xref: /openbmc/linux/tools/perf/perf.c (revision 6b66a6f2) 
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 	{ "c2c",	cmd_c2c,	0 },
47 	{ "diff",	cmd_diff,	0 },
48 	{ "evlist",	cmd_evlist,	0 },
49 	{ "help",	cmd_help,	0 },
50 	{ "list",	cmd_list,	0 },
51 	{ "record",	cmd_record,	0 },
52 	{ "report",	cmd_report,	0 },
53 	{ "bench",	cmd_bench,	0 },
54 	{ "stat",	cmd_stat,	0 },
55 	{ "timechart",	cmd_timechart,	0 },
56 	{ "top",	cmd_top,	0 },
57 	{ "annotate",	cmd_annotate,	0 },
58 	{ "version",	cmd_version,	0 },
59 	{ "script",	cmd_script,	0 },
60 	{ "sched",	cmd_sched,	0 },
61 #ifdef HAVE_LIBELF_SUPPORT
62 	{ "probe",	cmd_probe,	0 },
63 #endif
64 	{ "kmem",	cmd_kmem,	0 },
65 	{ "lock",	cmd_lock,	0 },
66 	{ "kvm",	cmd_kvm,	0 },
67 	{ "test",	cmd_test,	0 },
68 #ifdef HAVE_LIBAUDIT_SUPPORT
69 	{ "trace",	cmd_trace,	0 },
70 #endif
71 	{ "inject",	cmd_inject,	0 },
72 	{ "mem",	cmd_mem,	0 },
73 	{ "data",	cmd_data,	0 },
74 };
75 
76 struct pager_config {
77 	const char *cmd;
78 	int val;
79 };
80 
81 static int pager_command_config(const char *var, const char *value, void *data)
82 {
83 	struct pager_config *c = data;
84 	if (!prefixcmp(var, "pager.") && !strcmp(var + 6, c->cmd))
85 		c->val = perf_config_bool(var, value);
86 	return 0;
87 }
88 
89 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
90 int check_pager_config(const char *cmd)
91 {
92 	struct pager_config c;
93 	c.cmd = cmd;
94 	c.val = -1;
95 	perf_config(pager_command_config, &c);
96 	return c.val;
97 }
98 
99 static int browser_command_config(const char *var, const char *value, void *data)
100 {
101 	struct pager_config *c = data;
102 	if (!prefixcmp(var, "tui.") && !strcmp(var + 4, c->cmd))
103 		c->val = perf_config_bool(var, value);
104 	if (!prefixcmp(var, "gtk.") && !strcmp(var + 4, c->cmd))
105 		c->val = perf_config_bool(var, value) ? 2 : 0;
106 	return 0;
107 }
108 
109 /*
110  * returns 0 for "no tui", 1 for "use tui", 2 for "use gtk",
111  * and -1 for "not specified"
112  */
113 static int check_browser_config(const char *cmd)
114 {
115 	struct pager_config c;
116 	c.cmd = cmd;
117 	c.val = -1;
118 	perf_config(browser_command_config, &c);
119 	return c.val;
120 }
121 
122 static void commit_pager_choice(void)
123 {
124 	switch (use_pager) {
125 	case 0:
126 		setenv(PERF_PAGER_ENVIRONMENT, "cat", 1);
127 		break;
128 	case 1:
129 		/* setup_pager(); */
130 		break;
131 	default:
132 		break;
133 	}
134 }
135 
136 struct option options[] = {
137 	OPT_ARGUMENT("help", "help"),
138 	OPT_ARGUMENT("version", "version"),
139 	OPT_ARGUMENT("exec-path", "exec-path"),
140 	OPT_ARGUMENT("html-path", "html-path"),
141 	OPT_ARGUMENT("paginate", "paginate"),
142 	OPT_ARGUMENT("no-pager", "no-pager"),
143 	OPT_ARGUMENT("debugfs-dir", "debugfs-dir"),
144 	OPT_ARGUMENT("buildid-dir", "buildid-dir"),
145 	OPT_ARGUMENT("list-cmds", "list-cmds"),
146 	OPT_ARGUMENT("list-opts", "list-opts"),
147 	OPT_ARGUMENT("debug", "debug"),
148 	OPT_END()
149 };
150 
151 static int handle_options(const char ***argv, int *argc, int *envchanged)
152 {
153 	int handled = 0;
154 
155 	while (*argc > 0) {
156 		const char *cmd = (*argv)[0];
157 		if (cmd[0] != '-')
158 			break;
159 
160 		/*
161 		 * For legacy reasons, the "version" and "help"
162 		 * commands can be written with "--" prepended
163 		 * to make them look like flags.
164 		 */
165 		if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
166 			break;
167 
168 		/*
169 		 * Shortcut for '-h' and '-v' options to invoke help
170 		 * and version command.
171 		 */
172 		if (!strcmp(cmd, "-h")) {
173 			(*argv)[0] = "--help";
174 			break;
175 		}
176 
177 		if (!strcmp(cmd, "-v")) {
178 			(*argv)[0] = "--version";
179 			break;
180 		}
181 
182 		/*
183 		 * Check remaining flags.
184 		 */
185 		if (!prefixcmp(cmd, CMD_EXEC_PATH)) {
186 			cmd += strlen(CMD_EXEC_PATH);
187 			if (*cmd == '=')
188 				set_argv_exec_path(cmd + 1);
189 			else {
190 				puts(get_argv_exec_path());
191 				exit(0);
192 			}
193 		} else if (!strcmp(cmd, "--html-path")) {
194 			puts(system_path(PERF_HTML_PATH));
195 			exit(0);
196 		} else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
197 			use_pager = 1;
198 		} else if (!strcmp(cmd, "--no-pager")) {
199 			use_pager = 0;
200 			if (envchanged)
201 				*envchanged = 1;
202 		} else if (!strcmp(cmd, "--debugfs-dir")) {
203 			if (*argc < 2) {
204 				fprintf(stderr, "No directory given for --debugfs-dir.\n");
205 				usage(perf_usage_string);
206 			}
207 			tracing_path_set((*argv)[1]);
208 			if (envchanged)
209 				*envchanged = 1;
210 			(*argv)++;
211 			(*argc)--;
212 		} else if (!strcmp(cmd, "--buildid-dir")) {
213 			if (*argc < 2) {
214 				fprintf(stderr, "No directory given for --buildid-dir.\n");
215 				usage(perf_usage_string);
216 			}
217 			set_buildid_dir((*argv)[1]);
218 			if (envchanged)
219 				*envchanged = 1;
220 			(*argv)++;
221 			(*argc)--;
222 		} else if (!prefixcmp(cmd, CMD_DEBUGFS_DIR)) {
223 			tracing_path_set(cmd + strlen(CMD_DEBUGFS_DIR));
224 			fprintf(stderr, "dir: %s\n", tracing_path);
225 			if (envchanged)
226 				*envchanged = 1;
227 		} else if (!strcmp(cmd, "--list-cmds")) {
228 			unsigned int i;
229 
230 			for (i = 0; i < ARRAY_SIZE(commands); i++) {
231 				struct cmd_struct *p = commands+i;
232 				printf("%s ", p->cmd);
233 			}
234 			putchar('\n');
235 			exit(0);
236 		} else if (!strcmp(cmd, "--list-opts")) {
237 			unsigned int i;
238 
239 			for (i = 0; i < ARRAY_SIZE(options)-1; i++) {
240 				struct option *p = options+i;
241 				printf("--%s ", p->long_name);
242 			}
243 			putchar('\n');
244 			exit(0);
245 		} else if (!strcmp(cmd, "--debug")) {
246 			if (*argc < 2) {
247 				fprintf(stderr, "No variable specified for --debug.\n");
248 				usage(perf_usage_string);
249 			}
250 			if (perf_debug_option((*argv)[1]))
251 				usage(perf_usage_string);
252 
253 			(*argv)++;
254 			(*argc)--;
255 		} else {
256 			fprintf(stderr, "Unknown option: %s\n", cmd);
257 			usage(perf_usage_string);
258 		}
259 
260 		(*argv)++;
261 		(*argc)--;
262 		handled++;
263 	}
264 	return handled;
265 }
266 
267 static int handle_alias(int *argcp, const char ***argv)
268 {
269 	int envchanged = 0, ret = 0, saved_errno = errno;
270 	int count, option_count;
271 	const char **new_argv;
272 	const char *alias_command;
273 	char *alias_string;
274 
275 	alias_command = (*argv)[0];
276 	alias_string = alias_lookup(alias_command);
277 	if (alias_string) {
278 		if (alias_string[0] == '!') {
279 			if (*argcp > 1) {
280 				struct strbuf buf;
281 
282 				if (strbuf_init(&buf, PATH_MAX) < 0 ||
283 				    strbuf_addstr(&buf, alias_string) < 0 ||
284 				    sq_quote_argv(&buf, (*argv) + 1,
285 						  PATH_MAX) < 0)
286 					die("Failed to allocate memory.");
287 				free(alias_string);
288 				alias_string = buf.buf;
289 			}
290 			ret = system(alias_string + 1);
291 			if (ret >= 0 && WIFEXITED(ret) &&
292 			    WEXITSTATUS(ret) != 127)
293 				exit(WEXITSTATUS(ret));
294 			die("Failed to run '%s' when expanding alias '%s'",
295 			    alias_string + 1, alias_command);
296 		}
297 		count = split_cmdline(alias_string, &new_argv);
298 		if (count < 0)
299 			die("Bad alias.%s string", alias_command);
300 		option_count = handle_options(&new_argv, &count, &envchanged);
301 		if (envchanged)
302 			die("alias '%s' changes environment variables\n"
303 				 "You can use '!perf' in the alias to do this.",
304 				 alias_command);
305 		memmove(new_argv - option_count, new_argv,
306 				count * sizeof(char *));
307 		new_argv -= option_count;
308 
309 		if (count < 1)
310 			die("empty alias for %s", alias_command);
311 
312 		if (!strcmp(alias_command, new_argv[0]))
313 			die("recursive alias: %s", alias_command);
314 
315 		new_argv = realloc(new_argv, sizeof(char *) *
316 				    (count + *argcp + 1));
317 		/* insert after command name */
318 		memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
319 		new_argv[count + *argcp] = NULL;
320 
321 		*argv = new_argv;
322 		*argcp += count - 1;
323 
324 		ret = 1;
325 	}
326 
327 	errno = saved_errno;
328 
329 	return ret;
330 }
331 
332 const char perf_version_string[] = PERF_VERSION;
333 
334 #define RUN_SETUP	(1<<0)
335 #define USE_PAGER	(1<<1)
336 
337 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
338 {
339 	int status;
340 	struct stat st;
341 	const char *prefix;
342 	char sbuf[STRERR_BUFSIZE];
343 
344 	prefix = NULL;
345 	if (p->option & RUN_SETUP)
346 		prefix = NULL; /* setup_perf_directory(); */
347 
348 	if (use_browser == -1)
349 		use_browser = check_browser_config(p->cmd);
350 
351 	if (use_pager == -1 && p->option & RUN_SETUP)
352 		use_pager = check_pager_config(p->cmd);
353 	if (use_pager == -1 && p->option & USE_PAGER)
354 		use_pager = 1;
355 	commit_pager_choice();
356 
357 	perf_env__set_cmdline(&perf_env, argc, argv);
358 	status = p->fn(argc, argv, prefix);
359 	perf_config__exit();
360 	exit_browser(status);
361 	perf_env__exit(&perf_env);
362 	bpf__clear();
363 
364 	if (status)
365 		return status & 0xff;
366 
367 	/* Somebody closed stdout? */
368 	if (fstat(fileno(stdout), &st))
369 		return 0;
370 	/* Ignore write errors for pipes and sockets.. */
371 	if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
372 		return 0;
373 
374 	status = 1;
375 	/* Check for ENOSPC and EIO errors.. */
376 	if (fflush(stdout)) {
377 		fprintf(stderr, "write failure on standard output: %s",
378 			str_error_r(errno, sbuf, sizeof(sbuf)));
379 		goto out;
380 	}
381 	if (ferror(stdout)) {
382 		fprintf(stderr, "unknown write failure on standard output");
383 		goto out;
384 	}
385 	if (fclose(stdout)) {
386 		fprintf(stderr, "close failed on standard output: %s",
387 			str_error_r(errno, sbuf, sizeof(sbuf)));
388 		goto out;
389 	}
390 	status = 0;
391 out:
392 	return status;
393 }
394 
395 static void handle_internal_command(int argc, const char **argv)
396 {
397 	const char *cmd = argv[0];
398 	unsigned int i;
399 	static const char ext[] = STRIP_EXTENSION;
400 
401 	if (sizeof(ext) > 1) {
402 		i = strlen(argv[0]) - strlen(ext);
403 		if (i > 0 && !strcmp(argv[0] + i, ext)) {
404 			char *argv0 = strdup(argv[0]);
405 			argv[0] = cmd = argv0;
406 			argv0[i] = '\0';
407 		}
408 	}
409 
410 	/* Turn "perf cmd --help" into "perf help cmd" */
411 	if (argc > 1 && !strcmp(argv[1], "--help")) {
412 		argv[1] = argv[0];
413 		argv[0] = cmd = "help";
414 	}
415 
416 	for (i = 0; i < ARRAY_SIZE(commands); i++) {
417 		struct cmd_struct *p = commands+i;
418 		if (strcmp(p->cmd, cmd))
419 			continue;
420 		exit(run_builtin(p, argc, argv));
421 	}
422 }
423 
424 static void execv_dashed_external(const char **argv)
425 {
426 	char *cmd;
427 	const char *tmp;
428 	int status;
429 
430 	if (asprintf(&cmd, "perf-%s", argv[0]) < 0)
431 		goto do_die;
432 
433 	/*
434 	 * argv[0] must be the perf command, but the argv array
435 	 * belongs to the caller, and may be reused in
436 	 * subsequent loop iterations. Save argv[0] and
437 	 * restore it on error.
438 	 */
439 	tmp = argv[0];
440 	argv[0] = cmd;
441 
442 	/*
443 	 * if we fail because the command is not found, it is
444 	 * OK to return. Otherwise, we just pass along the status code.
445 	 */
446 	status = run_command_v_opt(argv, 0);
447 	if (status != -ERR_RUN_COMMAND_EXEC) {
448 		if (IS_RUN_COMMAND_ERR(status)) {
449 do_die:
450 			die("unable to run '%s'", argv[0]);
451 		}
452 		exit(-status);
453 	}
454 	errno = ENOENT; /* as if we called execvp */
455 
456 	argv[0] = tmp;
457 	zfree(&cmd);
458 }
459 
460 static int run_argv(int *argcp, const char ***argv)
461 {
462 	int done_alias = 0;
463 
464 	while (1) {
465 		/* See if it's an internal command */
466 		handle_internal_command(*argcp, *argv);
467 
468 		/* .. then try the external ones */
469 		execv_dashed_external(*argv);
470 
471 		/* It could be an alias -- this works around the insanity
472 		 * of overriding "perf log" with "perf show" by having
473 		 * alias.log = show
474 		 */
475 		if (done_alias || !handle_alias(argcp, argv))
476 			break;
477 		done_alias = 1;
478 	}
479 
480 	return done_alias;
481 }
482 
483 static void pthread__block_sigwinch(void)
484 {
485 	sigset_t set;
486 
487 	sigemptyset(&set);
488 	sigaddset(&set, SIGWINCH);
489 	pthread_sigmask(SIG_BLOCK, &set, NULL);
490 }
491 
492 void pthread__unblock_sigwinch(void)
493 {
494 	sigset_t set;
495 
496 	sigemptyset(&set);
497 	sigaddset(&set, SIGWINCH);
498 	pthread_sigmask(SIG_UNBLOCK, &set, NULL);
499 }
500 
501 #ifdef _SC_LEVEL1_DCACHE_LINESIZE
502 #define cache_line_size(cacheline_sizep) *cacheline_sizep = sysconf(_SC_LEVEL1_DCACHE_LINESIZE)
503 #else
504 static void cache_line_size(int *cacheline_sizep)
505 {
506 	if (sysfs__read_int("devices/system/cpu/cpu0/cache/index0/coherency_line_size", cacheline_sizep))
507 		pr_debug("cannot determine cache line size");
508 }
509 #endif
510 
511 int main(int argc, const char **argv)
512 {
513 	const char *cmd;
514 	char sbuf[STRERR_BUFSIZE];
515 	int value;
516 
517 	/* libsubcmd init */
518 	exec_cmd_init("perf", PREFIX, PERF_EXEC_PATH, EXEC_PATH_ENVIRONMENT);
519 	pager_init(PERF_PAGER_ENVIRONMENT);
520 
521 	/* The page_size is placed in util object. */
522 	page_size = sysconf(_SC_PAGE_SIZE);
523 	cache_line_size(&cacheline_size);
524 
525 	if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0)
526 		sysctl_perf_event_max_stack = value;
527 
528 	if (sysctl__read_int("kernel/perf_event_max_contexts_per_stack", &value) == 0)
529 		sysctl_perf_event_max_contexts_per_stack = value;
530 
531 	cmd = extract_argv0_path(argv[0]);
532 	if (!cmd)
533 		cmd = "perf-help";
534 
535 	srandom(time(NULL));
536 
537 	perf_config__init();
538 	perf_config(perf_default_config, NULL);
539 	set_buildid_dir(NULL);
540 
541 	/* get debugfs/tracefs mount point from /proc/mounts */
542 	tracing_path_mount();
543 
544 	/*
545 	 * "perf-xxxx" is the same as "perf xxxx", but we obviously:
546 	 *
547 	 *  - cannot take flags in between the "perf" and the "xxxx".
548 	 *  - cannot execute it externally (since it would just do
549 	 *    the same thing over again)
550 	 *
551 	 * So we just directly call the internal command handler, and
552 	 * die if that one cannot handle it.
553 	 */
554 	if (!prefixcmp(cmd, "perf-")) {
555 		cmd += 5;
556 		argv[0] = cmd;
557 		handle_internal_command(argc, argv);
558 		fprintf(stderr, "cannot handle %s internally", cmd);
559 		goto out;
560 	}
561 	if (!prefixcmp(cmd, "trace")) {
562 #ifdef HAVE_LIBAUDIT_SUPPORT
563 		setup_path();
564 		argv[0] = "trace";
565 		return cmd_trace(argc, argv, NULL);
566 #else
567 		fprintf(stderr,
568 			"trace command not available: missing audit-libs devel package at build time.\n");
569 		goto out;
570 #endif
571 	}
572 	/* Look for flags.. */
573 	argv++;
574 	argc--;
575 	handle_options(&argv, &argc, NULL);
576 	commit_pager_choice();
577 
578 	if (argc > 0) {
579 		if (!prefixcmp(argv[0], "--"))
580 			argv[0] += 2;
581 	} else {
582 		/* The user didn't specify a command; give them help */
583 		printf("\n usage: %s\n\n", perf_usage_string);
584 		list_common_cmds_help();
585 		printf("\n %s\n\n", perf_more_info_string);
586 		goto out;
587 	}
588 	cmd = argv[0];
589 
590 	test_attr__init();
591 
592 	/*
593 	 * We use PATH to find perf commands, but we prepend some higher
594 	 * precedence paths: the "--exec-path" option, the PERF_EXEC_PATH
595 	 * environment, and the $(perfexecdir) from the Makefile at build
596 	 * time.
597 	 */
598 	setup_path();
599 	/*
600 	 * Block SIGWINCH notifications so that the thread that wants it can
601 	 * unblock and get syscalls like select interrupted instead of waiting
602 	 * forever while the signal goes to some other non interested thread.
603 	 */
604 	pthread__block_sigwinch();
605 
606 	perf_debug_setup();
607 
608 	while (1) {
609 		static int done_help;
610 		int was_alias = run_argv(&argc, &argv);
611 
612 		if (errno != ENOENT)
613 			break;
614 
615 		if (was_alias) {
616 			fprintf(stderr, "Expansion of alias '%s' failed; "
617 				"'%s' is not a perf-command\n",
618 				cmd, argv[0]);
619 			goto out;
620 		}
621 		if (!done_help) {
622 			cmd = argv[0] = help_unknown_cmd(cmd);
623 			done_help = 1;
624 		} else
625 			break;
626 	}
627 
628 	fprintf(stderr, "Failed to run command '%s': %s\n",
629 		cmd, str_error_r(errno, sbuf, sizeof(sbuf)));
630 out:
631 	return 1;
632 }
633