {
 845         char *trace_file;
 846         int fd;
 847
 848         if (ftrace->target.use_bpf)
 849                 return perf_ftrace__latency_prepare_bpf(ftrace);
 850
 851         if (reset_tracing_files(ftrace) < 0) {
 852                 pr_err("failed to reset ftrace\n");
 853                 return -1;
 854         }
 855
 856         /* reset ftrace buffer */
 857         if (write_tracing_file("trace", "0") < 0)
 858                 return -1;
 859
 860         if (set_tracing_options(ftrace) < 0)
 861                 return -1;
 862
 863         /* force to use the function_graph tracer to track duration */
 864         if (write_tracing_file("current_tracer", "function_graph") < 0) {
 865                 pr_err("failed to set current_tracer to function_graph\n");
 866                 return -1;
 867         }
 868
 869         trace_file = get_tracing_file("trace_pipe");
 870         if (!trace_file) {
 871                 pr_err("failed to open trace_pipe\n");
 872                 return -1;
 873         }
 874
 875         fd = open(trace_file, O_RDONLY);
 876         if (fd < 0)
 877                 pr_err("failed to open trace_pipe\n");
 878
 879         put_tracing_file(trace_file);
 880         return fd;
 881 }
 882
 883 static int start_func_latency(struct perf_ftrace *ftrace)
 884 {
 885         if (ftrace->target.use_bpf)
 886                 return perf_ftrace__latency_start_bpf(ftrace);
 887
 888         if (write_tracing_file("tracing_on", "1") < 0) {
 889                 pr_err("can't enable tracing\n");
 890                 return -1;
 891         }
 892
 893         return 0;
 894 }
 895
 896 static int stop_func_latency(struct perf_ftrace *ftrace)
 897 {
 898         if (ftrace->target.use_bpf)
 899                 return perf_ftrace__latency_stop_bpf(ftrace);
 900
 901         write_tracing_file("tracing_on", "0");
 902         return 0;
 903 }
 904
 905 static int read_func_latency(struct perf_ftrace *ftrace, int buckets[])
 906 {
 907         if (ftrace->target.use_bpf)
 908                 return perf_ftrace__latency_read_bpf(ftrace, buckets);
 909
 910         return 0;
 911 }
 912
 913 static int cleanup_func_latency(struct perf_ftrace *ftrace)
 914 {
 915         if (ftrace->target.use_bpf)
 916                 return perf_ftrace__latency_cleanup_bpf(ftrace);
 917
 918         reset_tracing_files(ftrace);
 919         return 0;
 920 }
 921
 922 static int __cmd_latency(struct perf_ftrace *ftrace)
 923 {
 924         int trace_fd;
 925         char buf[4096];
 926         char line[256];
 927         struct pollfd pollfd = {
 928                 .events = POLLIN,
 929         };
 930         int buckets[NUM_BUCKET] = { };
 931
 932         trace_fd = prepare_func_latency(ftrace);
 933         if (trace_fd < 0)
 934                 goto out;
 935
 936         fcntl(trace_fd, F_SETFL, O_NONBLOCK);
 937         pollfd.fd = trace_fd;
 938
 939         if (start_func_latency(ftrace) < 0)
 940                 goto out;
 941
 942         evlist__start_workload(ftrace->evlist);
 943
 944         line[0] = '\0';
 945         while (!done) {
 946                 if (poll(&pollfd, 1, -1) < 0)
 947                         break;
 948
 949                 if (pollfd.revents & POLLIN) {
 950                         int n = read(trace_fd, buf, sizeof(buf) - 1);
 951                         if (n < 0)
 952                                 break;
 953
 954                         make_histogram(buckets, buf, n, line, ftrace->use_nsec);
 955                 }
 956         }
 957
 958         stop_func_latency(ftrace);
 959
 960         if (workload_exec_errno) {
 961                 const char *emsg = str_error_r(workload_exec_errno, buf, sizeof(buf));
 962                 pr_err("workload failed: %s\n", emsg);
 963                 goto out;
 964         }
 965
 966         /* read remaining buffer contents */
 967         while (!ftrace->target.use_bpf) {
 968                 int n = read(trace_fd, buf, sizeof(buf) - 1);
 969                 if (n <= 0)
 970                         break;
 971                 make_histogram(buckets, buf, n, line, ftrace->use_nsec);
 972         }
 973
 974         read_func_latency(ftrace, buckets);
 975
 976         display_histogram(buckets, ftrace->use_nsec);
 977
 978 out:
 979         close(trace_fd);
 980         cleanup_func_latency(ftrace);
 981
 982         return (done && !workload_exec_errno) ? 0 : -1;
 983 }
 984
 985 static size_t profile_hash(long func, void *ctx __maybe_unused)
 986 {
 987         return str_hash((char *)func);
 988 }
 989
 990 static bool profile_equal(long func1, long func2, void *ctx __maybe_unused)
 991 {
 992         return !strcmp((char *)func1, (char *)func2);
 993 }
 994
 995 static int prepare_func_profile(struct perf_ftrace *ftrace)
 996 {
 997         ftrace->tracer = "function_graph";
 998         ftrace->graph_tail = 1;
 999
1000         ftrace->profile_hash = hashmap__new(profile_hash, profile_equal, NULL);
1001         if (ftrace->profile_hash == NULL)
1002                 return -ENOMEM;
1003
1004         return 0;
1005 }
1006
1007 /* This is saved in a hashmap keyed by the function name */
1008 struct ftrace_profile_data {
1009         struct stats st;
1010 };
1011
1012 static int add_func_duration(struct perf_ftrace *ftrace, char *func, double time_ns)
1013 {
1014         struct ftrace_profile_data *prof = NULL;
1015
1016         if (!hashmap__find(ftrace->profile_hash, func, &prof)) {
1017                 char *key = strdup(func);
1018
1019                 if (key == NULL)
1020                         return -ENOMEM;
1021
1022                 prof = zalloc(sizeof(*prof));
1023                 if (prof == NULL) {
1024                         free(key);
1025                         return -ENOMEM;
1026                 }
1027
1028                 init_stats(&prof->st);
1029                 hashmap__add(ftrace->profile_hash, key, prof);
1030         }
1031
1032         update_stats(&prof->st, time_ns);
1033         return 0;
1034 }
1035
1036 /*
1037  * The ftrace function_graph text output normally looks like below:
1038  *
1039  * CPU   DURATION       FUNCTION
1040  *
1041  *  0)               |  syscall_trace_enter.isra.0() {
1042  *  0)               |    __audit_syscall_entry() {
1043  *  0)               |      auditd_test_task() {
1044  *  0)   0.271 us    |        __rcu_read_lock();
1045  *  0)   0.275 us    |        __rcu_read_unlock();
1046  *  0)   1.254 us    |      } /\* auditd_test_task *\/
1047  *  0)   0.279 us    |      ktime_get_coarse_real_ts64();
1048  *  0)   2.227 us    |    } /\* __audit_syscall_entry *\/
1049  *  0)   2.713 us    |  } /\* syscall_trace_enter.isra.0 *\/
1050  *
1051  *  Parse the line and get the duration and function name.
1052  */
1053 static int parse_func_duration(struct perf_ftrace *ftrace, char *line, size_t len)
1054 {
1055         char *p;
1056         char *func;
1057         double duration;
1058
1059         /* skip CPU */
1060         p = strchr(line, ')');
1061         if (p == NULL)
1062                 return 0;
1063
1064         /* get duration */
1065         p = skip_spaces(p + 1);
1066
1067         /* no duration? */
1068         if (p == NULL || *p == '|')
1069                 return 0;
1070
1071         /* skip markers like '*' or '!' for longer than ms */
1072         if (!isdigit(*p))
1073                 p++;
1074
1075         duration = strtod(p, &p);
1076
1077         if (strncmp(p, " us", 3)) {
1078                 pr_debug("non-usec time found.. ignoring\n");
1079                 return 0;
1080         }
1081
1082         /*
1083          * profile stat keeps the max and min values as integer,
1084          * convert to nsec time so that we can have accurate max.
1085          */
1086         duration *= 1000;
1087
1088         /* skip to the pipe */
1089         while (p < line + len && *p != '|')
1090                 p++;
1091
1092         if (*p++ != '|')
1093                 return -EINVAL;
1094
1095         /* get function name */
1096         func = skip_spaces(p);
1097
1098         /* skip the closing bracket and the start of comment */
1099         if (*func == '}')
1100                 func += 5;
1101
1102         /* remove semi-colon or end of comment at the end */
1103         p = line + len - 1;
1104         while (!isalnum(*p) && *p != ']') {
1105                 *p = '\0';
1106                 --p;
1107         }
1108
1109         return add_func_duration(ftrace, func, duration);
1110 }
1111
1112 enum perf_ftrace_profile_sort_key {
1113         PFP_SORT_TOTAL = 0,
1114         PFP_SORT_AVG,
1115         PFP_SORT_MAX,
1116         PFP_SORT_COUNT,
1117         PFP_SORT_NAME,
1118 };
1119
1120 static enum perf_ftrace_profile_sort_key profile_sort = PFP_SORT_TOTAL;
1121
1122 static int cmp_profile_data(const void *a, const void *b)
1123 {
1124         const struct hashmap_entry *e1 = *(const struct hashmap_entry **)a;
1125         const struct hashmap_entry *e2 = *(const struct hashmap_entry **)b;
1126         struct ftrace_profile_data *p1 = e1->pvalue;
1127         struct ftrace_profile_data *p2 = e2->pvalue;
1128         double v1, v2;
1129
1130         switch (profile_sort) {
1131         case PFP_SORT_NAME:
1132                 return strcmp(e1->pkey, e2->pkey);
1133         case PFP_SORT_AVG:
1134                 v1 = p1->st.mean;
1135                 v2 = p2->st.mean;
1136                 break;
1137         case PFP_SORT_MAX:
1138                 v1 = p1->st.max;
1139                 v2 = p2->st.max;
1140                 break;
1141         case PFP_SORT_COUNT:
1142                 v1 = p1->st.n;
1143                 v2 = p2->st.n;
1144                 break;
1145         case PFP_SORT_TOTAL:
1146         default:
1147                 v1 = p1->st.n * p1->st.mean;
1148                 v2 = p2->st.n * p2->st.mean;
1149                 break;
1150         }
1151
1152         if (v1 > v2)
1153                 return -1;
1154         if (v1 < v2)
1155                 return 1;
1156         return 0;
1157 }
1158
1159 static void print_profile_result(struct perf_ftrace *ftrace)
1160 {
1161         struct hashmap_entry *entry, **profile;
1162         size_t i, nr, bkt;
1163
1164         nr = hashmap__size(ftrace->profile_hash);
1165         if (nr == 0)
1166                 return;
1167
1168         profile = calloc(nr, sizeof(*profile));
1169         if (profile == NULL) {
1170                 pr_err("failed to allocate memory for the result\n");
1171                 return;
1172         }
1173
1174         i = 0;
1175         hashmap__for_each_entry(ftrace->profile_hash, entry, bkt)
1176                 profile[i++] = entry;
1177
1178         assert(i == nr);
1179
1180         //cmp_profile_data(profile[0], profile[1]);
1181         qsort(profile, nr, sizeof(*profile), cmp_profile_data);
1182
1183         printf("# %10s %10s %10s %10s   %s\n",
1184                "Total (us)", "Avg (us)", "Max (us)", "Count", "Function");
1185
1186         for (i = 0; i < nr; i++) {
1187                 const char *name = profile[i]->pkey;
1188                 struct ftrace_profile_data *p = profile[i]->pvalue;
1189
1190                 printf("%12.3f %10.3f %6"PRIu64".%03"PRIu64" %10.0f   %s\n",
1191                        p->st.n * p->st.mean / 1000, p->st.mean / 1000,
1192                        p->st.max / 1000, p->st.max % 1000, p->st.n, name);
1193         }
1194
1195         free(profile);
1196
1197         hashmap__for_each_entry(ftrace->profile_hash, entry, bkt) {
1198                 free((char *)entry->pkey);
1199                 free(entry->pvalue);
1200         }
1201
1202         hashmap__free(ftrace->profile_hash);
1203         ftrace->profile_hash = NULL;
1204 }
1205
1206 static int __cmd_profile(struct perf_ftrace *ftrace)
1207 {
1208         char *trace_file;
1209         int trace_fd;
1210         char buf[4096];
1211         struct io io;
1212         char *line = NULL;
1213         size_t line_len = 0;
1214
1215         if (prepare_func_profile(ftrace) < 0) {
1216                 pr_err("failed to prepare func profiler\n");
1217                 goto out;
1218         }
1219
1220         if (reset_tracing_files(ftrace) < 0) {
1221                 pr_err("failed to reset ftrace\n");
1222                 goto out;
1223         }
1224
1225         /* reset ftrace buffer */
1226         if (write_tracing_file("trace", "0") < 0)
1227                 goto out;
1228
1229         if (set_tracing_options(ftrace) < 0)
1230                 return -1;
1231
1232         if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
1233                 pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
1234                 goto out_reset;
1235         }
1236
1237         setup_pager();
1238
1239         trace_file = get_tracing_file("trace_pipe");
1240         if (!trace_file) {
1241                 pr_err("failed to open trace_pipe\n");
1242                 goto out_reset;
1243         }
1244
1245         trace_fd = open(trace_file, O_RDONLY);
1246
1247         put_tracing_file(trace_file);
1248
1249         if (trace_fd < 0) {
1250                 pr_err("failed to open trace_pipe\n");
1251                 goto out_reset;
1252         }
1253
1254         fcntl(trace_fd, F_SETFL, O_NONBLOCK);
1255
1256         if (write_tracing_file("tracing_on", "1") < 0) {
1257                 pr_err("can't enable tracing\n");
1258                 goto out_close_fd;
1259         }
1260
1261         evlist__start_workload(ftrace->evlist);
1262
1263         io__init(&io, trace_fd, buf, sizeof(buf));
1264         io.timeout_ms = -1;
1265
1266         while (!done && !io.eof) {
1267                 if (io__getline(&io, &line, &line_len) < 0)
1268                         break;
1269
1270                 if (parse_func_duration(ftrace, line, line_len) < 0)
1271                         break;
1272         }
1273
1274         write_tracing_file("tracing_on", "0");
1275
1276         if (workload_exec_errno) {
1277                 const char *emsg = str_error_r(workload_exec_errno, buf, sizeof(buf));
1278                 /* flush stdout first so below error msg appears at the end. */
1279                 fflush(stdout);
1280                 pr_err("workload failed: %s\n", emsg);
1281                 goto out_free_line;
1282         }
1283
1284         /* read remaining buffer contents */
1285         io.timeout_ms = 0;
1286         while (!io.eof) {
1287                 if (io__getline(&io, &line, &line_len) < 0)
1288                         break;
1289
1290                 if (parse_func_duration(ftrace, line, line_len) < 0)
1291                         break;
1292         }
1293
1294         print_profile_result(ftrace);
1295
1296 out_free_line:
1297         free(line);
1298 out_close_fd:
1299         close(trace_fd);
1300 out_reset:
1301         reset_tracing_files(ftrace);
1302 out:
1303         return (done && !workload_exec_errno) ? 0 : -1;
1304 }
1305
1306 static int perf_ftrace_config(const char *var, const char *value, void *cb)
1307 {
1308         struct perf_ftrace *ftrace = cb;
1309
1310         if (!strstarts(var, "ftrace."))
1311                 return 0;
1312
1313         if (strcmp(var, "ftrace.tracer"))
1314                 return -1;
1315
1316         if (!strcmp(value, "function_graph") ||
1317             !strcmp(value, "function")) {
1318                 ftrace->tracer = value;
1319                 return 0;
1320         }
1321
1322         pr_err("Please select \"function_graph\" (default) or \"function\"\n");
1323         return -1;
1324 }
1325
1326 static void list_function_cb(char *str, void *arg)
1327 {
1328         struct strfilter *filter = (struct strfilter *)arg;
1329
1330         if (strfilter__compare(filter, str))
1331                 printf("%s", str);
1332 }
1333
1334 static int opt_list_avail_functions(const struct option *opt __maybe_unused,
1335                                     const char *str, int unset)
1336 {
1337         struct strfilter *filter;
1338         const char *err = NULL;
1339         int ret;
1340
1341         if (unset || !str)
1342                 return -1;
1343
1344         filter = strfilter__new(str, &err);
1345         if (!filter)
1346                 return err ? -EINVAL : -ENOMEM;
1347
1348         ret = strfilter__or(filter, str, &err);
1349         if (ret == -EINVAL) {
1350                 pr_err("Filter parse error at %td.\n", err - str + 1);
1351                 pr_err("Source: \"%s\"\n", str);
1352                 pr_err("         %*c\n", (int)(err - str + 1), '^');
1353                 strfilter__delete(filter);
1354                 return ret;
1355         }
1356
1357         ret = read_tracing_file_by_line("available_filter_functions",
1358                                         list_function_cb, filter);
1359         strfilter__delete(filter);
1360         if (ret < 0)
1361                 return ret;
1362
1363         exit(0);
1364 }
1365
1366 static int parse_filter_func(const struct option *opt, const char *str,
1367                              int unset __maybe_unused)
1368 {
1369         struct list_head *head = opt->value;
1370         struct filter_entry *entry;
1371
1372         entry = malloc(sizeof(*entry) + strlen(str) + 1);
1373         if (entry == NULL)
1374                 return -ENOMEM;
1375
1376         strcpy(entry->name, str);
1377         list_add_tail(&entry->list, head);
1378
1379         return 0;
1380 }
1381
1382 static void delete_filter_func(struct list_head *head)
1383 {
1384         struct filter_entry *pos, *tmp;
1385
1386         list_for_each_entry_safe(pos, tmp, head, list) {
1387                 list_del_init(&pos->list);
1388                 free(pos);
1389         }
1390 }
1391
1392 static int parse_buffer_size(const struct option *opt,
1393                              const char *str, int unset)
1394 {
1395         unsigned long *s = (unsigned long *)opt->value;
1396         static struct parse_tag tags_size[] = {
1397                 { .tag  = 'B', .mult = 1       },
1398                 { .tag  = 'K', .mult = 1 << 10 },
1399                 { .tag  = 'M', .mult = 1 << 20 },
1400                 { .tag  = 'G', .mult = 1 << 30 },
1401                 { .tag  = 0 },
1402         };
1403         unsigned long val;
1404
1405         if (unset) {
1406                 *s = 0;
1407                 return 0;
1408         }
1409
1410         val = parse_tag_value(str, tags_size);
1411         if (val != (unsigned long) -1) {
1412                 if (val < 1024) {
1413                         pr_err("buffer size too small, must larger than 1KB.");
1414                         return -1;
1415                 }
1416                 *s = val;
1417                 return 0;
1418         }
1419
1420         return -1;
1421 }
1422
1423 static int parse_func_tracer_opts(const struct option *opt,
1424                                   const char *str, int unset)
1425 {
1426         int ret;
1427         struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value;
1428         struct sublevel_option func_tracer_opts[] = {
1429                 { .name = "call-graph", .value_ptr = &ftrace->func_stack_trace },
1430                 { .name = "irq-info",   .value_ptr = &ftrace->func_irq_info },
1431                 { .name = NULL, }
1432         };
1433
1434         if (unset)
1435                 return 0;
1436
1437         ret = perf_parse_sublevel_options(str, func_tracer_opts);
1438         if (ret)
1439                 return ret;
1440
1441         return 0;
1442 }
1443
1444 static int parse_graph_tracer_opts(const struct option *opt,
1445                                   const char *str, int unset)
1446 {
1447         int ret;
1448         struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value;
1449         struct sublevel_option graph_tracer_opts[] = {
1450                 { .name = "nosleep-time",       .value_ptr = &ftrace->graph_nosleep_time },
1451                 { .name = "noirqs",             .value_ptr = &ftrace->graph_noirqs },
1452                 { .name = "verbose",            .value_ptr = &ftrace->graph_verbose },
1453                 { .name = "thresh",             .value_ptr = &ftrace->graph_thresh },
1454                 { .name = "depth",              .value_ptr = &ftrace->graph_depth },
1455                 { .name = "tail",               .value_ptr = &ftrace->graph_tail },
1456                 { .name = NULL, }
1457         };
1458
1459         if (unset)
1460                 return 0;
1461
1462         ret = perf_parse_sublevel_options(str, graph_tracer_opts);
1463         if (ret)
1464                 return ret;
1465
1466         return 0;
1467 }
1468
1469 static int parse_sort_key(const struct option *opt, const char *str, int unset)
1470 {
1471         enum perf_ftrace_profile_sort_key *key = (void *)opt->value;
1472
1473         if (unset)
1474                 return 0;
1475
1476         if (!strcmp(str, "total"))
1477                 *key = PFP_SORT_TOTAL;
1478         else if (!strcmp(str, "avg"))
1479                 *key = PFP_SORT_AVG;
1480         else if (!strcmp(str, "max"))
1481                 *key = PFP_SORT_MAX;
1482         else if (!strcmp(str, "count"))
1483                 *key = PFP_SORT_COUNT;
1484         else if (!strcmp(str, "name"))
1485                 *key = PFP_SORT_NAME;
1486         else {
1487                 pr_err("Unknown sort key: %s\n", str);
1488                 return -1;
1489         }
1490         return 0;
1491 }
1492
1493 enum perf_ftrace_subcommand {
1494         PERF_FTRACE_NONE,
1495         PERF_FTRACE_TRACE,
1496         PERF_FTRACE_LATENCY,
1497         PERF_FTRACE_PROFILE,
1498 };
1499
1500 int cmd_ftrace(int argc, const char **argv)
1501 {
1502         int ret;
1503         int (*cmd_func)(struct perf_ftrace *) = NULL;
1504         struct perf_ftrace ftrace = {
1505                 .tracer = DEFAULT_TRACER,
1506                 .target = { .uid = UINT_MAX, },
1507         };
1508         const struct option common_options[] = {
1509         OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
1510                    "Trace on existing process id"),
1511         /* TODO: Add short option -t after -t/--tracer can be removed. */
1512         OPT_STRING(0, "tid", &ftrace.target.tid, "tid",
1513                    "Trace on existing thread id (exclusive to --pid)"),
1514         OPT_INCR('v', "verbose", &verbose,
1515                  "Be more verbose"),
1516         OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide,
1517                     "System-wide collection from all CPUs"),
1518         OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu",
1519                     "List of cpus to monitor"),
1520         OPT_END()
1521         };
1522         const struct option ftrace_options[] = {
1523         OPT_STRING('t', "tracer", &ftrace.tracer, "tracer",
1524                    "Tracer to use: function_graph(default) or function"),
1525         OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",
1526                              "Show available functions to filter",
1527                              opt_list_avail_functions, "*"),
1528         OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func",
1529                      "Trace given functions using function tracer",
1530                      parse_filter_func),
1531         OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func",
1532                      "Do not trace given functions", parse_filter_func),
1533         OPT_CALLBACK(0, "func-opts", &ftrace, "options",
1534                      "Function tracer options, available options: call-graph,irq-info",
1535                      parse_func_tracer_opts),
1536         OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func",
1537                      "Trace given functions using function_graph tracer",
1538                      parse_filter_func),
1539         OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func",
1540                      "Set nograph filter on given functions", parse_filter_func),
1541         OPT_CALLBACK(0, "graph-opts", &ftrace, "options",
1542                      "Graph tracer options, available options: nosleep-time,noirqs,verbose,thresh=<n>,depth=<n>",
1543                      parse_graph_tracer_opts),
1544         OPT_CALLBACK('m', "buffer-size", &ftrace.percpu_buffer_size, "size",
1545                      "Size of per cpu buffer, needs to use a B, K, M or G suffix.", parse_buffer_size),
1546         OPT_BOOLEAN(0, "inherit", &ftrace.inherit,
1547                     "Trace children processes"),
1548         OPT_INTEGER('D', "delay", &ftrace.target.initial_delay,
1549                     "Number of milliseconds to wait before starting tracing after program start"),
1550         OPT_PARENT(common_options),
1551         };
1552         const struct option latency_options[] = {
1553         OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func",
1554                      "Show latency of given function", parse_filter_func),
1555 #ifdef HAVE_BPF_SKEL
1556         OPT_BOOLEAN('b', "use-bpf", &ftrace.target.use_bpf,
1557                     "Use BPF to measure function latency"),
1558 #endif
1559         OPT_BOOLEAN('n', "use-nsec", &ftrace.use_nsec,
1560                     "Use nano-second histogram"),
1561         OPT_PARENT(common_options),
1562         };
1563         const struct option profile_options[] = {
1564         OPT_CALLBACK('T', "trace-funcs", &ftrace.filters, "func",
1565                      "Trace given functions using function tracer",
1566                      parse_filter_func),
1567         OPT_CALLBACK('N', "notrace-funcs", &ftrace.notrace, "func",
1568                      "Do not trace given functions", parse_filter_func),
1569         OPT_CALLBACK('G', "graph-funcs", &ftrace.graph_funcs, "func",
1570                      "Trace given functions using function_graph tracer",
1571                      parse_filter_func),
1572         OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func",
1573                      "Set nograph filter on given functions", parse_filter_func),
1574         OPT_CALLBACK('m', "buffer-size", &ftrace.percpu_buffer_size, "size",
1575                      "Size of per cpu buffer, needs to use a B, K, M or G suffix.", parse_buffer_size),
1576         OPT_CALLBACK('s', "sort", &profile_sort, "key",
1577                      "Sort result by key: total (default), avg, max, count, name.",
1578                      parse_sort_key),
1579         OPT_PARENT(common_options),
1580         };
1581         const struct option *options = ftrace_options;
1582
1583         const char * const ftrace_usage[] = {
1584                 "perf ftrace [<options>] [<command>]",
1585                 "perf ftrace [<options>] -- [<command>] [<options>]",
1586                 "perf ftrace {trace|latency|profile} [<options>] [<command>]",
1587                 "perf ftrace {trace|latency|profile} [<options>] -- [<command>] [<options>]",
1588                 NULL
1589         };
1590         enum perf_ftrace_subcommand subcmd = PERF_FTRACE_NONE;
1591
1592         INIT_LIST_HEAD(&ftrace.filters);
1593         INIT_LIST_HEAD(&ftrace.notrace);
1594         INIT_LIST_HEAD(&ftrace.graph_funcs);
1595         INIT_LIST_HEAD(&ftrace.nograph_funcs);
1596
1597         signal(SIGINT, sig_handler);
1598         signal(SIGUSR1, sig_handler);
1599         signal(SIGCHLD, sig_handler);
1600         signal(SIGPIPE, sig_handler);
1601
1602         if (!check_ftrace_capable())
1603                 return -1;
1604
1605         if (!is_ftrace_supported()) {
1606                 pr_err("ftrace is not supported on this system\n");
1607                 return -ENOTSUP;
1608         }
1609
1610         ret = perf_config(perf_ftrace_config, &ftrace);
1611         if (ret < 0)
1612                 return -1;
1613
1614         if (argc > 1) {
1615                 if (!strcmp(argv[1], "trace")) {
1616                         subcmd = PERF_FTRACE_TRACE;
1617                 } else if (!strcmp(argv[1], "latency")) {
1618                         subcmd = PERF_FTRACE_LATENCY;
1619                         options = latency_options;
1620                 } else if (!strcmp(argv[1], "profile")) {
1621                         subcmd = PERF_FTRACE_PROFILE;
1622                         options = profile_options;
1623                 }
1624
1625                 if (subcmd != PERF_FTRACE_NONE) {
1626                         argc--;
1627                         argv++;
1628                 }
1629         }
1630         /* for backward compatibility */
1631         if (subcmd == PERF_FTRACE_NONE)
1632                 subcmd = PERF_FTRACE_TRACE;
1633
1634         argc = parse_options(argc, argv, options, ftrace_usage,
1635                             PARSE_OPT_STOP_AT_NON_OPTION);
1636         if (argc < 0) {
1637                 ret = -EINVAL;
1638                 goto out_delete_filters;
1639         }
1640
1641         /* Make system wide (-a) the default target. */
1642         if (!argc && target__none(&ftrace.target))
1643                 ftrace.target.system_wide = true;
1644
1645         switch (subcmd) {
1646         case PERF_FTRACE_TRACE:
1647                 cmd_func = __cmd_ftrace;
1648                 break;
1649         case PERF_FTRACE_LATENCY:
1650                 if (list_empty(&ftrace.filters)) {
1651                         pr_err("Should provide a function to measure\n");
1652                         parse_options_usage(ftrace_usage, options, "T", 1);
1653                         ret = -EINVAL;
1654                         goto out_delete_filters;
1655                 }
1656                 cmd_func = __cmd_latency;
1657                 break;
1658         case PERF_FTRACE_PROFILE:
1659                 cmd_func = __cmd_profile;
1660                 break;
1661         case PERF_FTRACE_NONE:
1662         default:
1663                 pr_err("Invalid subcommand\n");
1664                 ret = -EINVAL;
1665                 goto out_delete_filters;
1666         }
1667
1668         ret = target__validate(&ftrace.target);
1669         if (ret) {
1670                 char errbuf[512];
1671
1672                 target__strerror(&ftrace.target, ret, errbuf, 512);
1673                 pr_err("%s\n", errbuf);
1674                 goto out_delete_filters;
1675         }
1676
1677         ftrace.evlist = evlist__new();
1678         if (ftrace.evlist == NULL) {
1679                 ret = -ENOMEM;
1680                 goto out_delete_filters;
1681         }
1682
1683         ret = evlist__create_maps(ftrace.evlist, &ftrace.target);
1684         if (ret < 0)
1685                 goto out_delete_evlist;
1686
1687         if (argc) {
1688                 ret = evlist__prepare_workload(ftrace.evlist, &ftrace.target,
1689                                                argv, false,
1690                                                ftrace__workload_exec_failed_signal);
1691                 if (ret < 0)
1692                         goto out_delete_evlist;
1693         }
1694
1695         ret = cmd_func(&ftrace);
1696
1697 out_delete_evlist:
1698         evlist__delete(ftrace.evlist);
1699
1700 out_delete_filters:
1701         delete_filter_func(&ftrace.filters);
1702         delete_filter_func(&ftrace.notrace);
1703         delete_filter_func(&ftrace.graph_funcs);
1704         delete_filter_func(&ftrace.nograph_funcs);
1705
1706         return ret;
1707 }