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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * builtin-probe.c4 *5 * Builtin probe command: Set up probe events by C expression6 *7 * Written by Masami Hiramatsu <mhiramat@redhat.com>8 */9#include <sys/utsname.h>10#include <sys/types.h>11#include <sys/stat.h>12#include <fcntl.h>13#include <errno.h>14#include <stdio.h>15#include <unistd.h>16#include <stdlib.h>17#include <string.h>18 19#include "builtin.h"20#include "namespaces.h"21#include "util/build-id.h"22#include "util/strlist.h"23#include "util/strfilter.h"24#include "util/symbol.h"25#include "util/symbol_conf.h"26#include "util/debug.h"27#include <subcmd/parse-options.h>28#include "util/probe-finder.h"29#include "util/probe-event.h"30#include "util/probe-file.h"31#include <linux/string.h>32#include <linux/zalloc.h>33 34#define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"35#define DEFAULT_FUNC_FILTER "!_* & !*@plt"36#define DEFAULT_LIST_FILTER "*"37 38/* Session management structure */39static struct {40 int command; /* Command short_name */41 bool list_events;42 bool uprobes;43 bool target_used;44 int nevents;45 struct perf_probe_event events[MAX_PROBES];46 struct line_range line_range;47 char *target;48 struct strfilter *filter;49 struct nsinfo *nsi;50} *params;51 52/* Parse an event definition. Note that any error must die. */53static int parse_probe_event(const char *str)54{55 struct perf_probe_event *pev = ¶ms->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 } else92 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 path110 * 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 else179 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 && nsinfo__need_setns(nsip))220 params->nsi = nsinfo__get(nsip);221 nsinfo__put(nsip);222 223 ret = 0;224 }225 226 return ret;227}228 229 230/* Command option callbacks */231 232#ifdef HAVE_DWARF_SUPPORT233static 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, ¶ms->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 = ¶ms->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#else272# define opt_show_lines NULL273# define opt_show_vars NULL274#endif275static 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 int ret;310 311 params = calloc(1, sizeof(*params));312 if (!params)313 return -ENOMEM;314 315 ret = line_range__init(¶ms->line_range);316 if (ret)317 zfree(¶ms);318 return ret;319}320 321static void cleanup_params(void)322{323 int i;324 325 for (i = 0; i < params->nevents; i++)326 clear_perf_probe_event(params->events + i);327 line_range__clear(¶ms->line_range);328 zfree(¶ms->target);329 strfilter__delete(params->filter);330 nsinfo__put(params->nsi);331 zfree(¶ms);332}333 334static void pr_err_with_code(const char *msg, int err)335{336 char sbuf[STRERR_BUFSIZE];337 338 pr_err("%s", msg);339 pr_debug(" Reason: %s (Code: %d)",340 str_error_r(-err, sbuf, sizeof(sbuf)), err);341 pr_err("\n");342}343 344static int perf_add_probe_events(struct perf_probe_event *pevs, int npevs)345{346 int ret;347 int i, k;348 const char *event = NULL, *group = NULL;349 350 ret = init_probe_symbol_maps(pevs->uprobes);351 if (ret < 0)352 return ret;353 354 ret = convert_perf_probe_events(pevs, npevs);355 if (ret < 0)356 goto out_cleanup;357 358 if (params->command == 'D') { /* it shows definition */359 if (probe_conf.bootconfig)360 ret = show_bootconfig_events(pevs, npevs);361 else362 ret = show_probe_trace_events(pevs, npevs);363 goto out_cleanup;364 }365 366 ret = apply_perf_probe_events(pevs, npevs);367 if (ret < 0)368 goto out_cleanup;369 370 for (i = k = 0; i < npevs; i++)371 k += pevs[i].ntevs;372 373 pr_info("Added new event%s\n", (k > 1) ? "s:" : ":");374 for (i = 0; i < npevs; i++) {375 struct perf_probe_event *pev = &pevs[i];376 377 for (k = 0; k < pev->ntevs; k++) {378 struct probe_trace_event *tev = &pev->tevs[k];379 /* Skipped events have no event name */380 if (!tev->event)381 continue;382 383 /* We use tev's name for showing new events */384 show_perf_probe_event(tev->group, tev->event, pev,385 tev->point.module, false);386 387 /* Save the last valid name */388 event = tev->event;389 group = tev->group;390 }391 }392 393 /* Note that it is possible to skip all events because of blacklist */394 if (event) {395#ifndef HAVE_LIBTRACEEVENT396 pr_info("\nperf is not linked with libtraceevent, to use the new probe you can use tracefs:\n\n");397 pr_info("\tcd /sys/kernel/tracing/\n");398 pr_info("\techo 1 > events/%s/%s/enable\n", group, event);399 pr_info("\techo 1 > tracing_on\n");400 pr_info("\tcat trace_pipe\n");401 pr_info("\tBefore removing the probe, echo 0 > events/%s/%s/enable\n", group, event);402#else403 /* Show how to use the event. */404 pr_info("\nYou can now use it in all perf tools, such as:\n\n");405 pr_info("\tperf record -e %s:%s -aR sleep 1\n\n", group, event);406#endif407 }408 409out_cleanup:410 cleanup_perf_probe_events(pevs, npevs);411 exit_probe_symbol_maps();412 return ret;413}414 415static int del_perf_probe_caches(struct strfilter *filter)416{417 struct probe_cache *cache;418 struct strlist *bidlist;419 struct str_node *nd;420 int ret;421 422 bidlist = build_id_cache__list_all(false);423 if (!bidlist) {424 ret = -errno;425 pr_debug("Failed to get buildids: %d\n", ret);426 return ret ?: -ENOMEM;427 }428 429 strlist__for_each_entry(nd, bidlist) {430 cache = probe_cache__new(nd->s, NULL);431 if (!cache)432 continue;433 if (probe_cache__filter_purge(cache, filter) < 0 ||434 probe_cache__commit(cache) < 0)435 pr_warning("Failed to remove entries for %s\n", nd->s);436 probe_cache__delete(cache);437 }438 return 0;439}440 441static int perf_del_probe_events(struct strfilter *filter)442{443 int ret, ret2, ufd = -1, kfd = -1;444 char *str = strfilter__string(filter);445 struct strlist *klist = NULL, *ulist = NULL;446 struct str_node *ent;447 448 if (!str)449 return -EINVAL;450 451 pr_debug("Delete filter: \'%s\'\n", str);452 453 if (probe_conf.cache)454 return del_perf_probe_caches(filter);455 456 /* Get current event names */457 ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);458 if (ret < 0)459 goto out;460 461 klist = strlist__new(NULL, NULL);462 ulist = strlist__new(NULL, NULL);463 if (!klist || !ulist) {464 ret = -ENOMEM;465 goto out;466 }467 468 ret = probe_file__get_events(kfd, filter, klist);469 if (ret == 0) {470 strlist__for_each_entry(ent, klist)471 pr_info("Removed event: %s\n", ent->s);472 473 ret = probe_file__del_strlist(kfd, klist);474 if (ret < 0)475 goto error;476 } else if (ret == -ENOMEM)477 goto error;478 479 ret2 = probe_file__get_events(ufd, filter, ulist);480 if (ret2 == 0) {481 strlist__for_each_entry(ent, ulist)482 pr_info("Removed event: %s\n", ent->s);483 484 ret2 = probe_file__del_strlist(ufd, ulist);485 if (ret2 < 0)486 goto error;487 } else if (ret2 == -ENOMEM)488 goto error;489 490 if (ret == -ENOENT && ret2 == -ENOENT)491 pr_warning("\"%s\" does not hit any event.\n", str);492 else493 ret = 0;494 495error:496 if (kfd >= 0)497 close(kfd);498 if (ufd >= 0)499 close(ufd);500out:501 strlist__delete(klist);502 strlist__delete(ulist);503 free(str);504 505 return ret;506}507 508#ifdef HAVE_DWARF_SUPPORT509#define PROBEDEF_STR \510 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT [[NAME=]ARG ...]"511#else512#define PROBEDEF_STR "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]"513#endif514 515 516static int517__cmd_probe(int argc, const char **argv)518{519 const char * const probe_usage[] = {520 "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",521 "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",522 "perf probe [<options>] --del '[GROUP:]EVENT' ...",523 "perf probe --list [GROUP:]EVENT ...",524#ifdef HAVE_DWARF_SUPPORT525 "perf probe [<options>] --line 'LINEDESC'",526 "perf probe [<options>] --vars 'PROBEPOINT'",527#endif528 "perf probe [<options>] --funcs",529 NULL530 };531 struct option options[] = {532 OPT_INCR('v', "verbose", &verbose,533 "be more verbose (show parsed arguments, etc)"),534 OPT_BOOLEAN('q', "quiet", &quiet,535 "be quiet (do not show any warnings or messages)"),536 OPT_CALLBACK_DEFAULT('l', "list", NULL, "[GROUP:]EVENT",537 "list up probe events",538 opt_set_filter_with_command, DEFAULT_LIST_FILTER),539 OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",540 opt_set_filter_with_command),541 OPT_CALLBACK('a', "add", NULL, PROBEDEF_STR,542 "probe point definition, where\n"543 "\t\tGROUP:\tGroup name (optional)\n"544 "\t\tEVENT:\tEvent name\n"545 "\t\tFUNC:\tFunction name\n"546 "\t\tOFF:\tOffset from function entry (in byte)\n"547 "\t\t%return:\tPut the probe at function return\n"548#ifdef HAVE_DWARF_SUPPORT549 "\t\tSRC:\tSource code path\n"550 "\t\tRL:\tRelative line number from function entry.\n"551 "\t\tAL:\tAbsolute line number in file.\n"552 "\t\tPT:\tLazy expression of line code.\n"553 "\t\tARG:\tProbe argument (local variable name or\n"554 "\t\t\tkprobe-tracer argument format.)\n",555#else556 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",557#endif558 opt_add_probe_event),559 OPT_CALLBACK('D', "definition", NULL, PROBEDEF_STR,560 "Show trace event definition of given traceevent for k/uprobe_events.",561 opt_add_probe_event),562 OPT_BOOLEAN('f', "force", &probe_conf.force_add, "forcibly add events"563 " with existing name"),564 OPT_CALLBACK('L', "line", NULL,565 "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",566 "Show source code lines.", opt_show_lines),567 OPT_CALLBACK('V', "vars", NULL,568 "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",569 "Show accessible variables on PROBEDEF", opt_show_vars),570 OPT_BOOLEAN('\0', "externs", &probe_conf.show_ext_vars,571 "Show external variables too (with --vars only)"),572 OPT_BOOLEAN('\0', "range", &probe_conf.show_location_range,573 "Show variables location range in scope (with --vars only)"),574 OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,575 "file", "vmlinux pathname"),576 OPT_STRING('s', "source", &symbol_conf.source_prefix,577 "directory", "path to kernel source"),578 OPT_BOOLEAN('\0', "no-inlines", &probe_conf.no_inlines,579 "Don't search inlined functions"),580 OPT__DRY_RUN(&probe_event_dry_run),581 OPT_INTEGER('\0', "max-probes", &probe_conf.max_probes,582 "Set how many probe points can be found for a probe."),583 OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",584 "Show potential probe-able functions.",585 opt_set_filter_with_command, DEFAULT_FUNC_FILTER),586 OPT_CALLBACK('\0', "filter", NULL,587 "[!]FILTER", "Set a filter (with --vars/funcs only)\n"588 "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"589 "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",590 opt_set_filter),591 OPT_CALLBACK('x', "exec", NULL, "executable|path",592 "target executable name or path", opt_set_target),593 OPT_CALLBACK('m', "module", NULL, "modname|path",594 "target module name (for online) or path (for offline)",595 opt_set_target),596 OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,597 "Enable symbol demangling"),598 OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,599 "Enable kernel symbol demangling"),600 OPT_BOOLEAN(0, "cache", &probe_conf.cache, "Manipulate probe cache"),601 OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",602 "Look for files with symbols relative to this directory"),603 OPT_CALLBACK(0, "target-ns", NULL, "pid",604 "target pid for namespace contexts", opt_set_target_ns),605 OPT_BOOLEAN(0, "bootconfig", &probe_conf.bootconfig,606 "Output probe definition with bootconfig format"),607 OPT_END()608 };609 int ret;610 611 set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);612 set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);613 set_option_flag(options, 'D', "definition", PARSE_OPT_EXCLUSIVE);614 set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);615#ifdef HAVE_DWARF_SUPPORT616 set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);617 set_option_flag(options, 'V', "vars", PARSE_OPT_EXCLUSIVE);618#else619# define set_nobuild(s, l, c) set_option_nobuild(options, s, l, "NO_DWARF=1", c)620 set_nobuild('L', "line", false);621 set_nobuild('V', "vars", false);622 set_nobuild('\0', "externs", false);623 set_nobuild('\0', "range", false);624 set_nobuild('k', "vmlinux", true);625 set_nobuild('s', "source", true);626 set_nobuild('\0', "no-inlines", true);627# undef set_nobuild628#endif629 set_option_flag(options, 'F', "funcs", PARSE_OPT_EXCLUSIVE);630 631 argc = parse_options(argc, argv, options, probe_usage,632 PARSE_OPT_STOP_AT_NON_OPTION);633 634 if (quiet) {635 if (verbose != 0) {636 pr_err(" Error: -v and -q are exclusive.\n");637 return -EINVAL;638 }639 verbose = -1;640 }641 642 if (argc > 0) {643 if (strcmp(argv[0], "-") == 0) {644 usage_with_options_msg(probe_usage, options,645 "'-' is not supported.\n");646 }647 if (params->command && params->command != 'a') {648 usage_with_options_msg(probe_usage, options,649 "another command except --add is set.\n");650 }651 ret = parse_probe_event_argv(argc, argv);652 if (ret < 0) {653 pr_err_with_code(" Error: Command Parse Error.", ret);654 return ret;655 }656 params->command = 'a';657 }658 659 ret = symbol__validate_sym_arguments();660 if (ret)661 return ret;662 663 if (probe_conf.max_probes == 0)664 probe_conf.max_probes = MAX_PROBES;665 666 /*667 * Only consider the user's kernel image path if given.668 */669 symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);670 671 /*672 * Except for --list, --del and --add, other command doesn't depend673 * nor change running kernel. So if user gives offline vmlinux,674 * ignore its buildid.675 */676 if (!strchr("lda", params->command) && symbol_conf.vmlinux_name)677 symbol_conf.ignore_vmlinux_buildid = true;678 679 switch (params->command) {680 case 'l':681 if (params->uprobes) {682 pr_err(" Error: Don't use --list with --exec.\n");683 parse_options_usage(probe_usage, options, "l", true);684 parse_options_usage(NULL, options, "x", true);685 return -EINVAL;686 }687 ret = show_perf_probe_events(params->filter);688 if (ret < 0)689 pr_err_with_code(" Error: Failed to show event list.", ret);690 return ret;691 case 'F':692 ret = show_available_funcs(params->target, params->nsi,693 params->filter, params->uprobes);694 if (ret < 0)695 pr_err_with_code(" Error: Failed to show functions.", ret);696 return ret;697#ifdef HAVE_DWARF_SUPPORT698 case 'L':699 ret = show_line_range(¶ms->line_range, params->target,700 params->nsi, params->uprobes);701 if (ret < 0)702 pr_err_with_code(" Error: Failed to show lines.", ret);703 return ret;704 case 'V':705 if (!params->filter)706 params->filter = strfilter__new(DEFAULT_VAR_FILTER,707 NULL);708 709 ret = show_available_vars(params->events, params->nevents,710 params->filter);711 if (ret < 0)712 pr_err_with_code(" Error: Failed to show vars.", ret);713 return ret;714#endif715 case 'd':716 ret = perf_del_probe_events(params->filter);717 if (ret < 0) {718 pr_err_with_code(" Error: Failed to delete events.", ret);719 return ret;720 }721 break;722 case 'D':723 if (probe_conf.bootconfig && params->uprobes) {724 pr_err(" Error: --bootconfig doesn't support uprobes.\n");725 return -EINVAL;726 }727 fallthrough;728 case 'a':729 730 /* Ensure the last given target is used */731 if (params->target && !params->target_used) {732 pr_err(" Error: -x/-m must follow the probe definitions.\n");733 parse_options_usage(probe_usage, options, "m", true);734 parse_options_usage(NULL, options, "x", true);735 return -EINVAL;736 }737 738 ret = perf_add_probe_events(params->events, params->nevents);739 if (ret < 0) {740 741 /*742 * When perf_add_probe_events() fails it calls743 * cleanup_perf_probe_events(pevs, npevs), i.e.744 * cleanup_perf_probe_events(params->events, params->nevents), which745 * will call clear_perf_probe_event(), so set nevents to zero746 * to avoid cleanup_params() to call clear_perf_probe_event() again747 * on the same pevs.748 */749 params->nevents = 0;750 pr_err_with_code(" Error: Failed to add events.", ret);751 return ret;752 }753 break;754 default:755 usage_with_options(probe_usage, options);756 }757 return 0;758}759 760int cmd_probe(int argc, const char **argv)761{762 int ret;763 764 ret = init_params();765 if (!ret) {766 ret = __cmd_probe(argc, argv);767 cleanup_params();768 }769 770 return ret < 0 ? ret : 0;771}772