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/exec_cmd.h"
12 #include "util/cache.h"
13 #include "util/quote.h"
14 #include "util/run-command.h"
15 #include "util/parse-events.h"
16 #include <lk/debugfs.h>
17 #include <pthread.h>
18 
19 const char perf_usage_string[] =
20 	"perf [--version] [--help] COMMAND [ARGS]";
21 
22 const char perf_more_info_string[] =
23 	"See 'perf help COMMAND' for more information on a specific command.";
24 
25 int use_browser = -1;
26 static int use_pager = -1;
27 const char *input_name;
28 
29 struct cmd_struct {
30 	const char *cmd;
31 	int (*fn)(int, const char **, const char *);
32 	int option;
33 };
34 
35 static struct cmd_struct commands[] = {
36 	{ "buildid-cache", cmd_buildid_cache, 0 },
37 	{ "buildid-list", cmd_buildid_list, 0 },
38 	{ "diff",	cmd_diff,	0 },
39 	{ "evlist",	cmd_evlist,	0 },
40 	{ "help",	cmd_help,	0 },
41 	{ "list",	cmd_list,	0 },
42 	{ "record",	cmd_record,	0 },
43 	{ "report",	cmd_report,	0 },
44 	{ "bench",	cmd_bench,	0 },
45 	{ "stat",	cmd_stat,	0 },
46 	{ "timechart",	cmd_timechart,	0 },
47 	{ "top",	cmd_top,	0 },
48 	{ "annotate",	cmd_annotate,	0 },
49 	{ "version",	cmd_version,	0 },
50 	{ "script",	cmd_script,	0 },
51 	{ "sched",	cmd_sched,	0 },
52 #ifdef LIBELF_SUPPORT
53 	{ "probe",	cmd_probe,	0 },
54 #endif
55 	{ "kmem",	cmd_kmem,	0 },
56 	{ "lock",	cmd_lock,	0 },
57 	{ "kvm",	cmd_kvm,	0 },
58 	{ "test",	cmd_test,	0 },
59 #ifdef LIBAUDIT_SUPPORT
60 	{ "trace",	cmd_trace,	0 },
61 #endif
62 	{ "inject",	cmd_inject,	0 },
63 	{ "mem",	cmd_mem,	0 },
64 };
65 
66 struct pager_config {
67 	const char *cmd;
68 	int val;
69 };
70 
pager_command_config(const char * var,const char * value,void * data)71 static int pager_command_config(const char *var, const char *value, void *data)
72 {
73 	struct pager_config *c = data;
74 	if (!prefixcmp(var, "pager.") && !strcmp(var + 6, c->cmd))
75 		c->val = perf_config_bool(var, value);
76 	return 0;
77 }
78 
79 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
check_pager_config(const char * cmd)80 int check_pager_config(const char *cmd)
81 {
82 	struct pager_config c;
83 	c.cmd = cmd;
84 	c.val = -1;
85 	perf_config(pager_command_config, &c);
86 	return c.val;
87 }
88 
browser_command_config(const char * var,const char * value,void * data)89 static int browser_command_config(const char *var, const char *value, void *data)
90 {
91 	struct pager_config *c = data;
92 	if (!prefixcmp(var, "tui.") && !strcmp(var + 4, c->cmd))
93 		c->val = perf_config_bool(var, value);
94 	if (!prefixcmp(var, "gtk.") && !strcmp(var + 4, c->cmd))
95 		c->val = perf_config_bool(var, value) ? 2 : 0;
96 	return 0;
97 }
98 
99 /*
100  * returns 0 for "no tui", 1 for "use tui", 2 for "use gtk",
101  * and -1 for "not specified"
102  */
check_browser_config(const char * cmd)103 static int check_browser_config(const char *cmd)
104 {
105 	struct pager_config c;
106 	c.cmd = cmd;
107 	c.val = -1;
108 	perf_config(browser_command_config, &c);
109 	return c.val;
110 }
111 
commit_pager_choice(void)112 static void commit_pager_choice(void)
113 {
114 	switch (use_pager) {
115 	case 0:
116 		setenv("PERF_PAGER", "cat", 1);
117 		break;
118 	case 1:
119 		/* setup_pager(); */
120 		break;
121 	default:
122 		break;
123 	}
124 }
125 
handle_options(const char *** argv,int * argc,int * envchanged)126 static int handle_options(const char ***argv, int *argc, int *envchanged)
127 {
128 	int handled = 0;
129 
130 	while (*argc > 0) {
131 		const char *cmd = (*argv)[0];
132 		if (cmd[0] != '-')
133 			break;
134 
135 		/*
136 		 * For legacy reasons, the "version" and "help"
137 		 * commands can be written with "--" prepended
138 		 * to make them look like flags.
139 		 */
140 		if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
141 			break;
142 
143 		/*
144 		 * Check remaining flags.
145 		 */
146 		if (!prefixcmp(cmd, CMD_EXEC_PATH)) {
147 			cmd += strlen(CMD_EXEC_PATH);
148 			if (*cmd == '=')
149 				perf_set_argv_exec_path(cmd + 1);
150 			else {
151 				puts(perf_exec_path());
152 				exit(0);
153 			}
154 		} else if (!strcmp(cmd, "--html-path")) {
155 			puts(system_path(PERF_HTML_PATH));
156 			exit(0);
157 		} else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
158 			use_pager = 1;
159 		} else if (!strcmp(cmd, "--no-pager")) {
160 			use_pager = 0;
161 			if (envchanged)
162 				*envchanged = 1;
163 		} else if (!strcmp(cmd, "--perf-dir")) {
164 			if (*argc < 2) {
165 				fprintf(stderr, "No directory given for --perf-dir.\n");
166 				usage(perf_usage_string);
167 			}
168 			setenv(PERF_DIR_ENVIRONMENT, (*argv)[1], 1);
169 			if (envchanged)
170 				*envchanged = 1;
171 			(*argv)++;
172 			(*argc)--;
173 			handled++;
174 		} else if (!prefixcmp(cmd, CMD_PERF_DIR)) {
175 			setenv(PERF_DIR_ENVIRONMENT, cmd + strlen(CMD_PERF_DIR), 1);
176 			if (envchanged)
177 				*envchanged = 1;
178 		} else if (!strcmp(cmd, "--work-tree")) {
179 			if (*argc < 2) {
180 				fprintf(stderr, "No directory given for --work-tree.\n");
181 				usage(perf_usage_string);
182 			}
183 			setenv(PERF_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
184 			if (envchanged)
185 				*envchanged = 1;
186 			(*argv)++;
187 			(*argc)--;
188 		} else if (!prefixcmp(cmd, CMD_WORK_TREE)) {
189 			setenv(PERF_WORK_TREE_ENVIRONMENT, cmd + strlen(CMD_WORK_TREE), 1);
190 			if (envchanged)
191 				*envchanged = 1;
192 		} else if (!strcmp(cmd, "--debugfs-dir")) {
193 			if (*argc < 2) {
194 				fprintf(stderr, "No directory given for --debugfs-dir.\n");
195 				usage(perf_usage_string);
196 			}
197 			perf_debugfs_set_path((*argv)[1]);
198 			if (envchanged)
199 				*envchanged = 1;
200 			(*argv)++;
201 			(*argc)--;
202 		} else if (!prefixcmp(cmd, CMD_DEBUGFS_DIR)) {
203 			perf_debugfs_set_path(cmd + strlen(CMD_DEBUGFS_DIR));
204 			fprintf(stderr, "dir: %s\n", debugfs_mountpoint);
205 			if (envchanged)
206 				*envchanged = 1;
207 		} else if (!strcmp(cmd, "--list-cmds")) {
208 			unsigned int i;
209 
210 			for (i = 0; i < ARRAY_SIZE(commands); i++) {
211 				struct cmd_struct *p = commands+i;
212 				printf("%s ", p->cmd);
213 			}
214 			exit(0);
215 		} else {
216 			fprintf(stderr, "Unknown option: %s\n", cmd);
217 			usage(perf_usage_string);
218 		}
219 
220 		(*argv)++;
221 		(*argc)--;
222 		handled++;
223 	}
224 	return handled;
225 }
226 
handle_alias(int * argcp,const char *** argv)227 static int handle_alias(int *argcp, const char ***argv)
228 {
229 	int envchanged = 0, ret = 0, saved_errno = errno;
230 	int count, option_count;
231 	const char **new_argv;
232 	const char *alias_command;
233 	char *alias_string;
234 
235 	alias_command = (*argv)[0];
236 	alias_string = alias_lookup(alias_command);
237 	if (alias_string) {
238 		if (alias_string[0] == '!') {
239 			if (*argcp > 1) {
240 				struct strbuf buf;
241 
242 				strbuf_init(&buf, PATH_MAX);
243 				strbuf_addstr(&buf, alias_string);
244 				sq_quote_argv(&buf, (*argv) + 1, PATH_MAX);
245 				free(alias_string);
246 				alias_string = buf.buf;
247 			}
248 			ret = system(alias_string + 1);
249 			if (ret >= 0 && WIFEXITED(ret) &&
250 			    WEXITSTATUS(ret) != 127)
251 				exit(WEXITSTATUS(ret));
252 			die("Failed to run '%s' when expanding alias '%s'",
253 			    alias_string + 1, alias_command);
254 		}
255 		count = split_cmdline(alias_string, &new_argv);
256 		if (count < 0)
257 			die("Bad alias.%s string", alias_command);
258 		option_count = handle_options(&new_argv, &count, &envchanged);
259 		if (envchanged)
260 			die("alias '%s' changes environment variables\n"
261 				 "You can use '!perf' in the alias to do this.",
262 				 alias_command);
263 		memmove(new_argv - option_count, new_argv,
264 				count * sizeof(char *));
265 		new_argv -= option_count;
266 
267 		if (count < 1)
268 			die("empty alias for %s", alias_command);
269 
270 		if (!strcmp(alias_command, new_argv[0]))
271 			die("recursive alias: %s", alias_command);
272 
273 		new_argv = realloc(new_argv, sizeof(char *) *
274 				    (count + *argcp + 1));
275 		/* insert after command name */
276 		memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
277 		new_argv[count + *argcp] = NULL;
278 
279 		*argv = new_argv;
280 		*argcp += count - 1;
281 
282 		ret = 1;
283 	}
284 
285 	errno = saved_errno;
286 
287 	return ret;
288 }
289 
290 const char perf_version_string[] = PERF_VERSION;
291 
292 #define RUN_SETUP	(1<<0)
293 #define USE_PAGER	(1<<1)
294 /*
295  * require working tree to be present -- anything uses this needs
296  * RUN_SETUP for reading from the configuration file.
297  */
298 #define NEED_WORK_TREE	(1<<2)
299 
run_builtin(struct cmd_struct * p,int argc,const char ** argv)300 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
301 {
302 	int status;
303 	struct stat st;
304 	const char *prefix;
305 
306 	prefix = NULL;
307 	if (p->option & RUN_SETUP)
308 		prefix = NULL; /* setup_perf_directory(); */
309 
310 	if (use_browser == -1)
311 		use_browser = check_browser_config(p->cmd);
312 
313 	if (use_pager == -1 && p->option & RUN_SETUP)
314 		use_pager = check_pager_config(p->cmd);
315 	if (use_pager == -1 && p->option & USE_PAGER)
316 		use_pager = 1;
317 	commit_pager_choice();
318 
319 	status = p->fn(argc, argv, prefix);
320 	exit_browser(status);
321 
322 	if (status)
323 		return status & 0xff;
324 
325 	/* Somebody closed stdout? */
326 	if (fstat(fileno(stdout), &st))
327 		return 0;
328 	/* Ignore write errors for pipes and sockets.. */
329 	if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
330 		return 0;
331 
332 	status = 1;
333 	/* Check for ENOSPC and EIO errors.. */
334 	if (fflush(stdout)) {
335 		fprintf(stderr, "write failure on standard output: %s", strerror(errno));
336 		goto out;
337 	}
338 	if (ferror(stdout)) {
339 		fprintf(stderr, "unknown write failure on standard output");
340 		goto out;
341 	}
342 	if (fclose(stdout)) {
343 		fprintf(stderr, "close failed on standard output: %s", strerror(errno));
344 		goto out;
345 	}
346 	status = 0;
347 out:
348 	return status;
349 }
350 
handle_internal_command(int argc,const char ** argv)351 static void handle_internal_command(int argc, const char **argv)
352 {
353 	const char *cmd = argv[0];
354 	unsigned int i;
355 	static const char ext[] = STRIP_EXTENSION;
356 
357 	if (sizeof(ext) > 1) {
358 		i = strlen(argv[0]) - strlen(ext);
359 		if (i > 0 && !strcmp(argv[0] + i, ext)) {
360 			char *argv0 = strdup(argv[0]);
361 			argv[0] = cmd = argv0;
362 			argv0[i] = '\0';
363 		}
364 	}
365 
366 	/* Turn "perf cmd --help" into "perf help cmd" */
367 	if (argc > 1 && !strcmp(argv[1], "--help")) {
368 		argv[1] = argv[0];
369 		argv[0] = cmd = "help";
370 	}
371 
372 	for (i = 0; i < ARRAY_SIZE(commands); i++) {
373 		struct cmd_struct *p = commands+i;
374 		if (strcmp(p->cmd, cmd))
375 			continue;
376 		exit(run_builtin(p, argc, argv));
377 	}
378 }
379 
execv_dashed_external(const char ** argv)380 static void execv_dashed_external(const char **argv)
381 {
382 	struct strbuf cmd = STRBUF_INIT;
383 	const char *tmp;
384 	int status;
385 
386 	strbuf_addf(&cmd, "perf-%s", argv[0]);
387 
388 	/*
389 	 * argv[0] must be the perf command, but the argv array
390 	 * belongs to the caller, and may be reused in
391 	 * subsequent loop iterations. Save argv[0] and
392 	 * restore it on error.
393 	 */
394 	tmp = argv[0];
395 	argv[0] = cmd.buf;
396 
397 	/*
398 	 * if we fail because the command is not found, it is
399 	 * OK to return. Otherwise, we just pass along the status code.
400 	 */
401 	status = run_command_v_opt(argv, 0);
402 	if (status != -ERR_RUN_COMMAND_EXEC) {
403 		if (IS_RUN_COMMAND_ERR(status))
404 			die("unable to run '%s'", argv[0]);
405 		exit(-status);
406 	}
407 	errno = ENOENT; /* as if we called execvp */
408 
409 	argv[0] = tmp;
410 
411 	strbuf_release(&cmd);
412 }
413 
run_argv(int * argcp,const char *** argv)414 static int run_argv(int *argcp, const char ***argv)
415 {
416 	int done_alias = 0;
417 
418 	while (1) {
419 		/* See if it's an internal command */
420 		handle_internal_command(*argcp, *argv);
421 
422 		/* .. then try the external ones */
423 		execv_dashed_external(*argv);
424 
425 		/* It could be an alias -- this works around the insanity
426 		 * of overriding "perf log" with "perf show" by having
427 		 * alias.log = show
428 		 */
429 		if (done_alias || !handle_alias(argcp, argv))
430 			break;
431 		done_alias = 1;
432 	}
433 
434 	return done_alias;
435 }
436 
pthread__block_sigwinch(void)437 static void pthread__block_sigwinch(void)
438 {
439 	sigset_t set;
440 
441 	sigemptyset(&set);
442 	sigaddset(&set, SIGWINCH);
443 	pthread_sigmask(SIG_BLOCK, &set, NULL);
444 }
445 
pthread__unblock_sigwinch(void)446 void pthread__unblock_sigwinch(void)
447 {
448 	sigset_t set;
449 
450 	sigemptyset(&set);
451 	sigaddset(&set, SIGWINCH);
452 	pthread_sigmask(SIG_UNBLOCK, &set, NULL);
453 }
454 
main(int argc,const char ** argv)455 int main(int argc, const char **argv)
456 {
457 	const char *cmd;
458 
459 	page_size = sysconf(_SC_PAGE_SIZE);
460 
461 	cmd = perf_extract_argv0_path(argv[0]);
462 	if (!cmd)
463 		cmd = "perf-help";
464 	/* get debugfs mount point from /proc/mounts */
465 	perf_debugfs_mount(NULL);
466 	/*
467 	 * "perf-xxxx" is the same as "perf xxxx", but we obviously:
468 	 *
469 	 *  - cannot take flags in between the "perf" and the "xxxx".
470 	 *  - cannot execute it externally (since it would just do
471 	 *    the same thing over again)
472 	 *
473 	 * So we just directly call the internal command handler, and
474 	 * die if that one cannot handle it.
475 	 */
476 	if (!prefixcmp(cmd, "perf-")) {
477 		cmd += 5;
478 		argv[0] = cmd;
479 		handle_internal_command(argc, argv);
480 		fprintf(stderr, "cannot handle %s internally", cmd);
481 		goto out;
482 	}
483 
484 	/* Look for flags.. */
485 	argv++;
486 	argc--;
487 	handle_options(&argv, &argc, NULL);
488 	commit_pager_choice();
489 	set_buildid_dir();
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 	while (1) {
520 		static int done_help;
521 		int was_alias = run_argv(&argc, &argv);
522 
523 		if (errno != ENOENT)
524 			break;
525 
526 		if (was_alias) {
527 			fprintf(stderr, "Expansion of alias '%s' failed; "
528 				"'%s' is not a perf-command\n",
529 				cmd, argv[0]);
530 			goto out;
531 		}
532 		if (!done_help) {
533 			cmd = argv[0] = help_unknown_cmd(cmd);
534 			done_help = 1;
535 		} else
536 			break;
537 	}
538 
539 	fprintf(stderr, "Failed to run command '%s': %s\n",
540 		cmd, strerror(errno));
541 out:
542 	return 1;
543 }
544