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 "util/debugfs.h"
17 
18 const char perf_usage_string[] =
19 	"perf [--version] [--help] COMMAND [ARGS]";
20 
21 const char perf_more_info_string[] =
22 	"See 'perf help COMMAND' for more information on a specific command.";
23 
24 int use_browser = -1;
25 static int use_pager = -1;
26 
27 struct pager_config {
28 	const char *cmd;
29 	int val;
30 };
31 
32 static char debugfs_mntpt[MAXPATHLEN];
33 
pager_command_config(const char * var,const char * value,void * data)34 static int pager_command_config(const char *var, const char *value, void *data)
35 {
36 	struct pager_config *c = data;
37 	if (!prefixcmp(var, "pager.") && !strcmp(var + 6, c->cmd))
38 		c->val = perf_config_bool(var, value);
39 	return 0;
40 }
41 
42 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
check_pager_config(const char * cmd)43 int check_pager_config(const char *cmd)
44 {
45 	struct pager_config c;
46 	c.cmd = cmd;
47 	c.val = -1;
48 	perf_config(pager_command_config, &c);
49 	return c.val;
50 }
51 
tui_command_config(const char * var,const char * value,void * data)52 static int tui_command_config(const char *var, const char *value, void *data)
53 {
54 	struct pager_config *c = data;
55 	if (!prefixcmp(var, "tui.") && !strcmp(var + 4, c->cmd))
56 		c->val = perf_config_bool(var, value);
57 	return 0;
58 }
59 
60 /* returns 0 for "no tui", 1 for "use tui", and -1 for "not specified" */
check_tui_config(const char * cmd)61 static int check_tui_config(const char *cmd)
62 {
63 	struct pager_config c;
64 	c.cmd = cmd;
65 	c.val = -1;
66 	perf_config(tui_command_config, &c);
67 	return c.val;
68 }
69 
commit_pager_choice(void)70 static void commit_pager_choice(void)
71 {
72 	switch (use_pager) {
73 	case 0:
74 		setenv("PERF_PAGER", "cat", 1);
75 		break;
76 	case 1:
77 		/* setup_pager(); */
78 		break;
79 	default:
80 		break;
81 	}
82 }
83 
set_debugfs_path(void)84 static void set_debugfs_path(void)
85 {
86 	char *path;
87 
88 	path = getenv(PERF_DEBUGFS_ENVIRONMENT);
89 	snprintf(debugfs_path, MAXPATHLEN, "%s/%s", path ?: debugfs_mntpt,
90 		 "tracing/events");
91 }
92 
handle_options(const char *** argv,int * argc,int * envchanged)93 static int handle_options(const char ***argv, int *argc, int *envchanged)
94 {
95 	int handled = 0;
96 
97 	while (*argc > 0) {
98 		const char *cmd = (*argv)[0];
99 		if (cmd[0] != '-')
100 			break;
101 
102 		/*
103 		 * For legacy reasons, the "version" and "help"
104 		 * commands can be written with "--" prepended
105 		 * to make them look like flags.
106 		 */
107 		if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
108 			break;
109 
110 		/*
111 		 * Check remaining flags.
112 		 */
113 		if (!prefixcmp(cmd, CMD_EXEC_PATH)) {
114 			cmd += strlen(CMD_EXEC_PATH);
115 			if (*cmd == '=')
116 				perf_set_argv_exec_path(cmd + 1);
117 			else {
118 				puts(perf_exec_path());
119 				exit(0);
120 			}
121 		} else if (!strcmp(cmd, "--html-path")) {
122 			puts(system_path(PERF_HTML_PATH));
123 			exit(0);
124 		} else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
125 			use_pager = 1;
126 		} else if (!strcmp(cmd, "--no-pager")) {
127 			use_pager = 0;
128 			if (envchanged)
129 				*envchanged = 1;
130 		} else if (!strcmp(cmd, "--perf-dir")) {
131 			if (*argc < 2) {
132 				fprintf(stderr, "No directory given for --perf-dir.\n");
133 				usage(perf_usage_string);
134 			}
135 			setenv(PERF_DIR_ENVIRONMENT, (*argv)[1], 1);
136 			if (envchanged)
137 				*envchanged = 1;
138 			(*argv)++;
139 			(*argc)--;
140 			handled++;
141 		} else if (!prefixcmp(cmd, CMD_PERF_DIR)) {
142 			setenv(PERF_DIR_ENVIRONMENT, cmd + strlen(CMD_PERF_DIR), 1);
143 			if (envchanged)
144 				*envchanged = 1;
145 		} else if (!strcmp(cmd, "--work-tree")) {
146 			if (*argc < 2) {
147 				fprintf(stderr, "No directory given for --work-tree.\n");
148 				usage(perf_usage_string);
149 			}
150 			setenv(PERF_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
151 			if (envchanged)
152 				*envchanged = 1;
153 			(*argv)++;
154 			(*argc)--;
155 		} else if (!prefixcmp(cmd, CMD_WORK_TREE)) {
156 			setenv(PERF_WORK_TREE_ENVIRONMENT, cmd + strlen(CMD_WORK_TREE), 1);
157 			if (envchanged)
158 				*envchanged = 1;
159 		} else if (!strcmp(cmd, "--debugfs-dir")) {
160 			if (*argc < 2) {
161 				fprintf(stderr, "No directory given for --debugfs-dir.\n");
162 				usage(perf_usage_string);
163 			}
164 			strncpy(debugfs_mntpt, (*argv)[1], MAXPATHLEN);
165 			debugfs_mntpt[MAXPATHLEN - 1] = '\0';
166 			if (envchanged)
167 				*envchanged = 1;
168 			(*argv)++;
169 			(*argc)--;
170 		} else if (!prefixcmp(cmd, CMD_DEBUGFS_DIR)) {
171 			strncpy(debugfs_mntpt, cmd + strlen(CMD_DEBUGFS_DIR), MAXPATHLEN);
172 			debugfs_mntpt[MAXPATHLEN - 1] = '\0';
173 			if (envchanged)
174 				*envchanged = 1;
175 		} else {
176 			fprintf(stderr, "Unknown option: %s\n", cmd);
177 			usage(perf_usage_string);
178 		}
179 
180 		(*argv)++;
181 		(*argc)--;
182 		handled++;
183 	}
184 	return handled;
185 }
186 
handle_alias(int * argcp,const char *** argv)187 static int handle_alias(int *argcp, const char ***argv)
188 {
189 	int envchanged = 0, ret = 0, saved_errno = errno;
190 	int count, option_count;
191 	const char **new_argv;
192 	const char *alias_command;
193 	char *alias_string;
194 
195 	alias_command = (*argv)[0];
196 	alias_string = alias_lookup(alias_command);
197 	if (alias_string) {
198 		if (alias_string[0] == '!') {
199 			if (*argcp > 1) {
200 				struct strbuf buf;
201 
202 				strbuf_init(&buf, PATH_MAX);
203 				strbuf_addstr(&buf, alias_string);
204 				sq_quote_argv(&buf, (*argv) + 1, PATH_MAX);
205 				free(alias_string);
206 				alias_string = buf.buf;
207 			}
208 			ret = system(alias_string + 1);
209 			if (ret >= 0 && WIFEXITED(ret) &&
210 			    WEXITSTATUS(ret) != 127)
211 				exit(WEXITSTATUS(ret));
212 			die("Failed to run '%s' when expanding alias '%s'",
213 			    alias_string + 1, alias_command);
214 		}
215 		count = split_cmdline(alias_string, &new_argv);
216 		if (count < 0)
217 			die("Bad alias.%s string", alias_command);
218 		option_count = handle_options(&new_argv, &count, &envchanged);
219 		if (envchanged)
220 			die("alias '%s' changes environment variables\n"
221 				 "You can use '!perf' in the alias to do this.",
222 				 alias_command);
223 		memmove(new_argv - option_count, new_argv,
224 				count * sizeof(char *));
225 		new_argv -= option_count;
226 
227 		if (count < 1)
228 			die("empty alias for %s", alias_command);
229 
230 		if (!strcmp(alias_command, new_argv[0]))
231 			die("recursive alias: %s", alias_command);
232 
233 		new_argv = realloc(new_argv, sizeof(char *) *
234 				    (count + *argcp + 1));
235 		/* insert after command name */
236 		memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
237 		new_argv[count + *argcp] = NULL;
238 
239 		*argv = new_argv;
240 		*argcp += count - 1;
241 
242 		ret = 1;
243 	}
244 
245 	errno = saved_errno;
246 
247 	return ret;
248 }
249 
250 const char perf_version_string[] = PERF_VERSION;
251 
252 #define RUN_SETUP	(1<<0)
253 #define USE_PAGER	(1<<1)
254 /*
255  * require working tree to be present -- anything uses this needs
256  * RUN_SETUP for reading from the configuration file.
257  */
258 #define NEED_WORK_TREE	(1<<2)
259 
260 struct cmd_struct {
261 	const char *cmd;
262 	int (*fn)(int, const char **, const char *);
263 	int option;
264 };
265 
run_builtin(struct cmd_struct * p,int argc,const char ** argv)266 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
267 {
268 	int status;
269 	struct stat st;
270 	const char *prefix;
271 
272 	prefix = NULL;
273 	if (p->option & RUN_SETUP)
274 		prefix = NULL; /* setup_perf_directory(); */
275 
276 	if (use_browser == -1)
277 		use_browser = check_tui_config(p->cmd);
278 
279 	if (use_pager == -1 && p->option & RUN_SETUP)
280 		use_pager = check_pager_config(p->cmd);
281 	if (use_pager == -1 && p->option & USE_PAGER)
282 		use_pager = 1;
283 	commit_pager_choice();
284 	set_debugfs_path();
285 
286 	status = p->fn(argc, argv, prefix);
287 	exit_browser(status);
288 
289 	if (status)
290 		return status & 0xff;
291 
292 	/* Somebody closed stdout? */
293 	if (fstat(fileno(stdout), &st))
294 		return 0;
295 	/* Ignore write errors for pipes and sockets.. */
296 	if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
297 		return 0;
298 
299 	/* Check for ENOSPC and EIO errors.. */
300 	if (fflush(stdout))
301 		die("write failure on standard output: %s", strerror(errno));
302 	if (ferror(stdout))
303 		die("unknown write failure on standard output");
304 	if (fclose(stdout))
305 		die("close failed on standard output: %s", strerror(errno));
306 	return 0;
307 }
308 
handle_internal_command(int argc,const char ** argv)309 static void handle_internal_command(int argc, const char **argv)
310 {
311 	const char *cmd = argv[0];
312 	static struct cmd_struct commands[] = {
313 		{ "buildid-cache", cmd_buildid_cache, 0 },
314 		{ "buildid-list", cmd_buildid_list, 0 },
315 		{ "diff",	cmd_diff,	0 },
316 		{ "evlist",	cmd_evlist,	0 },
317 		{ "help",	cmd_help,	0 },
318 		{ "list",	cmd_list,	0 },
319 		{ "record",	cmd_record,	0 },
320 		{ "report",	cmd_report,	0 },
321 		{ "bench",	cmd_bench,	0 },
322 		{ "stat",	cmd_stat,	0 },
323 		{ "timechart",	cmd_timechart,	0 },
324 		{ "top",	cmd_top,	0 },
325 		{ "annotate",	cmd_annotate,	0 },
326 		{ "version",	cmd_version,	0 },
327 		{ "script",	cmd_script,	0 },
328 		{ "sched",	cmd_sched,	0 },
329 		{ "probe",	cmd_probe,	0 },
330 		{ "kmem",	cmd_kmem,	0 },
331 		{ "lock",	cmd_lock,	0 },
332 		{ "kvm",	cmd_kvm,	0 },
333 		{ "test",	cmd_test,	0 },
334 		{ "inject",	cmd_inject,	0 },
335 	};
336 	unsigned int i;
337 	static const char ext[] = STRIP_EXTENSION;
338 
339 	if (sizeof(ext) > 1) {
340 		i = strlen(argv[0]) - strlen(ext);
341 		if (i > 0 && !strcmp(argv[0] + i, ext)) {
342 			char *argv0 = strdup(argv[0]);
343 			argv[0] = cmd = argv0;
344 			argv0[i] = '\0';
345 		}
346 	}
347 
348 	/* Turn "perf cmd --help" into "perf help cmd" */
349 	if (argc > 1 && !strcmp(argv[1], "--help")) {
350 		argv[1] = argv[0];
351 		argv[0] = cmd = "help";
352 	}
353 
354 	for (i = 0; i < ARRAY_SIZE(commands); i++) {
355 		struct cmd_struct *p = commands+i;
356 		if (strcmp(p->cmd, cmd))
357 			continue;
358 		exit(run_builtin(p, argc, argv));
359 	}
360 }
361 
execv_dashed_external(const char ** argv)362 static void execv_dashed_external(const char **argv)
363 {
364 	struct strbuf cmd = STRBUF_INIT;
365 	const char *tmp;
366 	int status;
367 
368 	strbuf_addf(&cmd, "perf-%s", argv[0]);
369 
370 	/*
371 	 * argv[0] must be the perf command, but the argv array
372 	 * belongs to the caller, and may be reused in
373 	 * subsequent loop iterations. Save argv[0] and
374 	 * restore it on error.
375 	 */
376 	tmp = argv[0];
377 	argv[0] = cmd.buf;
378 
379 	/*
380 	 * if we fail because the command is not found, it is
381 	 * OK to return. Otherwise, we just pass along the status code.
382 	 */
383 	status = run_command_v_opt(argv, 0);
384 	if (status != -ERR_RUN_COMMAND_EXEC) {
385 		if (IS_RUN_COMMAND_ERR(status))
386 			die("unable to run '%s'", argv[0]);
387 		exit(-status);
388 	}
389 	errno = ENOENT; /* as if we called execvp */
390 
391 	argv[0] = tmp;
392 
393 	strbuf_release(&cmd);
394 }
395 
run_argv(int * argcp,const char *** argv)396 static int run_argv(int *argcp, const char ***argv)
397 {
398 	int done_alias = 0;
399 
400 	while (1) {
401 		/* See if it's an internal command */
402 		handle_internal_command(*argcp, *argv);
403 
404 		/* .. then try the external ones */
405 		execv_dashed_external(*argv);
406 
407 		/* It could be an alias -- this works around the insanity
408 		 * of overriding "perf log" with "perf show" by having
409 		 * alias.log = show
410 		 */
411 		if (done_alias || !handle_alias(argcp, argv))
412 			break;
413 		done_alias = 1;
414 	}
415 
416 	return done_alias;
417 }
418 
419 /* mini /proc/mounts parser: searching for "^blah /mount/point debugfs" */
get_debugfs_mntpt(void)420 static void get_debugfs_mntpt(void)
421 {
422 	const char *path = debugfs_mount(NULL);
423 
424 	if (path)
425 		strncpy(debugfs_mntpt, path, sizeof(debugfs_mntpt));
426 	else
427 		debugfs_mntpt[0] = '\0';
428 }
429 
main(int argc,const char ** argv)430 int main(int argc, const char **argv)
431 {
432 	const char *cmd;
433 
434 	cmd = perf_extract_argv0_path(argv[0]);
435 	if (!cmd)
436 		cmd = "perf-help";
437 	/* get debugfs mount point from /proc/mounts */
438 	get_debugfs_mntpt();
439 	/*
440 	 * "perf-xxxx" is the same as "perf xxxx", but we obviously:
441 	 *
442 	 *  - cannot take flags in between the "perf" and the "xxxx".
443 	 *  - cannot execute it externally (since it would just do
444 	 *    the same thing over again)
445 	 *
446 	 * So we just directly call the internal command handler, and
447 	 * die if that one cannot handle it.
448 	 */
449 	if (!prefixcmp(cmd, "perf-")) {
450 		cmd += 5;
451 		argv[0] = cmd;
452 		handle_internal_command(argc, argv);
453 		die("cannot handle %s internally", cmd);
454 	}
455 
456 	/* Look for flags.. */
457 	argv++;
458 	argc--;
459 	handle_options(&argv, &argc, NULL);
460 	commit_pager_choice();
461 	set_debugfs_path();
462 	set_buildid_dir();
463 
464 	if (argc > 0) {
465 		if (!prefixcmp(argv[0], "--"))
466 			argv[0] += 2;
467 	} else {
468 		/* The user didn't specify a command; give them help */
469 		printf("\n usage: %s\n\n", perf_usage_string);
470 		list_common_cmds_help();
471 		printf("\n %s\n\n", perf_more_info_string);
472 		exit(1);
473 	}
474 	cmd = argv[0];
475 
476 	/*
477 	 * We use PATH to find perf commands, but we prepend some higher
478 	 * precedence paths: the "--exec-path" option, the PERF_EXEC_PATH
479 	 * environment, and the $(perfexecdir) from the Makefile at build
480 	 * time.
481 	 */
482 	setup_path();
483 
484 	while (1) {
485 		static int done_help;
486 		static int was_alias;
487 
488 		was_alias = run_argv(&argc, &argv);
489 		if (errno != ENOENT)
490 			break;
491 
492 		if (was_alias) {
493 			fprintf(stderr, "Expansion of alias '%s' failed; "
494 				"'%s' is not a perf-command\n",
495 				cmd, argv[0]);
496 			exit(1);
497 		}
498 		if (!done_help) {
499 			cmd = argv[0] = help_unknown_cmd(cmd);
500 			done_help = 1;
501 		} else
502 			break;
503 	}
504 
505 	fprintf(stderr, "Failed to run command '%s': %s\n",
506 		cmd, strerror(errno));
507 
508 	return 1;
509 }
510