xref: /openbmc/linux/tools/perf/builtin-probe.c (revision 151f4e2b)
1 /*
2  * builtin-probe.c
3  *
4  * Builtin probe command: Set up probe events by C expression
5  *
6  * Written by Masami Hiramatsu <mhiramat@redhat.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21  *
22  */
23 #include <sys/utsname.h>
24 #include <sys/types.h>
25 #include <sys/stat.h>
26 #include <fcntl.h>
27 #include <errno.h>
28 #include <stdio.h>
29 #include <unistd.h>
30 #include <stdlib.h>
31 #include <string.h>
32 
33 #include "perf.h"
34 #include "builtin.h"
35 #include "namespaces.h"
36 #include "util/util.h"
37 #include "util/strlist.h"
38 #include "util/strfilter.h"
39 #include "util/symbol.h"
40 #include "util/debug.h"
41 #include <subcmd/parse-options.h>
42 #include "util/probe-finder.h"
43 #include "util/probe-event.h"
44 #include "util/probe-file.h"
45 
46 #define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"
47 #define DEFAULT_FUNC_FILTER "!_*"
48 #define DEFAULT_LIST_FILTER "*"
49 
50 /* Session management structure */
51 static struct {
52 	int command;	/* Command short_name */
53 	bool list_events;
54 	bool uprobes;
55 	bool quiet;
56 	bool target_used;
57 	int nevents;
58 	struct perf_probe_event events[MAX_PROBES];
59 	struct line_range line_range;
60 	char *target;
61 	struct strfilter *filter;
62 	struct nsinfo *nsi;
63 } params;
64 
65 /* Parse an event definition. Note that any error must die. */
66 static int parse_probe_event(const char *str)
67 {
68 	struct perf_probe_event *pev = &params.events[params.nevents];
69 	int ret;
70 
71 	pr_debug("probe-definition(%d): %s\n", params.nevents, str);
72 	if (++params.nevents == MAX_PROBES) {
73 		pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
74 		return -1;
75 	}
76 
77 	pev->uprobes = params.uprobes;
78 	if (params.target) {
79 		pev->target = strdup(params.target);
80 		if (!pev->target)
81 			return -ENOMEM;
82 		params.target_used = true;
83 	}
84 
85 	pev->nsi = nsinfo__get(params.nsi);
86 
87 	/* Parse a perf-probe command into event */
88 	ret = parse_perf_probe_command(str, pev);
89 	pr_debug("%d arguments\n", pev->nargs);
90 
91 	return ret;
92 }
93 
94 static int params_add_filter(const char *str)
95 {
96 	const char *err = NULL;
97 	int ret = 0;
98 
99 	pr_debug2("Add filter: %s\n", str);
100 	if (!params.filter) {
101 		params.filter = strfilter__new(str, &err);
102 		if (!params.filter)
103 			ret = err ? -EINVAL : -ENOMEM;
104 	} else
105 		ret = strfilter__or(params.filter, str, &err);
106 
107 	if (ret == -EINVAL) {
108 		pr_err("Filter parse error at %td.\n", err - str + 1);
109 		pr_err("Source: \"%s\"\n", str);
110 		pr_err("         %*c\n", (int)(err - str + 1), '^');
111 	}
112 
113 	return ret;
114 }
115 
116 static int set_target(const char *ptr)
117 {
118 	int found = 0;
119 	const char *buf;
120 
121 	/*
122 	 * The first argument after options can be an absolute path
123 	 * to an executable / library or kernel module.
124 	 *
125 	 * TODO: Support relative path, and $PATH, $LD_LIBRARY_PATH,
126 	 * short module name.
127 	 */
128 	if (!params.target && ptr && *ptr == '/') {
129 		params.target = strdup(ptr);
130 		if (!params.target)
131 			return -ENOMEM;
132 		params.target_used = false;
133 
134 		found = 1;
135 		buf = ptr + (strlen(ptr) - 3);
136 
137 		if (strcmp(buf, ".ko"))
138 			params.uprobes = true;
139 
140 	}
141 
142 	return found;
143 }
144 
145 static int parse_probe_event_argv(int argc, const char **argv)
146 {
147 	int i, len, ret, found_target;
148 	char *buf;
149 
150 	found_target = set_target(argv[0]);
151 	if (found_target < 0)
152 		return found_target;
153 
154 	if (found_target && argc == 1)
155 		return 0;
156 
157 	/* Bind up rest arguments */
158 	len = 0;
159 	for (i = 0; i < argc; i++) {
160 		if (i == 0 && found_target)
161 			continue;
162 
163 		len += strlen(argv[i]) + 1;
164 	}
165 	buf = zalloc(len + 1);
166 	if (buf == NULL)
167 		return -ENOMEM;
168 	len = 0;
169 	for (i = 0; i < argc; i++) {
170 		if (i == 0 && found_target)
171 			continue;
172 
173 		len += sprintf(&buf[len], "%s ", argv[i]);
174 	}
175 	ret = parse_probe_event(buf);
176 	free(buf);
177 	return ret;
178 }
179 
180 static int opt_set_target(const struct option *opt, const char *str,
181 			int unset __maybe_unused)
182 {
183 	int ret = -ENOENT;
184 	char *tmp;
185 
186 	if  (str) {
187 		if (!strcmp(opt->long_name, "exec"))
188 			params.uprobes = true;
189 		else if (!strcmp(opt->long_name, "module"))
190 			params.uprobes = false;
191 		else
192 			return ret;
193 
194 		/* Expand given path to absolute path, except for modulename */
195 		if (params.uprobes || strchr(str, '/')) {
196 			tmp = nsinfo__realpath(str, params.nsi);
197 			if (!tmp) {
198 				pr_warning("Failed to get the absolute path of %s: %m\n", str);
199 				return ret;
200 			}
201 		} else {
202 			tmp = strdup(str);
203 			if (!tmp)
204 				return -ENOMEM;
205 		}
206 		free(params.target);
207 		params.target = tmp;
208 		params.target_used = false;
209 		ret = 0;
210 	}
211 
212 	return ret;
213 }
214 
215 static int opt_set_target_ns(const struct option *opt __maybe_unused,
216 			     const char *str, int unset __maybe_unused)
217 {
218 	int ret = -ENOENT;
219 	pid_t ns_pid;
220 	struct nsinfo *nsip;
221 
222 	if (str) {
223 		errno = 0;
224 		ns_pid = (pid_t)strtol(str, NULL, 10);
225 		if (errno != 0) {
226 			ret = -errno;
227 			pr_warning("Failed to parse %s as a pid: %s\n", str,
228 				   strerror(errno));
229 			return ret;
230 		}
231 		nsip = nsinfo__new(ns_pid);
232 		if (nsip && nsip->need_setns)
233 			params.nsi = nsinfo__get(nsip);
234 		nsinfo__put(nsip);
235 
236 		ret = 0;
237 	}
238 
239 	return ret;
240 }
241 
242 
243 /* Command option callbacks */
244 
245 #ifdef HAVE_DWARF_SUPPORT
246 static int opt_show_lines(const struct option *opt,
247 			  const char *str, int unset __maybe_unused)
248 {
249 	int ret = 0;
250 
251 	if (!str)
252 		return 0;
253 
254 	if (params.command == 'L') {
255 		pr_warning("Warning: more than one --line options are"
256 			   " detected. Only the first one is valid.\n");
257 		return 0;
258 	}
259 
260 	params.command = opt->short_name;
261 	ret = parse_line_range_desc(str, &params.line_range);
262 
263 	return ret;
264 }
265 
266 static int opt_show_vars(const struct option *opt,
267 			 const char *str, int unset __maybe_unused)
268 {
269 	struct perf_probe_event *pev = &params.events[params.nevents];
270 	int ret;
271 
272 	if (!str)
273 		return 0;
274 
275 	ret = parse_probe_event(str);
276 	if (!ret && pev->nargs != 0) {
277 		pr_err("  Error: '--vars' doesn't accept arguments.\n");
278 		return -EINVAL;
279 	}
280 	params.command = opt->short_name;
281 
282 	return ret;
283 }
284 #else
285 # define opt_show_lines NULL
286 # define opt_show_vars NULL
287 #endif
288 static int opt_add_probe_event(const struct option *opt,
289 			      const char *str, int unset __maybe_unused)
290 {
291 	if (str) {
292 		params.command = opt->short_name;
293 		return parse_probe_event(str);
294 	}
295 
296 	return 0;
297 }
298 
299 static int opt_set_filter_with_command(const struct option *opt,
300 				       const char *str, int unset)
301 {
302 	if (!unset)
303 		params.command = opt->short_name;
304 
305 	if (str)
306 		return params_add_filter(str);
307 
308 	return 0;
309 }
310 
311 static int opt_set_filter(const struct option *opt __maybe_unused,
312 			  const char *str, int unset __maybe_unused)
313 {
314 	if (str)
315 		return params_add_filter(str);
316 
317 	return 0;
318 }
319 
320 static int init_params(void)
321 {
322 	return line_range__init(&params.line_range);
323 }
324 
325 static void cleanup_params(void)
326 {
327 	int i;
328 
329 	for (i = 0; i < params.nevents; i++)
330 		clear_perf_probe_event(params.events + i);
331 	line_range__clear(&params.line_range);
332 	free(params.target);
333 	strfilter__delete(params.filter);
334 	nsinfo__put(params.nsi);
335 	memset(&params, 0, sizeof(params));
336 }
337 
338 static void pr_err_with_code(const char *msg, int err)
339 {
340 	char sbuf[STRERR_BUFSIZE];
341 
342 	pr_err("%s", msg);
343 	pr_debug(" Reason: %s (Code: %d)",
344 		 str_error_r(-err, sbuf, sizeof(sbuf)), err);
345 	pr_err("\n");
346 }
347 
348 static int perf_add_probe_events(struct perf_probe_event *pevs, int npevs)
349 {
350 	int ret;
351 	int i, k;
352 	const char *event = NULL, *group = NULL;
353 
354 	ret = init_probe_symbol_maps(pevs->uprobes);
355 	if (ret < 0)
356 		return ret;
357 
358 	ret = convert_perf_probe_events(pevs, npevs);
359 	if (ret < 0)
360 		goto out_cleanup;
361 
362 	if (params.command == 'D') {	/* it shows definition */
363 		ret = show_probe_trace_events(pevs, npevs);
364 		goto out_cleanup;
365 	}
366 
367 	ret = apply_perf_probe_events(pevs, npevs);
368 	if (ret < 0)
369 		goto out_cleanup;
370 
371 	for (i = k = 0; i < npevs; i++)
372 		k += pevs[i].ntevs;
373 
374 	pr_info("Added new event%s\n", (k > 1) ? "s:" : ":");
375 	for (i = 0; i < npevs; i++) {
376 		struct perf_probe_event *pev = &pevs[i];
377 
378 		for (k = 0; k < pev->ntevs; k++) {
379 			struct probe_trace_event *tev = &pev->tevs[k];
380 
381 			/* We use tev's name for showing new events */
382 			show_perf_probe_event(tev->group, tev->event, pev,
383 					      tev->point.module, false);
384 
385 			/* Save the last valid name */
386 			event = tev->event;
387 			group = tev->group;
388 		}
389 	}
390 
391 	/* Note that it is possible to skip all events because of blacklist */
392 	if (event) {
393 		/* Show how to use the event. */
394 		pr_info("\nYou can now use it in all perf tools, such as:\n\n");
395 		pr_info("\tperf record -e %s:%s -aR sleep 1\n\n", group, event);
396 	}
397 
398 out_cleanup:
399 	cleanup_perf_probe_events(pevs, npevs);
400 	exit_probe_symbol_maps();
401 	return ret;
402 }
403 
404 static int del_perf_probe_caches(struct strfilter *filter)
405 {
406 	struct probe_cache *cache;
407 	struct strlist *bidlist;
408 	struct str_node *nd;
409 	int ret;
410 
411 	bidlist = build_id_cache__list_all(false);
412 	if (!bidlist) {
413 		ret = -errno;
414 		pr_debug("Failed to get buildids: %d\n", ret);
415 		return ret ?: -ENOMEM;
416 	}
417 
418 	strlist__for_each_entry(nd, bidlist) {
419 		cache = probe_cache__new(nd->s, NULL);
420 		if (!cache)
421 			continue;
422 		if (probe_cache__filter_purge(cache, filter) < 0 ||
423 		    probe_cache__commit(cache) < 0)
424 			pr_warning("Failed to remove entries for %s\n", nd->s);
425 		probe_cache__delete(cache);
426 	}
427 	return 0;
428 }
429 
430 static int perf_del_probe_events(struct strfilter *filter)
431 {
432 	int ret, ret2, ufd = -1, kfd = -1;
433 	char *str = strfilter__string(filter);
434 	struct strlist *klist = NULL, *ulist = NULL;
435 	struct str_node *ent;
436 
437 	if (!str)
438 		return -EINVAL;
439 
440 	pr_debug("Delete filter: \'%s\'\n", str);
441 
442 	if (probe_conf.cache)
443 		return del_perf_probe_caches(filter);
444 
445 	/* Get current event names */
446 	ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
447 	if (ret < 0)
448 		goto out;
449 
450 	klist = strlist__new(NULL, NULL);
451 	ulist = strlist__new(NULL, NULL);
452 	if (!klist || !ulist) {
453 		ret = -ENOMEM;
454 		goto out;
455 	}
456 
457 	ret = probe_file__get_events(kfd, filter, klist);
458 	if (ret == 0) {
459 		strlist__for_each_entry(ent, klist)
460 			pr_info("Removed event: %s\n", ent->s);
461 
462 		ret = probe_file__del_strlist(kfd, klist);
463 		if (ret < 0)
464 			goto error;
465 	}
466 
467 	ret2 = probe_file__get_events(ufd, filter, ulist);
468 	if (ret2 == 0) {
469 		strlist__for_each_entry(ent, ulist)
470 			pr_info("Removed event: %s\n", ent->s);
471 
472 		ret2 = probe_file__del_strlist(ufd, ulist);
473 		if (ret2 < 0)
474 			goto error;
475 	}
476 
477 	if (ret == -ENOENT && ret2 == -ENOENT)
478 		pr_warning("\"%s\" does not hit any event.\n", str);
479 	else
480 		ret = 0;
481 
482 error:
483 	if (kfd >= 0)
484 		close(kfd);
485 	if (ufd >= 0)
486 		close(ufd);
487 out:
488 	strlist__delete(klist);
489 	strlist__delete(ulist);
490 	free(str);
491 
492 	return ret;
493 }
494 
495 #ifdef HAVE_DWARF_SUPPORT
496 #define PROBEDEF_STR	\
497 	"[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT [[NAME=]ARG ...]"
498 #else
499 #define PROBEDEF_STR	"[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]"
500 #endif
501 
502 
503 static int
504 __cmd_probe(int argc, const char **argv)
505 {
506 	const char * const probe_usage[] = {
507 		"perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
508 		"perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
509 		"perf probe [<options>] --del '[GROUP:]EVENT' ...",
510 		"perf probe --list [GROUP:]EVENT ...",
511 #ifdef HAVE_DWARF_SUPPORT
512 		"perf probe [<options>] --line 'LINEDESC'",
513 		"perf probe [<options>] --vars 'PROBEPOINT'",
514 #endif
515 		"perf probe [<options>] --funcs",
516 		NULL
517 	};
518 	struct option options[] = {
519 	OPT_INCR('v', "verbose", &verbose,
520 		    "be more verbose (show parsed arguments, etc)"),
521 	OPT_BOOLEAN('q', "quiet", &params.quiet,
522 		    "be quiet (do not show any messages)"),
523 	OPT_CALLBACK_DEFAULT('l', "list", NULL, "[GROUP:]EVENT",
524 			     "list up probe events",
525 			     opt_set_filter_with_command, DEFAULT_LIST_FILTER),
526 	OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
527 		     opt_set_filter_with_command),
528 	OPT_CALLBACK('a', "add", NULL, PROBEDEF_STR,
529 		"probe point definition, where\n"
530 		"\t\tGROUP:\tGroup name (optional)\n"
531 		"\t\tEVENT:\tEvent name\n"
532 		"\t\tFUNC:\tFunction name\n"
533 		"\t\tOFF:\tOffset from function entry (in byte)\n"
534 		"\t\t%return:\tPut the probe at function return\n"
535 #ifdef HAVE_DWARF_SUPPORT
536 		"\t\tSRC:\tSource code path\n"
537 		"\t\tRL:\tRelative line number from function entry.\n"
538 		"\t\tAL:\tAbsolute line number in file.\n"
539 		"\t\tPT:\tLazy expression of line code.\n"
540 		"\t\tARG:\tProbe argument (local variable name or\n"
541 		"\t\t\tkprobe-tracer argument format.)\n",
542 #else
543 		"\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
544 #endif
545 		opt_add_probe_event),
546 	OPT_CALLBACK('D', "definition", NULL, PROBEDEF_STR,
547 		"Show trace event definition of given traceevent for k/uprobe_events.",
548 		opt_add_probe_event),
549 	OPT_BOOLEAN('f', "force", &probe_conf.force_add, "forcibly add events"
550 		    " with existing name"),
551 	OPT_CALLBACK('L', "line", NULL,
552 		     "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
553 		     "Show source code lines.", opt_show_lines),
554 	OPT_CALLBACK('V', "vars", NULL,
555 		     "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
556 		     "Show accessible variables on PROBEDEF", opt_show_vars),
557 	OPT_BOOLEAN('\0', "externs", &probe_conf.show_ext_vars,
558 		    "Show external variables too (with --vars only)"),
559 	OPT_BOOLEAN('\0', "range", &probe_conf.show_location_range,
560 		"Show variables location range in scope (with --vars only)"),
561 	OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
562 		   "file", "vmlinux pathname"),
563 	OPT_STRING('s', "source", &symbol_conf.source_prefix,
564 		   "directory", "path to kernel source"),
565 	OPT_BOOLEAN('\0', "no-inlines", &probe_conf.no_inlines,
566 		"Don't search inlined functions"),
567 	OPT__DRY_RUN(&probe_event_dry_run),
568 	OPT_INTEGER('\0', "max-probes", &probe_conf.max_probes,
569 		 "Set how many probe points can be found for a probe."),
570 	OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",
571 			     "Show potential probe-able functions.",
572 			     opt_set_filter_with_command, DEFAULT_FUNC_FILTER),
573 	OPT_CALLBACK('\0', "filter", NULL,
574 		     "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
575 		     "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
576 		     "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
577 		     opt_set_filter),
578 	OPT_CALLBACK('x', "exec", NULL, "executable|path",
579 			"target executable name or path", opt_set_target),
580 	OPT_CALLBACK('m', "module", NULL, "modname|path",
581 		"target module name (for online) or path (for offline)",
582 		opt_set_target),
583 	OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
584 		    "Enable symbol demangling"),
585 	OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
586 		    "Enable kernel symbol demangling"),
587 	OPT_BOOLEAN(0, "cache", &probe_conf.cache, "Manipulate probe cache"),
588 	OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
589 		   "Look for files with symbols relative to this directory"),
590 	OPT_CALLBACK(0, "target-ns", NULL, "pid",
591 		     "target pid for namespace contexts", opt_set_target_ns),
592 	OPT_END()
593 	};
594 	int ret;
595 
596 	set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);
597 	set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);
598 	set_option_flag(options, 'D', "definition", PARSE_OPT_EXCLUSIVE);
599 	set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);
600 #ifdef HAVE_DWARF_SUPPORT
601 	set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);
602 	set_option_flag(options, 'V', "vars", PARSE_OPT_EXCLUSIVE);
603 #else
604 # define set_nobuild(s, l, c) set_option_nobuild(options, s, l, "NO_DWARF=1", c)
605 	set_nobuild('L', "line", false);
606 	set_nobuild('V', "vars", false);
607 	set_nobuild('\0', "externs", false);
608 	set_nobuild('\0', "range", false);
609 	set_nobuild('k', "vmlinux", true);
610 	set_nobuild('s', "source", true);
611 	set_nobuild('\0', "no-inlines", true);
612 # undef set_nobuild
613 #endif
614 	set_option_flag(options, 'F', "funcs", PARSE_OPT_EXCLUSIVE);
615 
616 	argc = parse_options(argc, argv, options, probe_usage,
617 			     PARSE_OPT_STOP_AT_NON_OPTION);
618 	if (argc > 0) {
619 		if (strcmp(argv[0], "-") == 0) {
620 			usage_with_options_msg(probe_usage, options,
621 				"'-' is not supported.\n");
622 		}
623 		if (params.command && params.command != 'a') {
624 			usage_with_options_msg(probe_usage, options,
625 				"another command except --add is set.\n");
626 		}
627 		ret = parse_probe_event_argv(argc, argv);
628 		if (ret < 0) {
629 			pr_err_with_code("  Error: Command Parse Error.", ret);
630 			return ret;
631 		}
632 		params.command = 'a';
633 	}
634 
635 	if (params.quiet) {
636 		if (verbose != 0) {
637 			pr_err("  Error: -v and -q are exclusive.\n");
638 			return -EINVAL;
639 		}
640 		verbose = -1;
641 	}
642 
643 	if (probe_conf.max_probes == 0)
644 		probe_conf.max_probes = MAX_PROBES;
645 
646 	/*
647 	 * Only consider the user's kernel image path if given.
648 	 */
649 	symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
650 
651 	/*
652 	 * Except for --list, --del and --add, other command doesn't depend
653 	 * nor change running kernel. So if user gives offline vmlinux,
654 	 * ignore its buildid.
655 	 */
656 	if (!strchr("lda", params.command) && symbol_conf.vmlinux_name)
657 		symbol_conf.ignore_vmlinux_buildid = true;
658 
659 	switch (params.command) {
660 	case 'l':
661 		if (params.uprobes) {
662 			pr_err("  Error: Don't use --list with --exec.\n");
663 			parse_options_usage(probe_usage, options, "l", true);
664 			parse_options_usage(NULL, options, "x", true);
665 			return -EINVAL;
666 		}
667 		ret = show_perf_probe_events(params.filter);
668 		if (ret < 0)
669 			pr_err_with_code("  Error: Failed to show event list.", ret);
670 		return ret;
671 	case 'F':
672 		ret = show_available_funcs(params.target, params.nsi,
673 					   params.filter, params.uprobes);
674 		if (ret < 0)
675 			pr_err_with_code("  Error: Failed to show functions.", ret);
676 		return ret;
677 #ifdef HAVE_DWARF_SUPPORT
678 	case 'L':
679 		ret = show_line_range(&params.line_range, params.target,
680 				      params.nsi, params.uprobes);
681 		if (ret < 0)
682 			pr_err_with_code("  Error: Failed to show lines.", ret);
683 		return ret;
684 	case 'V':
685 		if (!params.filter)
686 			params.filter = strfilter__new(DEFAULT_VAR_FILTER,
687 						       NULL);
688 
689 		ret = show_available_vars(params.events, params.nevents,
690 					  params.filter);
691 		if (ret < 0)
692 			pr_err_with_code("  Error: Failed to show vars.", ret);
693 		return ret;
694 #endif
695 	case 'd':
696 		ret = perf_del_probe_events(params.filter);
697 		if (ret < 0) {
698 			pr_err_with_code("  Error: Failed to delete events.", ret);
699 			return ret;
700 		}
701 		break;
702 	case 'D':
703 	case 'a':
704 
705 		/* Ensure the last given target is used */
706 		if (params.target && !params.target_used) {
707 			pr_err("  Error: -x/-m must follow the probe definitions.\n");
708 			parse_options_usage(probe_usage, options, "m", true);
709 			parse_options_usage(NULL, options, "x", true);
710 			return -EINVAL;
711 		}
712 
713 		ret = perf_add_probe_events(params.events, params.nevents);
714 		if (ret < 0) {
715 			pr_err_with_code("  Error: Failed to add events.", ret);
716 			return ret;
717 		}
718 		break;
719 	default:
720 		usage_with_options(probe_usage, options);
721 	}
722 	return 0;
723 }
724 
725 int cmd_probe(int argc, const char **argv)
726 {
727 	int ret;
728 
729 	ret = init_params();
730 	if (!ret) {
731 		ret = __cmd_probe(argc, argv);
732 		cleanup_params();
733 	}
734 
735 	return ret < 0 ? ret : 0;
736 }
737