xref: /openbmc/linux/tools/perf/perf.c (revision 4cff79e9)
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 "util/quote.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 <api/fs/fs.h>
23 #include <api/fs/tracing_path.h>
24 #include <errno.h>
25 #include <pthread.h>
26 #include <signal.h>
27 #include <stdlib.h>
28 #include <time.h>
29 #include <sys/types.h>
30 #include <sys/stat.h>
31 #include <unistd.h>
32 #include <linux/kernel.h>
33 
34 const char perf_usage_string[] =
35 	"perf [--version] [--help] [OPTIONS] COMMAND [ARGS]";
36 
37 const char perf_more_info_string[] =
38 	"See 'perf help COMMAND' for more information on a specific command.";
39 
40 static int use_pager = -1;
41 const char *input_name;
42 
43 struct cmd_struct {
44 	const char *cmd;
45 	int (*fn)(int, const char **);
46 	int option;
47 };
48 
49 static struct cmd_struct commands[] = {
50 	{ "buildid-cache", cmd_buildid_cache, 0 },
51 	{ "buildid-list", cmd_buildid_list, 0 },
52 	{ "config",	cmd_config,	0 },
53 	{ "c2c",	cmd_c2c,	0 },
54 	{ "diff",	cmd_diff,	0 },
55 	{ "evlist",	cmd_evlist,	0 },
56 	{ "help",	cmd_help,	0 },
57 	{ "kallsyms",	cmd_kallsyms,	0 },
58 	{ "list",	cmd_list,	0 },
59 	{ "record",	cmd_record,	0 },
60 	{ "report",	cmd_report,	0 },
61 	{ "bench",	cmd_bench,	0 },
62 	{ "stat",	cmd_stat,	0 },
63 	{ "timechart",	cmd_timechart,	0 },
64 	{ "top",	cmd_top,	0 },
65 	{ "annotate",	cmd_annotate,	0 },
66 	{ "version",	cmd_version,	0 },
67 	{ "script",	cmd_script,	0 },
68 	{ "sched",	cmd_sched,	0 },
69 #ifdef HAVE_LIBELF_SUPPORT
70 	{ "probe",	cmd_probe,	0 },
71 #endif
72 	{ "kmem",	cmd_kmem,	0 },
73 	{ "lock",	cmd_lock,	0 },
74 	{ "kvm",	cmd_kvm,	0 },
75 	{ "test",	cmd_test,	0 },
76 #if defined(HAVE_LIBAUDIT_SUPPORT) || defined(HAVE_SYSCALL_TABLE_SUPPORT)
77 	{ "trace",	cmd_trace,	0 },
78 #endif
79 	{ "inject",	cmd_inject,	0 },
80 	{ "mem",	cmd_mem,	0 },
81 	{ "data",	cmd_data,	0 },
82 	{ "ftrace",	cmd_ftrace,	0 },
83 };
84 
85 struct pager_config {
86 	const char *cmd;
87 	int val;
88 };
89 
90 static int pager_command_config(const char *var, const char *value, void *data)
91 {
92 	struct pager_config *c = data;
93 	if (strstarts(var, "pager.") && !strcmp(var + 6, c->cmd))
94 		c->val = perf_config_bool(var, value);
95 	return 0;
96 }
97 
98 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
99 static int check_pager_config(const char *cmd)
100 {
101 	int err;
102 	struct pager_config c;
103 	c.cmd = cmd;
104 	c.val = -1;
105 	err = perf_config(pager_command_config, &c);
106 	return err ?: c.val;
107 }
108 
109 static int browser_command_config(const char *var, const char *value, void *data)
110 {
111 	struct pager_config *c = data;
112 	if (strstarts(var, "tui.") && !strcmp(var + 4, c->cmd))
113 		c->val = perf_config_bool(var, value);
114 	if (strstarts(var, "gtk.") && !strcmp(var + 4, c->cmd))
115 		c->val = perf_config_bool(var, value) ? 2 : 0;
116 	return 0;
117 }
118 
119 /*
120  * returns 0 for "no tui", 1 for "use tui", 2 for "use gtk",
121  * and -1 for "not specified"
122  */
123 static int check_browser_config(const char *cmd)
124 {
125 	int err;
126 	struct pager_config c;
127 	c.cmd = cmd;
128 	c.val = -1;
129 	err = perf_config(browser_command_config, &c);
130 	return err ?: c.val;
131 }
132 
133 static void commit_pager_choice(void)
134 {
135 	switch (use_pager) {
136 	case 0:
137 		setenv(PERF_PAGER_ENVIRONMENT, "cat", 1);
138 		break;
139 	case 1:
140 		/* setup_pager(); */
141 		break;
142 	default:
143 		break;
144 	}
145 }
146 
147 struct option options[] = {
148 	OPT_ARGUMENT("help", "help"),
149 	OPT_ARGUMENT("version", "version"),
150 	OPT_ARGUMENT("exec-path", "exec-path"),
151 	OPT_ARGUMENT("html-path", "html-path"),
152 	OPT_ARGUMENT("paginate", "paginate"),
153 	OPT_ARGUMENT("no-pager", "no-pager"),
154 	OPT_ARGUMENT("debugfs-dir", "debugfs-dir"),
155 	OPT_ARGUMENT("buildid-dir", "buildid-dir"),
156 	OPT_ARGUMENT("list-cmds", "list-cmds"),
157 	OPT_ARGUMENT("list-opts", "list-opts"),
158 	OPT_ARGUMENT("debug", "debug"),
159 	OPT_END()
160 };
161 
162 static int handle_options(const char ***argv, int *argc, int *envchanged)
163 {
164 	int handled = 0;
165 
166 	while (*argc > 0) {
167 		const char *cmd = (*argv)[0];
168 		if (cmd[0] != '-')
169 			break;
170 
171 		/*
172 		 * For legacy reasons, the "version" and "help"
173 		 * commands can be written with "--" prepended
174 		 * to make them look like flags.
175 		 */
176 		if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
177 			break;
178 
179 		/*
180 		 * Shortcut for '-h' and '-v' options to invoke help
181 		 * and version command.
182 		 */
183 		if (!strcmp(cmd, "-h")) {
184 			(*argv)[0] = "--help";
185 			break;
186 		}
187 
188 		if (!strcmp(cmd, "-v")) {
189 			(*argv)[0] = "--version";
190 			break;
191 		}
192 
193 		if (!strcmp(cmd, "-vv")) {
194 			(*argv)[0] = "version";
195 			version_verbose = 1;
196 			break;
197 		}
198 
199 		/*
200 		 * Check remaining flags.
201 		 */
202 		if (strstarts(cmd, CMD_EXEC_PATH)) {
203 			cmd += strlen(CMD_EXEC_PATH);
204 			if (*cmd == '=')
205 				set_argv_exec_path(cmd + 1);
206 			else {
207 				puts(get_argv_exec_path());
208 				exit(0);
209 			}
210 		} else if (!strcmp(cmd, "--html-path")) {
211 			puts(system_path(PERF_HTML_PATH));
212 			exit(0);
213 		} else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
214 			use_pager = 1;
215 		} else if (!strcmp(cmd, "--no-pager")) {
216 			use_pager = 0;
217 			if (envchanged)
218 				*envchanged = 1;
219 		} else if (!strcmp(cmd, "--debugfs-dir")) {
220 			if (*argc < 2) {
221 				fprintf(stderr, "No directory given for --debugfs-dir.\n");
222 				usage(perf_usage_string);
223 			}
224 			tracing_path_set((*argv)[1]);
225 			if (envchanged)
226 				*envchanged = 1;
227 			(*argv)++;
228 			(*argc)--;
229 		} else if (!strcmp(cmd, "--buildid-dir")) {
230 			if (*argc < 2) {
231 				fprintf(stderr, "No directory given for --buildid-dir.\n");
232 				usage(perf_usage_string);
233 			}
234 			set_buildid_dir((*argv)[1]);
235 			if (envchanged)
236 				*envchanged = 1;
237 			(*argv)++;
238 			(*argc)--;
239 		} else if (strstarts(cmd, CMD_DEBUGFS_DIR)) {
240 			tracing_path_set(cmd + strlen(CMD_DEBUGFS_DIR));
241 			fprintf(stderr, "dir: %s\n", tracing_path);
242 			if (envchanged)
243 				*envchanged = 1;
244 		} else if (!strcmp(cmd, "--list-cmds")) {
245 			unsigned int i;
246 
247 			for (i = 0; i < ARRAY_SIZE(commands); i++) {
248 				struct cmd_struct *p = commands+i;
249 				printf("%s ", p->cmd);
250 			}
251 			putchar('\n');
252 			exit(0);
253 		} else if (!strcmp(cmd, "--list-opts")) {
254 			unsigned int i;
255 
256 			for (i = 0; i < ARRAY_SIZE(options)-1; i++) {
257 				struct option *p = options+i;
258 				printf("--%s ", p->long_name);
259 			}
260 			putchar('\n');
261 			exit(0);
262 		} else if (!strcmp(cmd, "--debug")) {
263 			if (*argc < 2) {
264 				fprintf(stderr, "No variable specified for --debug.\n");
265 				usage(perf_usage_string);
266 			}
267 			if (perf_debug_option((*argv)[1]))
268 				usage(perf_usage_string);
269 
270 			(*argv)++;
271 			(*argc)--;
272 		} else {
273 			fprintf(stderr, "Unknown option: %s\n", cmd);
274 			usage(perf_usage_string);
275 		}
276 
277 		(*argv)++;
278 		(*argc)--;
279 		handled++;
280 	}
281 	return handled;
282 }
283 
284 #define RUN_SETUP	(1<<0)
285 #define USE_PAGER	(1<<1)
286 
287 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
288 {
289 	int status;
290 	struct stat st;
291 	char sbuf[STRERR_BUFSIZE];
292 
293 	if (use_browser == -1)
294 		use_browser = check_browser_config(p->cmd);
295 
296 	if (use_pager == -1 && p->option & RUN_SETUP)
297 		use_pager = check_pager_config(p->cmd);
298 	if (use_pager == -1 && p->option & USE_PAGER)
299 		use_pager = 1;
300 	commit_pager_choice();
301 
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 #ifdef _SC_LEVEL1_DCACHE_LINESIZE
425 #define cache_line_size(cacheline_sizep) *cacheline_sizep = sysconf(_SC_LEVEL1_DCACHE_LINESIZE)
426 #else
427 static void cache_line_size(int *cacheline_sizep)
428 {
429 	if (sysfs__read_int("devices/system/cpu/cpu0/cache/index0/coherency_line_size", cacheline_sizep))
430 		pr_debug("cannot determine cache line size");
431 }
432 #endif
433 
434 int main(int argc, const char **argv)
435 {
436 	int err;
437 	const char *cmd;
438 	char sbuf[STRERR_BUFSIZE];
439 	int value;
440 
441 	/* libsubcmd init */
442 	exec_cmd_init("perf", PREFIX, PERF_EXEC_PATH, EXEC_PATH_ENVIRONMENT);
443 	pager_init(PERF_PAGER_ENVIRONMENT);
444 
445 	/* The page_size is placed in util object. */
446 	page_size = sysconf(_SC_PAGE_SIZE);
447 	cache_line_size(&cacheline_size);
448 
449 	if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0)
450 		sysctl_perf_event_max_stack = value;
451 
452 	if (sysctl__read_int("kernel/perf_event_max_contexts_per_stack", &value) == 0)
453 		sysctl_perf_event_max_contexts_per_stack = value;
454 
455 	cmd = extract_argv0_path(argv[0]);
456 	if (!cmd)
457 		cmd = "perf-help";
458 
459 	srandom(time(NULL));
460 
461 	perf_config__init();
462 	err = perf_config(perf_default_config, NULL);
463 	if (err)
464 		return err;
465 	set_buildid_dir(NULL);
466 
467 	/* get debugfs/tracefs mount point from /proc/mounts */
468 	tracing_path_mount();
469 
470 	/*
471 	 * "perf-xxxx" is the same as "perf xxxx", but we obviously:
472 	 *
473 	 *  - cannot take flags in between the "perf" and the "xxxx".
474 	 *  - cannot execute it externally (since it would just do
475 	 *    the same thing over again)
476 	 *
477 	 * So we just directly call the internal command handler. If that one
478 	 * fails to handle this, then maybe we just run a renamed perf binary
479 	 * that contains a dash in its name. To handle this scenario, we just
480 	 * fall through and ignore the "xxxx" part of the command string.
481 	 */
482 	if (strstarts(cmd, "perf-")) {
483 		cmd += 5;
484 		argv[0] = cmd;
485 		handle_internal_command(argc, argv);
486 		/*
487 		 * If the command is handled, the above function does not
488 		 * return undo changes and fall through in such a case.
489 		 */
490 		cmd -= 5;
491 		argv[0] = cmd;
492 	}
493 	if (strstarts(cmd, "trace")) {
494 #if defined(HAVE_LIBAUDIT_SUPPORT) || defined(HAVE_SYSCALL_TABLE_SUPPORT)
495 		setup_path();
496 		argv[0] = "trace";
497 		return cmd_trace(argc, argv);
498 #else
499 		fprintf(stderr,
500 			"trace command not available: missing audit-libs devel package at build time.\n");
501 		goto out;
502 #endif
503 	}
504 	/* Look for flags.. */
505 	argv++;
506 	argc--;
507 	handle_options(&argv, &argc, NULL);
508 	commit_pager_choice();
509 
510 	if (argc > 0) {
511 		if (strstarts(argv[0], "--"))
512 			argv[0] += 2;
513 	} else {
514 		/* The user didn't specify a command; give them help */
515 		printf("\n usage: %s\n\n", perf_usage_string);
516 		list_common_cmds_help();
517 		printf("\n %s\n\n", perf_more_info_string);
518 		goto out;
519 	}
520 	cmd = argv[0];
521 
522 	test_attr__init();
523 
524 	/*
525 	 * We use PATH to find perf commands, but we prepend some higher
526 	 * precedence paths: the "--exec-path" option, the PERF_EXEC_PATH
527 	 * environment, and the $(perfexecdir) from the Makefile at build
528 	 * time.
529 	 */
530 	setup_path();
531 	/*
532 	 * Block SIGWINCH notifications so that the thread that wants it can
533 	 * unblock and get syscalls like select interrupted instead of waiting
534 	 * forever while the signal goes to some other non interested thread.
535 	 */
536 	pthread__block_sigwinch();
537 
538 	perf_debug_setup();
539 
540 	while (1) {
541 		static int done_help;
542 
543 		run_argv(&argc, &argv);
544 
545 		if (errno != ENOENT)
546 			break;
547 
548 		if (!done_help) {
549 			cmd = argv[0] = help_unknown_cmd(cmd);
550 			done_help = 1;
551 		} else
552 			break;
553 	}
554 
555 	fprintf(stderr, "Failed to run command '%s': %s\n",
556 		cmd, str_error_r(errno, sbuf, sizeof(sbuf)));
557 out:
558 	return 1;
559 }
560