tools/perf/builtin-probe.c

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