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v5.4
  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_conf.h"
 25#include "util/debug.h"
 26#include <subcmd/parse-options.h>
 27#include "util/probe-finder.h"
 28#include "util/probe-event.h"
 29#include "util/probe-file.h"
 30#include <linux/string.h>
 31#include <linux/zalloc.h>
 32
 33#define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"
 34#define DEFAULT_FUNC_FILTER "!_*"
 35#define DEFAULT_LIST_FILTER "*"
 36
 37/* Session management structure */
 38static struct {
 39	int command;	/* Command short_name */
 40	bool list_events;
 41	bool uprobes;
 42	bool quiet;
 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. */
 53static 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
 81static 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
103static 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
132static 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
167static 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
202static 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 && nsip->need_setns)
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
233static 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
253static 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
275static 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
286static 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
298static 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
307static int init_params(void)
308{
309	return line_range__init(&params.line_range);
310}
311
312static void cleanup_params(void)
313{
314	int i;
315
316	for (i = 0; i < params.nevents; i++)
317		clear_perf_probe_event(params.events + i);
318	line_range__clear(&params.line_range);
319	free(params.target);
320	strfilter__delete(params.filter);
321	nsinfo__put(params.nsi);
322	memset(&params, 0, sizeof(params));
323}
324
325static void pr_err_with_code(const char *msg, int err)
326{
327	char sbuf[STRERR_BUFSIZE];
328
329	pr_err("%s", msg);
330	pr_debug(" Reason: %s (Code: %d)",
331		 str_error_r(-err, sbuf, sizeof(sbuf)), err);
332	pr_err("\n");
333}
334
335static int perf_add_probe_events(struct perf_probe_event *pevs, int npevs)
336{
337	int ret;
338	int i, k;
339	const char *event = NULL, *group = NULL;
340
341	ret = init_probe_symbol_maps(pevs->uprobes);
342	if (ret < 0)
343		return ret;
344
345	ret = convert_perf_probe_events(pevs, npevs);
346	if (ret < 0)
347		goto out_cleanup;
348
349	if (params.command == 'D') {	/* it shows definition */
350		ret = show_probe_trace_events(pevs, npevs);
 
 
 
351		goto out_cleanup;
352	}
353
354	ret = apply_perf_probe_events(pevs, npevs);
355	if (ret < 0)
356		goto out_cleanup;
357
358	for (i = k = 0; i < npevs; i++)
359		k += pevs[i].ntevs;
360
361	pr_info("Added new event%s\n", (k > 1) ? "s:" : ":");
362	for (i = 0; i < npevs; i++) {
363		struct perf_probe_event *pev = &pevs[i];
364
365		for (k = 0; k < pev->ntevs; k++) {
366			struct probe_trace_event *tev = &pev->tevs[k];
 
 
 
367
368			/* We use tev's name for showing new events */
369			show_perf_probe_event(tev->group, tev->event, pev,
370					      tev->point.module, false);
371
372			/* Save the last valid name */
373			event = tev->event;
374			group = tev->group;
375		}
376	}
377
378	/* Note that it is possible to skip all events because of blacklist */
379	if (event) {
380		/* Show how to use the event. */
381		pr_info("\nYou can now use it in all perf tools, such as:\n\n");
382		pr_info("\tperf record -e %s:%s -aR sleep 1\n\n", group, event);
383	}
384
385out_cleanup:
386	cleanup_perf_probe_events(pevs, npevs);
387	exit_probe_symbol_maps();
388	return ret;
389}
390
391static int del_perf_probe_caches(struct strfilter *filter)
392{
393	struct probe_cache *cache;
394	struct strlist *bidlist;
395	struct str_node *nd;
396	int ret;
397
398	bidlist = build_id_cache__list_all(false);
399	if (!bidlist) {
400		ret = -errno;
401		pr_debug("Failed to get buildids: %d\n", ret);
402		return ret ?: -ENOMEM;
403	}
404
405	strlist__for_each_entry(nd, bidlist) {
406		cache = probe_cache__new(nd->s, NULL);
407		if (!cache)
408			continue;
409		if (probe_cache__filter_purge(cache, filter) < 0 ||
410		    probe_cache__commit(cache) < 0)
411			pr_warning("Failed to remove entries for %s\n", nd->s);
412		probe_cache__delete(cache);
413	}
414	return 0;
415}
416
417static int perf_del_probe_events(struct strfilter *filter)
418{
419	int ret, ret2, ufd = -1, kfd = -1;
420	char *str = strfilter__string(filter);
421	struct strlist *klist = NULL, *ulist = NULL;
422	struct str_node *ent;
423
424	if (!str)
425		return -EINVAL;
426
427	pr_debug("Delete filter: \'%s\'\n", str);
428
429	if (probe_conf.cache)
430		return del_perf_probe_caches(filter);
431
432	/* Get current event names */
433	ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
434	if (ret < 0)
435		goto out;
436
437	klist = strlist__new(NULL, NULL);
438	ulist = strlist__new(NULL, NULL);
439	if (!klist || !ulist) {
440		ret = -ENOMEM;
441		goto out;
442	}
443
444	ret = probe_file__get_events(kfd, filter, klist);
445	if (ret == 0) {
446		strlist__for_each_entry(ent, klist)
447			pr_info("Removed event: %s\n", ent->s);
448
449		ret = probe_file__del_strlist(kfd, klist);
450		if (ret < 0)
451			goto error;
452	}
 
453
454	ret2 = probe_file__get_events(ufd, filter, ulist);
455	if (ret2 == 0) {
456		strlist__for_each_entry(ent, ulist)
457			pr_info("Removed event: %s\n", ent->s);
458
459		ret2 = probe_file__del_strlist(ufd, ulist);
460		if (ret2 < 0)
461			goto error;
462	}
 
463
464	if (ret == -ENOENT && ret2 == -ENOENT)
465		pr_warning("\"%s\" does not hit any event.\n", str);
466	else
467		ret = 0;
468
469error:
470	if (kfd >= 0)
471		close(kfd);
472	if (ufd >= 0)
473		close(ufd);
474out:
475	strlist__delete(klist);
476	strlist__delete(ulist);
477	free(str);
478
479	return ret;
480}
481
482#ifdef HAVE_DWARF_SUPPORT
483#define PROBEDEF_STR	\
484	"[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT [[NAME=]ARG ...]"
485#else
486#define PROBEDEF_STR	"[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]"
487#endif
488
489
490static int
491__cmd_probe(int argc, const char **argv)
492{
493	const char * const probe_usage[] = {
494		"perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
495		"perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
496		"perf probe [<options>] --del '[GROUP:]EVENT' ...",
497		"perf probe --list [GROUP:]EVENT ...",
498#ifdef HAVE_DWARF_SUPPORT
499		"perf probe [<options>] --line 'LINEDESC'",
500		"perf probe [<options>] --vars 'PROBEPOINT'",
501#endif
502		"perf probe [<options>] --funcs",
503		NULL
504	};
505	struct option options[] = {
506	OPT_INCR('v', "verbose", &verbose,
507		    "be more verbose (show parsed arguments, etc)"),
508	OPT_BOOLEAN('q', "quiet", &params.quiet,
509		    "be quiet (do not show any messages)"),
510	OPT_CALLBACK_DEFAULT('l', "list", NULL, "[GROUP:]EVENT",
511			     "list up probe events",
512			     opt_set_filter_with_command, DEFAULT_LIST_FILTER),
513	OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
514		     opt_set_filter_with_command),
515	OPT_CALLBACK('a', "add", NULL, PROBEDEF_STR,
516		"probe point definition, where\n"
517		"\t\tGROUP:\tGroup name (optional)\n"
518		"\t\tEVENT:\tEvent name\n"
519		"\t\tFUNC:\tFunction name\n"
520		"\t\tOFF:\tOffset from function entry (in byte)\n"
521		"\t\t%return:\tPut the probe at function return\n"
522#ifdef HAVE_DWARF_SUPPORT
523		"\t\tSRC:\tSource code path\n"
524		"\t\tRL:\tRelative line number from function entry.\n"
525		"\t\tAL:\tAbsolute line number in file.\n"
526		"\t\tPT:\tLazy expression of line code.\n"
527		"\t\tARG:\tProbe argument (local variable name or\n"
528		"\t\t\tkprobe-tracer argument format.)\n",
529#else
530		"\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
531#endif
532		opt_add_probe_event),
533	OPT_CALLBACK('D', "definition", NULL, PROBEDEF_STR,
534		"Show trace event definition of given traceevent for k/uprobe_events.",
535		opt_add_probe_event),
536	OPT_BOOLEAN('f', "force", &probe_conf.force_add, "forcibly add events"
537		    " with existing name"),
538	OPT_CALLBACK('L', "line", NULL,
539		     "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
540		     "Show source code lines.", opt_show_lines),
541	OPT_CALLBACK('V', "vars", NULL,
542		     "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
543		     "Show accessible variables on PROBEDEF", opt_show_vars),
544	OPT_BOOLEAN('\0', "externs", &probe_conf.show_ext_vars,
545		    "Show external variables too (with --vars only)"),
546	OPT_BOOLEAN('\0', "range", &probe_conf.show_location_range,
547		"Show variables location range in scope (with --vars only)"),
548	OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
549		   "file", "vmlinux pathname"),
550	OPT_STRING('s', "source", &symbol_conf.source_prefix,
551		   "directory", "path to kernel source"),
552	OPT_BOOLEAN('\0', "no-inlines", &probe_conf.no_inlines,
553		"Don't search inlined functions"),
554	OPT__DRY_RUN(&probe_event_dry_run),
555	OPT_INTEGER('\0', "max-probes", &probe_conf.max_probes,
556		 "Set how many probe points can be found for a probe."),
557	OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",
558			     "Show potential probe-able functions.",
559			     opt_set_filter_with_command, DEFAULT_FUNC_FILTER),
560	OPT_CALLBACK('\0', "filter", NULL,
561		     "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
562		     "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
563		     "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
564		     opt_set_filter),
565	OPT_CALLBACK('x', "exec", NULL, "executable|path",
566			"target executable name or path", opt_set_target),
567	OPT_CALLBACK('m', "module", NULL, "modname|path",
568		"target module name (for online) or path (for offline)",
569		opt_set_target),
570	OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
571		    "Enable symbol demangling"),
572	OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
573		    "Enable kernel symbol demangling"),
574	OPT_BOOLEAN(0, "cache", &probe_conf.cache, "Manipulate probe cache"),
575	OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
576		   "Look for files with symbols relative to this directory"),
577	OPT_CALLBACK(0, "target-ns", NULL, "pid",
578		     "target pid for namespace contexts", opt_set_target_ns),
 
 
579	OPT_END()
580	};
581	int ret;
582
583	set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);
584	set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);
585	set_option_flag(options, 'D', "definition", PARSE_OPT_EXCLUSIVE);
586	set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);
587#ifdef HAVE_DWARF_SUPPORT
588	set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);
589	set_option_flag(options, 'V', "vars", PARSE_OPT_EXCLUSIVE);
590#else
591# define set_nobuild(s, l, c) set_option_nobuild(options, s, l, "NO_DWARF=1", c)
592	set_nobuild('L', "line", false);
593	set_nobuild('V', "vars", false);
594	set_nobuild('\0', "externs", false);
595	set_nobuild('\0', "range", false);
596	set_nobuild('k', "vmlinux", true);
597	set_nobuild('s', "source", true);
598	set_nobuild('\0', "no-inlines", true);
599# undef set_nobuild
600#endif
601	set_option_flag(options, 'F', "funcs", PARSE_OPT_EXCLUSIVE);
602
603	argc = parse_options(argc, argv, options, probe_usage,
604			     PARSE_OPT_STOP_AT_NON_OPTION);
605	if (argc > 0) {
606		if (strcmp(argv[0], "-") == 0) {
607			usage_with_options_msg(probe_usage, options,
608				"'-' is not supported.\n");
609		}
610		if (params.command && params.command != 'a') {
611			usage_with_options_msg(probe_usage, options,
612				"another command except --add is set.\n");
613		}
614		ret = parse_probe_event_argv(argc, argv);
615		if (ret < 0) {
616			pr_err_with_code("  Error: Command Parse Error.", ret);
617			return ret;
618		}
619		params.command = 'a';
620	}
621
622	if (params.quiet) {
623		if (verbose != 0) {
624			pr_err("  Error: -v and -q are exclusive.\n");
625			return -EINVAL;
626		}
627		verbose = -1;
628	}
629
630	if (probe_conf.max_probes == 0)
631		probe_conf.max_probes = MAX_PROBES;
632
633	/*
634	 * Only consider the user's kernel image path if given.
635	 */
636	symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
637
638	/*
639	 * Except for --list, --del and --add, other command doesn't depend
640	 * nor change running kernel. So if user gives offline vmlinux,
641	 * ignore its buildid.
642	 */
643	if (!strchr("lda", params.command) && symbol_conf.vmlinux_name)
644		symbol_conf.ignore_vmlinux_buildid = true;
645
646	switch (params.command) {
647	case 'l':
648		if (params.uprobes) {
649			pr_err("  Error: Don't use --list with --exec.\n");
650			parse_options_usage(probe_usage, options, "l", true);
651			parse_options_usage(NULL, options, "x", true);
652			return -EINVAL;
653		}
654		ret = show_perf_probe_events(params.filter);
655		if (ret < 0)
656			pr_err_with_code("  Error: Failed to show event list.", ret);
657		return ret;
658	case 'F':
659		ret = show_available_funcs(params.target, params.nsi,
660					   params.filter, params.uprobes);
661		if (ret < 0)
662			pr_err_with_code("  Error: Failed to show functions.", ret);
663		return ret;
664#ifdef HAVE_DWARF_SUPPORT
665	case 'L':
666		ret = show_line_range(&params.line_range, params.target,
667				      params.nsi, params.uprobes);
668		if (ret < 0)
669			pr_err_with_code("  Error: Failed to show lines.", ret);
670		return ret;
671	case 'V':
672		if (!params.filter)
673			params.filter = strfilter__new(DEFAULT_VAR_FILTER,
674						       NULL);
675
676		ret = show_available_vars(params.events, params.nevents,
677					  params.filter);
678		if (ret < 0)
679			pr_err_with_code("  Error: Failed to show vars.", ret);
680		return ret;
681#endif
682	case 'd':
683		ret = perf_del_probe_events(params.filter);
684		if (ret < 0) {
685			pr_err_with_code("  Error: Failed to delete events.", ret);
686			return ret;
687		}
688		break;
689	case 'D':
 
 
 
 
 
690	case 'a':
691
692		/* Ensure the last given target is used */
693		if (params.target && !params.target_used) {
694			pr_err("  Error: -x/-m must follow the probe definitions.\n");
695			parse_options_usage(probe_usage, options, "m", true);
696			parse_options_usage(NULL, options, "x", true);
697			return -EINVAL;
698		}
699
700		ret = perf_add_probe_events(params.events, params.nevents);
701		if (ret < 0) {
702
703			/*
704			 * When perf_add_probe_events() fails it calls
705			 * cleanup_perf_probe_events(pevs, npevs), i.e.
706			 * cleanup_perf_probe_events(params.events, params.nevents), which
707			 * will call clear_perf_probe_event(), so set nevents to zero
708			 * to avoid cleanup_params() to call clear_perf_probe_event() again
709			 * on the same pevs.
710			 */
711			params.nevents = 0;
712			pr_err_with_code("  Error: Failed to add events.", ret);
713			return ret;
714		}
715		break;
716	default:
717		usage_with_options(probe_usage, options);
718	}
719	return 0;
720}
721
722int cmd_probe(int argc, const char **argv)
723{
724	int ret;
725
726	ret = init_params();
727	if (!ret) {
728		ret = __cmd_probe(argc, argv);
729		cleanup_params();
730	}
731
732	return ret < 0 ? ret : 0;
733}
v5.14.15
  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_conf.h"
 25#include "util/debug.h"
 26#include <subcmd/parse-options.h>
 27#include "util/probe-finder.h"
 28#include "util/probe-event.h"
 29#include "util/probe-file.h"
 30#include <linux/string.h>
 31#include <linux/zalloc.h>
 32
 33#define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"
 34#define DEFAULT_FUNC_FILTER "!_* & !*@plt"
 35#define DEFAULT_LIST_FILTER "*"
 36
 37/* Session management structure */
 38static struct {
 39	int command;	/* Command short_name */
 40	bool list_events;
 41	bool uprobes;
 42	bool quiet;
 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. */
 53static 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
 81static 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
103static 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
132static 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
167static 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
202static 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 && nsip->need_setns)
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
233static 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
253static 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
275static 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
286static 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
298static 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
307static int init_params(void)
308{
309	return line_range__init(&params.line_range);
310}
311
312static void cleanup_params(void)
313{
314	int i;
315
316	for (i = 0; i < params.nevents; i++)
317		clear_perf_probe_event(params.events + i);
318	line_range__clear(&params.line_range);
319	free(params.target);
320	strfilter__delete(params.filter);
321	nsinfo__put(params.nsi);
322	memset(&params, 0, sizeof(params));
323}
324
325static void pr_err_with_code(const char *msg, int err)
326{
327	char sbuf[STRERR_BUFSIZE];
328
329	pr_err("%s", msg);
330	pr_debug(" Reason: %s (Code: %d)",
331		 str_error_r(-err, sbuf, sizeof(sbuf)), err);
332	pr_err("\n");
333}
334
335static int perf_add_probe_events(struct perf_probe_event *pevs, int npevs)
336{
337	int ret;
338	int i, k;
339	const char *event = NULL, *group = NULL;
340
341	ret = init_probe_symbol_maps(pevs->uprobes);
342	if (ret < 0)
343		return ret;
344
345	ret = convert_perf_probe_events(pevs, npevs);
346	if (ret < 0)
347		goto out_cleanup;
348
349	if (params.command == 'D') {	/* it shows definition */
350		if (probe_conf.bootconfig)
351			ret = show_bootconfig_events(pevs, npevs);
352		else
353			ret = show_probe_trace_events(pevs, npevs);
354		goto out_cleanup;
355	}
356
357	ret = apply_perf_probe_events(pevs, npevs);
358	if (ret < 0)
359		goto out_cleanup;
360
361	for (i = k = 0; i < npevs; i++)
362		k += pevs[i].ntevs;
363
364	pr_info("Added new event%s\n", (k > 1) ? "s:" : ":");
365	for (i = 0; i < npevs; i++) {
366		struct perf_probe_event *pev = &pevs[i];
367
368		for (k = 0; k < pev->ntevs; k++) {
369			struct probe_trace_event *tev = &pev->tevs[k];
370			/* Skipped events have no event name */
371			if (!tev->event)
372				continue;
373
374			/* We use tev's name for showing new events */
375			show_perf_probe_event(tev->group, tev->event, pev,
376					      tev->point.module, false);
377
378			/* Save the last valid name */
379			event = tev->event;
380			group = tev->group;
381		}
382	}
383
384	/* Note that it is possible to skip all events because of blacklist */
385	if (event) {
386		/* Show how to use the event. */
387		pr_info("\nYou can now use it in all perf tools, such as:\n\n");
388		pr_info("\tperf record -e %s:%s -aR sleep 1\n\n", group, event);
389	}
390
391out_cleanup:
392	cleanup_perf_probe_events(pevs, npevs);
393	exit_probe_symbol_maps();
394	return ret;
395}
396
397static int del_perf_probe_caches(struct strfilter *filter)
398{
399	struct probe_cache *cache;
400	struct strlist *bidlist;
401	struct str_node *nd;
402	int ret;
403
404	bidlist = build_id_cache__list_all(false);
405	if (!bidlist) {
406		ret = -errno;
407		pr_debug("Failed to get buildids: %d\n", ret);
408		return ret ?: -ENOMEM;
409	}
410
411	strlist__for_each_entry(nd, bidlist) {
412		cache = probe_cache__new(nd->s, NULL);
413		if (!cache)
414			continue;
415		if (probe_cache__filter_purge(cache, filter) < 0 ||
416		    probe_cache__commit(cache) < 0)
417			pr_warning("Failed to remove entries for %s\n", nd->s);
418		probe_cache__delete(cache);
419	}
420	return 0;
421}
422
423static int perf_del_probe_events(struct strfilter *filter)
424{
425	int ret, ret2, ufd = -1, kfd = -1;
426	char *str = strfilter__string(filter);
427	struct strlist *klist = NULL, *ulist = NULL;
428	struct str_node *ent;
429
430	if (!str)
431		return -EINVAL;
432
433	pr_debug("Delete filter: \'%s\'\n", str);
434
435	if (probe_conf.cache)
436		return del_perf_probe_caches(filter);
437
438	/* Get current event names */
439	ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
440	if (ret < 0)
441		goto out;
442
443	klist = strlist__new(NULL, NULL);
444	ulist = strlist__new(NULL, NULL);
445	if (!klist || !ulist) {
446		ret = -ENOMEM;
447		goto out;
448	}
449
450	ret = probe_file__get_events(kfd, filter, klist);
451	if (ret == 0) {
452		strlist__for_each_entry(ent, klist)
453			pr_info("Removed event: %s\n", ent->s);
454
455		ret = probe_file__del_strlist(kfd, klist);
456		if (ret < 0)
457			goto error;
458	} else if (ret == -ENOMEM)
459		goto error;
460
461	ret2 = probe_file__get_events(ufd, filter, ulist);
462	if (ret2 == 0) {
463		strlist__for_each_entry(ent, ulist)
464			pr_info("Removed event: %s\n", ent->s);
465
466		ret2 = probe_file__del_strlist(ufd, ulist);
467		if (ret2 < 0)
468			goto error;
469	} else if (ret2 == -ENOMEM)
470		goto error;
471
472	if (ret == -ENOENT && ret2 == -ENOENT)
473		pr_warning("\"%s\" does not hit any event.\n", str);
474	else
475		ret = 0;
476
477error:
478	if (kfd >= 0)
479		close(kfd);
480	if (ufd >= 0)
481		close(ufd);
482out:
483	strlist__delete(klist);
484	strlist__delete(ulist);
485	free(str);
486
487	return ret;
488}
489
490#ifdef HAVE_DWARF_SUPPORT
491#define PROBEDEF_STR	\
492	"[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT [[NAME=]ARG ...]"
493#else
494#define PROBEDEF_STR	"[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]"
495#endif
496
497
498static int
499__cmd_probe(int argc, const char **argv)
500{
501	const char * const probe_usage[] = {
502		"perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
503		"perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
504		"perf probe [<options>] --del '[GROUP:]EVENT' ...",
505		"perf probe --list [GROUP:]EVENT ...",
506#ifdef HAVE_DWARF_SUPPORT
507		"perf probe [<options>] --line 'LINEDESC'",
508		"perf probe [<options>] --vars 'PROBEPOINT'",
509#endif
510		"perf probe [<options>] --funcs",
511		NULL
512	};
513	struct option options[] = {
514	OPT_INCR('v', "verbose", &verbose,
515		    "be more verbose (show parsed arguments, etc)"),
516	OPT_BOOLEAN('q', "quiet", &params.quiet,
517		    "be quiet (do not show any messages)"),
518	OPT_CALLBACK_DEFAULT('l', "list", NULL, "[GROUP:]EVENT",
519			     "list up probe events",
520			     opt_set_filter_with_command, DEFAULT_LIST_FILTER),
521	OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
522		     opt_set_filter_with_command),
523	OPT_CALLBACK('a', "add", NULL, PROBEDEF_STR,
524		"probe point definition, where\n"
525		"\t\tGROUP:\tGroup name (optional)\n"
526		"\t\tEVENT:\tEvent name\n"
527		"\t\tFUNC:\tFunction name\n"
528		"\t\tOFF:\tOffset from function entry (in byte)\n"
529		"\t\t%return:\tPut the probe at function return\n"
530#ifdef HAVE_DWARF_SUPPORT
531		"\t\tSRC:\tSource code path\n"
532		"\t\tRL:\tRelative line number from function entry.\n"
533		"\t\tAL:\tAbsolute line number in file.\n"
534		"\t\tPT:\tLazy expression of line code.\n"
535		"\t\tARG:\tProbe argument (local variable name or\n"
536		"\t\t\tkprobe-tracer argument format.)\n",
537#else
538		"\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
539#endif
540		opt_add_probe_event),
541	OPT_CALLBACK('D', "definition", NULL, PROBEDEF_STR,
542		"Show trace event definition of given traceevent for k/uprobe_events.",
543		opt_add_probe_event),
544	OPT_BOOLEAN('f', "force", &probe_conf.force_add, "forcibly add events"
545		    " with existing name"),
546	OPT_CALLBACK('L', "line", NULL,
547		     "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
548		     "Show source code lines.", opt_show_lines),
549	OPT_CALLBACK('V', "vars", NULL,
550		     "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
551		     "Show accessible variables on PROBEDEF", opt_show_vars),
552	OPT_BOOLEAN('\0', "externs", &probe_conf.show_ext_vars,
553		    "Show external variables too (with --vars only)"),
554	OPT_BOOLEAN('\0', "range", &probe_conf.show_location_range,
555		"Show variables location range in scope (with --vars only)"),
556	OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
557		   "file", "vmlinux pathname"),
558	OPT_STRING('s', "source", &symbol_conf.source_prefix,
559		   "directory", "path to kernel source"),
560	OPT_BOOLEAN('\0', "no-inlines", &probe_conf.no_inlines,
561		"Don't search inlined functions"),
562	OPT__DRY_RUN(&probe_event_dry_run),
563	OPT_INTEGER('\0', "max-probes", &probe_conf.max_probes,
564		 "Set how many probe points can be found for a probe."),
565	OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",
566			     "Show potential probe-able functions.",
567			     opt_set_filter_with_command, DEFAULT_FUNC_FILTER),
568	OPT_CALLBACK('\0', "filter", NULL,
569		     "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
570		     "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
571		     "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
572		     opt_set_filter),
573	OPT_CALLBACK('x', "exec", NULL, "executable|path",
574			"target executable name or path", opt_set_target),
575	OPT_CALLBACK('m', "module", NULL, "modname|path",
576		"target module name (for online) or path (for offline)",
577		opt_set_target),
578	OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
579		    "Enable symbol demangling"),
580	OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
581		    "Enable kernel symbol demangling"),
582	OPT_BOOLEAN(0, "cache", &probe_conf.cache, "Manipulate probe cache"),
583	OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
584		   "Look for files with symbols relative to this directory"),
585	OPT_CALLBACK(0, "target-ns", NULL, "pid",
586		     "target pid for namespace contexts", opt_set_target_ns),
587	OPT_BOOLEAN(0, "bootconfig", &probe_conf.bootconfig,
588		    "Output probe definition with bootconfig format"),
589	OPT_END()
590	};
591	int ret;
592
593	set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);
594	set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);
595	set_option_flag(options, 'D', "definition", PARSE_OPT_EXCLUSIVE);
596	set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);
597#ifdef HAVE_DWARF_SUPPORT
598	set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);
599	set_option_flag(options, 'V', "vars", PARSE_OPT_EXCLUSIVE);
600#else
601# define set_nobuild(s, l, c) set_option_nobuild(options, s, l, "NO_DWARF=1", c)
602	set_nobuild('L', "line", false);
603	set_nobuild('V', "vars", false);
604	set_nobuild('\0', "externs", false);
605	set_nobuild('\0', "range", false);
606	set_nobuild('k', "vmlinux", true);
607	set_nobuild('s', "source", true);
608	set_nobuild('\0', "no-inlines", true);
609# undef set_nobuild
610#endif
611	set_option_flag(options, 'F', "funcs", PARSE_OPT_EXCLUSIVE);
612
613	argc = parse_options(argc, argv, options, probe_usage,
614			     PARSE_OPT_STOP_AT_NON_OPTION);
615	if (argc > 0) {
616		if (strcmp(argv[0], "-") == 0) {
617			usage_with_options_msg(probe_usage, options,
618				"'-' is not supported.\n");
619		}
620		if (params.command && params.command != 'a') {
621			usage_with_options_msg(probe_usage, options,
622				"another command except --add is set.\n");
623		}
624		ret = parse_probe_event_argv(argc, argv);
625		if (ret < 0) {
626			pr_err_with_code("  Error: Command Parse Error.", ret);
627			return ret;
628		}
629		params.command = 'a';
630	}
631
632	if (params.quiet) {
633		if (verbose != 0) {
634			pr_err("  Error: -v and -q are exclusive.\n");
635			return -EINVAL;
636		}
637		verbose = -1;
638	}
639
640	if (probe_conf.max_probes == 0)
641		probe_conf.max_probes = MAX_PROBES;
642
643	/*
644	 * Only consider the user's kernel image path if given.
645	 */
646	symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
647
648	/*
649	 * Except for --list, --del and --add, other command doesn't depend
650	 * nor change running kernel. So if user gives offline vmlinux,
651	 * ignore its buildid.
652	 */
653	if (!strchr("lda", params.command) && symbol_conf.vmlinux_name)
654		symbol_conf.ignore_vmlinux_buildid = true;
655
656	switch (params.command) {
657	case 'l':
658		if (params.uprobes) {
659			pr_err("  Error: Don't use --list with --exec.\n");
660			parse_options_usage(probe_usage, options, "l", true);
661			parse_options_usage(NULL, options, "x", true);
662			return -EINVAL;
663		}
664		ret = show_perf_probe_events(params.filter);
665		if (ret < 0)
666			pr_err_with_code("  Error: Failed to show event list.", ret);
667		return ret;
668	case 'F':
669		ret = show_available_funcs(params.target, params.nsi,
670					   params.filter, params.uprobes);
671		if (ret < 0)
672			pr_err_with_code("  Error: Failed to show functions.", ret);
673		return ret;
674#ifdef HAVE_DWARF_SUPPORT
675	case 'L':
676		ret = show_line_range(&params.line_range, params.target,
677				      params.nsi, params.uprobes);
678		if (ret < 0)
679			pr_err_with_code("  Error: Failed to show lines.", ret);
680		return ret;
681	case 'V':
682		if (!params.filter)
683			params.filter = strfilter__new(DEFAULT_VAR_FILTER,
684						       NULL);
685
686		ret = show_available_vars(params.events, params.nevents,
687					  params.filter);
688		if (ret < 0)
689			pr_err_with_code("  Error: Failed to show vars.", ret);
690		return ret;
691#endif
692	case 'd':
693		ret = perf_del_probe_events(params.filter);
694		if (ret < 0) {
695			pr_err_with_code("  Error: Failed to delete events.", ret);
696			return ret;
697		}
698		break;
699	case 'D':
700		if (probe_conf.bootconfig && params.uprobes) {
701			pr_err("  Error: --bootconfig doesn't support uprobes.\n");
702			return -EINVAL;
703		}
704		__fallthrough;
705	case 'a':
706
707		/* Ensure the last given target is used */
708		if (params.target && !params.target_used) {
709			pr_err("  Error: -x/-m must follow the probe definitions.\n");
710			parse_options_usage(probe_usage, options, "m", true);
711			parse_options_usage(NULL, options, "x", true);
712			return -EINVAL;
713		}
714
715		ret = perf_add_probe_events(params.events, params.nevents);
716		if (ret < 0) {
717
718			/*
719			 * When perf_add_probe_events() fails it calls
720			 * cleanup_perf_probe_events(pevs, npevs), i.e.
721			 * cleanup_perf_probe_events(params.events, params.nevents), which
722			 * will call clear_perf_probe_event(), so set nevents to zero
723			 * to avoid cleanup_params() to call clear_perf_probe_event() again
724			 * on the same pevs.
725			 */
726			params.nevents = 0;
727			pr_err_with_code("  Error: Failed to add events.", ret);
728			return ret;
729		}
730		break;
731	default:
732		usage_with_options(probe_usage, options);
733	}
734	return 0;
735}
736
737int cmd_probe(int argc, const char **argv)
738{
739	int ret;
740
741	ret = init_params();
742	if (!ret) {
743		ret = __cmd_probe(argc, argv);
744		cleanup_params();
745	}
746
747	return ret < 0 ? ret : 0;
748}