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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 <lk/debugfs.h>
     17 #include <pthread.h>
     18 
     19 const char perf_usage_string[] =
     20 	"perf [--version] [--help] COMMAND [ARGS]";
     21 
     22 const char perf_more_info_string[] =
     23 	"See 'perf help COMMAND' for more information on a specific command.";
     24 
     25 int use_browser = -1;
     26 static int use_pager = -1;
     27 const char *input_name;
     28 
     29 struct cmd_struct {
     30 	const char *cmd;
     31 	int (*fn)(int, const char **, const char *);
     32 	int option;
     33 };
     34 
     35 static struct cmd_struct commands[] = {
     36 	{ "buildid-cache", cmd_buildid_cache, 0 },
     37 	{ "buildid-list", cmd_buildid_list, 0 },
     38 	{ "diff",	cmd_diff,	0 },
     39 	{ "evlist",	cmd_evlist,	0 },
     40 	{ "help",	cmd_help,	0 },
     41 	{ "list",	cmd_list,	0 },
     42 	{ "record",	cmd_record,	0 },
     43 	{ "report",	cmd_report,	0 },
     44 	{ "bench",	cmd_bench,	0 },
     45 	{ "stat",	cmd_stat,	0 },
     46 	{ "timechart",	cmd_timechart,	0 },
     47 	{ "top",	cmd_top,	0 },
     48 	{ "annotate",	cmd_annotate,	0 },
     49 	{ "version",	cmd_version,	0 },
     50 	{ "script",	cmd_script,	0 },
     51 	{ "sched",	cmd_sched,	0 },
     52 #ifdef LIBELF_SUPPORT
     53 	{ "probe",	cmd_probe,	0 },
     54 #endif
     55 	{ "kmem",	cmd_kmem,	0 },
     56 	{ "lock",	cmd_lock,	0 },
     57 	{ "kvm",	cmd_kvm,	0 },
     58 	{ "test",	cmd_test,	0 },
     59 #ifdef LIBAUDIT_SUPPORT
     60 	{ "trace",	cmd_trace,	0 },
     61 #endif
     62 	{ "inject",	cmd_inject,	0 },
     63 	{ "mem",	cmd_mem,	0 },
     64 };
     65 
     66 struct pager_config {
     67 	const char *cmd;
     68 	int val;
     69 };
     70 
     71 static int pager_command_config(const char *var, const char *value, void *data)
     72 {
     73 	struct pager_config *c = data;
     74 	if (!prefixcmp(var, "pager.") && !strcmp(var + 6, c->cmd))
     75 		c->val = perf_config_bool(var, value);
     76 	return 0;
     77 }
     78 
     79 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
     80 int check_pager_config(const char *cmd)
     81 {
     82 	struct pager_config c;
     83 	c.cmd = cmd;
     84 	c.val = -1;
     85 	perf_config(pager_command_config, &c);
     86 	return c.val;
     87 }
     88 
     89 static int browser_command_config(const char *var, const char *value, void *data)
     90 {
     91 	struct pager_config *c = data;
     92 	if (!prefixcmp(var, "tui.") && !strcmp(var + 4, c->cmd))
     93 		c->val = perf_config_bool(var, value);
     94 	if (!prefixcmp(var, "gtk.") && !strcmp(var + 4, c->cmd))
     95 		c->val = perf_config_bool(var, value) ? 2 : 0;
     96 	return 0;
     97 }
     98 
     99 /*
    100  * returns 0 for "no tui", 1 for "use tui", 2 for "use gtk",
    101  * and -1 for "not specified"
    102  */
    103 static int check_browser_config(const char *cmd)
    104 {
    105 	struct pager_config c;
    106 	c.cmd = cmd;
    107 	c.val = -1;
    108 	perf_config(browser_command_config, &c);
    109 	return c.val;
    110 }
    111 
    112 static void commit_pager_choice(void)
    113 {
    114 	switch (use_pager) {
    115 	case 0:
    116 		setenv("PERF_PAGER", "cat", 1);
    117 		break;
    118 	case 1:
    119 		/* setup_pager(); */
    120 		break;
    121 	default:
    122 		break;
    123 	}
    124 }
    125 
    126 static int handle_options(const char ***argv, int *argc, int *envchanged)
    127 {
    128 	int handled = 0;
    129 
    130 	while (*argc > 0) {
    131 		const char *cmd = (*argv)[0];
    132 		if (cmd[0] != '-')
    133 			break;
    134 
    135 		/*
    136 		 * For legacy reasons, the "version" and "help"
    137 		 * commands can be written with "--" prepended
    138 		 * to make them look like flags.
    139 		 */
    140 		if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
    141 			break;
    142 
    143 		/*
    144 		 * Check remaining flags.
    145 		 */
    146 		if (!prefixcmp(cmd, CMD_EXEC_PATH)) {
    147 			cmd += strlen(CMD_EXEC_PATH);
    148 			if (*cmd == '=')
    149 				perf_set_argv_exec_path(cmd + 1);
    150 			else {
    151 				puts(perf_exec_path());
    152 				exit(0);
    153 			}
    154 		} else if (!strcmp(cmd, "--html-path")) {
    155 			puts(system_path(PERF_HTML_PATH));
    156 			exit(0);
    157 		} else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
    158 			use_pager = 1;
    159 		} else if (!strcmp(cmd, "--no-pager")) {
    160 			use_pager = 0;
    161 			if (envchanged)
    162 				*envchanged = 1;
    163 		} else if (!strcmp(cmd, "--perf-dir")) {
    164 			if (*argc < 2) {
    165 				fprintf(stderr, "No directory given for --perf-dir.\n");
    166 				usage(perf_usage_string);
    167 			}
    168 			setenv(PERF_DIR_ENVIRONMENT, (*argv)[1], 1);
    169 			if (envchanged)
    170 				*envchanged = 1;
    171 			(*argv)++;
    172 			(*argc)--;
    173 			handled++;
    174 		} else if (!prefixcmp(cmd, CMD_PERF_DIR)) {
    175 			setenv(PERF_DIR_ENVIRONMENT, cmd + strlen(CMD_PERF_DIR), 1);
    176 			if (envchanged)
    177 				*envchanged = 1;
    178 		} else if (!strcmp(cmd, "--work-tree")) {
    179 			if (*argc < 2) {
    180 				fprintf(stderr, "No directory given for --work-tree.\n");
    181 				usage(perf_usage_string);
    182 			}
    183 			setenv(PERF_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
    184 			if (envchanged)
    185 				*envchanged = 1;
    186 			(*argv)++;
    187 			(*argc)--;
    188 		} else if (!prefixcmp(cmd, CMD_WORK_TREE)) {
    189 			setenv(PERF_WORK_TREE_ENVIRONMENT, cmd + strlen(CMD_WORK_TREE), 1);
    190 			if (envchanged)
    191 				*envchanged = 1;
    192 		} else if (!strcmp(cmd, "--debugfs-dir")) {
    193 			if (*argc < 2) {
    194 				fprintf(stderr, "No directory given for --debugfs-dir.\n");
    195 				usage(perf_usage_string);
    196 			}
    197 			perf_debugfs_set_path((*argv)[1]);
    198 			if (envchanged)
    199 				*envchanged = 1;
    200 			(*argv)++;
    201 			(*argc)--;
    202 		} else if (!prefixcmp(cmd, CMD_DEBUGFS_DIR)) {
    203 			perf_debugfs_set_path(cmd + strlen(CMD_DEBUGFS_DIR));
    204 			fprintf(stderr, "dir: %s\n", debugfs_mountpoint);
    205 			if (envchanged)
    206 				*envchanged = 1;
    207 		} else if (!strcmp(cmd, "--list-cmds")) {
    208 			unsigned int i;
    209 
    210 			for (i = 0; i < ARRAY_SIZE(commands); i++) {
    211 				struct cmd_struct *p = commands+i;
    212 				printf("%s ", p->cmd);
    213 			}
    214 			exit(0);
    215 		} else {
    216 			fprintf(stderr, "Unknown option: %s\n", cmd);
    217 			usage(perf_usage_string);
    218 		}
    219 
    220 		(*argv)++;
    221 		(*argc)--;
    222 		handled++;
    223 	}
    224 	return handled;
    225 }
    226 
    227 static int handle_alias(int *argcp, const char ***argv)
    228 {
    229 	int envchanged = 0, ret = 0, saved_errno = errno;
    230 	int count, option_count;
    231 	const char **new_argv;
    232 	const char *alias_command;
    233 	char *alias_string;
    234 
    235 	alias_command = (*argv)[0];
    236 	alias_string = alias_lookup(alias_command);
    237 	if (alias_string) {
    238 		if (alias_string[0] == '!') {
    239 			if (*argcp > 1) {
    240 				struct strbuf buf;
    241 
    242 				strbuf_init(&buf, PATH_MAX);
    243 				strbuf_addstr(&buf, alias_string);
    244 				sq_quote_argv(&buf, (*argv) + 1, PATH_MAX);
    245 				free(alias_string);
    246 				alias_string = buf.buf;
    247 			}
    248 			ret = system(alias_string + 1);
    249 			if (ret >= 0 && WIFEXITED(ret) &&
    250 			    WEXITSTATUS(ret) != 127)
    251 				exit(WEXITSTATUS(ret));
    252 			die("Failed to run '%s' when expanding alias '%s'",
    253 			    alias_string + 1, alias_command);
    254 		}
    255 		count = split_cmdline(alias_string, &new_argv);
    256 		if (count < 0)
    257 			die("Bad alias.%s string", alias_command);
    258 		option_count = handle_options(&new_argv, &count, &envchanged);
    259 		if (envchanged)
    260 			die("alias '%s' changes environment variables\n"
    261 				 "You can use '!perf' in the alias to do this.",
    262 				 alias_command);
    263 		memmove(new_argv - option_count, new_argv,
    264 				count * sizeof(char *));
    265 		new_argv -= option_count;
    266 
    267 		if (count < 1)
    268 			die("empty alias for %s", alias_command);
    269 
    270 		if (!strcmp(alias_command, new_argv[0]))
    271 			die("recursive alias: %s", alias_command);
    272 
    273 		new_argv = realloc(new_argv, sizeof(char *) *
    274 				    (count + *argcp + 1));
    275 		/* insert after command name */
    276 		memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
    277 		new_argv[count + *argcp] = NULL;
    278 
    279 		*argv = new_argv;
    280 		*argcp += count - 1;
    281 
    282 		ret = 1;
    283 	}
    284 
    285 	errno = saved_errno;
    286 
    287 	return ret;
    288 }
    289 
    290 const char perf_version_string[] = PERF_VERSION;
    291 
    292 #define RUN_SETUP	(1<<0)
    293 #define USE_PAGER	(1<<1)
    294 /*
    295  * require working tree to be present -- anything uses this needs
    296  * RUN_SETUP for reading from the configuration file.
    297  */
    298 #define NEED_WORK_TREE	(1<<2)
    299 
    300 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
    301 {
    302 	int status;
    303 	struct stat st;
    304 	const char *prefix;
    305 
    306 	prefix = NULL;
    307 	if (p->option & RUN_SETUP)
    308 		prefix = NULL; /* setup_perf_directory(); */
    309 
    310 	if (use_browser == -1)
    311 		use_browser = check_browser_config(p->cmd);
    312 
    313 	if (use_pager == -1 && p->option & RUN_SETUP)
    314 		use_pager = check_pager_config(p->cmd);
    315 	if (use_pager == -1 && p->option & USE_PAGER)
    316 		use_pager = 1;
    317 	commit_pager_choice();
    318 
    319 	status = p->fn(argc, argv, prefix);
    320 	exit_browser(status);
    321 
    322 	if (status)
    323 		return status & 0xff;
    324 
    325 	/* Somebody closed stdout? */
    326 	if (fstat(fileno(stdout), &st))
    327 		return 0;
    328 	/* Ignore write errors for pipes and sockets.. */
    329 	if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
    330 		return 0;
    331 
    332 	status = 1;
    333 	/* Check for ENOSPC and EIO errors.. */
    334 	if (fflush(stdout)) {
    335 		fprintf(stderr, "write failure on standard output: %s", strerror(errno));
    336 		goto out;
    337 	}
    338 	if (ferror(stdout)) {
    339 		fprintf(stderr, "unknown write failure on standard output");
    340 		goto out;
    341 	}
    342 	if (fclose(stdout)) {
    343 		fprintf(stderr, "close failed on standard output: %s", strerror(errno));
    344 		goto out;
    345 	}
    346 	status = 0;
    347 out:
    348 	return status;
    349 }
    350 
    351 static void handle_internal_command(int argc, const char **argv)
    352 {
    353 	const char *cmd = argv[0];
    354 	unsigned int i;
    355 	static const char ext[] = STRIP_EXTENSION;
    356 
    357 	if (sizeof(ext) > 1) {
    358 		i = strlen(argv[0]) - strlen(ext);
    359 		if (i > 0 && !strcmp(argv[0] + i, ext)) {
    360 			char *argv0 = strdup(argv[0]);
    361 			argv[0] = cmd = argv0;
    362 			argv0[i] = '\0';
    363 		}
    364 	}
    365 
    366 	/* Turn "perf cmd --help" into "perf help cmd" */
    367 	if (argc > 1 && !strcmp(argv[1], "--help")) {
    368 		argv[1] = argv[0];
    369 		argv[0] = cmd = "help";
    370 	}
    371 
    372 	for (i = 0; i < ARRAY_SIZE(commands); i++) {
    373 		struct cmd_struct *p = commands+i;
    374 		if (strcmp(p->cmd, cmd))
    375 			continue;
    376 		exit(run_builtin(p, argc, argv));
    377 	}
    378 }
    379 
    380 static void execv_dashed_external(const char **argv)
    381 {
    382 	struct strbuf cmd = STRBUF_INIT;
    383 	const char *tmp;
    384 	int status;
    385 
    386 	strbuf_addf(&cmd, "perf-%s", argv[0]);
    387 
    388 	/*
    389 	 * argv[0] must be the perf command, but the argv array
    390 	 * belongs to the caller, and may be reused in
    391 	 * subsequent loop iterations. Save argv[0] and
    392 	 * restore it on error.
    393 	 */
    394 	tmp = argv[0];
    395 	argv[0] = cmd.buf;
    396 
    397 	/*
    398 	 * if we fail because the command is not found, it is
    399 	 * OK to return. Otherwise, we just pass along the status code.
    400 	 */
    401 	status = run_command_v_opt(argv, 0);
    402 	if (status != -ERR_RUN_COMMAND_EXEC) {
    403 		if (IS_RUN_COMMAND_ERR(status))
    404 			die("unable to run '%s'", argv[0]);
    405 		exit(-status);
    406 	}
    407 	errno = ENOENT; /* as if we called execvp */
    408 
    409 	argv[0] = tmp;
    410 
    411 	strbuf_release(&cmd);
    412 }
    413 
    414 static int run_argv(int *argcp, const char ***argv)
    415 {
    416 	int done_alias = 0;
    417 
    418 	while (1) {
    419 		/* See if it's an internal command */
    420 		handle_internal_command(*argcp, *argv);
    421 
    422 		/* .. then try the external ones */
    423 		execv_dashed_external(*argv);
    424 
    425 		/* It could be an alias -- this works around the insanity
    426 		 * of overriding "perf log" with "perf show" by having
    427 		 * alias.log = show
    428 		 */
    429 		if (done_alias || !handle_alias(argcp, argv))
    430 			break;
    431 		done_alias = 1;
    432 	}
    433 
    434 	return done_alias;
    435 }
    436 
    437 static void pthread__block_sigwinch(void)
    438 {
    439 	sigset_t set;
    440 
    441 	sigemptyset(&set);
    442 	sigaddset(&set, SIGWINCH);
    443 	pthread_sigmask(SIG_BLOCK, &set, NULL);
    444 }
    445 
    446 void pthread__unblock_sigwinch(void)
    447 {
    448 	sigset_t set;
    449 
    450 	sigemptyset(&set);
    451 	sigaddset(&set, SIGWINCH);
    452 	pthread_sigmask(SIG_UNBLOCK, &set, NULL);
    453 }
    454 
    455 int main(int argc, const char **argv)
    456 {
    457 	const char *cmd;
    458 
    459 	page_size = sysconf(_SC_PAGE_SIZE);
    460 
    461 	cmd = perf_extract_argv0_path(argv[0]);
    462 	if (!cmd)
    463 		cmd = "perf-help";
    464 	/* get debugfs mount point from /proc/mounts */
    465 	perf_debugfs_mount(NULL);
    466 	/*
    467 	 * "perf-xxxx" is the same as "perf xxxx", but we obviously:
    468 	 *
    469 	 *  - cannot take flags in between the "perf" and the "xxxx".
    470 	 *  - cannot execute it externally (since it would just do
    471 	 *    the same thing over again)
    472 	 *
    473 	 * So we just directly call the internal command handler, and
    474 	 * die if that one cannot handle it.
    475 	 */
    476 	if (!prefixcmp(cmd, "perf-")) {
    477 		cmd += 5;
    478 		argv[0] = cmd;
    479 		handle_internal_command(argc, argv);
    480 		fprintf(stderr, "cannot handle %s internally", cmd);
    481 		goto out;
    482 	}
    483 
    484 	/* Look for flags.. */
    485 	argv++;
    486 	argc--;
    487 	handle_options(&argv, &argc, NULL);
    488 	commit_pager_choice();
    489 	set_buildid_dir();
    490 
    491 	if (argc > 0) {
    492 		if (!prefixcmp(argv[0], "--"))
    493 			argv[0] += 2;
    494 	} else {
    495 		/* The user didn't specify a command; give them help */
    496 		printf("\n usage: %s\n\n", perf_usage_string);
    497 		list_common_cmds_help();
    498 		printf("\n %s\n\n", perf_more_info_string);
    499 		goto out;
    500 	}
    501 	cmd = argv[0];
    502 
    503 	test_attr__init();
    504 
    505 	/*
    506 	 * We use PATH to find perf commands, but we prepend some higher
    507 	 * precedence paths: the "--exec-path" option, the PERF_EXEC_PATH
    508 	 * environment, and the $(perfexecdir) from the Makefile at build
    509 	 * time.
    510 	 */
    511 	setup_path();
    512 	/*
    513 	 * Block SIGWINCH notifications so that the thread that wants it can
    514 	 * unblock and get syscalls like select interrupted instead of waiting
    515 	 * forever while the signal goes to some other non interested thread.
    516 	 */
    517 	pthread__block_sigwinch();
    518 
    519 	while (1) {
    520 		static int done_help;
    521 		int was_alias = run_argv(&argc, &argv);
    522 
    523 		if (errno != ENOENT)
    524 			break;
    525 
    526 		if (was_alias) {
    527 			fprintf(stderr, "Expansion of alias '%s' failed; "
    528 				"'%s' is not a perf-command\n",
    529 				cmd, argv[0]);
    530 			goto out;
    531 		}
    532 		if (!done_help) {
    533 			cmd = argv[0] = help_unknown_cmd(cmd);
    534 			done_help = 1;
    535 		} else
    536 			break;
    537 	}
    538 
    539 	fprintf(stderr, "Failed to run command '%s': %s\n",
    540 		cmd, strerror(errno));
    541 out:
    542 	return 1;
    543 }
    544