cregit-Linux how code gets into the kernel

Release 4.10 tools/perf/builtin-probe.c

Directory: tools/perf
 * builtin-probe.c
 * Builtin probe command: Set up probe events by C expression
 * Written by Masami Hiramatsu <>
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
#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 "perf.h"
#include "builtin.h"
#include "util/util.h"
#include "util/strlist.h"
#include "util/strfilter.h"
#include "util/symbol.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"

#define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"



/* Session management structure */
static struct {
int command;	/* Command short_name */
bool list_events;
bool uprobes;
bool quiet;
bool target_used;
int nevents;
struct perf_probe_event events[MAX_PROBES];
struct line_range line_range;
char *target;
struct strfilter *filter;

/* Parse an event definition. Note that any error must die. */

static int parse_probe_event(const char *str) { struct perf_probe_event *pev = &[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 ( { pev->target = strdup(; if (!pev->target) return -ENOMEM; params.target_used = true; } /* Parse a perf-probe command into event */ ret = parse_perf_probe_command(str, pev); pr_debug("%d arguments\n", pev->nargs); return ret; }


masami hiramatsumasami hiramatsu11186.72%1076.92%
arnaldo carvalho de meloarnaldo carvalho de melo97.03%215.38%
srikar dronamrajusrikar dronamraju86.25%17.69%

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; }


masami hiramatsumasami hiramatsu131100.00%1100.00%

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 (! && ptr && *ptr == '/') { = strdup(ptr); if (! return -ENOMEM; params.target_used = false; found = 1; buf = ptr + (strlen(ptr) - 3); if (strcmp(buf, ".ko")) params.uprobes = true; } return found; }


srikar dronamrajusrikar dronamraju7979.80%133.33%
masami hiramatsumasami hiramatsu2020.20%266.67%

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; }


masami hiramatsumasami hiramatsu12368.72%360.00%
srikar dronamrajusrikar dronamraju4525.14%120.00%
arnaldo carvalho de meloarnaldo carvalho de melo116.15%120.00%

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 = realpath(str, NULL); 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(; = tmp; params.target_used = false; ret = 0; } return ret; }


srikar dronamrajusrikar dronamraju8551.52%120.00%
masami hiramatsumasami hiramatsu7947.88%360.00%
irina tirdeairina tirdea10.61%120.00%

/* 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; }


masami hiramatsumasami hiramatsu4052.63%466.67%
hitoshi mitakehitoshi mitake3546.05%116.67%
irina tirdeairina tirdea11.32%116.67%

static int opt_show_vars(const struct option *opt, const char *str, int unset __maybe_unused) { struct perf_probe_event *pev = &[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; }


masami hiramatsumasami hiramatsu8698.85%266.67%
irina tirdeairina tirdea11.15%133.33%

#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; }


masami hiramatsumasami hiramatsu44100.00%2100.00%

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; }


masami hiramatsumasami hiramatsu46100.00%2100.00%

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; }


masami hiramatsumasami hiramatsu3394.29%266.67%
irina tirdeairina tirdea25.71%133.33%

static int init_params(void) { return line_range__init(&params.line_range); }


masami hiramatsumasami hiramatsu17100.00%2100.00%

static void cleanup_params(void) { int i; for (i = 0; i < params.nevents; i++) clear_perf_probe_event( + i); line_range__clear(&params.line_range); free(; strfilter__delete(params.filter); memset(&params, 0, sizeof(params)); }


masami hiramatsumasami hiramatsu6998.57%150.00%
arnaldo carvalho de meloarnaldo carvalho de melo11.43%150.00%

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"); }


masami hiramatsumasami hiramatsu5198.08%266.67%
arnaldo carvalho de meloarnaldo carvalho de melo11.92%133.33%

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 */ 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]; /* 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; }


namhyung kimnamhyung kim25591.73%266.67%
masami hiramatsumasami hiramatsu238.27%133.33%

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); 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; }


masami hiramatsumasami hiramatsu120100.00%2100.00%

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; } 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; } if (ret == -ENOENT && ret2 == -ENOENT) pr_debug("\"%s\" does not hit any event.\n", str); /* Note that this is silently ignored */ ret = 0; error: if (kfd >= 0) close(kfd); if (ufd >= 0) close(ufd); out: strlist__delete(klist); strlist__delete(ulist); free(str); return ret; }


namhyung kimnamhyung kim27789.07%125.00%
masami hiramatsumasami hiramatsu3210.29%250.00%
arnaldo carvalho de meloarnaldo carvalho de melo20.64%125.00%

#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 *prefix __maybe_unused) { 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", &params.quiet, "be quiet (do not show any mesages)"), 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_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 (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'; } if (params.quiet) { if (verbose != 0) { pr_err(" Error: -v and -q are exclusive.\n"); return -EINVAL; } verbose = -1; } 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.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(