1 files changed, 753 insertions, 0 deletions

diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
new file mode 100644
index 000000000..ed73d0b89
--- /dev/null
+++ b/tools/perf/builtin-probe.c
@@ -0,0 +1,753 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * builtin-probe.c
+ *
+ * Builtin probe command: Set up probe events by C expression
+ *
+ * Written by Masami Hiramatsu <mhiramat@redhat.com>
+ */
+#include <sys/utsname.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "builtin.h"
+#include "namespaces.h"
+#include "util/build-id.h"
+#include "util/strlist.h"
+#include "util/strfilter.h"
+#include "util/symbol.h"
+#include "util/symbol_conf.h"
+#include "util/debug.h"
+#include <subcmd/parse-options.h>
+#include "util/probe-finder.h"
+#include "util/probe-event.h"
+#include "util/probe-file.h"
+#include <linux/string.h>
+#include <linux/zalloc.h>
+
+#define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"
+#define DEFAULT_FUNC_FILTER "!_* & !*@plt"
+#define DEFAULT_LIST_FILTER "*"
+
+/* Session management structure */
+static struct {
+	int command;	/* Command short_name */
+	bool list_events;
+	bool uprobes;
+	bool target_used;
+	int nevents;
+	struct perf_probe_event events[MAX_PROBES];
+	struct line_range line_range;
+	char *target;
+	struct strfilter *filter;
+	struct nsinfo *nsi;
+} params;
+
+/* Parse an event definition. Note that any error must die. */
+static int parse_probe_event(const char *str)
+{
+	struct perf_probe_event *pev = &params.events[params.nevents];
+	int ret;
+
+	pr_debug("probe-definition(%d): %s\n", params.nevents, str);
+	if (++params.nevents == MAX_PROBES) {
+		pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
+		return -1;
+	}
+
+	pev->uprobes = params.uprobes;
+	if (params.target) {
+		pev->target = strdup(params.target);
+		if (!pev->target)
+			return -ENOMEM;
+		params.target_used = true;
+	}
+
+	pev->nsi = nsinfo__get(params.nsi);
+
+	/* Parse a perf-probe command into event */
+	ret = parse_perf_probe_command(str, pev);
+	pr_debug("%d arguments\n", pev->nargs);
+
+	return ret;
+}
+
+static int params_add_filter(const char *str)
+{
+	const char *err = NULL;
+	int ret = 0;
+
+	pr_debug2("Add filter: %s\n", str);
+	if (!params.filter) {
+		params.filter = strfilter__new(str, &err);
+		if (!params.filter)
+			ret = err ? -EINVAL : -ENOMEM;
+	} else
+		ret = strfilter__or(params.filter, str, &err);
+
+	if (ret == -EINVAL) {
+		pr_err("Filter parse error at %td.\n", err - str + 1);
+		pr_err("Source: \"%s\"\n", str);
+		pr_err("         %*c\n", (int)(err - str + 1), '^');
+	}
+
+	return ret;
+}
+
+static int set_target(const char *ptr)
+{
+	int found = 0;
+	const char *buf;
+
+	/*
+	 * The first argument after options can be an absolute path
+	 * to an executable / library or kernel module.
+	 *
+	 * TODO: Support relative path, and $PATH, $LD_LIBRARY_PATH,
+	 * short module name.
+	 */
+	if (!params.target && ptr && *ptr == '/') {
+		params.target = strdup(ptr);
+		if (!params.target)
+			return -ENOMEM;
+		params.target_used = false;
+
+		found = 1;
+		buf = ptr + (strlen(ptr) - 3);
+
+		if (strcmp(buf, ".ko"))
+			params.uprobes = true;
+
+	}
+
+	return found;
+}
+
+static int parse_probe_event_argv(int argc, const char **argv)
+{
+	int i, len, ret, found_target;
+	char *buf;
+
+	found_target = set_target(argv[0]);
+	if (found_target < 0)
+		return found_target;
+
+	if (found_target && argc == 1)
+		return 0;
+
+	/* Bind up rest arguments */
+	len = 0;
+	for (i = 0; i < argc; i++) {
+		if (i == 0 && found_target)
+			continue;
+
+		len += strlen(argv[i]) + 1;
+	}
+	buf = zalloc(len + 1);
+	if (buf == NULL)
+		return -ENOMEM;
+	len = 0;
+	for (i = 0; i < argc; i++) {
+		if (i == 0 && found_target)
+			continue;
+
+		len += sprintf(&buf[len], "%s ", argv[i]);
+	}
+	ret = parse_probe_event(buf);
+	free(buf);
+	return ret;
+}
+
+static int opt_set_target(const struct option *opt, const char *str,
+			int unset __maybe_unused)
+{
+	int ret = -ENOENT;
+	char *tmp;
+
+	if  (str) {
+		if (!strcmp(opt->long_name, "exec"))
+			params.uprobes = true;
+		else if (!strcmp(opt->long_name, "module"))
+			params.uprobes = false;
+		else
+			return ret;
+
+		/* Expand given path to absolute path, except for modulename */
+		if (params.uprobes || strchr(str, '/')) {
+			tmp = nsinfo__realpath(str, params.nsi);
+			if (!tmp) {
+				pr_warning("Failed to get the absolute path of %s: %m\n", str);
+				return ret;
+			}
+		} else {
+			tmp = strdup(str);
+			if (!tmp)
+				return -ENOMEM;
+		}
+		free(params.target);
+		params.target = tmp;
+		params.target_used = false;
+		ret = 0;
+	}
+
+	return ret;
+}
+
+static int opt_set_target_ns(const struct option *opt __maybe_unused,
+			     const char *str, int unset __maybe_unused)
+{
+	int ret = -ENOENT;
+	pid_t ns_pid;
+	struct nsinfo *nsip;
+
+	if (str) {
+		errno = 0;
+		ns_pid = (pid_t)strtol(str, NULL, 10);
+		if (errno != 0) {
+			ret = -errno;
+			pr_warning("Failed to parse %s as a pid: %s\n", str,
+				   strerror(errno));
+			return ret;
+		}
+		nsip = nsinfo__new(ns_pid);
+		if (nsip && nsinfo__need_setns(nsip))
+			params.nsi = nsinfo__get(nsip);
+		nsinfo__put(nsip);
+
+		ret = 0;
+	}
+
+	return ret;
+}
+
+
+/* Command option callbacks */
+
+#ifdef HAVE_DWARF_SUPPORT
+static int opt_show_lines(const struct option *opt,
+			  const char *str, int unset __maybe_unused)
+{
+	int ret = 0;
+
+	if (!str)
+		return 0;
+
+	if (params.command == 'L') {
+		pr_warning("Warning: more than one --line options are"
+			   " detected. Only the first one is valid.\n");
+		return 0;
+	}
+
+	params.command = opt->short_name;
+	ret = parse_line_range_desc(str, &params.line_range);
+
+	return ret;
+}
+
+static int opt_show_vars(const struct option *opt,
+			 const char *str, int unset __maybe_unused)
+{
+	struct perf_probe_event *pev = &params.events[params.nevents];
+	int ret;
+
+	if (!str)
+		return 0;
+
+	ret = parse_probe_event(str);
+	if (!ret && pev->nargs != 0) {
+		pr_err("  Error: '--vars' doesn't accept arguments.\n");
+		return -EINVAL;
+	}
+	params.command = opt->short_name;
+
+	return ret;
+}
+#else
+# define opt_show_lines NULL
+# define opt_show_vars NULL
+#endif
+static int opt_add_probe_event(const struct option *opt,
+			      const char *str, int unset __maybe_unused)
+{
+	if (str) {
+		params.command = opt->short_name;
+		return parse_probe_event(str);
+	}
+
+	return 0;
+}
+
+static int opt_set_filter_with_command(const struct option *opt,
+				       const char *str, int unset)
+{
+	if (!unset)
+		params.command = opt->short_name;
+
+	if (str)
+		return params_add_filter(str);
+
+	return 0;
+}
+
+static int opt_set_filter(const struct option *opt __maybe_unused,
+			  const char *str, int unset __maybe_unused)
+{
+	if (str)
+		return params_add_filter(str);
+
+	return 0;
+}
+
+static int init_params(void)
+{
+	return line_range__init(&params.line_range);
+}
+
+static void cleanup_params(void)
+{
+	int i;
+
+	for (i = 0; i < params.nevents; i++)
+		clear_perf_probe_event(params.events + i);
+	line_range__clear(&params.line_range);
+	free(params.target);
+	strfilter__delete(params.filter);
+	nsinfo__put(params.nsi);
+	memset(&params, 0, sizeof(params));
+}
+
+static void pr_err_with_code(const char *msg, int err)
+{
+	char sbuf[STRERR_BUFSIZE];
+
+	pr_err("%s", msg);
+	pr_debug(" Reason: %s (Code: %d)",
+		 str_error_r(-err, sbuf, sizeof(sbuf)), err);
+	pr_err("\n");
+}
+
+static int perf_add_probe_events(struct perf_probe_event *pevs, int npevs)
+{
+	int ret;
+	int i, k;
+	const char *event = NULL, *group = NULL;
+
+	ret = init_probe_symbol_maps(pevs->uprobes);
+	if (ret < 0)
+		return ret;
+
+	ret = convert_perf_probe_events(pevs, npevs);
+	if (ret < 0)
+		goto out_cleanup;
+
+	if (params.command == 'D') {	/* it shows definition */
+		if (probe_conf.bootconfig)
+			ret = show_bootconfig_events(pevs, npevs);
+		else
+			ret = show_probe_trace_events(pevs, npevs);
+		goto out_cleanup;
+	}
+
+	ret = apply_perf_probe_events(pevs, npevs);
+	if (ret < 0)
+		goto out_cleanup;
+
+	for (i = k = 0; i < npevs; i++)
+		k += pevs[i].ntevs;
+
+	pr_info("Added new event%s\n", (k > 1) ? "s:" : ":");
+	for (i = 0; i < npevs; i++) {
+		struct perf_probe_event *pev = &pevs[i];
+
+		for (k = 0; k < pev->ntevs; k++) {
+			struct probe_trace_event *tev = &pev->tevs[k];
+			/* Skipped events have no event name */
+			if (!tev->event)
+				continue;
+
+			/* We use tev's name for showing new events */
+			show_perf_probe_event(tev->group, tev->event, pev,
+					      tev->point.module, false);
+
+			/* Save the last valid name */
+			event = tev->event;
+			group = tev->group;
+		}
+	}
+
+	/* Note that it is possible to skip all events because of blacklist */
+	if (event) {
+		/* Show how to use the event. */
+		pr_info("\nYou can now use it in all perf tools, such as:\n\n");
+		pr_info("\tperf record -e %s:%s -aR sleep 1\n\n", group, event);
+	}
+
+out_cleanup:
+	cleanup_perf_probe_events(pevs, npevs);
+	exit_probe_symbol_maps();
+	return ret;
+}
+
+static int del_perf_probe_caches(struct strfilter *filter)
+{
+	struct probe_cache *cache;
+	struct strlist *bidlist;
+	struct str_node *nd;
+	int ret;
+
+	bidlist = build_id_cache__list_all(false);
+	if (!bidlist) {
+		ret = -errno;
+		pr_debug("Failed to get buildids: %d\n", ret);
+		return ret ?: -ENOMEM;
+	}
+
+	strlist__for_each_entry(nd, bidlist) {
+		cache = probe_cache__new(nd->s, NULL);
+		if (!cache)
+			continue;
+		if (probe_cache__filter_purge(cache, filter) < 0 ||
+		    probe_cache__commit(cache) < 0)
+			pr_warning("Failed to remove entries for %s\n", nd->s);
+		probe_cache__delete(cache);
+	}
+	return 0;
+}
+
+static int perf_del_probe_events(struct strfilter *filter)
+{
+	int ret, ret2, ufd = -1, kfd = -1;
+	char *str = strfilter__string(filter);
+	struct strlist *klist = NULL, *ulist = NULL;
+	struct str_node *ent;
+
+	if (!str)
+		return -EINVAL;
+
+	pr_debug("Delete filter: \'%s\'\n", str);
+
+	if (probe_conf.cache)
+		return del_perf_probe_caches(filter);
+
+	/* Get current event names */
+	ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
+	if (ret < 0)
+		goto out;
+
+	klist = strlist__new(NULL, NULL);
+	ulist = strlist__new(NULL, NULL);
+	if (!klist || !ulist) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ret = probe_file__get_events(kfd, filter, klist);
+	if (ret == 0) {
+		strlist__for_each_entry(ent, klist)
+			pr_info("Removed event: %s\n", ent->s);
+
+		ret = probe_file__del_strlist(kfd, klist);
+		if (ret < 0)
+			goto error;
+	} else if (ret == -ENOMEM)
+		goto error;
+
+	ret2 = probe_file__get_events(ufd, filter, ulist);
+	if (ret2 == 0) {
+		strlist__for_each_entry(ent, ulist)
+			pr_info("Removed event: %s\n", ent->s);
+
+		ret2 = probe_file__del_strlist(ufd, ulist);
+		if (ret2 < 0)
+			goto error;
+	} else if (ret2 == -ENOMEM)
+		goto error;
+
+	if (ret == -ENOENT && ret2 == -ENOENT)
+		pr_warning("\"%s\" does not hit any event.\n", str);
+	else
+		ret = 0;
+
+error:
+	if (kfd >= 0)
+		close(kfd);
+	if (ufd >= 0)
+		close(ufd);
+out:
+	strlist__delete(klist);
+	strlist__delete(ulist);
+	free(str);
+
+	return ret;
+}
+
+#ifdef HAVE_DWARF_SUPPORT
+#define PROBEDEF_STR	\
+	"[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT [[NAME=]ARG ...]"
+#else
+#define PROBEDEF_STR	"[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]"
+#endif
+
+
+static int
+__cmd_probe(int argc, const char **argv)
+{
+	const char * const probe_usage[] = {
+		"perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
+		"perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
+		"perf probe [<options>] --del '[GROUP:]EVENT' ...",
+		"perf probe --list [GROUP:]EVENT ...",
+#ifdef HAVE_DWARF_SUPPORT
+		"perf probe [<options>] --line 'LINEDESC'",
+		"perf probe [<options>] --vars 'PROBEPOINT'",
+#endif
+		"perf probe [<options>] --funcs",
+		NULL
+	};
+	struct option options[] = {
+	OPT_INCR('v', "verbose", &verbose,
+		    "be more verbose (show parsed arguments, etc)"),
+	OPT_BOOLEAN('q', "quiet", &quiet,
+		    "be quiet (do not show any warnings or messages)"),
+	OPT_CALLBACK_DEFAULT('l', "list", NULL, "[GROUP:]EVENT",
+			     "list up probe events",
+			     opt_set_filter_with_command, DEFAULT_LIST_FILTER),
+	OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
+		     opt_set_filter_with_command),
+	OPT_CALLBACK('a', "add", NULL, PROBEDEF_STR,
+		"probe point definition, where\n"
+		"\t\tGROUP:\tGroup name (optional)\n"
+		"\t\tEVENT:\tEvent name\n"
+		"\t\tFUNC:\tFunction name\n"
+		"\t\tOFF:\tOffset from function entry (in byte)\n"
+		"\t\t%return:\tPut the probe at function return\n"
+#ifdef HAVE_DWARF_SUPPORT
+		"\t\tSRC:\tSource code path\n"
+		"\t\tRL:\tRelative line number from function entry.\n"
+		"\t\tAL:\tAbsolute line number in file.\n"
+		"\t\tPT:\tLazy expression of line code.\n"
+		"\t\tARG:\tProbe argument (local variable name or\n"
+		"\t\t\tkprobe-tracer argument format.)\n",
+#else
+		"\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
+#endif
+		opt_add_probe_event),
+	OPT_CALLBACK('D', "definition", NULL, PROBEDEF_STR,
+		"Show trace event definition of given traceevent for k/uprobe_events.",
+		opt_add_probe_event),
+	OPT_BOOLEAN('f', "force", &probe_conf.force_add, "forcibly add events"
+		    " with existing name"),
+	OPT_CALLBACK('L', "line", NULL,
+		     "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
+		     "Show source code lines.", opt_show_lines),
+	OPT_CALLBACK('V', "vars", NULL,
+		     "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
+		     "Show accessible variables on PROBEDEF", opt_show_vars),
+	OPT_BOOLEAN('\0', "externs", &probe_conf.show_ext_vars,
+		    "Show external variables too (with --vars only)"),
+	OPT_BOOLEAN('\0', "range", &probe_conf.show_location_range,
+		"Show variables location range in scope (with --vars only)"),
+	OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
+		   "file", "vmlinux pathname"),
+	OPT_STRING('s', "source", &symbol_conf.source_prefix,
+		   "directory", "path to kernel source"),
+	OPT_BOOLEAN('\0', "no-inlines", &probe_conf.no_inlines,
+		"Don't search inlined functions"),
+	OPT__DRY_RUN(&probe_event_dry_run),
+	OPT_INTEGER('\0', "max-probes", &probe_conf.max_probes,
+		 "Set how many probe points can be found for a probe."),
+	OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",
+			     "Show potential probe-able functions.",
+			     opt_set_filter_with_command, DEFAULT_FUNC_FILTER),
+	OPT_CALLBACK('\0', "filter", NULL,
+		     "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
+		     "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
+		     "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
+		     opt_set_filter),
+	OPT_CALLBACK('x', "exec", NULL, "executable|path",
+			"target executable name or path", opt_set_target),
+	OPT_CALLBACK('m', "module", NULL, "modname|path",
+		"target module name (for online) or path (for offline)",
+		opt_set_target),
+	OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
+		    "Enable symbol demangling"),
+	OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
+		    "Enable kernel symbol demangling"),
+	OPT_BOOLEAN(0, "cache", &probe_conf.cache, "Manipulate probe cache"),
+	OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
+		   "Look for files with symbols relative to this directory"),
+	OPT_CALLBACK(0, "target-ns", NULL, "pid",
+		     "target pid for namespace contexts", opt_set_target_ns),
+	OPT_BOOLEAN(0, "bootconfig", &probe_conf.bootconfig,
+		    "Output probe definition with bootconfig format"),
+	OPT_END()
+	};
+	int ret;
+
+	set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);
+	set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);
+	set_option_flag(options, 'D', "definition", PARSE_OPT_EXCLUSIVE);
+	set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);
+#ifdef HAVE_DWARF_SUPPORT
+	set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);
+	set_option_flag(options, 'V', "vars", PARSE_OPT_EXCLUSIVE);
+#else
+# define set_nobuild(s, l, c) set_option_nobuild(options, s, l, "NO_DWARF=1", c)
+	set_nobuild('L', "line", false);
+	set_nobuild('V', "vars", false);
+	set_nobuild('\0', "externs", false);
+	set_nobuild('\0', "range", false);
+	set_nobuild('k', "vmlinux", true);
+	set_nobuild('s', "source", true);
+	set_nobuild('\0', "no-inlines", true);
+# undef set_nobuild
+#endif
+	set_option_flag(options, 'F', "funcs", PARSE_OPT_EXCLUSIVE);
+
+	argc = parse_options(argc, argv, options, probe_usage,
+			     PARSE_OPT_STOP_AT_NON_OPTION);
+
+	if (quiet) {
+		if (verbose != 0) {
+			pr_err("  Error: -v and -q are exclusive.\n");
+			return -EINVAL;
+		}
+		verbose = -1;
+	}
+
+	if (argc > 0) {
+		if (strcmp(argv[0], "-") == 0) {
+			usage_with_options_msg(probe_usage, options,
+				"'-' is not supported.\n");
+		}
+		if (params.command && params.command != 'a') {
+			usage_with_options_msg(probe_usage, options,
+				"another command except --add is set.\n");
+		}
+		ret = parse_probe_event_argv(argc, argv);
+		if (ret < 0) {
+			pr_err_with_code("  Error: Command Parse Error.", ret);
+			return ret;
+		}
+		params.command = 'a';
+	}
+
+	ret = symbol__validate_sym_arguments();
+	if (ret)
+		return ret;
+
+	if (probe_conf.max_probes == 0)
+		probe_conf.max_probes = MAX_PROBES;
+
+	/*
+	 * Only consider the user's kernel image path if given.
+	 */
+	symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
+
+	/*
+	 * Except for --list, --del and --add, other command doesn't depend
+	 * nor change running kernel. So if user gives offline vmlinux,
+	 * ignore its buildid.
+	 */
+	if (!strchr("lda", params.command) && symbol_conf.vmlinux_name)
+		symbol_conf.ignore_vmlinux_buildid = true;
+
+	switch (params.command) {
+	case 'l':
+		if (params.uprobes) {
+			pr_err("  Error: Don't use --list with --exec.\n");
+			parse_options_usage(probe_usage, options, "l", true);
+			parse_options_usage(NULL, options, "x", true);
+			return -EINVAL;
+		}
+		ret = show_perf_probe_events(params.filter);
+		if (ret < 0)
+			pr_err_with_code("  Error: Failed to show event list.", ret);
+		return ret;
+	case 'F':
+		ret = show_available_funcs(params.target, params.nsi,
+					   params.filter, params.uprobes);
+		if (ret < 0)
+			pr_err_with_code("  Error: Failed to show functions.", ret);
+		return ret;
+#ifdef HAVE_DWARF_SUPPORT
+	case 'L':
+		ret = show_line_range(&params.line_range, params.target,
+				      params.nsi, params.uprobes);
+		if (ret < 0)
+			pr_err_with_code("  Error: Failed to show lines.", ret);
+		return ret;
+	case 'V':
+		if (!params.filter)
+			params.filter = strfilter__new(DEFAULT_VAR_FILTER,
+						       NULL);
+
+		ret = show_available_vars(params.events, params.nevents,
+					  params.filter);
+		if (ret < 0)
+			pr_err_with_code("  Error: Failed to show vars.", ret);
+		return ret;
+#endif
+	case 'd':
+		ret = perf_del_probe_events(params.filter);
+		if (ret < 0) {
+			pr_err_with_code("  Error: Failed to delete events.", ret);
+			return ret;
+		}
+		break;
+	case 'D':
+		if (probe_conf.bootconfig && params.uprobes) {
+			pr_err("  Error: --bootconfig doesn't support uprobes.\n");
+			return -EINVAL;
+		}
+		__fallthrough;
+	case 'a':
+
+		/* Ensure the last given target is used */
+		if (params.target && !params.target_used) {
+			pr_err("  Error: -x/-m must follow the probe definitions.\n");
+			parse_options_usage(probe_usage, options, "m", true);
+			parse_options_usage(NULL, options, "x", true);
+			return -EINVAL;
+		}
+
+		ret = perf_add_probe_events(params.events, params.nevents);
+		if (ret < 0) {
+
+			/*
+			 * When perf_add_probe_events() fails it calls
+			 * cleanup_perf_probe_events(pevs, npevs), i.e.
+			 * cleanup_perf_probe_events(params.events, params.nevents), which
+			 * will call clear_perf_probe_event(), so set nevents to zero
+			 * to avoid cleanup_params() to call clear_perf_probe_event() again
+			 * on the same pevs.
+			 */
+			params.nevents = 0;
+			pr_err_with_code("  Error: Failed to add events.", ret);
+			return ret;
+		}
+		break;
+	default:
+		usage_with_options(probe_usage, options);
+	}
+	return 0;
+}
+
+int cmd_probe(int argc, const char **argv)
+{
+	int ret;
+
+	ret = init_params();
+	if (!ret) {
+		ret = __cmd_probe(argc, argv);
+		cleanup_params();
+	}
+
+	return ret < 0 ? ret : 0;
+}