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