xref: /openbmc/linux/tools/perf/builtin-probe.c (revision 430952e6)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * builtin-probe.c
4  *
5  * Builtin probe command: Set up probe events by C expression
6  *
7  * Written by Masami Hiramatsu <mhiramat@redhat.com>
8  */
9 #include <sys/utsname.h>
10 #include <sys/types.h>
11 #include <sys/stat.h>
12 #include <fcntl.h>
13 #include <errno.h>
14 #include <stdio.h>
15 #include <unistd.h>
16 #include <stdlib.h>
17 #include <string.h>
18 
19 #include "builtin.h"
20 #include "namespaces.h"
21 #include "util/build-id.h"
22 #include "util/strlist.h"
23 #include "util/strfilter.h"
24 #include "util/symbol.h"
25 #include "util/symbol_conf.h"
26 #include "util/debug.h"
27 #include <subcmd/parse-options.h>
28 #include "util/probe-finder.h"
29 #include "util/probe-event.h"
30 #include "util/probe-file.h"
31 #include <linux/string.h>
32 #include <linux/zalloc.h>
33 
34 #define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"
35 #define DEFAULT_FUNC_FILTER "!_* & !*@plt"
36 #define DEFAULT_LIST_FILTER "*"
37 
38 /* Session management structure */
39 static struct {
40 	int command;	/* Command short_name */
41 	bool list_events;
42 	bool uprobes;
43 	bool target_used;
44 	int nevents;
45 	struct perf_probe_event events[MAX_PROBES];
46 	struct line_range line_range;
47 	char *target;
48 	struct strfilter *filter;
49 	struct nsinfo *nsi;
50 } *params;
51 
52 /* Parse an event definition. Note that any error must die. */
parse_probe_event(const char * str)53 static int parse_probe_event(const char *str)
54 {
55 	struct perf_probe_event *pev = &params->events[params->nevents];
56 	int ret;
57 
58 	pr_debug("probe-definition(%d): %s\n", params->nevents, str);
59 	if (++params->nevents == MAX_PROBES) {
60 		pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
61 		return -1;
62 	}
63 
64 	pev->uprobes = params->uprobes;
65 	if (params->target) {
66 		pev->target = strdup(params->target);
67 		if (!pev->target)
68 			return -ENOMEM;
69 		params->target_used = true;
70 	}
71 
72 	pev->nsi = nsinfo__get(params->nsi);
73 
74 	/* Parse a perf-probe command into event */
75 	ret = parse_perf_probe_command(str, pev);
76 	pr_debug("%d arguments\n", pev->nargs);
77 
78 	return ret;
79 }
80 
params_add_filter(const char * str)81 static int params_add_filter(const char *str)
82 {
83 	const char *err = NULL;
84 	int ret = 0;
85 
86 	pr_debug2("Add filter: %s\n", str);
87 	if (!params->filter) {
88 		params->filter = strfilter__new(str, &err);
89 		if (!params->filter)
90 			ret = err ? -EINVAL : -ENOMEM;
91 	} else
92 		ret = strfilter__or(params->filter, str, &err);
93 
94 	if (ret == -EINVAL) {
95 		pr_err("Filter parse error at %td.\n", err - str + 1);
96 		pr_err("Source: \"%s\"\n", str);
97 		pr_err("         %*c\n", (int)(err - str + 1), '^');
98 	}
99 
100 	return ret;
101 }
102 
set_target(const char * ptr)103 static int set_target(const char *ptr)
104 {
105 	int found = 0;
106 	const char *buf;
107 
108 	/*
109 	 * The first argument after options can be an absolute path
110 	 * to an executable / library or kernel module.
111 	 *
112 	 * TODO: Support relative path, and $PATH, $LD_LIBRARY_PATH,
113 	 * short module name.
114 	 */
115 	if (!params->target && ptr && *ptr == '/') {
116 		params->target = strdup(ptr);
117 		if (!params->target)
118 			return -ENOMEM;
119 		params->target_used = false;
120 
121 		found = 1;
122 		buf = ptr + (strlen(ptr) - 3);
123 
124 		if (strcmp(buf, ".ko"))
125 			params->uprobes = true;
126 
127 	}
128 
129 	return found;
130 }
131 
parse_probe_event_argv(int argc,const char ** argv)132 static int parse_probe_event_argv(int argc, const char **argv)
133 {
134 	int i, len, ret, found_target;
135 	char *buf;
136 
137 	found_target = set_target(argv[0]);
138 	if (found_target < 0)
139 		return found_target;
140 
141 	if (found_target && argc == 1)
142 		return 0;
143 
144 	/* Bind up rest arguments */
145 	len = 0;
146 	for (i = 0; i < argc; i++) {
147 		if (i == 0 && found_target)
148 			continue;
149 
150 		len += strlen(argv[i]) + 1;
151 	}
152 	buf = zalloc(len + 1);
153 	if (buf == NULL)
154 		return -ENOMEM;
155 	len = 0;
156 	for (i = 0; i < argc; i++) {
157 		if (i == 0 && found_target)
158 			continue;
159 
160 		len += sprintf(&buf[len], "%s ", argv[i]);
161 	}
162 	ret = parse_probe_event(buf);
163 	free(buf);
164 	return ret;
165 }
166 
opt_set_target(const struct option * opt,const char * str,int unset __maybe_unused)167 static int opt_set_target(const struct option *opt, const char *str,
168 			int unset __maybe_unused)
169 {
170 	int ret = -ENOENT;
171 	char *tmp;
172 
173 	if  (str) {
174 		if (!strcmp(opt->long_name, "exec"))
175 			params->uprobes = true;
176 		else if (!strcmp(opt->long_name, "module"))
177 			params->uprobes = false;
178 		else
179 			return ret;
180 
181 		/* Expand given path to absolute path, except for modulename */
182 		if (params->uprobes || strchr(str, '/')) {
183 			tmp = nsinfo__realpath(str, params->nsi);
184 			if (!tmp) {
185 				pr_warning("Failed to get the absolute path of %s: %m\n", str);
186 				return ret;
187 			}
188 		} else {
189 			tmp = strdup(str);
190 			if (!tmp)
191 				return -ENOMEM;
192 		}
193 		free(params->target);
194 		params->target = tmp;
195 		params->target_used = false;
196 		ret = 0;
197 	}
198 
199 	return ret;
200 }
201 
opt_set_target_ns(const struct option * opt __maybe_unused,const char * str,int unset __maybe_unused)202 static int opt_set_target_ns(const struct option *opt __maybe_unused,
203 			     const char *str, int unset __maybe_unused)
204 {
205 	int ret = -ENOENT;
206 	pid_t ns_pid;
207 	struct nsinfo *nsip;
208 
209 	if (str) {
210 		errno = 0;
211 		ns_pid = (pid_t)strtol(str, NULL, 10);
212 		if (errno != 0) {
213 			ret = -errno;
214 			pr_warning("Failed to parse %s as a pid: %s\n", str,
215 				   strerror(errno));
216 			return ret;
217 		}
218 		nsip = nsinfo__new(ns_pid);
219 		if (nsip && nsinfo__need_setns(nsip))
220 			params->nsi = nsinfo__get(nsip);
221 		nsinfo__put(nsip);
222 
223 		ret = 0;
224 	}
225 
226 	return ret;
227 }
228 
229 
230 /* Command option callbacks */
231 
232 #ifdef HAVE_DWARF_SUPPORT
opt_show_lines(const struct option * opt,const char * str,int unset __maybe_unused)233 static int opt_show_lines(const struct option *opt,
234 			  const char *str, int unset __maybe_unused)
235 {
236 	int ret = 0;
237 
238 	if (!str)
239 		return 0;
240 
241 	if (params->command == 'L') {
242 		pr_warning("Warning: more than one --line options are"
243 			   " detected. Only the first one is valid.\n");
244 		return 0;
245 	}
246 
247 	params->command = opt->short_name;
248 	ret = parse_line_range_desc(str, &params->line_range);
249 
250 	return ret;
251 }
252 
opt_show_vars(const struct option * opt,const char * str,int unset __maybe_unused)253 static int opt_show_vars(const struct option *opt,
254 			 const char *str, int unset __maybe_unused)
255 {
256 	struct perf_probe_event *pev = &params->events[params->nevents];
257 	int ret;
258 
259 	if (!str)
260 		return 0;
261 
262 	ret = parse_probe_event(str);
263 	if (!ret && pev->nargs != 0) {
264 		pr_err("  Error: '--vars' doesn't accept arguments.\n");
265 		return -EINVAL;
266 	}
267 	params->command = opt->short_name;
268 
269 	return ret;
270 }
271 #else
272 # define opt_show_lines NULL
273 # define opt_show_vars NULL
274 #endif
opt_add_probe_event(const struct option * opt,const char * str,int unset __maybe_unused)275 static int opt_add_probe_event(const struct option *opt,
276 			      const char *str, int unset __maybe_unused)
277 {
278 	if (str) {
279 		params->command = opt->short_name;
280 		return parse_probe_event(str);
281 	}
282 
283 	return 0;
284 }
285 
opt_set_filter_with_command(const struct option * opt,const char * str,int unset)286 static int opt_set_filter_with_command(const struct option *opt,
287 				       const char *str, int unset)
288 {
289 	if (!unset)
290 		params->command = opt->short_name;
291 
292 	if (str)
293 		return params_add_filter(str);
294 
295 	return 0;
296 }
297 
opt_set_filter(const struct option * opt __maybe_unused,const char * str,int unset __maybe_unused)298 static int opt_set_filter(const struct option *opt __maybe_unused,
299 			  const char *str, int unset __maybe_unused)
300 {
301 	if (str)
302 		return params_add_filter(str);
303 
304 	return 0;
305 }
306 
init_params(void)307 static int init_params(void)
308 {
309 	int ret;
310 
311 	params = calloc(1, sizeof(*params));
312 	if (!params)
313 		return -ENOMEM;
314 
315 	ret = line_range__init(&params->line_range);
316 	if (ret)
317 		zfree(&params);
318 	return ret;
319 }
320 
cleanup_params(void)321 static void cleanup_params(void)
322 {
323 	int i;
324 
325 	for (i = 0; i < params->nevents; i++)
326 		clear_perf_probe_event(params->events + i);
327 	line_range__clear(&params->line_range);
328 	free(params->target);
329 	strfilter__delete(params->filter);
330 	nsinfo__put(params->nsi);
331 	zfree(&params);
332 }
333 
pr_err_with_code(const char * msg,int err)334 static void pr_err_with_code(const char *msg, int err)
335 {
336 	char sbuf[STRERR_BUFSIZE];
337 
338 	pr_err("%s", msg);
339 	pr_debug(" Reason: %s (Code: %d)",
340 		 str_error_r(-err, sbuf, sizeof(sbuf)), err);
341 	pr_err("\n");
342 }
343 
perf_add_probe_events(struct perf_probe_event * pevs,int npevs)344 static int perf_add_probe_events(struct perf_probe_event *pevs, int npevs)
345 {
346 	int ret;
347 	int i, k;
348 	const char *event = NULL, *group = NULL;
349 
350 	ret = init_probe_symbol_maps(pevs->uprobes);
351 	if (ret < 0)
352 		return ret;
353 
354 	ret = convert_perf_probe_events(pevs, npevs);
355 	if (ret < 0)
356 		goto out_cleanup;
357 
358 	if (params->command == 'D') {	/* it shows definition */
359 		if (probe_conf.bootconfig)
360 			ret = show_bootconfig_events(pevs, npevs);
361 		else
362 			ret = show_probe_trace_events(pevs, npevs);
363 		goto out_cleanup;
364 	}
365 
366 	ret = apply_perf_probe_events(pevs, npevs);
367 	if (ret < 0)
368 		goto out_cleanup;
369 
370 	for (i = k = 0; i < npevs; i++)
371 		k += pevs[i].ntevs;
372 
373 	pr_info("Added new event%s\n", (k > 1) ? "s:" : ":");
374 	for (i = 0; i < npevs; i++) {
375 		struct perf_probe_event *pev = &pevs[i];
376 
377 		for (k = 0; k < pev->ntevs; k++) {
378 			struct probe_trace_event *tev = &pev->tevs[k];
379 			/* Skipped events have no event name */
380 			if (!tev->event)
381 				continue;
382 
383 			/* We use tev's name for showing new events */
384 			show_perf_probe_event(tev->group, tev->event, pev,
385 					      tev->point.module, false);
386 
387 			/* Save the last valid name */
388 			event = tev->event;
389 			group = tev->group;
390 		}
391 	}
392 
393 	/* Note that it is possible to skip all events because of blacklist */
394 	if (event) {
395 #ifndef HAVE_LIBTRACEEVENT
396 		pr_info("\nperf is not linked with libtraceevent, to use the new probe you can use tracefs:\n\n");
397 		pr_info("\tcd /sys/kernel/tracing/\n");
398 		pr_info("\techo 1 > events/%s/%s/enable\n", group, event);
399 		pr_info("\techo 1 > tracing_on\n");
400 		pr_info("\tcat trace_pipe\n");
401 		pr_info("\tBefore removing the probe, echo 0 > events/%s/%s/enable\n", group, event);
402 #else
403 		/* Show how to use the event. */
404 		pr_info("\nYou can now use it in all perf tools, such as:\n\n");
405 		pr_info("\tperf record -e %s:%s -aR sleep 1\n\n", group, event);
406 #endif
407 	}
408 
409 out_cleanup:
410 	cleanup_perf_probe_events(pevs, npevs);
411 	exit_probe_symbol_maps();
412 	return ret;
413 }
414 
del_perf_probe_caches(struct strfilter * filter)415 static int del_perf_probe_caches(struct strfilter *filter)
416 {
417 	struct probe_cache *cache;
418 	struct strlist *bidlist;
419 	struct str_node *nd;
420 	int ret;
421 
422 	bidlist = build_id_cache__list_all(false);
423 	if (!bidlist) {
424 		ret = -errno;
425 		pr_debug("Failed to get buildids: %d\n", ret);
426 		return ret ?: -ENOMEM;
427 	}
428 
429 	strlist__for_each_entry(nd, bidlist) {
430 		cache = probe_cache__new(nd->s, NULL);
431 		if (!cache)
432 			continue;
433 		if (probe_cache__filter_purge(cache, filter) < 0 ||
434 		    probe_cache__commit(cache) < 0)
435 			pr_warning("Failed to remove entries for %s\n", nd->s);
436 		probe_cache__delete(cache);
437 	}
438 	return 0;
439 }
440 
perf_del_probe_events(struct strfilter * filter)441 static int perf_del_probe_events(struct strfilter *filter)
442 {
443 	int ret, ret2, ufd = -1, kfd = -1;
444 	char *str = strfilter__string(filter);
445 	struct strlist *klist = NULL, *ulist = NULL;
446 	struct str_node *ent;
447 
448 	if (!str)
449 		return -EINVAL;
450 
451 	pr_debug("Delete filter: \'%s\'\n", str);
452 
453 	if (probe_conf.cache)
454 		return del_perf_probe_caches(filter);
455 
456 	/* Get current event names */
457 	ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
458 	if (ret < 0)
459 		goto out;
460 
461 	klist = strlist__new(NULL, NULL);
462 	ulist = strlist__new(NULL, NULL);
463 	if (!klist || !ulist) {
464 		ret = -ENOMEM;
465 		goto out;
466 	}
467 
468 	ret = probe_file__get_events(kfd, filter, klist);
469 	if (ret == 0) {
470 		strlist__for_each_entry(ent, klist)
471 			pr_info("Removed event: %s\n", ent->s);
472 
473 		ret = probe_file__del_strlist(kfd, klist);
474 		if (ret < 0)
475 			goto error;
476 	} else if (ret == -ENOMEM)
477 		goto error;
478 
479 	ret2 = probe_file__get_events(ufd, filter, ulist);
480 	if (ret2 == 0) {
481 		strlist__for_each_entry(ent, ulist)
482 			pr_info("Removed event: %s\n", ent->s);
483 
484 		ret2 = probe_file__del_strlist(ufd, ulist);
485 		if (ret2 < 0)
486 			goto error;
487 	} else if (ret2 == -ENOMEM)
488 		goto error;
489 
490 	if (ret == -ENOENT && ret2 == -ENOENT)
491 		pr_warning("\"%s\" does not hit any event.\n", str);
492 	else
493 		ret = 0;
494 
495 error:
496 	if (kfd >= 0)
497 		close(kfd);
498 	if (ufd >= 0)
499 		close(ufd);
500 out:
501 	strlist__delete(klist);
502 	strlist__delete(ulist);
503 	free(str);
504 
505 	return ret;
506 }
507 
508 #ifdef HAVE_DWARF_SUPPORT
509 #define PROBEDEF_STR	\
510 	"[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT [[NAME=]ARG ...]"
511 #else
512 #define PROBEDEF_STR	"[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]"
513 #endif
514 
515 
516 static int
__cmd_probe(int argc,const char ** argv)517 __cmd_probe(int argc, const char **argv)
518 {
519 	const char * const probe_usage[] = {
520 		"perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
521 		"perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
522 		"perf probe [<options>] --del '[GROUP:]EVENT' ...",
523 		"perf probe --list [GROUP:]EVENT ...",
524 #ifdef HAVE_DWARF_SUPPORT
525 		"perf probe [<options>] --line 'LINEDESC'",
526 		"perf probe [<options>] --vars 'PROBEPOINT'",
527 #endif
528 		"perf probe [<options>] --funcs",
529 		NULL
530 	};
531 	struct option options[] = {
532 	OPT_INCR('v', "verbose", &verbose,
533 		    "be more verbose (show parsed arguments, etc)"),
534 	OPT_BOOLEAN('q', "quiet", &quiet,
535 		    "be quiet (do not show any warnings or messages)"),
536 	OPT_CALLBACK_DEFAULT('l', "list", NULL, "[GROUP:]EVENT",
537 			     "list up probe events",
538 			     opt_set_filter_with_command, DEFAULT_LIST_FILTER),
539 	OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
540 		     opt_set_filter_with_command),
541 	OPT_CALLBACK('a', "add", NULL, PROBEDEF_STR,
542 		"probe point definition, where\n"
543 		"\t\tGROUP:\tGroup name (optional)\n"
544 		"\t\tEVENT:\tEvent name\n"
545 		"\t\tFUNC:\tFunction name\n"
546 		"\t\tOFF:\tOffset from function entry (in byte)\n"
547 		"\t\t%return:\tPut the probe at function return\n"
548 #ifdef HAVE_DWARF_SUPPORT
549 		"\t\tSRC:\tSource code path\n"
550 		"\t\tRL:\tRelative line number from function entry.\n"
551 		"\t\tAL:\tAbsolute line number in file.\n"
552 		"\t\tPT:\tLazy expression of line code.\n"
553 		"\t\tARG:\tProbe argument (local variable name or\n"
554 		"\t\t\tkprobe-tracer argument format.)\n",
555 #else
556 		"\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
557 #endif
558 		opt_add_probe_event),
559 	OPT_CALLBACK('D', "definition", NULL, PROBEDEF_STR,
560 		"Show trace event definition of given traceevent for k/uprobe_events.",
561 		opt_add_probe_event),
562 	OPT_BOOLEAN('f', "force", &probe_conf.force_add, "forcibly add events"
563 		    " with existing name"),
564 	OPT_CALLBACK('L', "line", NULL,
565 		     "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
566 		     "Show source code lines.", opt_show_lines),
567 	OPT_CALLBACK('V', "vars", NULL,
568 		     "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
569 		     "Show accessible variables on PROBEDEF", opt_show_vars),
570 	OPT_BOOLEAN('\0', "externs", &probe_conf.show_ext_vars,
571 		    "Show external variables too (with --vars only)"),
572 	OPT_BOOLEAN('\0', "range", &probe_conf.show_location_range,
573 		"Show variables location range in scope (with --vars only)"),
574 	OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
575 		   "file", "vmlinux pathname"),
576 	OPT_STRING('s', "source", &symbol_conf.source_prefix,
577 		   "directory", "path to kernel source"),
578 	OPT_BOOLEAN('\0', "no-inlines", &probe_conf.no_inlines,
579 		"Don't search inlined functions"),
580 	OPT__DRY_RUN(&probe_event_dry_run),
581 	OPT_INTEGER('\0', "max-probes", &probe_conf.max_probes,
582 		 "Set how many probe points can be found for a probe."),
583 	OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",
584 			     "Show potential probe-able functions.",
585 			     opt_set_filter_with_command, DEFAULT_FUNC_FILTER),
586 	OPT_CALLBACK('\0', "filter", NULL,
587 		     "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
588 		     "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
589 		     "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
590 		     opt_set_filter),
591 	OPT_CALLBACK('x', "exec", NULL, "executable|path",
592 			"target executable name or path", opt_set_target),
593 	OPT_CALLBACK('m', "module", NULL, "modname|path",
594 		"target module name (for online) or path (for offline)",
595 		opt_set_target),
596 	OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
597 		    "Enable symbol demangling"),
598 	OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
599 		    "Enable kernel symbol demangling"),
600 	OPT_BOOLEAN(0, "cache", &probe_conf.cache, "Manipulate probe cache"),
601 	OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
602 		   "Look for files with symbols relative to this directory"),
603 	OPT_CALLBACK(0, "target-ns", NULL, "pid",
604 		     "target pid for namespace contexts", opt_set_target_ns),
605 	OPT_BOOLEAN(0, "bootconfig", &probe_conf.bootconfig,
606 		    "Output probe definition with bootconfig format"),
607 	OPT_END()
608 	};
609 	int ret;
610 
611 	set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);
612 	set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);
613 	set_option_flag(options, 'D', "definition", PARSE_OPT_EXCLUSIVE);
614 	set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);
615 #ifdef HAVE_DWARF_SUPPORT
616 	set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);
617 	set_option_flag(options, 'V', "vars", PARSE_OPT_EXCLUSIVE);
618 #else
619 # define set_nobuild(s, l, c) set_option_nobuild(options, s, l, "NO_DWARF=1", c)
620 	set_nobuild('L', "line", false);
621 	set_nobuild('V', "vars", false);
622 	set_nobuild('\0', "externs", false);
623 	set_nobuild('\0', "range", false);
624 	set_nobuild('k', "vmlinux", true);
625 	set_nobuild('s', "source", true);
626 	set_nobuild('\0', "no-inlines", true);
627 # undef set_nobuild
628 #endif
629 	set_option_flag(options, 'F', "funcs", PARSE_OPT_EXCLUSIVE);
630 
631 	argc = parse_options(argc, argv, options, probe_usage,
632 			     PARSE_OPT_STOP_AT_NON_OPTION);
633 
634 	if (quiet) {
635 		if (verbose != 0) {
636 			pr_err("  Error: -v and -q are exclusive.\n");
637 			return -EINVAL;
638 		}
639 		verbose = -1;
640 	}
641 
642 	if (argc > 0) {
643 		if (strcmp(argv[0], "-") == 0) {
644 			usage_with_options_msg(probe_usage, options,
645 				"'-' is not supported.\n");
646 		}
647 		if (params->command && params->command != 'a') {
648 			usage_with_options_msg(probe_usage, options,
649 				"another command except --add is set.\n");
650 		}
651 		ret = parse_probe_event_argv(argc, argv);
652 		if (ret < 0) {
653 			pr_err_with_code("  Error: Command Parse Error.", ret);
654 			return ret;
655 		}
656 		params->command = 'a';
657 	}
658 
659 	ret = symbol__validate_sym_arguments();
660 	if (ret)
661 		return ret;
662 
663 	if (probe_conf.max_probes == 0)
664 		probe_conf.max_probes = MAX_PROBES;
665 
666 	/*
667 	 * Only consider the user's kernel image path if given.
668 	 */
669 	symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
670 
671 	/*
672 	 * Except for --list, --del and --add, other command doesn't depend
673 	 * nor change running kernel. So if user gives offline vmlinux,
674 	 * ignore its buildid.
675 	 */
676 	if (!strchr("lda", params->command) && symbol_conf.vmlinux_name)
677 		symbol_conf.ignore_vmlinux_buildid = true;
678 
679 	switch (params->command) {
680 	case 'l':
681 		if (params->uprobes) {
682 			pr_err("  Error: Don't use --list with --exec.\n");
683 			parse_options_usage(probe_usage, options, "l", true);
684 			parse_options_usage(NULL, options, "x", true);
685 			return -EINVAL;
686 		}
687 		ret = show_perf_probe_events(params->filter);
688 		if (ret < 0)
689 			pr_err_with_code("  Error: Failed to show event list.", ret);
690 		return ret;
691 	case 'F':
692 		ret = show_available_funcs(params->target, params->nsi,
693 					   params->filter, params->uprobes);
694 		if (ret < 0)
695 			pr_err_with_code("  Error: Failed to show functions.", ret);
696 		return ret;
697 #ifdef HAVE_DWARF_SUPPORT
698 	case 'L':
699 		ret = show_line_range(&params->line_range, params->target,
700 				      params->nsi, params->uprobes);
701 		if (ret < 0)
702 			pr_err_with_code("  Error: Failed to show lines.", ret);
703 		return ret;
704 	case 'V':
705 		if (!params->filter)
706 			params->filter = strfilter__new(DEFAULT_VAR_FILTER,
707 						       NULL);
708 
709 		ret = show_available_vars(params->events, params->nevents,
710 					  params->filter);
711 		if (ret < 0)
712 			pr_err_with_code("  Error: Failed to show vars.", ret);
713 		return ret;
714 #endif
715 	case 'd':
716 		ret = perf_del_probe_events(params->filter);
717 		if (ret < 0) {
718 			pr_err_with_code("  Error: Failed to delete events.", ret);
719 			return ret;
720 		}
721 		break;
722 	case 'D':
723 		if (probe_conf.bootconfig && params->uprobes) {
724 			pr_err("  Error: --bootconfig doesn't support uprobes.\n");
725 			return -EINVAL;
726 		}
727 		fallthrough;
728 	case 'a':
729 
730 		/* Ensure the last given target is used */
731 		if (params->target && !params->target_used) {
732 			pr_err("  Error: -x/-m must follow the probe definitions.\n");
733 			parse_options_usage(probe_usage, options, "m", true);
734 			parse_options_usage(NULL, options, "x", true);
735 			return -EINVAL;
736 		}
737 
738 		ret = perf_add_probe_events(params->events, params->nevents);
739 		if (ret < 0) {
740 
741 			/*
742 			 * When perf_add_probe_events() fails it calls
743 			 * cleanup_perf_probe_events(pevs, npevs), i.e.
744 			 * cleanup_perf_probe_events(params->events, params->nevents), which
745 			 * will call clear_perf_probe_event(), so set nevents to zero
746 			 * to avoid cleanup_params() to call clear_perf_probe_event() again
747 			 * on the same pevs.
748 			 */
749 			params->nevents = 0;
750 			pr_err_with_code("  Error: Failed to add events.", ret);
751 			return ret;
752 		}
753 		break;
754 	default:
755 		usage_with_options(probe_usage, options);
756 	}
757 	return 0;
758 }
759 
cmd_probe(int argc,const char ** argv)760 int cmd_probe(int argc, const char **argv)
761 {
762 	int ret;
763 
764 	ret = init_params();
765 	if (!ret) {
766 		ret = __cmd_probe(argc, argv);
767 		cleanup_params();
768 	}
769 
770 	return ret < 0 ? ret : 0;
771 }
772