xref: /linux/tools/perf/perf.c (revision 63307d015b91e626c97bb82e88054af3d0b74643) 
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 
12 #include "util/env.h"
13 #include <subcmd/exec-cmd.h>
14 #include "util/config.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 "util/event.h"
21 #include <api/fs/fs.h>
22 #include <api/fs/tracing_path.h>
23 #include <errno.h>
24 #include <pthread.h>
25 #include <signal.h>
26 #include <stdlib.h>
27 #include <time.h>
28 #include <sys/types.h>
29 #include <sys/stat.h>
30 #include <unistd.h>
31 #include <linux/kernel.h>
32 
33 const char perf_usage_string[] =
34 	"perf [--version] [--help] [OPTIONS] COMMAND [ARGS]";
35 
36 const char perf_more_info_string[] =
37 	"See 'perf help COMMAND' for more information on a specific command.";
38 
39 static int use_pager = -1;
40 const char *input_name;
41 
42 struct cmd_struct {
43 	const char *cmd;
44 	int (*fn)(int, const char **);
45 	int option;
46 };
47 
48 static struct cmd_struct commands[] = {
49 	{ "buildid-cache", cmd_buildid_cache, 0 },
50 	{ "buildid-list", cmd_buildid_list, 0 },
51 	{ "config",	cmd_config,	0 },
52 	{ "c2c",	cmd_c2c,	0 },
53 	{ "diff",	cmd_diff,	0 },
54 	{ "evlist",	cmd_evlist,	0 },
55 	{ "help",	cmd_help,	0 },
56 	{ "kallsyms",	cmd_kallsyms,	0 },
57 	{ "list",	cmd_list,	0 },
58 	{ "record",	cmd_record,	0 },
59 	{ "report",	cmd_report,	0 },
60 	{ "bench",	cmd_bench,	0 },
61 	{ "stat",	cmd_stat,	0 },
62 	{ "timechart",	cmd_timechart,	0 },
63 	{ "top",	cmd_top,	0 },
64 	{ "annotate",	cmd_annotate,	0 },
65 	{ "version",	cmd_version,	0 },
66 	{ "script",	cmd_script,	0 },
67 	{ "sched",	cmd_sched,	0 },
68 #ifdef HAVE_LIBELF_SUPPORT
69 	{ "probe",	cmd_probe,	0 },
70 #endif
71 	{ "kmem",	cmd_kmem,	0 },
72 	{ "lock",	cmd_lock,	0 },
73 	{ "kvm",	cmd_kvm,	0 },
74 	{ "test",	cmd_test,	0 },
75 #if defined(HAVE_LIBAUDIT_SUPPORT) || defined(HAVE_SYSCALL_TABLE_SUPPORT)
76 	{ "trace",	cmd_trace,	0 },
77 #endif
78 	{ "inject",	cmd_inject,	0 },
79 	{ "mem",	cmd_mem,	0 },
80 	{ "data",	cmd_data,	0 },
81 	{ "ftrace",	cmd_ftrace,	0 },
82 };
83 
84 struct pager_config {
85 	const char *cmd;
86 	int val;
87 };
88 
89 static int pager_command_config(const char *var, const char *value, void *data)
90 {
91 	struct pager_config *c = data;
92 	if (strstarts(var, "pager.") && !strcmp(var + 6, c->cmd))
93 		c->val = perf_config_bool(var, value);
94 	return 0;
95 }
96 
97 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
98 static int check_pager_config(const char *cmd)
99 {
100 	int err;
101 	struct pager_config c;
102 	c.cmd = cmd;
103 	c.val = -1;
104 	err = perf_config(pager_command_config, &c);
105 	return err ?: c.val;
106 }
107 
108 static int browser_command_config(const char *var, const char *value, void *data)
109 {
110 	struct pager_config *c = data;
111 	if (strstarts(var, "tui.") && !strcmp(var + 4, c->cmd))
112 		c->val = perf_config_bool(var, value);
113 	if (strstarts(var, "gtk.") && !strcmp(var + 4, c->cmd))
114 		c->val = perf_config_bool(var, value) ? 2 : 0;
115 	return 0;
116 }
117 
118 /*
119  * returns 0 for "no tui", 1 for "use tui", 2 for "use gtk",
120  * and -1 for "not specified"
121  */
122 static int check_browser_config(const char *cmd)
123 {
124 	int err;
125 	struct pager_config c;
126 	c.cmd = cmd;
127 	c.val = -1;
128 	err = perf_config(browser_command_config, &c);
129 	return err ?: c.val;
130 }
131 
132 static void commit_pager_choice(void)
133 {
134 	switch (use_pager) {
135 	case 0:
136 		setenv(PERF_PAGER_ENVIRONMENT, "cat", 1);
137 		break;
138 	case 1:
139 		/* setup_pager(); */
140 		break;
141 	default:
142 		break;
143 	}
144 }
145 
146 struct option options[] = {
147 	OPT_ARGUMENT("help", "help"),
148 	OPT_ARGUMENT("version", "version"),
149 	OPT_ARGUMENT("exec-path", "exec-path"),
150 	OPT_ARGUMENT("html-path", "html-path"),
151 	OPT_ARGUMENT("paginate", "paginate"),
152 	OPT_ARGUMENT("no-pager", "no-pager"),
153 	OPT_ARGUMENT("debugfs-dir", "debugfs-dir"),
154 	OPT_ARGUMENT("buildid-dir", "buildid-dir"),
155 	OPT_ARGUMENT("list-cmds", "list-cmds"),
156 	OPT_ARGUMENT("list-opts", "list-opts"),
157 	OPT_ARGUMENT("debug", "debug"),
158 	OPT_END()
159 };
160 
161 static int handle_options(const char ***argv, int *argc, int *envchanged)
162 {
163 	int handled = 0;
164 
165 	while (*argc > 0) {
166 		const char *cmd = (*argv)[0];
167 		if (cmd[0] != '-')
168 			break;
169 
170 		/*
171 		 * For legacy reasons, the "version" and "help"
172 		 * commands can be written with "--" prepended
173 		 * to make them look like flags.
174 		 */
175 		if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
176 			break;
177 
178 		/*
179 		 * Shortcut for '-h' and '-v' options to invoke help
180 		 * and version command.
181 		 */
182 		if (!strcmp(cmd, "-h")) {
183 			(*argv)[0] = "--help";
184 			break;
185 		}
186 
187 		if (!strcmp(cmd, "-v")) {
188 			(*argv)[0] = "--version";
189 			break;
190 		}
191 
192 		if (!strcmp(cmd, "-vv")) {
193 			(*argv)[0] = "version";
194 			version_verbose = 1;
195 			break;
196 		}
197 
198 		/*
199 		 * Check remaining flags.
200 		 */
201 		if (strstarts(cmd, CMD_EXEC_PATH)) {
202 			cmd += strlen(CMD_EXEC_PATH);
203 			if (*cmd == '=')
204 				set_argv_exec_path(cmd + 1);
205 			else {
206 				puts(get_argv_exec_path());
207 				exit(0);
208 			}
209 		} else if (!strcmp(cmd, "--html-path")) {
210 			puts(system_path(PERF_HTML_PATH));
211 			exit(0);
212 		} else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
213 			use_pager = 1;
214 		} else if (!strcmp(cmd, "--no-pager")) {
215 			use_pager = 0;
216 			if (envchanged)
217 				*envchanged = 1;
218 		} else if (!strcmp(cmd, "--debugfs-dir")) {
219 			if (*argc < 2) {
220 				fprintf(stderr, "No directory given for --debugfs-dir.\n");
221 				usage(perf_usage_string);
222 			}
223 			tracing_path_set((*argv)[1]);
224 			if (envchanged)
225 				*envchanged = 1;
226 			(*argv)++;
227 			(*argc)--;
228 		} else if (!strcmp(cmd, "--buildid-dir")) {
229 			if (*argc < 2) {
230 				fprintf(stderr, "No directory given for --buildid-dir.\n");
231 				usage(perf_usage_string);
232 			}
233 			set_buildid_dir((*argv)[1]);
234 			if (envchanged)
235 				*envchanged = 1;
236 			(*argv)++;
237 			(*argc)--;
238 		} else if (strstarts(cmd, CMD_DEBUGFS_DIR)) {
239 			tracing_path_set(cmd + strlen(CMD_DEBUGFS_DIR));
240 			fprintf(stderr, "dir: %s\n", tracing_path_mount());
241 			if (envchanged)
242 				*envchanged = 1;
243 		} else if (!strcmp(cmd, "--list-cmds")) {
244 			unsigned int i;
245 
246 			for (i = 0; i < ARRAY_SIZE(commands); i++) {
247 				struct cmd_struct *p = commands+i;
248 				printf("%s ", p->cmd);
249 			}
250 			putchar('\n');
251 			exit(0);
252 		} else if (!strcmp(cmd, "--list-opts")) {
253 			unsigned int i;
254 
255 			for (i = 0; i < ARRAY_SIZE(options)-1; i++) {
256 				struct option *p = options+i;
257 				printf("--%s ", p->long_name);
258 			}
259 			putchar('\n');
260 			exit(0);
261 		} else if (!strcmp(cmd, "--debug")) {
262 			if (*argc < 2) {
263 				fprintf(stderr, "No variable specified for --debug.\n");
264 				usage(perf_usage_string);
265 			}
266 			if (perf_debug_option((*argv)[1]))
267 				usage(perf_usage_string);
268 
269 			(*argv)++;
270 			(*argc)--;
271 		} else {
272 			fprintf(stderr, "Unknown option: %s\n", cmd);
273 			usage(perf_usage_string);
274 		}
275 
276 		(*argv)++;
277 		(*argc)--;
278 		handled++;
279 	}
280 	return handled;
281 }
282 
283 #define RUN_SETUP	(1<<0)
284 #define USE_PAGER	(1<<1)
285 
286 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
287 {
288 	int status;
289 	struct stat st;
290 	char sbuf[STRERR_BUFSIZE];
291 
292 	if (use_browser == -1)
293 		use_browser = check_browser_config(p->cmd);
294 
295 	if (use_pager == -1 && p->option & RUN_SETUP)
296 		use_pager = check_pager_config(p->cmd);
297 	if (use_pager == -1 && p->option & USE_PAGER)
298 		use_pager = 1;
299 	commit_pager_choice();
300 
301 	perf_env__init(&perf_env);
302 	perf_env__set_cmdline(&perf_env, argc, argv);
303 	status = p->fn(argc, argv);
304 	perf_config__exit();
305 	exit_browser(status);
306 	perf_env__exit(&perf_env);
307 	bpf__clear();
308 
309 	if (status)
310 		return status & 0xff;
311 
312 	/* Somebody closed stdout? */
313 	if (fstat(fileno(stdout), &st))
314 		return 0;
315 	/* Ignore write errors for pipes and sockets.. */
316 	if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
317 		return 0;
318 
319 	status = 1;
320 	/* Check for ENOSPC and EIO errors.. */
321 	if (fflush(stdout)) {
322 		fprintf(stderr, "write failure on standard output: %s",
323 			str_error_r(errno, sbuf, sizeof(sbuf)));
324 		goto out;
325 	}
326 	if (ferror(stdout)) {
327 		fprintf(stderr, "unknown write failure on standard output");
328 		goto out;
329 	}
330 	if (fclose(stdout)) {
331 		fprintf(stderr, "close failed on standard output: %s",
332 			str_error_r(errno, sbuf, sizeof(sbuf)));
333 		goto out;
334 	}
335 	status = 0;
336 out:
337 	return status;
338 }
339 
340 static void handle_internal_command(int argc, const char **argv)
341 {
342 	const char *cmd = argv[0];
343 	unsigned int i;
344 
345 	/* Turn "perf cmd --help" into "perf help cmd" */
346 	if (argc > 1 && !strcmp(argv[1], "--help")) {
347 		argv[1] = argv[0];
348 		argv[0] = cmd = "help";
349 	}
350 
351 	for (i = 0; i < ARRAY_SIZE(commands); i++) {
352 		struct cmd_struct *p = commands+i;
353 		if (strcmp(p->cmd, cmd))
354 			continue;
355 		exit(run_builtin(p, argc, argv));
356 	}
357 }
358 
359 static void execv_dashed_external(const char **argv)
360 {
361 	char *cmd;
362 	const char *tmp;
363 	int status;
364 
365 	if (asprintf(&cmd, "perf-%s", argv[0]) < 0)
366 		goto do_die;
367 
368 	/*
369 	 * argv[0] must be the perf command, but the argv array
370 	 * belongs to the caller, and may be reused in
371 	 * subsequent loop iterations. Save argv[0] and
372 	 * restore it on error.
373 	 */
374 	tmp = argv[0];
375 	argv[0] = cmd;
376 
377 	/*
378 	 * if we fail because the command is not found, it is
379 	 * OK to return. Otherwise, we just pass along the status code.
380 	 */
381 	status = run_command_v_opt(argv, 0);
382 	if (status != -ERR_RUN_COMMAND_EXEC) {
383 		if (IS_RUN_COMMAND_ERR(status)) {
384 do_die:
385 			pr_err("FATAL: unable to run '%s'", argv[0]);
386 			status = -128;
387 		}
388 		exit(-status);
389 	}
390 	errno = ENOENT; /* as if we called execvp */
391 
392 	argv[0] = tmp;
393 	zfree(&cmd);
394 }
395 
396 static int run_argv(int *argcp, const char ***argv)
397 {
398 	/* See if it's an internal command */
399 	handle_internal_command(*argcp, *argv);
400 
401 	/* .. then try the external ones */
402 	execv_dashed_external(*argv);
403 	return 0;
404 }
405 
406 static void pthread__block_sigwinch(void)
407 {
408 	sigset_t set;
409 
410 	sigemptyset(&set);
411 	sigaddset(&set, SIGWINCH);
412 	pthread_sigmask(SIG_BLOCK, &set, NULL);
413 }
414 
415 void pthread__unblock_sigwinch(void)
416 {
417 	sigset_t set;
418 
419 	sigemptyset(&set);
420 	sigaddset(&set, SIGWINCH);
421 	pthread_sigmask(SIG_UNBLOCK, &set, NULL);
422 }
423 
424 int main(int argc, const char **argv)
425 {
426 	int err;
427 	const char *cmd;
428 	char sbuf[STRERR_BUFSIZE];
429 
430 	/* libsubcmd init */
431 	exec_cmd_init("perf", PREFIX, PERF_EXEC_PATH, EXEC_PATH_ENVIRONMENT);
432 	pager_init(PERF_PAGER_ENVIRONMENT);
433 
434 	/* The page_size is placed in util object. */
435 	page_size = sysconf(_SC_PAGE_SIZE);
436 
437 	cmd = extract_argv0_path(argv[0]);
438 	if (!cmd)
439 		cmd = "perf-help";
440 
441 	srandom(time(NULL));
442 
443 	err = perf_config(perf_default_config, NULL);
444 	if (err)
445 		return err;
446 	set_buildid_dir(NULL);
447 
448 	/*
449 	 * "perf-xxxx" is the same as "perf xxxx", but we obviously:
450 	 *
451 	 *  - cannot take flags in between the "perf" and the "xxxx".
452 	 *  - cannot execute it externally (since it would just do
453 	 *    the same thing over again)
454 	 *
455 	 * So we just directly call the internal command handler. If that one
456 	 * fails to handle this, then maybe we just run a renamed perf binary
457 	 * that contains a dash in its name. To handle this scenario, we just
458 	 * fall through and ignore the "xxxx" part of the command string.
459 	 */
460 	if (strstarts(cmd, "perf-")) {
461 		cmd += 5;
462 		argv[0] = cmd;
463 		handle_internal_command(argc, argv);
464 		/*
465 		 * If the command is handled, the above function does not
466 		 * return undo changes and fall through in such a case.
467 		 */
468 		cmd -= 5;
469 		argv[0] = cmd;
470 	}
471 	if (strstarts(cmd, "trace")) {
472 #if defined(HAVE_LIBAUDIT_SUPPORT) || defined(HAVE_SYSCALL_TABLE_SUPPORT)
473 		setup_path();
474 		argv[0] = "trace";
475 		return cmd_trace(argc, argv);
476 #else
477 		fprintf(stderr,
478 			"trace command not available: missing audit-libs devel package at build time.\n");
479 		goto out;
480 #endif
481 	}
482 	/* Look for flags.. */
483 	argv++;
484 	argc--;
485 	handle_options(&argv, &argc, NULL);
486 	commit_pager_choice();
487 
488 	if (argc > 0) {
489 		if (strstarts(argv[0], "--"))
490 			argv[0] += 2;
491 	} else {
492 		/* The user didn't specify a command; give them help */
493 		printf("\n usage: %s\n\n", perf_usage_string);
494 		list_common_cmds_help();
495 		printf("\n %s\n\n", perf_more_info_string);
496 		goto out;
497 	}
498 	cmd = argv[0];
499 
500 	test_attr__init();
501 
502 	/*
503 	 * We use PATH to find perf commands, but we prepend some higher
504 	 * precedence paths: the "--exec-path" option, the PERF_EXEC_PATH
505 	 * environment, and the $(perfexecdir) from the Makefile at build
506 	 * time.
507 	 */
508 	setup_path();
509 	/*
510 	 * Block SIGWINCH notifications so that the thread that wants it can
511 	 * unblock and get syscalls like select interrupted instead of waiting
512 	 * forever while the signal goes to some other non interested thread.
513 	 */
514 	pthread__block_sigwinch();
515 
516 	perf_debug_setup();
517 
518 	while (1) {
519 		static int done_help;
520 
521 		run_argv(&argc, &argv);
522 
523 		if (errno != ENOENT)
524 			break;
525 
526 		if (!done_help) {
527 			cmd = argv[0] = help_unknown_cmd(cmd);
528 			done_help = 1;
529 		} else
530 			break;
531 	}
532 
533 	fprintf(stderr, "Failed to run command '%s': %s\n",
534 		cmd, str_error_r(errno, sbuf, sizeof(sbuf)));
535 out:
536 	return 1;
537 }
538