tools/perf/perf.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * perf.c
   4  *
   5  * Performance analysis utility.
   6  *
   7  * This is the main hub from which the sub-commands (perf stat,
   8  * perf top, perf record, perf report, etc.) are started.
   9  */
  10 #include "builtin.h"
  11
  12 #include "util/env.h"
  13 #include <subcmd/exec-cmd.h>
  14 #include "util/config.h"
  15 #include "util/quote.h"
  16 #include <subcmd/run-command.h>
  17 #include "util/parse-events.h"
  18 #include <subcmd/parse-options.h>
  19 #include "util/bpf-loader.h"
  20 #include "util/debug.h"
  21 #include "util/event.h"
  22 #include <api/fs/fs.h>
  23 #include <api/fs/tracing_path.h>
  24 #include <errno.h>
  25 #include <pthread.h>
  26 #include <signal.h>
  27 #include <stdlib.h>
  28 #include <time.h>
  29 #include <sys/types.h>
  30 #include <sys/stat.h>
  31 #include <unistd.h>
  32 #include <linux/kernel.h>
  33
  34 const char perf_usage_string[] =
  35         "perf [--version] [--help] [OPTIONS] COMMAND [ARGS]";
  36
  37 const char perf_more_info_string[] =
  38         "See 'perf help COMMAND' for more information on a specific command.";
  39
  40 static int use_pager = -1;
  41 const char *input_name;
  42
  43 struct cmd_struct {
  44         const char *cmd;
  45         int (*fn)(int, const char **);
  46         int option;
  47 };
  48
  49 static struct cmd_struct commands[] = {
  50         { "buildid-cache", cmd_buildid_cache, 0 },
  51         { "buildid-list", cmd_buildid_list, 0 },
  52         { "config",     cmd_config,     0 },
  53         { "c2c",        cmd_c2c,        0 },
  54         { "diff",       cmd_diff,       0 },
  55         { "evlist",     cmd_evlist,     0 },
  56         { "help",       cmd_help,       0 },
  57         { "kallsyms",   cmd_kallsyms,   0 },
  58         { "list",       cmd_list,       0 },
  59         { "record",     cmd_record,     0 },
  60         { "report",     cmd_report,     0 },
  61         { "bench",      cmd_bench,      0 },
  62         { "stat",       cmd_stat,       0 },
  63         { "timechart",  cmd_timechart,  0 },
  64         { "top",        cmd_top,        0 },
  65         { "annotate",   cmd_annotate,   0 },
  66         { "version",    cmd_version,    0 },
  67         { "script",     cmd_script,     0 },
  68         { "sched",      cmd_sched,      0 },
  69 #ifdef HAVE_LIBELF_SUPPORT
  70         { "probe",      cmd_probe,      0 },
  71 #endif
  72         { "kmem",       cmd_kmem,       0 },
  73         { "lock",       cmd_lock,       0 },
  74         { "kvm",        cmd_kvm,        0 },
  75         { "test",       cmd_test,       0 },
  76 #ifdef HAVE_LIBAUDIT_SUPPORT
  77         { "trace",      cmd_trace,      0 },
  78 #endif
  79         { "inject",     cmd_inject,     0 },
  80         { "mem",        cmd_mem,        0 },
  81         { "data",       cmd_data,       0 },
  82         { "ftrace",     cmd_ftrace,     0 },
  83 };
  84
  85 struct pager_config {
  86         const char *cmd;
  87         int val;
  88 };
  89
  90 static int pager_command_config(const char *var, const char *value, void *data)
  91 {
  92         struct pager_config *c = data;
  93         if (strstarts(var, "pager.") && !strcmp(var + 6, c->cmd))
  94                 c->val = perf_config_bool(var, value);
  95         return 0;
  96 }
  97
  98 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
  99 static int check_pager_config(const char *cmd)
 100 {
 101         int err;
 102         struct pager_config c;
 103         c.cmd = cmd;
 104         c.val = -1;
 105         err = perf_config(pager_command_config, &c);
 106         return err ?: c.val;
 107 }
 108
 109 static int browser_command_config(const char *var, const char *value, void *data)
 110 {
 111         struct pager_config *c = data;
 112         if (strstarts(var, "tui.") && !strcmp(var + 4, c->cmd))
 113                 c->val = perf_config_bool(var, value);
 114         if (strstarts(var, "gtk.") && !strcmp(var + 4, c->cmd))
 115                 c->val = perf_config_bool(var, value) ? 2 : 0;
 116         return 0;
 117 }
 118
 119 /*
 120  * returns 0 for "no tui", 1 for "use tui", 2 for "use gtk",
 121  * and -1 for "not specified"
 122  */
 123 static int check_browser_config(const char *cmd)
 124 {
 125         int err;
 126         struct pager_config c;
 127         c.cmd = cmd;
 128         c.val = -1;
 129         err = perf_config(browser_command_config, &c);
 130         return err ?: c.val;
 131 }
 132
 133 static void commit_pager_choice(void)
 134 {
 135         switch (use_pager) {
 136         case 0:
 137                 setenv(PERF_PAGER_ENVIRONMENT, "cat", 1);
 138                 break;
 139         case 1:
 140                 /* setup_pager(); */
 141                 break;
 142         default:
 143                 break;
 144         }
 145 }
 146
 147 struct option options[] = {
 148         OPT_ARGUMENT("help", "help"),
 149         OPT_ARGUMENT("version", "version"),
 150         OPT_ARGUMENT("exec-path", "exec-path"),
 151         OPT_ARGUMENT("html-path", "html-path"),
 152         OPT_ARGUMENT("paginate", "paginate"),
 153         OPT_ARGUMENT("no-pager", "no-pager"),
 154         OPT_ARGUMENT("debugfs-dir", "debugfs-dir"),
 155         OPT_ARGUMENT("buildid-dir", "buildid-dir"),
 156         OPT_ARGUMENT("list-cmds", "list-cmds"),
 157         OPT_ARGUMENT("list-opts", "list-opts"),
 158         OPT_ARGUMENT("debug", "debug"),
 159         OPT_END()
 160 };
 161
 162 static int handle_options(const char ***argv, int *argc, int *envchanged)
 163 {
 164         int handled = 0;
 165
 166         while (*argc > 0) {
 167                 const char *cmd = (*argv)[0];
 168                 if (cmd[0] != '-')
 169                         break;
 170
 171                 /*
 172                  * For legacy reasons, the "version" and "help"
 173                  * commands can be written with "--" prepended
 174                  * to make them look like flags.
 175                  */
 176                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
 177                         break;
 178
 179                 /*
 180                  * Shortcut for '-h' and '-v' options to invoke help
 181                  * and version command.
 182                  */
 183                 if (!strcmp(cmd, "-h")) {
 184                         (*argv)[0] = "--help";
 185                         break;
 186                 }
 187
 188                 if (!strcmp(cmd, "-v")) {
 189                         (*argv)[0] = "--version";
 190                         break;
 191                 }
 192
 193                 /*
 194                  * Check remaining flags.
 195                  */
 196                 if (strstarts(cmd, CMD_EXEC_PATH)) {
 197                         cmd += strlen(CMD_EXEC_PATH);
 198                         if (*cmd == '=')
 199                                 set_argv_exec_path(cmd + 1);
 200                         else {
 201                                 puts(get_argv_exec_path());
 202                                 exit(0);
 203                         }
 204                 } else if (!strcmp(cmd, "--html-path")) {
 205                         puts(system_path(PERF_HTML_PATH));
 206                         exit(0);
 207                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
 208                         use_pager = 1;
 209                 } else if (!strcmp(cmd, "--no-pager")) {
 210                         use_pager = 0;
 211                         if (envchanged)
 212                                 *envchanged = 1;
 213                 } else if (!strcmp(cmd, "--debugfs-dir")) {
 214                         if (*argc < 2) {
 215                                 fprintf(stderr, "No directory given for --debugfs-dir.\n");
 216                                 usage(perf_usage_string);
 217                         }
 218                         tracing_path_set((*argv)[1]);
 219                         if (envchanged)
 220                                 *envchanged = 1;
 221                         (*argv)++;
 222                         (*argc)--;
 223                 } else if (!strcmp(cmd, "--buildid-dir")) {
 224                         if (*argc < 2) {
 225                                 fprintf(stderr, "No directory given for --buildid-dir.\n");
 226                                 usage(perf_usage_string);
 227                         }
 228                         set_buildid_dir((*argv)[1]);
 229                         if (envchanged)
 230                                 *envchanged = 1;
 231                         (*argv)++;
 232                         (*argc)--;
 233                 } else if (strstarts(cmd, CMD_DEBUGFS_DIR)) {
 234                         tracing_path_set(cmd + strlen(CMD_DEBUGFS_DIR));
 235                         fprintf(stderr, "dir: %s\n", tracing_path);
 236                         if (envchanged)
 237                                 *envchanged = 1;
 238                 } else if (!strcmp(cmd, "--list-cmds")) {
 239                         unsigned int i;
 240
 241                         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 242                                 struct cmd_struct *p = commands+i;
 243                                 printf("%s ", p->cmd);
 244                         }
 245                         putchar('\n');
 246                         exit(0);
 247                 } else if (!strcmp(cmd, "--list-opts")) {
 248                         unsigned int i;
 249
 250                         for (i = 0; i < ARRAY_SIZE(options)-1; i++) {
 251                                 struct option *p = options+i;
 252                                 printf("--%s ", p->long_name);
 253                         }
 254                         putchar('\n');
 255                         exit(0);
 256                 } else if (!strcmp(cmd, "--debug")) {
 257                         if (*argc < 2) {
 258                                 fprintf(stderr, "No variable specified for --debug.\n");
 259                                 usage(perf_usage_string);
 260                         }
 261                         if (perf_debug_option((*argv)[1]))
 262                                 usage(perf_usage_string);
 263
 264                         (*argv)++;
 265                         (*argc)--;
 266                 } else {
 267                         fprintf(stderr, "Unknown option: %s\n", cmd);
 268                         usage(perf_usage_string);
 269                 }
 270
 271                 (*argv)++;
 272                 (*argc)--;
 273                 handled++;
 274         }
 275         return handled;
 276 }
 277
 278 #define RUN_SETUP       (1<<0)
 279 #define USE_PAGER       (1<<1)
 280
 281 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 282 {
 283         int status;
 284         struct stat st;
 285         char sbuf[STRERR_BUFSIZE];
 286
 287         if (use_browser == -1)
 288                 use_browser = check_browser_config(p->cmd);
 289
 290         if (use_pager == -1 && p->option & RUN_SETUP)
 291                 use_pager = check_pager_config(p->cmd);
 292         if (use_pager == -1 && p->option & USE_PAGER)
 293                 use_pager = 1;
 294         commit_pager_choice();
 295
 296         perf_env__set_cmdline(&perf_env, argc, argv);
 297         status = p->fn(argc, argv);
 298         perf_config__exit();
 299         exit_browser(status);
 300         perf_env__exit(&perf_env);
 301         bpf__clear();
 302
 303         if (status)
 304                 return status & 0xff;
 305
 306         /* Somebody closed stdout? */
 307         if (fstat(fileno(stdout), &st))
 308                 return 0;
 309         /* Ignore write errors for pipes and sockets.. */
 310         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 311                 return 0;
 312
 313         status = 1;
 314         /* Check for ENOSPC and EIO errors.. */
 315         if (fflush(stdout)) {
 316                 fprintf(stderr, "write failure on standard output: %s",
 317                         str_error_r(errno, sbuf, sizeof(sbuf)));
 318                 goto out;
 319         }
 320         if (ferror(stdout)) {
 321                 fprintf(stderr, "unknown write failure on standard output");
 322                 goto out;
 323         }
 324         if (fclose(stdout)) {
 325                 fprintf(stderr, "close failed on standard output: %s",
 326                         str_error_r(errno, sbuf, sizeof(sbuf)));
 327                 goto out;
 328         }
 329         status = 0;
 330 out:
 331         return status;
 332 }
 333
 334 static void handle_internal_command(int argc, const char **argv)
 335 {
 336         const char *cmd = argv[0];
 337         unsigned int i;
 338
 339         /* Turn "perf cmd --help" into "perf help cmd" */
 340         if (argc > 1 && !strcmp(argv[1], "--help")) {
 341                 argv[1] = argv[0];
 342                 argv[0] = cmd = "help";
 343         }
 344
 345         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 346                 struct cmd_struct *p = commands+i;
 347                 if (strcmp(p->cmd, cmd))
 348                         continue;
 349                 exit(run_builtin(p, argc, argv));
 350         }
 351 }
 352
 353 static void execv_dashed_external(const char **argv)
 354 {
 355         char *cmd;
 356         const char *tmp;
 357         int status;
 358
 359         if (asprintf(&cmd, "perf-%s", argv[0]) < 0)
 360                 goto do_die;
 361
 362         /*
 363          * argv[0] must be the perf command, but the argv array
 364          * belongs to the caller, and may be reused in
 365          * subsequent loop iterations. Save argv[0] and
 366          * restore it on error.
 367          */
 368         tmp = argv[0];
 369         argv[0] = cmd;
 370
 371         /*
 372          * if we fail because the command is not found, it is
 373          * OK to return. Otherwise, we just pass along the status code.
 374          */
 375         status = run_command_v_opt(argv, 0);
 376         if (status != -ERR_RUN_COMMAND_EXEC) {
 377                 if (IS_RUN_COMMAND_ERR(status)) {
 378 do_die:
 379                         pr_err("FATAL: unable to run '%s'", argv[0]);
 380                         status = -128;
 381                 }
 382                 exit(-status);
 383         }
 384         errno = ENOENT; /* as if we called execvp */
 385
 386         argv[0] = tmp;
 387         zfree(&cmd);
 388 }
 389
 390 static int run_argv(int *argcp, const char ***argv)
 391 {
 392         /* See if it's an internal command */
 393         handle_internal_command(*argcp, *argv);
 394
 395         /* .. then try the external ones */
 396         execv_dashed_external(*argv);
 397         return 0;
 398 }
 399
 400 static void pthread__block_sigwinch(void)
 401 {
 402         sigset_t set;
 403
 404         sigemptyset(&set);
 405         sigaddset(&set, SIGWINCH);
 406         pthread_sigmask(SIG_BLOCK, &set, NULL);
 407 }
 408
 409 void pthread__unblock_sigwinch(void)
 410 {
 411         sigset_t set;
 412
 413         sigemptyset(&set);
 414         sigaddset(&set, SIGWINCH);
 415         pthread_sigmask(SIG_UNBLOCK, &set, NULL);
 416 }
 417
 418 #ifdef _SC_LEVEL1_DCACHE_LINESIZE
 419 #define cache_line_size(cacheline_sizep) *cacheline_sizep = sysconf(_SC_LEVEL1_DCACHE_LINESIZE)
 420 #else
 421 static void cache_line_size(int *cacheline_sizep)
 422 {
 423         if (sysfs__read_int("devices/system/cpu/cpu0/cache/index0/coherency_line_size", cacheline_sizep))
 424                 pr_debug("cannot determine cache line size");
 425 }
 426 #endif
 427
 428 int main(int argc, const char **argv)
 429 {
 430         int err;
 431         const char *cmd;
 432         char sbuf[STRERR_BUFSIZE];
 433         int value;
 434
 435         /* libsubcmd init */
 436         exec_cmd_init("perf", PREFIX, PERF_EXEC_PATH, EXEC_PATH_ENVIRONMENT);
 437         pager_init(PERF_PAGER_ENVIRONMENT);
 438
 439         /* The page_size is placed in util object. */
 440         page_size = sysconf(_SC_PAGE_SIZE);
 441         cache_line_size(&cacheline_size);
 442
 443         if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0)
 444                 sysctl_perf_event_max_stack = value;
 445
 446         if (sysctl__read_int("kernel/perf_event_max_contexts_per_stack", &value) == 0)
 447                 sysctl_perf_event_max_contexts_per_stack = value;
 448
 449         cmd = extract_argv0_path(argv[0]);
 450         if (!cmd)
 451                 cmd = "perf-help";
 452
 453         srandom(time(NULL));
 454
 455         perf_config__init();
 456         err = perf_config(perf_default_config, NULL);
 457         if (err)
 458                 return err;
 459         set_buildid_dir(NULL);
 460
 461         /* get debugfs/tracefs mount point from /proc/mounts */
 462         tracing_path_mount();
 463
 464         /*
 465          * "perf-xxxx" is the same as "perf xxxx", but we obviously:
 466          *
 467          *  - cannot take flags in between the "perf" and the "xxxx".
 468          *  - cannot execute it externally (since it would just do
 469          *    the same thing over again)
 470          *
 471          * So we just directly call the internal command handler. If that one
 472          * fails to handle this, then maybe we just run a renamed perf binary
 473          * that contains a dash in its name. To handle this scenario, we just
 474          * fall through and ignore the "xxxx" part of the command string.
 475          */
 476         if (strstarts(cmd, "perf-")) {
 477                 cmd += 5;
 478                 argv[0] = cmd;
 479                 handle_internal_command(argc, argv);
 480                 /*
 481                  * If the command is handled, the above function does not
 482                  * return undo changes and fall through in such a case.
 483                  */
 484                 cmd -= 5;
 485                 argv[0] = cmd;
 486         }
 487         if (strstarts(cmd, "trace")) {
 488 #ifdef HAVE_LIBAUDIT_SUPPORT
 489                 setup_path();
 490                 argv[0] = "trace";
 491                 return cmd_trace(argc, argv);
 492 #else
 493                 fprintf(stderr,
 494                         "trace command not available: missing audit-libs devel package at build time.\n");
 495                 goto out;
 496 #endif
 497         }
 498         /* Look for flags.. */
 499         argv++;
 500         argc--;
 501         handle_options(&argv, &argc, NULL);
 502         commit_pager_choice();
 503
 504         if (argc > 0) {
 505                 if (strstarts(argv[0], "--"))
 506                         argv[0] += 2;
 507         } else {
 508                 /* The user didn't specify a command; give them help */
 509                 printf("\n usage: %s\n\n", perf_usage_string);
 510                 list_common_cmds_help();
 511                 printf("\n %s\n\n", perf_more_info_string);
 512                 goto out;
 513         }
 514         cmd = argv[0];
 515
 516         test_attr__init();
 517
 518         /*
 519          * We use PATH to find perf commands, but we prepend some higher
 520          * precedence paths: the "--exec-path" option, the PERF_EXEC_PATH
 521          * environment, and the $(perfexecdir) from the Makefile at build
 522          * time.
 523          */
 524         setup_path();
 525         /*
 526          * Block SIGWINCH notifications so that the thread that wants it can
 527          * unblock and get syscalls like select interrupted instead of waiting
 528          * forever while the signal goes to some other non interested thread.
 529          */
 530         pthread__block_sigwinch();
 531
 532         perf_debug_setup();
 533
 534         while (1) {
 535                 static int done_help;
 536
 537                 run_argv(&argc, &argv);
 538
 539                 if (errno != ENOENT)
 540                         break;
 541
 542                 if (!done_help) {
 543                         cmd = argv[0] = help_unknown_cmd(cmd);
 544                         done_help = 1;
 545                 } else
 546                         break;
 547         }
 548
 549         fprintf(stderr, "Failed to run command '%s': %s\n",
 550                 cmd, str_error_r(errno, sbuf, sizeof(sbuf)));
 551 out:
 552         return 1;
 553 }