xref: /linux/tools/perf/perf.c (revision 3d689ed6099a1a11c38bb78aff7498e78e287e0b)
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 #include <linux/kernel.h>
26 
27 const char perf_usage_string[] =
28 	"perf [--version] [--help] [OPTIONS] COMMAND [ARGS]";
29 
30 const char perf_more_info_string[] =
31 	"See 'perf help COMMAND' for more information on a specific command.";
32 
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 **);
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 	{ "kallsyms",	cmd_kallsyms,	0 },
51 	{ "list",	cmd_list,	0 },
52 	{ "record",	cmd_record,	0 },
53 	{ "report",	cmd_report,	0 },
54 	{ "bench",	cmd_bench,	0 },
55 	{ "stat",	cmd_stat,	0 },
56 	{ "timechart",	cmd_timechart,	0 },
57 	{ "top",	cmd_top,	0 },
58 	{ "annotate",	cmd_annotate,	0 },
59 	{ "version",	cmd_version,	0 },
60 	{ "script",	cmd_script,	0 },
61 	{ "sched",	cmd_sched,	0 },
62 #ifdef HAVE_LIBELF_SUPPORT
63 	{ "probe",	cmd_probe,	0 },
64 #endif
65 	{ "kmem",	cmd_kmem,	0 },
66 	{ "lock",	cmd_lock,	0 },
67 	{ "kvm",	cmd_kvm,	0 },
68 	{ "test",	cmd_test,	0 },
69 #ifdef HAVE_LIBAUDIT_SUPPORT
70 	{ "trace",	cmd_trace,	0 },
71 #endif
72 	{ "inject",	cmd_inject,	0 },
73 	{ "mem",	cmd_mem,	0 },
74 	{ "data",	cmd_data,	0 },
75 	{ "ftrace",	cmd_ftrace,	0 },
76 };
77 
78 struct pager_config {
79 	const char *cmd;
80 	int val;
81 };
82 
83 static int pager_command_config(const char *var, const char *value, void *data)
84 {
85 	struct pager_config *c = data;
86 	if (!prefixcmp(var, "pager.") && !strcmp(var + 6, c->cmd))
87 		c->val = perf_config_bool(var, value);
88 	return 0;
89 }
90 
91 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
92 int check_pager_config(const char *cmd)
93 {
94 	int err;
95 	struct pager_config c;
96 	c.cmd = cmd;
97 	c.val = -1;
98 	err = perf_config(pager_command_config, &c);
99 	return err ?: c.val;
100 }
101 
102 static int browser_command_config(const char *var, const char *value, void *data)
103 {
104 	struct pager_config *c = data;
105 	if (!prefixcmp(var, "tui.") && !strcmp(var + 4, c->cmd))
106 		c->val = perf_config_bool(var, value);
107 	if (!prefixcmp(var, "gtk.") && !strcmp(var + 4, c->cmd))
108 		c->val = perf_config_bool(var, value) ? 2 : 0;
109 	return 0;
110 }
111 
112 /*
113  * returns 0 for "no tui", 1 for "use tui", 2 for "use gtk",
114  * and -1 for "not specified"
115  */
116 static int check_browser_config(const char *cmd)
117 {
118 	int err;
119 	struct pager_config c;
120 	c.cmd = cmd;
121 	c.val = -1;
122 	err = perf_config(browser_command_config, &c);
123 	return err ?: c.val;
124 }
125 
126 static void commit_pager_choice(void)
127 {
128 	switch (use_pager) {
129 	case 0:
130 		setenv(PERF_PAGER_ENVIRONMENT, "cat", 1);
131 		break;
132 	case 1:
133 		/* setup_pager(); */
134 		break;
135 	default:
136 		break;
137 	}
138 }
139 
140 struct option options[] = {
141 	OPT_ARGUMENT("help", "help"),
142 	OPT_ARGUMENT("version", "version"),
143 	OPT_ARGUMENT("exec-path", "exec-path"),
144 	OPT_ARGUMENT("html-path", "html-path"),
145 	OPT_ARGUMENT("paginate", "paginate"),
146 	OPT_ARGUMENT("no-pager", "no-pager"),
147 	OPT_ARGUMENT("debugfs-dir", "debugfs-dir"),
148 	OPT_ARGUMENT("buildid-dir", "buildid-dir"),
149 	OPT_ARGUMENT("list-cmds", "list-cmds"),
150 	OPT_ARGUMENT("list-opts", "list-opts"),
151 	OPT_ARGUMENT("debug", "debug"),
152 	OPT_END()
153 };
154 
155 static int handle_options(const char ***argv, int *argc, int *envchanged)
156 {
157 	int handled = 0;
158 
159 	while (*argc > 0) {
160 		const char *cmd = (*argv)[0];
161 		if (cmd[0] != '-')
162 			break;
163 
164 		/*
165 		 * For legacy reasons, the "version" and "help"
166 		 * commands can be written with "--" prepended
167 		 * to make them look like flags.
168 		 */
169 		if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
170 			break;
171 
172 		/*
173 		 * Shortcut for '-h' and '-v' options to invoke help
174 		 * and version command.
175 		 */
176 		if (!strcmp(cmd, "-h")) {
177 			(*argv)[0] = "--help";
178 			break;
179 		}
180 
181 		if (!strcmp(cmd, "-v")) {
182 			(*argv)[0] = "--version";
183 			break;
184 		}
185 
186 		/*
187 		 * Check remaining flags.
188 		 */
189 		if (!prefixcmp(cmd, CMD_EXEC_PATH)) {
190 			cmd += strlen(CMD_EXEC_PATH);
191 			if (*cmd == '=')
192 				set_argv_exec_path(cmd + 1);
193 			else {
194 				puts(get_argv_exec_path());
195 				exit(0);
196 			}
197 		} else if (!strcmp(cmd, "--html-path")) {
198 			puts(system_path(PERF_HTML_PATH));
199 			exit(0);
200 		} else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
201 			use_pager = 1;
202 		} else if (!strcmp(cmd, "--no-pager")) {
203 			use_pager = 0;
204 			if (envchanged)
205 				*envchanged = 1;
206 		} else if (!strcmp(cmd, "--debugfs-dir")) {
207 			if (*argc < 2) {
208 				fprintf(stderr, "No directory given for --debugfs-dir.\n");
209 				usage(perf_usage_string);
210 			}
211 			tracing_path_set((*argv)[1]);
212 			if (envchanged)
213 				*envchanged = 1;
214 			(*argv)++;
215 			(*argc)--;
216 		} else if (!strcmp(cmd, "--buildid-dir")) {
217 			if (*argc < 2) {
218 				fprintf(stderr, "No directory given for --buildid-dir.\n");
219 				usage(perf_usage_string);
220 			}
221 			set_buildid_dir((*argv)[1]);
222 			if (envchanged)
223 				*envchanged = 1;
224 			(*argv)++;
225 			(*argc)--;
226 		} else if (!prefixcmp(cmd, CMD_DEBUGFS_DIR)) {
227 			tracing_path_set(cmd + strlen(CMD_DEBUGFS_DIR));
228 			fprintf(stderr, "dir: %s\n", tracing_path);
229 			if (envchanged)
230 				*envchanged = 1;
231 		} else if (!strcmp(cmd, "--list-cmds")) {
232 			unsigned int i;
233 
234 			for (i = 0; i < ARRAY_SIZE(commands); i++) {
235 				struct cmd_struct *p = commands+i;
236 				printf("%s ", p->cmd);
237 			}
238 			putchar('\n');
239 			exit(0);
240 		} else if (!strcmp(cmd, "--list-opts")) {
241 			unsigned int i;
242 
243 			for (i = 0; i < ARRAY_SIZE(options)-1; i++) {
244 				struct option *p = options+i;
245 				printf("--%s ", p->long_name);
246 			}
247 			putchar('\n');
248 			exit(0);
249 		} else if (!strcmp(cmd, "--debug")) {
250 			if (*argc < 2) {
251 				fprintf(stderr, "No variable specified for --debug.\n");
252 				usage(perf_usage_string);
253 			}
254 			if (perf_debug_option((*argv)[1]))
255 				usage(perf_usage_string);
256 
257 			(*argv)++;
258 			(*argc)--;
259 		} else {
260 			fprintf(stderr, "Unknown option: %s\n", cmd);
261 			usage(perf_usage_string);
262 		}
263 
264 		(*argv)++;
265 		(*argc)--;
266 		handled++;
267 	}
268 	return handled;
269 }
270 
271 #define RUN_SETUP	(1<<0)
272 #define USE_PAGER	(1<<1)
273 
274 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
275 {
276 	int status;
277 	struct stat st;
278 	char sbuf[STRERR_BUFSIZE];
279 
280 	if (use_browser == -1)
281 		use_browser = check_browser_config(p->cmd);
282 
283 	if (use_pager == -1 && p->option & RUN_SETUP)
284 		use_pager = check_pager_config(p->cmd);
285 	if (use_pager == -1 && p->option & USE_PAGER)
286 		use_pager = 1;
287 	commit_pager_choice();
288 
289 	perf_env__set_cmdline(&perf_env, argc, argv);
290 	status = p->fn(argc, argv);
291 	perf_config__exit();
292 	exit_browser(status);
293 	perf_env__exit(&perf_env);
294 	bpf__clear();
295 
296 	if (status)
297 		return status & 0xff;
298 
299 	/* Somebody closed stdout? */
300 	if (fstat(fileno(stdout), &st))
301 		return 0;
302 	/* Ignore write errors for pipes and sockets.. */
303 	if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
304 		return 0;
305 
306 	status = 1;
307 	/* Check for ENOSPC and EIO errors.. */
308 	if (fflush(stdout)) {
309 		fprintf(stderr, "write failure on standard output: %s",
310 			str_error_r(errno, sbuf, sizeof(sbuf)));
311 		goto out;
312 	}
313 	if (ferror(stdout)) {
314 		fprintf(stderr, "unknown write failure on standard output");
315 		goto out;
316 	}
317 	if (fclose(stdout)) {
318 		fprintf(stderr, "close failed on standard output: %s",
319 			str_error_r(errno, sbuf, sizeof(sbuf)));
320 		goto out;
321 	}
322 	status = 0;
323 out:
324 	return status;
325 }
326 
327 static void handle_internal_command(int argc, const char **argv)
328 {
329 	const char *cmd = argv[0];
330 	unsigned int i;
331 
332 	/* Turn "perf cmd --help" into "perf help cmd" */
333 	if (argc > 1 && !strcmp(argv[1], "--help")) {
334 		argv[1] = argv[0];
335 		argv[0] = cmd = "help";
336 	}
337 
338 	for (i = 0; i < ARRAY_SIZE(commands); i++) {
339 		struct cmd_struct *p = commands+i;
340 		if (strcmp(p->cmd, cmd))
341 			continue;
342 		exit(run_builtin(p, argc, argv));
343 	}
344 }
345 
346 static void execv_dashed_external(const char **argv)
347 {
348 	char *cmd;
349 	const char *tmp;
350 	int status;
351 
352 	if (asprintf(&cmd, "perf-%s", argv[0]) < 0)
353 		goto do_die;
354 
355 	/*
356 	 * argv[0] must be the perf command, but the argv array
357 	 * belongs to the caller, and may be reused in
358 	 * subsequent loop iterations. Save argv[0] and
359 	 * restore it on error.
360 	 */
361 	tmp = argv[0];
362 	argv[0] = cmd;
363 
364 	/*
365 	 * if we fail because the command is not found, it is
366 	 * OK to return. Otherwise, we just pass along the status code.
367 	 */
368 	status = run_command_v_opt(argv, 0);
369 	if (status != -ERR_RUN_COMMAND_EXEC) {
370 		if (IS_RUN_COMMAND_ERR(status)) {
371 do_die:
372 			pr_err("FATAL: unable to run '%s'", argv[0]);
373 			status = -128;
374 		}
375 		exit(-status);
376 	}
377 	errno = ENOENT; /* as if we called execvp */
378 
379 	argv[0] = tmp;
380 	zfree(&cmd);
381 }
382 
383 static int run_argv(int *argcp, const char ***argv)
384 {
385 	/* See if it's an internal command */
386 	handle_internal_command(*argcp, *argv);
387 
388 	/* .. then try the external ones */
389 	execv_dashed_external(*argv);
390 	return 0;
391 }
392 
393 static void pthread__block_sigwinch(void)
394 {
395 	sigset_t set;
396 
397 	sigemptyset(&set);
398 	sigaddset(&set, SIGWINCH);
399 	pthread_sigmask(SIG_BLOCK, &set, NULL);
400 }
401 
402 void pthread__unblock_sigwinch(void)
403 {
404 	sigset_t set;
405 
406 	sigemptyset(&set);
407 	sigaddset(&set, SIGWINCH);
408 	pthread_sigmask(SIG_UNBLOCK, &set, NULL);
409 }
410 
411 #ifdef _SC_LEVEL1_DCACHE_LINESIZE
412 #define cache_line_size(cacheline_sizep) *cacheline_sizep = sysconf(_SC_LEVEL1_DCACHE_LINESIZE)
413 #else
414 static void cache_line_size(int *cacheline_sizep)
415 {
416 	if (sysfs__read_int("devices/system/cpu/cpu0/cache/index0/coherency_line_size", cacheline_sizep))
417 		pr_debug("cannot determine cache line size");
418 }
419 #endif
420 
421 int main(int argc, const char **argv)
422 {
423 	int err;
424 	const char *cmd;
425 	char sbuf[STRERR_BUFSIZE];
426 	int value;
427 
428 	/* libsubcmd init */
429 	exec_cmd_init("perf", PREFIX, PERF_EXEC_PATH, EXEC_PATH_ENVIRONMENT);
430 	pager_init(PERF_PAGER_ENVIRONMENT);
431 
432 	/* The page_size is placed in util object. */
433 	page_size = sysconf(_SC_PAGE_SIZE);
434 	cache_line_size(&cacheline_size);
435 
436 	if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0)
437 		sysctl_perf_event_max_stack = value;
438 
439 	if (sysctl__read_int("kernel/perf_event_max_contexts_per_stack", &value) == 0)
440 		sysctl_perf_event_max_contexts_per_stack = value;
441 
442 	cmd = extract_argv0_path(argv[0]);
443 	if (!cmd)
444 		cmd = "perf-help";
445 
446 	srandom(time(NULL));
447 
448 	perf_config__init();
449 	err = perf_config(perf_default_config, NULL);
450 	if (err)
451 		return err;
452 	set_buildid_dir(NULL);
453 
454 	/* get debugfs/tracefs mount point from /proc/mounts */
455 	tracing_path_mount();
456 
457 	/*
458 	 * "perf-xxxx" is the same as "perf xxxx", but we obviously:
459 	 *
460 	 *  - cannot take flags in between the "perf" and the "xxxx".
461 	 *  - cannot execute it externally (since it would just do
462 	 *    the same thing over again)
463 	 *
464 	 * So we just directly call the internal command handler, and
465 	 * die if that one cannot handle it.
466 	 */
467 	if (!prefixcmp(cmd, "perf-")) {
468 		cmd += 5;
469 		argv[0] = cmd;
470 		handle_internal_command(argc, argv);
471 		fprintf(stderr, "cannot handle %s internally", cmd);
472 		goto out;
473 	}
474 	if (!prefixcmp(cmd, "trace")) {
475 #ifdef HAVE_LIBAUDIT_SUPPORT
476 		setup_path();
477 		argv[0] = "trace";
478 		return cmd_trace(argc, argv);
479 #else
480 		fprintf(stderr,
481 			"trace command not available: missing audit-libs devel package at build time.\n");
482 		goto out;
483 #endif
484 	}
485 	/* Look for flags.. */
486 	argv++;
487 	argc--;
488 	handle_options(&argv, &argc, NULL);
489 	commit_pager_choice();
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 	perf_debug_setup();
520 
521 	while (1) {
522 		static int done_help;
523 
524 		run_argv(&argc, &argv);
525 
526 		if (errno != ENOENT)
527 			break;
528 
529 		if (!done_help) {
530 			cmd = argv[0] = help_unknown_cmd(cmd);
531 			done_help = 1;
532 		} else
533 			break;
534 	}
535 
536 	fprintf(stderr, "Failed to run command '%s': %s\n",
537 		cmd, str_error_r(errno, sbuf, sizeof(sbuf)));
538 out:
539 	return 1;
540 }
541