xref: /openbmc/linux/tools/perf/perf.c (revision f3a8b664) 
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/env.h"
12 #include <subcmd/exec-cmd.h>
13 #include "util/config.h"
14 #include "util/quote.h"
15 #include <subcmd/run-command.h>
16 #include "util/parse-events.h"
17 #include <subcmd/parse-options.h>
18 #include "util/bpf-loader.h"
19 #include "util/debug.h"
20 #include <api/fs/fs.h>
21 #include <api/fs/tracing_path.h>
22 #include <pthread.h>
23 #include <stdlib.h>
24 #include <time.h>
25 
26 const char perf_usage_string[] =
27 	"perf [--version] [--help] [OPTIONS] COMMAND [ARGS]";
28 
29 const char perf_more_info_string[] =
30 	"See 'perf help COMMAND' for more information on a specific command.";
31 
32 int use_browser = -1;
33 static int use_pager = -1;
34 const char *input_name;
35 
36 struct cmd_struct {
37 	const char *cmd;
38 	int (*fn)(int, const char **, const char *);
39 	int option;
40 };
41 
42 static struct cmd_struct commands[] = {
43 	{ "buildid-cache", cmd_buildid_cache, 0 },
44 	{ "buildid-list", cmd_buildid_list, 0 },
45 	{ "config",	cmd_config,	0 },
46 	{ "diff",	cmd_diff,	0 },
47 	{ "evlist",	cmd_evlist,	0 },
48 	{ "help",	cmd_help,	0 },
49 	{ "list",	cmd_list,	0 },
50 	{ "record",	cmd_record,	0 },
51 	{ "report",	cmd_report,	0 },
52 	{ "bench",	cmd_bench,	0 },
53 	{ "stat",	cmd_stat,	0 },
54 	{ "timechart",	cmd_timechart,	0 },
55 	{ "top",	cmd_top,	0 },
56 	{ "annotate",	cmd_annotate,	0 },
57 	{ "version",	cmd_version,	0 },
58 	{ "script",	cmd_script,	0 },
59 	{ "sched",	cmd_sched,	0 },
60 #ifdef HAVE_LIBELF_SUPPORT
61 	{ "probe",	cmd_probe,	0 },
62 #endif
63 	{ "kmem",	cmd_kmem,	0 },
64 	{ "lock",	cmd_lock,	0 },
65 	{ "kvm",	cmd_kvm,	0 },
66 	{ "test",	cmd_test,	0 },
67 #ifdef HAVE_LIBAUDIT_SUPPORT
68 	{ "trace",	cmd_trace,	0 },
69 #endif
70 	{ "inject",	cmd_inject,	0 },
71 	{ "mem",	cmd_mem,	0 },
72 	{ "data",	cmd_data,	0 },
73 };
74 
75 struct pager_config {
76 	const char *cmd;
77 	int val;
78 };
79 
80 static int pager_command_config(const char *var, const char *value, void *data)
81 {
82 	struct pager_config *c = data;
83 	if (!prefixcmp(var, "pager.") && !strcmp(var + 6, c->cmd))
84 		c->val = perf_config_bool(var, value);
85 	return 0;
86 }
87 
88 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
89 int check_pager_config(const char *cmd)
90 {
91 	struct pager_config c;
92 	c.cmd = cmd;
93 	c.val = -1;
94 	perf_config(pager_command_config, &c);
95 	return c.val;
96 }
97 
98 static int browser_command_config(const char *var, const char *value, void *data)
99 {
100 	struct pager_config *c = data;
101 	if (!prefixcmp(var, "tui.") && !strcmp(var + 4, c->cmd))
102 		c->val = perf_config_bool(var, value);
103 	if (!prefixcmp(var, "gtk.") && !strcmp(var + 4, c->cmd))
104 		c->val = perf_config_bool(var, value) ? 2 : 0;
105 	return 0;
106 }
107 
108 /*
109  * returns 0 for "no tui", 1 for "use tui", 2 for "use gtk",
110  * and -1 for "not specified"
111  */
112 static int check_browser_config(const char *cmd)
113 {
114 	struct pager_config c;
115 	c.cmd = cmd;
116 	c.val = -1;
117 	perf_config(browser_command_config, &c);
118 	return c.val;
119 }
120 
121 static void commit_pager_choice(void)
122 {
123 	switch (use_pager) {
124 	case 0:
125 		setenv(PERF_PAGER_ENVIRONMENT, "cat", 1);
126 		break;
127 	case 1:
128 		/* setup_pager(); */
129 		break;
130 	default:
131 		break;
132 	}
133 }
134 
135 struct option options[] = {
136 	OPT_ARGUMENT("help", "help"),
137 	OPT_ARGUMENT("version", "version"),
138 	OPT_ARGUMENT("exec-path", "exec-path"),
139 	OPT_ARGUMENT("html-path", "html-path"),
140 	OPT_ARGUMENT("paginate", "paginate"),
141 	OPT_ARGUMENT("no-pager", "no-pager"),
142 	OPT_ARGUMENT("debugfs-dir", "debugfs-dir"),
143 	OPT_ARGUMENT("buildid-dir", "buildid-dir"),
144 	OPT_ARGUMENT("list-cmds", "list-cmds"),
145 	OPT_ARGUMENT("list-opts", "list-opts"),
146 	OPT_ARGUMENT("debug", "debug"),
147 	OPT_END()
148 };
149 
150 static int handle_options(const char ***argv, int *argc, int *envchanged)
151 {
152 	int handled = 0;
153 
154 	while (*argc > 0) {
155 		const char *cmd = (*argv)[0];
156 		if (cmd[0] != '-')
157 			break;
158 
159 		/*
160 		 * For legacy reasons, the "version" and "help"
161 		 * commands can be written with "--" prepended
162 		 * to make them look like flags.
163 		 */
164 		if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
165 			break;
166 
167 		/*
168 		 * Shortcut for '-h' and '-v' options to invoke help
169 		 * and version command.
170 		 */
171 		if (!strcmp(cmd, "-h")) {
172 			(*argv)[0] = "--help";
173 			break;
174 		}
175 
176 		if (!strcmp(cmd, "-v")) {
177 			(*argv)[0] = "--version";
178 			break;
179 		}
180 
181 		/*
182 		 * Check remaining flags.
183 		 */
184 		if (!prefixcmp(cmd, CMD_EXEC_PATH)) {
185 			cmd += strlen(CMD_EXEC_PATH);
186 			if (*cmd == '=')
187 				set_argv_exec_path(cmd + 1);
188 			else {
189 				puts(get_argv_exec_path());
190 				exit(0);
191 			}
192 		} else if (!strcmp(cmd, "--html-path")) {
193 			puts(system_path(PERF_HTML_PATH));
194 			exit(0);
195 		} else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
196 			use_pager = 1;
197 		} else if (!strcmp(cmd, "--no-pager")) {
198 			use_pager = 0;
199 			if (envchanged)
200 				*envchanged = 1;
201 		} else if (!strcmp(cmd, "--debugfs-dir")) {
202 			if (*argc < 2) {
203 				fprintf(stderr, "No directory given for --debugfs-dir.\n");
204 				usage(perf_usage_string);
205 			}
206 			tracing_path_set((*argv)[1]);
207 			if (envchanged)
208 				*envchanged = 1;
209 			(*argv)++;
210 			(*argc)--;
211 		} else if (!strcmp(cmd, "--buildid-dir")) {
212 			if (*argc < 2) {
213 				fprintf(stderr, "No directory given for --buildid-dir.\n");
214 				usage(perf_usage_string);
215 			}
216 			set_buildid_dir((*argv)[1]);
217 			if (envchanged)
218 				*envchanged = 1;
219 			(*argv)++;
220 			(*argc)--;
221 		} else if (!prefixcmp(cmd, CMD_DEBUGFS_DIR)) {
222 			tracing_path_set(cmd + strlen(CMD_DEBUGFS_DIR));
223 			fprintf(stderr, "dir: %s\n", tracing_path);
224 			if (envchanged)
225 				*envchanged = 1;
226 		} else if (!strcmp(cmd, "--list-cmds")) {
227 			unsigned int i;
228 
229 			for (i = 0; i < ARRAY_SIZE(commands); i++) {
230 				struct cmd_struct *p = commands+i;
231 				printf("%s ", p->cmd);
232 			}
233 			putchar('\n');
234 			exit(0);
235 		} else if (!strcmp(cmd, "--list-opts")) {
236 			unsigned int i;
237 
238 			for (i = 0; i < ARRAY_SIZE(options)-1; i++) {
239 				struct option *p = options+i;
240 				printf("--%s ", p->long_name);
241 			}
242 			putchar('\n');
243 			exit(0);
244 		} else if (!strcmp(cmd, "--debug")) {
245 			if (*argc < 2) {
246 				fprintf(stderr, "No variable specified for --debug.\n");
247 				usage(perf_usage_string);
248 			}
249 			if (perf_debug_option((*argv)[1]))
250 				usage(perf_usage_string);
251 
252 			(*argv)++;
253 			(*argc)--;
254 		} else {
255 			fprintf(stderr, "Unknown option: %s\n", cmd);
256 			usage(perf_usage_string);
257 		}
258 
259 		(*argv)++;
260 		(*argc)--;
261 		handled++;
262 	}
263 	return handled;
264 }
265 
266 static int handle_alias(int *argcp, const char ***argv)
267 {
268 	int envchanged = 0, ret = 0, saved_errno = errno;
269 	int count, option_count;
270 	const char **new_argv;
271 	const char *alias_command;
272 	char *alias_string;
273 
274 	alias_command = (*argv)[0];
275 	alias_string = alias_lookup(alias_command);
276 	if (alias_string) {
277 		if (alias_string[0] == '!') {
278 			if (*argcp > 1) {
279 				struct strbuf buf;
280 
281 				if (strbuf_init(&buf, PATH_MAX) < 0 ||
282 				    strbuf_addstr(&buf, alias_string) < 0 ||
283 				    sq_quote_argv(&buf, (*argv) + 1,
284 						  PATH_MAX) < 0)
285 					die("Failed to allocate memory.");
286 				free(alias_string);
287 				alias_string = buf.buf;
288 			}
289 			ret = system(alias_string + 1);
290 			if (ret >= 0 && WIFEXITED(ret) &&
291 			    WEXITSTATUS(ret) != 127)
292 				exit(WEXITSTATUS(ret));
293 			die("Failed to run '%s' when expanding alias '%s'",
294 			    alias_string + 1, alias_command);
295 		}
296 		count = split_cmdline(alias_string, &new_argv);
297 		if (count < 0)
298 			die("Bad alias.%s string", alias_command);
299 		option_count = handle_options(&new_argv, &count, &envchanged);
300 		if (envchanged)
301 			die("alias '%s' changes environment variables\n"
302 				 "You can use '!perf' in the alias to do this.",
303 				 alias_command);
304 		memmove(new_argv - option_count, new_argv,
305 				count * sizeof(char *));
306 		new_argv -= option_count;
307 
308 		if (count < 1)
309 			die("empty alias for %s", alias_command);
310 
311 		if (!strcmp(alias_command, new_argv[0]))
312 			die("recursive alias: %s", alias_command);
313 
314 		new_argv = realloc(new_argv, sizeof(char *) *
315 				    (count + *argcp + 1));
316 		/* insert after command name */
317 		memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
318 		new_argv[count + *argcp] = NULL;
319 
320 		*argv = new_argv;
321 		*argcp += count - 1;
322 
323 		ret = 1;
324 	}
325 
326 	errno = saved_errno;
327 
328 	return ret;
329 }
330 
331 const char perf_version_string[] = PERF_VERSION;
332 
333 #define RUN_SETUP	(1<<0)
334 #define USE_PAGER	(1<<1)
335 
336 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
337 {
338 	int status;
339 	struct stat st;
340 	const char *prefix;
341 	char sbuf[STRERR_BUFSIZE];
342 
343 	prefix = NULL;
344 	if (p->option & RUN_SETUP)
345 		prefix = NULL; /* setup_perf_directory(); */
346 
347 	if (use_browser == -1)
348 		use_browser = check_browser_config(p->cmd);
349 
350 	if (use_pager == -1 && p->option & RUN_SETUP)
351 		use_pager = check_pager_config(p->cmd);
352 	if (use_pager == -1 && p->option & USE_PAGER)
353 		use_pager = 1;
354 	commit_pager_choice();
355 
356 	perf_env__set_cmdline(&perf_env, argc, argv);
357 	status = p->fn(argc, argv, prefix);
358 	perf_config__exit();
359 	exit_browser(status);
360 	perf_env__exit(&perf_env);
361 	bpf__clear();
362 
363 	if (status)
364 		return status & 0xff;
365 
366 	/* Somebody closed stdout? */
367 	if (fstat(fileno(stdout), &st))
368 		return 0;
369 	/* Ignore write errors for pipes and sockets.. */
370 	if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
371 		return 0;
372 
373 	status = 1;
374 	/* Check for ENOSPC and EIO errors.. */
375 	if (fflush(stdout)) {
376 		fprintf(stderr, "write failure on standard output: %s",
377 			str_error_r(errno, sbuf, sizeof(sbuf)));
378 		goto out;
379 	}
380 	if (ferror(stdout)) {
381 		fprintf(stderr, "unknown write failure on standard output");
382 		goto out;
383 	}
384 	if (fclose(stdout)) {
385 		fprintf(stderr, "close failed on standard output: %s",
386 			str_error_r(errno, sbuf, sizeof(sbuf)));
387 		goto out;
388 	}
389 	status = 0;
390 out:
391 	return status;
392 }
393 
394 static void handle_internal_command(int argc, const char **argv)
395 {
396 	const char *cmd = argv[0];
397 	unsigned int i;
398 	static const char ext[] = STRIP_EXTENSION;
399 
400 	if (sizeof(ext) > 1) {
401 		i = strlen(argv[0]) - strlen(ext);
402 		if (i > 0 && !strcmp(argv[0] + i, ext)) {
403 			char *argv0 = strdup(argv[0]);
404 			argv[0] = cmd = argv0;
405 			argv0[i] = '\0';
406 		}
407 	}
408 
409 	/* Turn "perf cmd --help" into "perf help cmd" */
410 	if (argc > 1 && !strcmp(argv[1], "--help")) {
411 		argv[1] = argv[0];
412 		argv[0] = cmd = "help";
413 	}
414 
415 	for (i = 0; i < ARRAY_SIZE(commands); i++) {
416 		struct cmd_struct *p = commands+i;
417 		if (strcmp(p->cmd, cmd))
418 			continue;
419 		exit(run_builtin(p, argc, argv));
420 	}
421 }
422 
423 static void execv_dashed_external(const char **argv)
424 {
425 	char *cmd;
426 	const char *tmp;
427 	int status;
428 
429 	if (asprintf(&cmd, "perf-%s", argv[0]) < 0)
430 		goto do_die;
431 
432 	/*
433 	 * argv[0] must be the perf command, but the argv array
434 	 * belongs to the caller, and may be reused in
435 	 * subsequent loop iterations. Save argv[0] and
436 	 * restore it on error.
437 	 */
438 	tmp = argv[0];
439 	argv[0] = cmd;
440 
441 	/*
442 	 * if we fail because the command is not found, it is
443 	 * OK to return. Otherwise, we just pass along the status code.
444 	 */
445 	status = run_command_v_opt(argv, 0);
446 	if (status != -ERR_RUN_COMMAND_EXEC) {
447 		if (IS_RUN_COMMAND_ERR(status)) {
448 do_die:
449 			die("unable to run '%s'", argv[0]);
450 		}
451 		exit(-status);
452 	}
453 	errno = ENOENT; /* as if we called execvp */
454 
455 	argv[0] = tmp;
456 	zfree(&cmd);
457 }
458 
459 static int run_argv(int *argcp, const char ***argv)
460 {
461 	int done_alias = 0;
462 
463 	while (1) {
464 		/* See if it's an internal command */
465 		handle_internal_command(*argcp, *argv);
466 
467 		/* .. then try the external ones */
468 		execv_dashed_external(*argv);
469 
470 		/* It could be an alias -- this works around the insanity
471 		 * of overriding "perf log" with "perf show" by having
472 		 * alias.log = show
473 		 */
474 		if (done_alias || !handle_alias(argcp, argv))
475 			break;
476 		done_alias = 1;
477 	}
478 
479 	return done_alias;
480 }
481 
482 static void pthread__block_sigwinch(void)
483 {
484 	sigset_t set;
485 
486 	sigemptyset(&set);
487 	sigaddset(&set, SIGWINCH);
488 	pthread_sigmask(SIG_BLOCK, &set, NULL);
489 }
490 
491 void pthread__unblock_sigwinch(void)
492 {
493 	sigset_t set;
494 
495 	sigemptyset(&set);
496 	sigaddset(&set, SIGWINCH);
497 	pthread_sigmask(SIG_UNBLOCK, &set, NULL);
498 }
499 
500 #ifdef _SC_LEVEL1_DCACHE_LINESIZE
501 #define cache_line_size(cacheline_sizep) *cacheline_sizep = sysconf(_SC_LEVEL1_DCACHE_LINESIZE)
502 #else
503 static void cache_line_size(int *cacheline_sizep)
504 {
505 	if (sysfs__read_int("devices/system/cpu/cpu0/cache/index0/coherency_line_size", cacheline_sizep))
506 		pr_debug("cannot determine cache line size");
507 }
508 #endif
509 
510 int main(int argc, const char **argv)
511 {
512 	const char *cmd;
513 	char sbuf[STRERR_BUFSIZE];
514 	int value;
515 
516 	/* libsubcmd init */
517 	exec_cmd_init("perf", PREFIX, PERF_EXEC_PATH, EXEC_PATH_ENVIRONMENT);
518 	pager_init(PERF_PAGER_ENVIRONMENT);
519 
520 	/* The page_size is placed in util object. */
521 	page_size = sysconf(_SC_PAGE_SIZE);
522 	cache_line_size(&cacheline_size);
523 
524 	if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0)
525 		sysctl_perf_event_max_stack = value;
526 
527 	if (sysctl__read_int("kernel/perf_event_max_contexts_per_stack", &value) == 0)
528 		sysctl_perf_event_max_contexts_per_stack = value;
529 
530 	cmd = extract_argv0_path(argv[0]);
531 	if (!cmd)
532 		cmd = "perf-help";
533 
534 	srandom(time(NULL));
535 
536 	perf_config__init();
537 	perf_config(perf_default_config, NULL);
538 	set_buildid_dir(NULL);
539 
540 	/* get debugfs/tracefs mount point from /proc/mounts */
541 	tracing_path_mount();
542 
543 	/*
544 	 * "perf-xxxx" is the same as "perf xxxx", but we obviously:
545 	 *
546 	 *  - cannot take flags in between the "perf" and the "xxxx".
547 	 *  - cannot execute it externally (since it would just do
548 	 *    the same thing over again)
549 	 *
550 	 * So we just directly call the internal command handler, and
551 	 * die if that one cannot handle it.
552 	 */
553 	if (!prefixcmp(cmd, "perf-")) {
554 		cmd += 5;
555 		argv[0] = cmd;
556 		handle_internal_command(argc, argv);
557 		fprintf(stderr, "cannot handle %s internally", cmd);
558 		goto out;
559 	}
560 	if (!prefixcmp(cmd, "trace")) {
561 #ifdef HAVE_LIBAUDIT_SUPPORT
562 		setup_path();
563 		argv[0] = "trace";
564 		return cmd_trace(argc, argv, NULL);
565 #else
566 		fprintf(stderr,
567 			"trace command not available: missing audit-libs devel package at build time.\n");
568 		goto out;
569 #endif
570 	}
571 	/* Look for flags.. */
572 	argv++;
573 	argc--;
574 	handle_options(&argv, &argc, NULL);
575 	commit_pager_choice();
576 
577 	if (argc > 0) {
578 		if (!prefixcmp(argv[0], "--"))
579 			argv[0] += 2;
580 	} else {
581 		/* The user didn't specify a command; give them help */
582 		printf("\n usage: %s\n\n", perf_usage_string);
583 		list_common_cmds_help();
584 		printf("\n %s\n\n", perf_more_info_string);
585 		goto out;
586 	}
587 	cmd = argv[0];
588 
589 	test_attr__init();
590 
591 	/*
592 	 * We use PATH to find perf commands, but we prepend some higher
593 	 * precedence paths: the "--exec-path" option, the PERF_EXEC_PATH
594 	 * environment, and the $(perfexecdir) from the Makefile at build
595 	 * time.
596 	 */
597 	setup_path();
598 	/*
599 	 * Block SIGWINCH notifications so that the thread that wants it can
600 	 * unblock and get syscalls like select interrupted instead of waiting
601 	 * forever while the signal goes to some other non interested thread.
602 	 */
603 	pthread__block_sigwinch();
604 
605 	perf_debug_setup();
606 
607 	while (1) {
608 		static int done_help;
609 		int was_alias = run_argv(&argc, &argv);
610 
611 		if (errno != ENOENT)
612 			break;
613 
614 		if (was_alias) {
615 			fprintf(stderr, "Expansion of alias '%s' failed; "
616 				"'%s' is not a perf-command\n",
617 				cmd, argv[0]);
618 			goto out;
619 		}
620 		if (!done_help) {
621 			cmd = argv[0] = help_unknown_cmd(cmd);
622 			done_help = 1;
623 		} else
624 			break;
625 	}
626 
627 	fprintf(stderr, "Failed to run command '%s': %s\n",
628 		cmd, str_error_r(errno, sbuf, sizeof(sbuf)));
629 out:
630 	return 1;
631 }
632