xref: /openbmc/linux/tools/perf/perf.c (revision 133f9794)
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)
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 		/*
194 		 * Check remaining flags.
195 		 */
196 		if (strstarts(cmd, CMD_EXEC_PATH)) {
197 			cmd += strlen(CMD_EXEC_PATH);
198 			if (*cmd == '=')
199 				set_argv_exec_path(cmd + 1);
200 			else {
201 				puts(get_argv_exec_path());
202 				exit(0);
203 			}
204 		} else if (!strcmp(cmd, "--html-path")) {
205 			puts(system_path(PERF_HTML_PATH));
206 			exit(0);
207 		} else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
208 			use_pager = 1;
209 		} else if (!strcmp(cmd, "--no-pager")) {
210 			use_pager = 0;
211 			if (envchanged)
212 				*envchanged = 1;
213 		} else if (!strcmp(cmd, "--debugfs-dir")) {
214 			if (*argc < 2) {
215 				fprintf(stderr, "No directory given for --debugfs-dir.\n");
216 				usage(perf_usage_string);
217 			}
218 			tracing_path_set((*argv)[1]);
219 			if (envchanged)
220 				*envchanged = 1;
221 			(*argv)++;
222 			(*argc)--;
223 		} else if (!strcmp(cmd, "--buildid-dir")) {
224 			if (*argc < 2) {
225 				fprintf(stderr, "No directory given for --buildid-dir.\n");
226 				usage(perf_usage_string);
227 			}
228 			set_buildid_dir((*argv)[1]);
229 			if (envchanged)
230 				*envchanged = 1;
231 			(*argv)++;
232 			(*argc)--;
233 		} else if (strstarts(cmd, CMD_DEBUGFS_DIR)) {
234 			tracing_path_set(cmd + strlen(CMD_DEBUGFS_DIR));
235 			fprintf(stderr, "dir: %s\n", tracing_path);
236 			if (envchanged)
237 				*envchanged = 1;
238 		} else if (!strcmp(cmd, "--list-cmds")) {
239 			unsigned int i;
240 
241 			for (i = 0; i < ARRAY_SIZE(commands); i++) {
242 				struct cmd_struct *p = commands+i;
243 				printf("%s ", p->cmd);
244 			}
245 			putchar('\n');
246 			exit(0);
247 		} else if (!strcmp(cmd, "--list-opts")) {
248 			unsigned int i;
249 
250 			for (i = 0; i < ARRAY_SIZE(options)-1; i++) {
251 				struct option *p = options+i;
252 				printf("--%s ", p->long_name);
253 			}
254 			putchar('\n');
255 			exit(0);
256 		} else if (!strcmp(cmd, "--debug")) {
257 			if (*argc < 2) {
258 				fprintf(stderr, "No variable specified for --debug.\n");
259 				usage(perf_usage_string);
260 			}
261 			if (perf_debug_option((*argv)[1]))
262 				usage(perf_usage_string);
263 
264 			(*argv)++;
265 			(*argc)--;
266 		} else {
267 			fprintf(stderr, "Unknown option: %s\n", cmd);
268 			usage(perf_usage_string);
269 		}
270 
271 		(*argv)++;
272 		(*argc)--;
273 		handled++;
274 	}
275 	return handled;
276 }
277 
278 #define RUN_SETUP	(1<<0)
279 #define USE_PAGER	(1<<1)
280 
281 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
282 {
283 	int status;
284 	struct stat st;
285 	char sbuf[STRERR_BUFSIZE];
286 
287 	if (use_browser == -1)
288 		use_browser = check_browser_config(p->cmd);
289 
290 	if (use_pager == -1 && p->option & RUN_SETUP)
291 		use_pager = check_pager_config(p->cmd);
292 	if (use_pager == -1 && p->option & USE_PAGER)
293 		use_pager = 1;
294 	commit_pager_choice();
295 
296 	perf_env__set_cmdline(&perf_env, argc, argv);
297 	status = p->fn(argc, argv);
298 	perf_config__exit();
299 	exit_browser(status);
300 	perf_env__exit(&perf_env);
301 	bpf__clear();
302 
303 	if (status)
304 		return status & 0xff;
305 
306 	/* Somebody closed stdout? */
307 	if (fstat(fileno(stdout), &st))
308 		return 0;
309 	/* Ignore write errors for pipes and sockets.. */
310 	if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
311 		return 0;
312 
313 	status = 1;
314 	/* Check for ENOSPC and EIO errors.. */
315 	if (fflush(stdout)) {
316 		fprintf(stderr, "write failure on standard output: %s",
317 			str_error_r(errno, sbuf, sizeof(sbuf)));
318 		goto out;
319 	}
320 	if (ferror(stdout)) {
321 		fprintf(stderr, "unknown write failure on standard output");
322 		goto out;
323 	}
324 	if (fclose(stdout)) {
325 		fprintf(stderr, "close failed on standard output: %s",
326 			str_error_r(errno, sbuf, sizeof(sbuf)));
327 		goto out;
328 	}
329 	status = 0;
330 out:
331 	return status;
332 }
333 
334 static void handle_internal_command(int argc, const char **argv)
335 {
336 	const char *cmd = argv[0];
337 	unsigned int i;
338 
339 	/* Turn "perf cmd --help" into "perf help cmd" */
340 	if (argc > 1 && !strcmp(argv[1], "--help")) {
341 		argv[1] = argv[0];
342 		argv[0] = cmd = "help";
343 	}
344 
345 	for (i = 0; i < ARRAY_SIZE(commands); i++) {
346 		struct cmd_struct *p = commands+i;
347 		if (strcmp(p->cmd, cmd))
348 			continue;
349 		exit(run_builtin(p, argc, argv));
350 	}
351 }
352 
353 static void execv_dashed_external(const char **argv)
354 {
355 	char *cmd;
356 	const char *tmp;
357 	int status;
358 
359 	if (asprintf(&cmd, "perf-%s", argv[0]) < 0)
360 		goto do_die;
361 
362 	/*
363 	 * argv[0] must be the perf command, but the argv array
364 	 * belongs to the caller, and may be reused in
365 	 * subsequent loop iterations. Save argv[0] and
366 	 * restore it on error.
367 	 */
368 	tmp = argv[0];
369 	argv[0] = cmd;
370 
371 	/*
372 	 * if we fail because the command is not found, it is
373 	 * OK to return. Otherwise, we just pass along the status code.
374 	 */
375 	status = run_command_v_opt(argv, 0);
376 	if (status != -ERR_RUN_COMMAND_EXEC) {
377 		if (IS_RUN_COMMAND_ERR(status)) {
378 do_die:
379 			pr_err("FATAL: unable to run '%s'", argv[0]);
380 			status = -128;
381 		}
382 		exit(-status);
383 	}
384 	errno = ENOENT; /* as if we called execvp */
385 
386 	argv[0] = tmp;
387 	zfree(&cmd);
388 }
389 
390 static int run_argv(int *argcp, const char ***argv)
391 {
392 	/* See if it's an internal command */
393 	handle_internal_command(*argcp, *argv);
394 
395 	/* .. then try the external ones */
396 	execv_dashed_external(*argv);
397 	return 0;
398 }
399 
400 static void pthread__block_sigwinch(void)
401 {
402 	sigset_t set;
403 
404 	sigemptyset(&set);
405 	sigaddset(&set, SIGWINCH);
406 	pthread_sigmask(SIG_BLOCK, &set, NULL);
407 }
408 
409 void pthread__unblock_sigwinch(void)
410 {
411 	sigset_t set;
412 
413 	sigemptyset(&set);
414 	sigaddset(&set, SIGWINCH);
415 	pthread_sigmask(SIG_UNBLOCK, &set, NULL);
416 }
417 
418 #ifdef _SC_LEVEL1_DCACHE_LINESIZE
419 #define cache_line_size(cacheline_sizep) *cacheline_sizep = sysconf(_SC_LEVEL1_DCACHE_LINESIZE)
420 #else
421 static void cache_line_size(int *cacheline_sizep)
422 {
423 	if (sysfs__read_int("devices/system/cpu/cpu0/cache/index0/coherency_line_size", cacheline_sizep))
424 		pr_debug("cannot determine cache line size");
425 }
426 #endif
427 
428 int main(int argc, const char **argv)
429 {
430 	int err;
431 	const char *cmd;
432 	char sbuf[STRERR_BUFSIZE];
433 	int value;
434 
435 	/* libsubcmd init */
436 	exec_cmd_init("perf", PREFIX, PERF_EXEC_PATH, EXEC_PATH_ENVIRONMENT);
437 	pager_init(PERF_PAGER_ENVIRONMENT);
438 
439 	/* The page_size is placed in util object. */
440 	page_size = sysconf(_SC_PAGE_SIZE);
441 	cache_line_size(&cacheline_size);
442 
443 	if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0)
444 		sysctl_perf_event_max_stack = value;
445 
446 	if (sysctl__read_int("kernel/perf_event_max_contexts_per_stack", &value) == 0)
447 		sysctl_perf_event_max_contexts_per_stack = value;
448 
449 	cmd = extract_argv0_path(argv[0]);
450 	if (!cmd)
451 		cmd = "perf-help";
452 
453 	srandom(time(NULL));
454 
455 	perf_config__init();
456 	err = perf_config(perf_default_config, NULL);
457 	if (err)
458 		return err;
459 	set_buildid_dir(NULL);
460 
461 	/* get debugfs/tracefs mount point from /proc/mounts */
462 	tracing_path_mount();
463 
464 	/*
465 	 * "perf-xxxx" is the same as "perf xxxx", but we obviously:
466 	 *
467 	 *  - cannot take flags in between the "perf" and the "xxxx".
468 	 *  - cannot execute it externally (since it would just do
469 	 *    the same thing over again)
470 	 *
471 	 * So we just directly call the internal command handler. If that one
472 	 * fails to handle this, then maybe we just run a renamed perf binary
473 	 * that contains a dash in its name. To handle this scenario, we just
474 	 * fall through and ignore the "xxxx" part of the command string.
475 	 */
476 	if (strstarts(cmd, "perf-")) {
477 		cmd += 5;
478 		argv[0] = cmd;
479 		handle_internal_command(argc, argv);
480 		/*
481 		 * If the command is handled, the above function does not
482 		 * return undo changes and fall through in such a case.
483 		 */
484 		cmd -= 5;
485 		argv[0] = cmd;
486 	}
487 	if (strstarts(cmd, "trace")) {
488 #if defined(HAVE_LIBAUDIT_SUPPORT) || defined(HAVE_SYSCALL_TABLE)
489 		setup_path();
490 		argv[0] = "trace";
491 		return cmd_trace(argc, argv);
492 #else
493 		fprintf(stderr,
494 			"trace command not available: missing audit-libs devel package at build time.\n");
495 		goto out;
496 #endif
497 	}
498 	/* Look for flags.. */
499 	argv++;
500 	argc--;
501 	handle_options(&argv, &argc, NULL);
502 	commit_pager_choice();
503 
504 	if (argc > 0) {
505 		if (strstarts(argv[0], "--"))
506 			argv[0] += 2;
507 	} else {
508 		/* The user didn't specify a command; give them help */
509 		printf("\n usage: %s\n\n", perf_usage_string);
510 		list_common_cmds_help();
511 		printf("\n %s\n\n", perf_more_info_string);
512 		goto out;
513 	}
514 	cmd = argv[0];
515 
516 	test_attr__init();
517 
518 	/*
519 	 * We use PATH to find perf commands, but we prepend some higher
520 	 * precedence paths: the "--exec-path" option, the PERF_EXEC_PATH
521 	 * environment, and the $(perfexecdir) from the Makefile at build
522 	 * time.
523 	 */
524 	setup_path();
525 	/*
526 	 * Block SIGWINCH notifications so that the thread that wants it can
527 	 * unblock and get syscalls like select interrupted instead of waiting
528 	 * forever while the signal goes to some other non interested thread.
529 	 */
530 	pthread__block_sigwinch();
531 
532 	perf_debug_setup();
533 
534 	while (1) {
535 		static int done_help;
536 
537 		run_argv(&argc, &argv);
538 
539 		if (errno != ENOENT)
540 			break;
541 
542 		if (!done_help) {
543 			cmd = argv[0] = help_unknown_cmd(cmd);
544 			done_help = 1;
545 		} else
546 			break;
547 	}
548 
549 	fprintf(stderr, "Failed to run command '%s': %s\n",
550 		cmd, str_error_r(errno, sbuf, sizeof(sbuf)));
551 out:
552 	return 1;
553 }
554