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