xref: /linux/tools/perf/perf.c (revision c1a604dff486399ae0be95e6396e0158df95ad5d) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * perf.c
4  *
5  * Performance analysis utility.
6  *
7  * This is the main hub from which the sub-commands (perf stat,
8  * perf top, perf record, perf report, etc.) are started.
9  */
10 #include "builtin.h"
11 #include "perf.h"
12 
13 #include "util/env.h"
14 #include <subcmd/exec-cmd.h>
15 #include "util/config.h"
16 #include <subcmd/run-command.h>
17 #include "util/parse-events.h"
18 #include <subcmd/parse-options.h>
19 #include "util/bpf-loader.h"
20 #include "util/debug.h"
21 #include "util/event.h"
22 #include "util/util.h"
23 #include "perf-sys.h"
24 #include <api/fs/fs.h>
25 #include <api/fs/tracing_path.h>
26 #include <errno.h>
27 #include <pthread.h>
28 #include <signal.h>
29 #include <stdlib.h>
30 #include <time.h>
31 #include <sys/types.h>
32 #include <sys/stat.h>
33 #include <unistd.h>
34 #include <linux/kernel.h>
35 #include <linux/zalloc.h>
36 
37 const char perf_usage_string[] =
38 	"perf [--version] [--help] [OPTIONS] COMMAND [ARGS]";
39 
40 const char perf_more_info_string[] =
41 	"See 'perf help COMMAND' for more information on a specific command.";
42 
43 static int use_pager = -1;
44 const char *input_name;
45 
46 struct cmd_struct {
47 	const char *cmd;
48 	int (*fn)(int, const char **);
49 	int option;
50 };
51 
52 static struct cmd_struct commands[] = {
53 	{ "buildid-cache", cmd_buildid_cache, 0 },
54 	{ "buildid-list", cmd_buildid_list, 0 },
55 	{ "config",	cmd_config,	0 },
56 	{ "c2c",	cmd_c2c,	0 },
57 	{ "diff",	cmd_diff,	0 },
58 	{ "evlist",	cmd_evlist,	0 },
59 	{ "help",	cmd_help,	0 },
60 	{ "kallsyms",	cmd_kallsyms,	0 },
61 	{ "list",	cmd_list,	0 },
62 	{ "record",	cmd_record,	0 },
63 	{ "report",	cmd_report,	0 },
64 	{ "bench",	cmd_bench,	0 },
65 	{ "stat",	cmd_stat,	0 },
66 	{ "timechart",	cmd_timechart,	0 },
67 	{ "top",	cmd_top,	0 },
68 	{ "annotate",	cmd_annotate,	0 },
69 	{ "version",	cmd_version,	0 },
70 	{ "script",	cmd_script,	0 },
71 	{ "sched",	cmd_sched,	0 },
72 #ifdef HAVE_LIBELF_SUPPORT
73 	{ "probe",	cmd_probe,	0 },
74 #endif
75 	{ "kmem",	cmd_kmem,	0 },
76 	{ "lock",	cmd_lock,	0 },
77 	{ "kvm",	cmd_kvm,	0 },
78 	{ "test",	cmd_test,	0 },
79 #if defined(HAVE_LIBAUDIT_SUPPORT) || defined(HAVE_SYSCALL_TABLE_SUPPORT)
80 	{ "trace",	cmd_trace,	0 },
81 #endif
82 	{ "inject",	cmd_inject,	0 },
83 	{ "mem",	cmd_mem,	0 },
84 	{ "data",	cmd_data,	0 },
85 	{ "ftrace",	cmd_ftrace,	0 },
86 };
87 
88 struct pager_config {
89 	const char *cmd;
90 	int val;
91 };
92 
93 static int pager_command_config(const char *var, const char *value, void *data)
94 {
95 	struct pager_config *c = data;
96 	if (strstarts(var, "pager.") && !strcmp(var + 6, c->cmd))
97 		c->val = perf_config_bool(var, value);
98 	return 0;
99 }
100 
101 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
102 static int check_pager_config(const char *cmd)
103 {
104 	int err;
105 	struct pager_config c;
106 	c.cmd = cmd;
107 	c.val = -1;
108 	err = perf_config(pager_command_config, &c);
109 	return err ?: c.val;
110 }
111 
112 static int browser_command_config(const char *var, const char *value, void *data)
113 {
114 	struct pager_config *c = data;
115 	if (strstarts(var, "tui.") && !strcmp(var + 4, c->cmd))
116 		c->val = perf_config_bool(var, value);
117 	if (strstarts(var, "gtk.") && !strcmp(var + 4, c->cmd))
118 		c->val = perf_config_bool(var, value) ? 2 : 0;
119 	return 0;
120 }
121 
122 /*
123  * returns 0 for "no tui", 1 for "use tui", 2 for "use gtk",
124  * and -1 for "not specified"
125  */
126 static int check_browser_config(const char *cmd)
127 {
128 	int err;
129 	struct pager_config c;
130 	c.cmd = cmd;
131 	c.val = -1;
132 	err = perf_config(browser_command_config, &c);
133 	return err ?: c.val;
134 }
135 
136 static void commit_pager_choice(void)
137 {
138 	switch (use_pager) {
139 	case 0:
140 		setenv(PERF_PAGER_ENVIRONMENT, "cat", 1);
141 		break;
142 	case 1:
143 		/* setup_pager(); */
144 		break;
145 	default:
146 		break;
147 	}
148 }
149 
150 struct option options[] = {
151 	OPT_ARGUMENT("help", "help"),
152 	OPT_ARGUMENT("version", "version"),
153 	OPT_ARGUMENT("exec-path", "exec-path"),
154 	OPT_ARGUMENT("html-path", "html-path"),
155 	OPT_ARGUMENT("paginate", "paginate"),
156 	OPT_ARGUMENT("no-pager", "no-pager"),
157 	OPT_ARGUMENT("debugfs-dir", "debugfs-dir"),
158 	OPT_ARGUMENT("buildid-dir", "buildid-dir"),
159 	OPT_ARGUMENT("list-cmds", "list-cmds"),
160 	OPT_ARGUMENT("list-opts", "list-opts"),
161 	OPT_ARGUMENT("debug", "debug"),
162 	OPT_END()
163 };
164 
165 static int handle_options(const char ***argv, int *argc, int *envchanged)
166 {
167 	int handled = 0;
168 
169 	while (*argc > 0) {
170 		const char *cmd = (*argv)[0];
171 		if (cmd[0] != '-')
172 			break;
173 
174 		/*
175 		 * For legacy reasons, the "version" and "help"
176 		 * commands can be written with "--" prepended
177 		 * to make them look like flags.
178 		 */
179 		if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
180 			break;
181 
182 		/*
183 		 * Shortcut for '-h' and '-v' options to invoke help
184 		 * and version command.
185 		 */
186 		if (!strcmp(cmd, "-h")) {
187 			(*argv)[0] = "--help";
188 			break;
189 		}
190 
191 		if (!strcmp(cmd, "-v")) {
192 			(*argv)[0] = "--version";
193 			break;
194 		}
195 
196 		if (!strcmp(cmd, "-vv")) {
197 			(*argv)[0] = "version";
198 			version_verbose = 1;
199 			break;
200 		}
201 
202 		/*
203 		 * Check remaining flags.
204 		 */
205 		if (strstarts(cmd, CMD_EXEC_PATH)) {
206 			cmd += strlen(CMD_EXEC_PATH);
207 			if (*cmd == '=')
208 				set_argv_exec_path(cmd + 1);
209 			else {
210 				puts(get_argv_exec_path());
211 				exit(0);
212 			}
213 		} else if (!strcmp(cmd, "--html-path")) {
214 			puts(system_path(PERF_HTML_PATH));
215 			exit(0);
216 		} else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
217 			use_pager = 1;
218 		} else if (!strcmp(cmd, "--no-pager")) {
219 			use_pager = 0;
220 			if (envchanged)
221 				*envchanged = 1;
222 		} else if (!strcmp(cmd, "--debugfs-dir")) {
223 			if (*argc < 2) {
224 				fprintf(stderr, "No directory given for --debugfs-dir.\n");
225 				usage(perf_usage_string);
226 			}
227 			tracing_path_set((*argv)[1]);
228 			if (envchanged)
229 				*envchanged = 1;
230 			(*argv)++;
231 			(*argc)--;
232 		} else if (!strcmp(cmd, "--buildid-dir")) {
233 			if (*argc < 2) {
234 				fprintf(stderr, "No directory given for --buildid-dir.\n");
235 				usage(perf_usage_string);
236 			}
237 			set_buildid_dir((*argv)[1]);
238 			if (envchanged)
239 				*envchanged = 1;
240 			(*argv)++;
241 			(*argc)--;
242 		} else if (strstarts(cmd, CMD_DEBUGFS_DIR)) {
243 			tracing_path_set(cmd + strlen(CMD_DEBUGFS_DIR));
244 			fprintf(stderr, "dir: %s\n", tracing_path_mount());
245 			if (envchanged)
246 				*envchanged = 1;
247 		} else if (!strcmp(cmd, "--list-cmds")) {
248 			unsigned int i;
249 
250 			for (i = 0; i < ARRAY_SIZE(commands); i++) {
251 				struct cmd_struct *p = commands+i;
252 				printf("%s ", p->cmd);
253 			}
254 			putchar('\n');
255 			exit(0);
256 		} else if (!strcmp(cmd, "--list-opts")) {
257 			unsigned int i;
258 
259 			for (i = 0; i < ARRAY_SIZE(options)-1; i++) {
260 				struct option *p = options+i;
261 				printf("--%s ", p->long_name);
262 			}
263 			putchar('\n');
264 			exit(0);
265 		} else if (!strcmp(cmd, "--debug")) {
266 			if (*argc < 2) {
267 				fprintf(stderr, "No variable specified for --debug.\n");
268 				usage(perf_usage_string);
269 			}
270 			if (perf_debug_option((*argv)[1]))
271 				usage(perf_usage_string);
272 
273 			(*argv)++;
274 			(*argc)--;
275 		} else {
276 			fprintf(stderr, "Unknown option: %s\n", cmd);
277 			usage(perf_usage_string);
278 		}
279 
280 		(*argv)++;
281 		(*argc)--;
282 		handled++;
283 	}
284 	return handled;
285 }
286 
287 #define RUN_SETUP	(1<<0)
288 #define USE_PAGER	(1<<1)
289 
290 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
291 {
292 	int status;
293 	struct stat st;
294 	char sbuf[STRERR_BUFSIZE];
295 
296 	if (use_browser == -1)
297 		use_browser = check_browser_config(p->cmd);
298 
299 	if (use_pager == -1 && p->option & RUN_SETUP)
300 		use_pager = check_pager_config(p->cmd);
301 	if (use_pager == -1 && p->option & USE_PAGER)
302 		use_pager = 1;
303 	commit_pager_choice();
304 
305 	perf_env__init(&perf_env);
306 	perf_env__set_cmdline(&perf_env, argc, argv);
307 	status = p->fn(argc, argv);
308 	perf_config__exit();
309 	exit_browser(status);
310 	perf_env__exit(&perf_env);
311 	bpf__clear();
312 
313 	if (status)
314 		return status & 0xff;
315 
316 	/* Somebody closed stdout? */
317 	if (fstat(fileno(stdout), &st))
318 		return 0;
319 	/* Ignore write errors for pipes and sockets.. */
320 	if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
321 		return 0;
322 
323 	status = 1;
324 	/* Check for ENOSPC and EIO errors.. */
325 	if (fflush(stdout)) {
326 		fprintf(stderr, "write failure on standard output: %s",
327 			str_error_r(errno, sbuf, sizeof(sbuf)));
328 		goto out;
329 	}
330 	if (ferror(stdout)) {
331 		fprintf(stderr, "unknown write failure on standard output");
332 		goto out;
333 	}
334 	if (fclose(stdout)) {
335 		fprintf(stderr, "close failed on standard output: %s",
336 			str_error_r(errno, sbuf, sizeof(sbuf)));
337 		goto out;
338 	}
339 	status = 0;
340 out:
341 	return status;
342 }
343 
344 static void handle_internal_command(int argc, const char **argv)
345 {
346 	const char *cmd = argv[0];
347 	unsigned int i;
348 
349 	/* Turn "perf cmd --help" into "perf help cmd" */
350 	if (argc > 1 && !strcmp(argv[1], "--help")) {
351 		argv[1] = argv[0];
352 		argv[0] = cmd = "help";
353 	}
354 
355 	for (i = 0; i < ARRAY_SIZE(commands); i++) {
356 		struct cmd_struct *p = commands+i;
357 		if (strcmp(p->cmd, cmd))
358 			continue;
359 		exit(run_builtin(p, argc, argv));
360 	}
361 }
362 
363 static void execv_dashed_external(const char **argv)
364 {
365 	char *cmd;
366 	const char *tmp;
367 	int status;
368 
369 	if (asprintf(&cmd, "perf-%s", argv[0]) < 0)
370 		goto do_die;
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;
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 do_die:
389 			pr_err("FATAL: unable to run '%s'", argv[0]);
390 			status = -128;
391 		}
392 		exit(-status);
393 	}
394 	errno = ENOENT; /* as if we called execvp */
395 
396 	argv[0] = tmp;
397 	zfree(&cmd);
398 }
399 
400 static int run_argv(int *argcp, const char ***argv)
401 {
402 	/* See if it's an internal command */
403 	handle_internal_command(*argcp, *argv);
404 
405 	/* .. then try the external ones */
406 	execv_dashed_external(*argv);
407 	return 0;
408 }
409 
410 static void pthread__block_sigwinch(void)
411 {
412 	sigset_t set;
413 
414 	sigemptyset(&set);
415 	sigaddset(&set, SIGWINCH);
416 	pthread_sigmask(SIG_BLOCK, &set, NULL);
417 }
418 
419 void pthread__unblock_sigwinch(void)
420 {
421 	sigset_t set;
422 
423 	sigemptyset(&set);
424 	sigaddset(&set, SIGWINCH);
425 	pthread_sigmask(SIG_UNBLOCK, &set, NULL);
426 }
427 
428 int main(int argc, const char **argv)
429 {
430 	int err;
431 	const char *cmd;
432 	char sbuf[STRERR_BUFSIZE];
433 
434 	/* libsubcmd init */
435 	exec_cmd_init("perf", PREFIX, PERF_EXEC_PATH, EXEC_PATH_ENVIRONMENT);
436 	pager_init(PERF_PAGER_ENVIRONMENT);
437 
438 	/* The page_size is placed in util object. */
439 	page_size = sysconf(_SC_PAGE_SIZE);
440 
441 	cmd = extract_argv0_path(argv[0]);
442 	if (!cmd)
443 		cmd = "perf-help";
444 
445 	srandom(time(NULL));
446 
447 	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
448 	config_exclusive_filename = getenv("PERF_CONFIG");
449 
450 	err = perf_config(perf_default_config, NULL);
451 	if (err)
452 		return err;
453 	set_buildid_dir(NULL);
454 
455 	/*
456 	 * "perf-xxxx" is the same as "perf xxxx", but we obviously:
457 	 *
458 	 *  - cannot take flags in between the "perf" and the "xxxx".
459 	 *  - cannot execute it externally (since it would just do
460 	 *    the same thing over again)
461 	 *
462 	 * So we just directly call the internal command handler. If that one
463 	 * fails to handle this, then maybe we just run a renamed perf binary
464 	 * that contains a dash in its name. To handle this scenario, we just
465 	 * fall through and ignore the "xxxx" part of the command string.
466 	 */
467 	if (strstarts(cmd, "perf-")) {
468 		cmd += 5;
469 		argv[0] = cmd;
470 		handle_internal_command(argc, argv);
471 		/*
472 		 * If the command is handled, the above function does not
473 		 * return undo changes and fall through in such a case.
474 		 */
475 		cmd -= 5;
476 		argv[0] = cmd;
477 	}
478 	if (strstarts(cmd, "trace")) {
479 #if defined(HAVE_LIBAUDIT_SUPPORT) || defined(HAVE_SYSCALL_TABLE_SUPPORT)
480 		setup_path();
481 		argv[0] = "trace";
482 		return cmd_trace(argc, argv);
483 #else
484 		fprintf(stderr,
485 			"trace command not available: missing audit-libs devel package at build time.\n");
486 		goto out;
487 #endif
488 	}
489 	/* Look for flags.. */
490 	argv++;
491 	argc--;
492 	handle_options(&argv, &argc, NULL);
493 	commit_pager_choice();
494 
495 	if (argc > 0) {
496 		if (strstarts(argv[0], "--"))
497 			argv[0] += 2;
498 	} else {
499 		/* The user didn't specify a command; give them help */
500 		printf("\n usage: %s\n\n", perf_usage_string);
501 		list_common_cmds_help();
502 		printf("\n %s\n\n", perf_more_info_string);
503 		goto out;
504 	}
505 	cmd = argv[0];
506 
507 	test_attr__init();
508 
509 	/*
510 	 * We use PATH to find perf commands, but we prepend some higher
511 	 * precedence paths: the "--exec-path" option, the PERF_EXEC_PATH
512 	 * environment, and the $(perfexecdir) from the Makefile at build
513 	 * time.
514 	 */
515 	setup_path();
516 	/*
517 	 * Block SIGWINCH notifications so that the thread that wants it can
518 	 * unblock and get syscalls like select interrupted instead of waiting
519 	 * forever while the signal goes to some other non interested thread.
520 	 */
521 	pthread__block_sigwinch();
522 
523 	perf_debug_setup();
524 
525 	while (1) {
526 		static int done_help;
527 
528 		run_argv(&argc, &argv);
529 
530 		if (errno != ENOENT)
531 			break;
532 
533 		if (!done_help) {
534 			cmd = argv[0] = help_unknown_cmd(cmd);
535 			done_help = 1;
536 		} else
537 			break;
538 	}
539 
540 	fprintf(stderr, "Failed to run command '%s': %s\n",
541 		cmd, str_error_r(errno, sbuf, sizeof(sbuf)));
542 out:
543 	return 1;
544 }
545