tools/perf/perf.c

   1 /*
   2  * perf.c
   3  *
   4  * Performance analysis utility.
   5  *
   6  * This is the main hub from which the sub-commands (perf stat,
   7  * perf top, perf record, perf report, etc.) are started.
   8  */
   9 #include "builtin.h"
  10
  11 #include "util/exec_cmd.h"
  12 #include "util/cache.h"
  13 #include "util/quote.h"
  14 #include "util/run-command.h"
  15 #include "util/parse-events.h"
  16 #include "util/debugfs.h"
  17
  18 const char perf_usage_string[] =
  19         "perf [--version] [--help] COMMAND [ARGS]";
  20
  21 const char perf_more_info_string[] =
  22         "See 'perf help COMMAND' for more information on a specific command.";
  23
  24 int use_browser = -1;
  25 static int use_pager = -1;
  26
  27 struct pager_config {
  28         const char *cmd;
  29         int val;
  30 };
  31
  32 static char debugfs_mntpt[MAXPATHLEN];
  33
  34 static int pager_command_config(const char *var, const char *value, void *data)
  35 {
  36         struct pager_config *c = data;
  37         if (!prefixcmp(var, "pager.") && !strcmp(var + 6, c->cmd))
  38                 c->val = perf_config_bool(var, value);
  39         return 0;
  40 }
  41
  42 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
  43 int check_pager_config(const char *cmd)
  44 {
  45         struct pager_config c;
  46         c.cmd = cmd;
  47         c.val = -1;
  48         perf_config(pager_command_config, &c);
  49         return c.val;
  50 }
  51
  52 static int tui_command_config(const char *var, const char *value, void *data)
  53 {
  54         struct pager_config *c = data;
  55         if (!prefixcmp(var, "tui.") && !strcmp(var + 4, c->cmd))
  56                 c->val = perf_config_bool(var, value);
  57         return 0;
  58 }
  59
  60 /* returns 0 for "no tui", 1 for "use tui", and -1 for "not specified" */
  61 static int check_tui_config(const char *cmd)
  62 {
  63         struct pager_config c;
  64         c.cmd = cmd;
  65         c.val = -1;
  66         perf_config(tui_command_config, &c);
  67         return c.val;
  68 }
  69
  70 static void commit_pager_choice(void)
  71 {
  72         switch (use_pager) {
  73         case 0:
  74                 setenv("PERF_PAGER", "cat", 1);
  75                 break;
  76         case 1:
  77                 /* setup_pager(); */
  78                 break;
  79         default:
  80                 break;
  81         }
  82 }
  83
  84 static void set_debugfs_path(void)
  85 {
  86         char *path;
  87
  88         path = getenv(PERF_DEBUGFS_ENVIRONMENT);
  89         snprintf(debugfs_path, MAXPATHLEN, "%s/%s", path ?: debugfs_mntpt,
  90                  "tracing/events");
  91 }
  92
  93 static int handle_options(const char ***argv, int *argc, int *envchanged)
  94 {
  95         int handled = 0;
  96
  97         while (*argc > 0) {
  98                 const char *cmd = (*argv)[0];
  99                 if (cmd[0] != '-')
 100                         break;
 101
 102                 /*
 103                  * For legacy reasons, the "version" and "help"
 104                  * commands can be written with "--" prepended
 105                  * to make them look like flags.
 106                  */
 107                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
 108                         break;
 109
 110                 /*
 111                  * Check remaining flags.
 112                  */
 113                 if (!prefixcmp(cmd, CMD_EXEC_PATH)) {
 114                         cmd += strlen(CMD_EXEC_PATH);
 115                         if (*cmd == '=')
 116                                 perf_set_argv_exec_path(cmd + 1);
 117                         else {
 118                                 puts(perf_exec_path());
 119                                 exit(0);
 120                         }
 121                 } else if (!strcmp(cmd, "--html-path")) {
 122                         puts(system_path(PERF_HTML_PATH));
 123                         exit(0);
 124                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
 125                         use_pager = 1;
 126                 } else if (!strcmp(cmd, "--no-pager")) {
 127                         use_pager = 0;
 128                         if (envchanged)
 129                                 *envchanged = 1;
 130                 } else if (!strcmp(cmd, "--perf-dir")) {
 131                         if (*argc < 2) {
 132                                 fprintf(stderr, "No directory given for --perf-dir.\n");
 133                                 usage(perf_usage_string);
 134                         }
 135                         setenv(PERF_DIR_ENVIRONMENT, (*argv)[1], 1);
 136                         if (envchanged)
 137                                 *envchanged = 1;
 138                         (*argv)++;
 139                         (*argc)--;
 140                         handled++;
 141                 } else if (!prefixcmp(cmd, CMD_PERF_DIR)) {
 142                         setenv(PERF_DIR_ENVIRONMENT, cmd + strlen(CMD_PERF_DIR), 1);
 143                         if (envchanged)
 144                                 *envchanged = 1;
 145                 } else if (!strcmp(cmd, "--work-tree")) {
 146                         if (*argc < 2) {
 147                                 fprintf(stderr, "No directory given for --work-tree.\n");
 148                                 usage(perf_usage_string);
 149                         }
 150                         setenv(PERF_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 151                         if (envchanged)
 152                                 *envchanged = 1;
 153                         (*argv)++;
 154                         (*argc)--;
 155                 } else if (!prefixcmp(cmd, CMD_WORK_TREE)) {
 156                         setenv(PERF_WORK_TREE_ENVIRONMENT, cmd + strlen(CMD_WORK_TREE), 1);
 157                         if (envchanged)
 158                                 *envchanged = 1;
 159                 } else if (!strcmp(cmd, "--debugfs-dir")) {
 160                         if (*argc < 2) {
 161                                 fprintf(stderr, "No directory given for --debugfs-dir.\n");
 162                                 usage(perf_usage_string);
 163                         }
 164                         strncpy(debugfs_mntpt, (*argv)[1], MAXPATHLEN);
 165                         debugfs_mntpt[MAXPATHLEN - 1] = '\0';
 166                         if (envchanged)
 167                                 *envchanged = 1;
 168                         (*argv)++;
 169                         (*argc)--;
 170                 } else if (!prefixcmp(cmd, CMD_DEBUGFS_DIR)) {
 171                         strncpy(debugfs_mntpt, cmd + strlen(CMD_DEBUGFS_DIR), MAXPATHLEN);
 172                         debugfs_mntpt[MAXPATHLEN - 1] = '\0';
 173                         if (envchanged)
 174                                 *envchanged = 1;
 175                 } else {
 176                         fprintf(stderr, "Unknown option: %s\n", cmd);
 177                         usage(perf_usage_string);
 178                 }
 179
 180                 (*argv)++;
 181                 (*argc)--;
 182                 handled++;
 183         }
 184         return handled;
 185 }
 186
 187 static int handle_alias(int *argcp, const char ***argv)
 188 {
 189         int envchanged = 0, ret = 0, saved_errno = errno;
 190         int count, option_count;
 191         const char **new_argv;
 192         const char *alias_command;
 193         char *alias_string;
 194
 195         alias_command = (*argv)[0];
 196         alias_string = alias_lookup(alias_command);
 197         if (alias_string) {
 198                 if (alias_string[0] == '!') {
 199                         if (*argcp > 1) {
 200                                 struct strbuf buf;
 201
 202                                 strbuf_init(&buf, PATH_MAX);
 203                                 strbuf_addstr(&buf, alias_string);
 204                                 sq_quote_argv(&buf, (*argv) + 1, PATH_MAX);
 205                                 free(alias_string);
 206                                 alias_string = buf.buf;
 207                         }
 208                         ret = system(alias_string + 1);
 209                         if (ret >= 0 && WIFEXITED(ret) &&
 210                             WEXITSTATUS(ret) != 127)
 211                                 exit(WEXITSTATUS(ret));
 212                         die("Failed to run '%s' when expanding alias '%s'",
 213                             alias_string + 1, alias_command);
 214                 }
 215                 count = split_cmdline(alias_string, &new_argv);
 216                 if (count < 0)
 217                         die("Bad alias.%s string", alias_command);
 218                 option_count = handle_options(&new_argv, &count, &envchanged);
 219                 if (envchanged)
 220                         die("alias '%s' changes environment variables\n"
 221                                  "You can use '!perf' in the alias to do this.",
 222                                  alias_command);
 223                 memmove(new_argv - option_count, new_argv,
 224                                 count * sizeof(char *));
 225                 new_argv -= option_count;
 226
 227                 if (count < 1)
 228                         die("empty alias for %s", alias_command);
 229
 230                 if (!strcmp(alias_command, new_argv[0]))
 231                         die("recursive alias: %s", alias_command);
 232
 233                 new_argv = realloc(new_argv, sizeof(char *) *
 234                                     (count + *argcp + 1));
 235                 /* insert after command name */
 236                 memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
 237                 new_argv[count + *argcp] = NULL;
 238
 239                 *argv = new_argv;
 240                 *argcp += count - 1;
 241
 242                 ret = 1;
 243         }
 244
 245         errno = saved_errno;
 246
 247         return ret;
 248 }
 249
 250 const char perf_version_string[] = PERF_VERSION;
 251
 252 #define RUN_SETUP       (1<<0)
 253 #define USE_PAGER       (1<<1)
 254 /*
 255  * require working tree to be present -- anything uses this needs
 256  * RUN_SETUP for reading from the configuration file.
 257  */
 258 #define NEED_WORK_TREE  (1<<2)
 259
 260 struct cmd_struct {
 261         const char *cmd;
 262         int (*fn)(int, const char **, const char *);
 263         int option;
 264 };
 265
 266 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 267 {
 268         int status;
 269         struct stat st;
 270         const char *prefix;
 271
 272         prefix = NULL;
 273         if (p->option & RUN_SETUP)
 274                 prefix = NULL; /* setup_perf_directory(); */
 275
 276         if (use_browser == -1)
 277                 use_browser = check_tui_config(p->cmd);
 278
 279         if (use_pager == -1 && p->option & RUN_SETUP)
 280                 use_pager = check_pager_config(p->cmd);
 281         if (use_pager == -1 && p->option & USE_PAGER)
 282                 use_pager = 1;
 283         commit_pager_choice();
 284         set_debugfs_path();
 285
 286         status = p->fn(argc, argv, prefix);
 287         exit_browser(status);
 288
 289         if (status)
 290                 return status & 0xff;
 291
 292         /* Somebody closed stdout? */
 293         if (fstat(fileno(stdout), &st))
 294                 return 0;
 295         /* Ignore write errors for pipes and sockets.. */
 296         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 297                 return 0;
 298
 299         /* Check for ENOSPC and EIO errors.. */
 300         if (fflush(stdout))
 301                 die("write failure on standard output: %s", strerror(errno));
 302         if (ferror(stdout))
 303                 die("unknown write failure on standard output");
 304         if (fclose(stdout))
 305                 die("close failed on standard output: %s", strerror(errno));
 306         return 0;
 307 }
 308
 309 static void handle_internal_command(int argc, const char **argv)
 310 {
 311         const char *cmd = argv[0];
 312         static struct cmd_struct commands[] = {
 313                 { "buildid-cache", cmd_buildid_cache, 0 },
 314                 { "buildid-list", cmd_buildid_list, 0 },
 315                 { "diff",       cmd_diff,       0 },
 316                 { "evlist",     cmd_evlist,     0 },
 317                 { "help",       cmd_help,       0 },
 318                 { "list",       cmd_list,       0 },
 319                 { "record",     cmd_record,     0 },
 320                 { "report",     cmd_report,     0 },
 321                 { "bench",      cmd_bench,      0 },
 322                 { "stat",       cmd_stat,       0 },
 323                 { "timechart",  cmd_timechart,  0 },
 324                 { "top",        cmd_top,        0 },
 325                 { "annotate",   cmd_annotate,   0 },
 326                 { "version",    cmd_version,    0 },
 327                 { "script",     cmd_script,     0 },
 328                 { "sched",      cmd_sched,      0 },
 329                 { "probe",      cmd_probe,      0 },
 330                 { "kmem",       cmd_kmem,       0 },
 331                 { "lock",       cmd_lock,       0 },
 332                 { "kvm",        cmd_kvm,        0 },
 333                 { "test",       cmd_test,       0 },
 334                 { "inject",     cmd_inject,     0 },
 335         };
 336         unsigned int i;
 337         static const char ext[] = STRIP_EXTENSION;
 338
 339         if (sizeof(ext) > 1) {
 340                 i = strlen(argv[0]) - strlen(ext);
 341                 if (i > 0 && !strcmp(argv[0] + i, ext)) {
 342                         char *argv0 = strdup(argv[0]);
 343                         argv[0] = cmd = argv0;
 344                         argv0[i] = '\0';
 345                 }
 346         }
 347
 348         /* Turn "perf cmd --help" into "perf help cmd" */
 349         if (argc > 1 && !strcmp(argv[1], "--help")) {
 350                 argv[1] = argv[0];
 351                 argv[0] = cmd = "help";
 352         }
 353
 354         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 355                 struct cmd_struct *p = commands+i;
 356                 if (strcmp(p->cmd, cmd))
 357                         continue;
 358                 exit(run_builtin(p, argc, argv));
 359         }
 360 }
 361
 362 static void execv_dashed_external(const char **argv)
 363 {
 364         struct strbuf cmd = STRBUF_INIT;
 365         const char *tmp;
 366         int status;
 367
 368         strbuf_addf(&cmd, "perf-%s", argv[0]);
 369
 370         /*
 371          * argv[0] must be the perf command, but the argv array
 372          * belongs to the caller, and may be reused in
 373          * subsequent loop iterations. Save argv[0] and
 374          * restore it on error.
 375          */
 376         tmp = argv[0];
 377         argv[0] = cmd.buf;
 378
 379         /*
 380          * if we fail because the command is not found, it is
 381          * OK to return. Otherwise, we just pass along the status code.
 382          */
 383         status = run_command_v_opt(argv, 0);
 384         if (status != -ERR_RUN_COMMAND_EXEC) {
 385                 if (IS_RUN_COMMAND_ERR(status))
 386                         die("unable to run '%s'", argv[0]);
 387                 exit(-status);
 388         }
 389         errno = ENOENT; /* as if we called execvp */
 390
 391         argv[0] = tmp;
 392
 393         strbuf_release(&cmd);
 394 }
 395
 396 static int run_argv(int *argcp, const char ***argv)
 397 {
 398         int done_alias = 0;
 399
 400         while (1) {
 401                 /* See if it's an internal command */
 402                 handle_internal_command(*argcp, *argv);
 403
 404                 /* .. then try the external ones */
 405                 execv_dashed_external(*argv);
 406
 407                 /* It could be an alias -- this works around the insanity
 408                  * of overriding "perf log" with "perf show" by having
 409                  * alias.log = show
 410                  */
 411                 if (done_alias || !handle_alias(argcp, argv))
 412                         break;
 413                 done_alias = 1;
 414         }
 415
 416         return done_alias;
 417 }
 418
 419 /* mini /proc/mounts parser: searching for "^blah /mount/point debugfs" */
 420 static void get_debugfs_mntpt(void)
 421 {
 422         const char *path = debugfs_mount(NULL);
 423
 424         if (path)
 425                 strncpy(debugfs_mntpt, path, sizeof(debugfs_mntpt));
 426         else
 427                 debugfs_mntpt[0] = '\0';
 428 }
 429
 430 static void pthread__block_sigwinch(void)
 431 {
 432         sigset_t set;
 433
 434         sigemptyset(&set);
 435         sigaddset(&set, SIGWINCH);
 436         pthread_sigmask(SIG_BLOCK, &set, NULL);
 437 }
 438
 439 void pthread__unblock_sigwinch(void)
 440 {
 441         sigset_t set;
 442
 443         sigemptyset(&set);
 444         sigaddset(&set, SIGWINCH);
 445         pthread_sigmask(SIG_UNBLOCK, &set, NULL);
 446 }
 447
 448 int main(int argc, const char **argv)
 449 {
 450         const char *cmd;
 451
 452         cmd = perf_extract_argv0_path(argv[0]);
 453         if (!cmd)
 454                 cmd = "perf-help";
 455         /* get debugfs mount point from /proc/mounts */
 456         get_debugfs_mntpt();
 457         /*
 458          * "perf-xxxx" is the same as "perf xxxx", but we obviously:
 459          *
 460          *  - cannot take flags in between the "perf" and the "xxxx".
 461          *  - cannot execute it externally (since it would just do
 462          *    the same thing over again)
 463          *
 464          * So we just directly call the internal command handler, and
 465          * die if that one cannot handle it.
 466          */
 467         if (!prefixcmp(cmd, "perf-")) {
 468                 cmd += 5;
 469                 argv[0] = cmd;
 470                 handle_internal_command(argc, argv);
 471                 die("cannot handle %s internally", cmd);
 472         }
 473
 474         /* Look for flags.. */
 475         argv++;
 476         argc--;
 477         handle_options(&argv, &argc, NULL);
 478         commit_pager_choice();
 479         set_debugfs_path();
 480         set_buildid_dir();
 481
 482         if (argc > 0) {
 483                 if (!prefixcmp(argv[0], "--"))
 484                         argv[0] += 2;
 485         } else {
 486                 /* The user didn't specify a command; give them help */
 487                 printf("\n usage: %s\n\n", perf_usage_string);
 488                 list_common_cmds_help();
 489                 printf("\n %s\n\n", perf_more_info_string);
 490                 exit(1);
 491         }
 492         cmd = argv[0];
 493
 494         /*
 495          * We use PATH to find perf commands, but we prepend some higher
 496          * precedence paths: the "--exec-path" option, the PERF_EXEC_PATH
 497          * environment, and the $(perfexecdir) from the Makefile at build
 498          * time.
 499          */
 500         setup_path();
 501         /*
 502          * Block SIGWINCH notifications so that the thread that wants it can
 503          * unblock and get syscalls like select interrupted instead of waiting
 504          * forever while the signal goes to some other non interested thread.
 505          */
 506         pthread__block_sigwinch();
 507
 508         while (1) {
 509                 static int done_help;
 510                 static int was_alias;
 511
 512                 was_alias = run_argv(&argc, &argv);
 513                 if (errno != ENOENT)
 514                         break;
 515
 516                 if (was_alias) {
 517                         fprintf(stderr, "Expansion of alias '%s' failed; "
 518                                 "'%s' is not a perf-command\n",
 519                                 cmd, argv[0]);
 520                         exit(1);
 521                 }
 522                 if (!done_help) {
 523                         cmd = argv[0] = help_unknown_cmd(cmd);
 524                         done_help = 1;
 525                 } else
 526                         break;
 527         }
 528
 529         fprintf(stderr, "Failed to run command '%s': %s\n",
 530                 cmd, strerror(errno));
 531
 532         return 1;
 533 }