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 "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 */
  39 static struct {
  40         int command;    /* Command short_name */
  41         bool list_events;
  42         bool uprobes;
  43         bool quiet;
  44         bool target_used;
  45         int nevents;
  46         struct perf_probe_event events[MAX_PROBES];
  47         struct line_range line_range;
  48         char *target;
  49         struct strfilter *filter;
  50         struct nsinfo *nsi;
  51 } params;
  52
  53 /* Parse an event definition. Note that any error must die. */
  54 static int parse_probe_event(const char *str)
  55 {
  56         struct perf_probe_event *pev = &params.events[params.nevents];
  57         int ret;
  58
  59         pr_debug("probe-definition(%d): %s\n", params.nevents, str);
  60         if (++params.nevents == MAX_PROBES) {
  61                 pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
  62                 return -1;
  63         }
  64
  65         pev->uprobes = params.uprobes;
  66         if (params.target) {
  67                 pev->target = strdup(params.target);
  68                 if (!pev->target)
  69                         return -ENOMEM;
  70                 params.target_used = true;
  71         }
  72
  73         pev->nsi = nsinfo__get(params.nsi);
  74
  75         /* Parse a perf-probe command into event */
  76         ret = parse_perf_probe_command(str, pev);
  77         pr_debug("%d arguments\n", pev->nargs);
  78
  79         return ret;
  80 }
  81
  82 static int params_add_filter(const char *str)
  83 {
  84         const char *err = NULL;
  85         int ret = 0;
  86
  87         pr_debug2("Add filter: %s\n", str);
  88         if (!params.filter) {
  89                 params.filter = strfilter__new(str, &err);
  90                 if (!params.filter)
  91                         ret = err ? -EINVAL : -ENOMEM;
  92         } else
  93                 ret = strfilter__or(params.filter, str, &err);
  94
  95         if (ret == -EINVAL) {
  96                 pr_err("Filter parse error at %td.\n", err - str + 1);
  97                 pr_err("Source: \"%s\"\n", str);
  98                 pr_err("         %*c\n", (int)(err - str + 1), '^');
  99         }
 100
 101         return ret;
 102 }
 103
 104 static int set_target(const char *ptr)
 105 {
 106         int found = 0;
 107         const char *buf;
 108
 109         /*
 110          * The first argument after options can be an absolute path
 111          * to an executable / library or kernel module.
 112          *
 113          * TODO: Support relative path, and $PATH, $LD_LIBRARY_PATH,
 114          * short module name.
 115          */
 116         if (!params.target && ptr && *ptr == '/') {
 117                 params.target = strdup(ptr);
 118                 if (!params.target)
 119                         return -ENOMEM;
 120                 params.target_used = false;
 121
 122                 found = 1;
 123                 buf = ptr + (strlen(ptr) - 3);
 124
 125                 if (strcmp(buf, ".ko"))
 126                         params.uprobes = true;
 127
 128         }
 129
 130         return found;
 131 }
 132
 133 static int parse_probe_event_argv(int argc, const char **argv)
 134 {
 135         int i, len, ret, found_target;
 136         char *buf;
 137
 138         found_target = set_target(argv[0]);
 139         if (found_target < 0)
 140                 return found_target;
 141
 142         if (found_target && argc == 1)
 143                 return 0;
 144
 145         /* Bind up rest arguments */
 146         len = 0;
 147         for (i = 0; i < argc; i++) {
 148                 if (i == 0 && found_target)
 149                         continue;
 150
 151                 len += strlen(argv[i]) + 1;
 152         }
 153         buf = zalloc(len + 1);
 154         if (buf == NULL)
 155                 return -ENOMEM;
 156         len = 0;
 157         for (i = 0; i < argc; i++) {
 158                 if (i == 0 && found_target)
 159                         continue;
 160
 161                 len += sprintf(&buf[len], "%s ", argv[i]);
 162         }
 163         ret = parse_probe_event(buf);
 164         free(buf);
 165         return ret;
 166 }
 167
 168 static int opt_set_target(const struct option *opt, const char *str,
 169                         int unset __maybe_unused)
 170 {
 171         int ret = -ENOENT;
 172         char *tmp;
 173
 174         if  (str) {
 175                 if (!strcmp(opt->long_name, "exec"))
 176                         params.uprobes = true;
 177                 else if (!strcmp(opt->long_name, "module"))
 178                         params.uprobes = false;
 179                 else
 180                         return ret;
 181
 182                 /* Expand given path to absolute path, except for modulename */
 183                 if (params.uprobes || strchr(str, '/')) {
 184                         tmp = nsinfo__realpath(str, params.nsi);
 185                         if (!tmp) {
 186                                 pr_warning("Failed to get the absolute path of %s: %m\n", str);
 187                                 return ret;
 188                         }
 189                 } else {
 190                         tmp = strdup(str);
 191                         if (!tmp)
 192                                 return -ENOMEM;
 193                 }
 194                 free(params.target);
 195                 params.target = tmp;
 196                 params.target_used = false;
 197                 ret = 0;
 198         }
 199
 200         return ret;
 201 }
 202
 203 static int opt_set_target_ns(const struct option *opt __maybe_unused,
 204                              const char *str, int unset __maybe_unused)
 205 {
 206         int ret = -ENOENT;
 207         pid_t ns_pid;
 208         struct nsinfo *nsip;
 209
 210         if (str) {
 211                 errno = 0;
 212                 ns_pid = (pid_t)strtol(str, NULL, 10);
 213                 if (errno != 0) {
 214                         ret = -errno;
 215                         pr_warning("Failed to parse %s as a pid: %s\n", str,
 216                                    strerror(errno));
 217                         return ret;
 218                 }
 219                 nsip = nsinfo__new(ns_pid);
 220                 if (nsip && nsip->need_setns)
 221                         params.nsi = nsinfo__get(nsip);
 222                 nsinfo__put(nsip);
 223
 224                 ret = 0;
 225         }
 226
 227         return ret;
 228 }
 229
 230
 231 /* Command option callbacks */
 232
 233 #ifdef HAVE_DWARF_SUPPORT
 234 static int opt_show_lines(const struct option *opt,
 235                           const char *str, int unset __maybe_unused)
 236 {
 237         int ret = 0;
 238
 239         if (!str)
 240                 return 0;
 241
 242         if (params.command == 'L') {
 243                 pr_warning("Warning: more than one --line options are"
 244                            " detected. Only the first one is valid.\n");
 245                 return 0;
 246         }
 247
 248         params.command = opt->short_name;
 249         ret = parse_line_range_desc(str, &params.line_range);
 250
 251         return ret;
 252 }
 253
 254 static int opt_show_vars(const struct option *opt,
 255                          const char *str, int unset __maybe_unused)
 256 {
 257         struct perf_probe_event *pev = &params.events[params.nevents];
 258         int ret;
 259
 260         if (!str)
 261                 return 0;
 262
 263         ret = parse_probe_event(str);
 264         if (!ret && pev->nargs != 0) {
 265                 pr_err("  Error: '--vars' doesn't accept arguments.\n");
 266                 return -EINVAL;
 267         }
 268         params.command = opt->short_name;
 269
 270         return ret;
 271 }
 272 #else
 273 # define opt_show_lines NULL
 274 # define opt_show_vars NULL
 275 #endif
 276 static int opt_add_probe_event(const struct option *opt,
 277                               const char *str, int unset __maybe_unused)
 278 {
 279         if (str) {
 280                 params.command = opt->short_name;
 281                 return parse_probe_event(str);
 282         }
 283
 284         return 0;
 285 }
 286
 287 static int opt_set_filter_with_command(const struct option *opt,
 288                                        const char *str, int unset)
 289 {
 290         if (!unset)
 291                 params.command = opt->short_name;
 292
 293         if (str)
 294                 return params_add_filter(str);
 295
 296         return 0;
 297 }
 298
 299 static int opt_set_filter(const struct option *opt __maybe_unused,
 300                           const char *str, int unset __maybe_unused)
 301 {
 302         if (str)
 303                 return params_add_filter(str);
 304
 305         return 0;
 306 }
 307
 308 static int init_params(void)
 309 {
 310         return line_range__init(&params.line_range);
 311 }
 312
 313 static void cleanup_params(void)
 314 {
 315         int i;
 316
 317         for (i = 0; i < params.nevents; i++)
 318                 clear_perf_probe_event(params.events + i);
 319         line_range__clear(&params.line_range);
 320         free(params.target);
 321         strfilter__delete(params.filter);
 322         nsinfo__put(params.nsi);
 323         memset(&params, 0, sizeof(params));
 324 }
 325
 326 static void pr_err_with_code(const char *msg, int err)
 327 {
 328         char sbuf[STRERR_BUFSIZE];
 329
 330         pr_err("%s", msg);
 331         pr_debug(" Reason: %s (Code: %d)",
 332                  str_error_r(-err, sbuf, sizeof(sbuf)), err);
 333         pr_err("\n");
 334 }
 335
 336 static int perf_add_probe_events(struct perf_probe_event *pevs, int npevs)
 337 {
 338         int ret;
 339         int i, k;
 340         const char *event = NULL, *group = NULL;
 341
 342         ret = init_probe_symbol_maps(pevs->uprobes);
 343         if (ret < 0)
 344                 return ret;
 345
 346         ret = convert_perf_probe_events(pevs, npevs);
 347         if (ret < 0)
 348                 goto out_cleanup;
 349
 350         if (params.command == 'D') {    /* it shows definition */
 351                 if (probe_conf.bootconfig)
 352                         ret = show_bootconfig_events(pevs, npevs);
 353                 else
 354                         ret = show_probe_trace_events(pevs, npevs);
 355                 goto out_cleanup;
 356         }
 357
 358         ret = apply_perf_probe_events(pevs, npevs);
 359         if (ret < 0)
 360                 goto out_cleanup;
 361
 362         for (i = k = 0; i < npevs; i++)
 363                 k += pevs[i].ntevs;
 364
 365         pr_info("Added new event%s\n", (k > 1) ? "s:" : ":");
 366         for (i = 0; i < npevs; i++) {
 367                 struct perf_probe_event *pev = &pevs[i];
 368
 369                 for (k = 0; k < pev->ntevs; k++) {
 370                         struct probe_trace_event *tev = &pev->tevs[k];
 371                         /* Skipped events have no event name */
 372                         if (!tev->event)
 373                                 continue;
 374
 375                         /* We use tev's name for showing new events */
 376                         show_perf_probe_event(tev->group, tev->event, pev,
 377                                               tev->point.module, false);
 378
 379                         /* Save the last valid name */
 380                         event = tev->event;
 381                         group = tev->group;
 382                 }
 383         }
 384
 385         /* Note that it is possible to skip all events because of blacklist */
 386         if (event) {
 387                 /* Show how to use the event. */
 388                 pr_info("\nYou can now use it in all perf tools, such as:\n\n");
 389                 pr_info("\tperf record -e %s:%s -aR sleep 1\n\n", group, event);
 390         }
 391
 392 out_cleanup:
 393         cleanup_perf_probe_events(pevs, npevs);
 394         exit_probe_symbol_maps();
 395         return ret;
 396 }
 397
 398 static int del_perf_probe_caches(struct strfilter *filter)
 399 {
 400         struct probe_cache *cache;
 401         struct strlist *bidlist;
 402         struct str_node *nd;
 403         int ret;
 404
 405         bidlist = build_id_cache__list_all(false);
 406         if (!bidlist) {
 407                 ret = -errno;
 408                 pr_debug("Failed to get buildids: %d\n", ret);
 409                 return ret ?: -ENOMEM;
 410         }
 411
 412         strlist__for_each_entry(nd, bidlist) {
 413                 cache = probe_cache__new(nd->s, NULL);
 414                 if (!cache)
 415                         continue;
 416                 if (probe_cache__filter_purge(cache, filter) < 0 ||
 417                     probe_cache__commit(cache) < 0)
 418                         pr_warning("Failed to remove entries for %s\n", nd->s);
 419                 probe_cache__delete(cache);
 420         }
 421         return 0;
 422 }
 423
 424 static int perf_del_probe_events(struct strfilter *filter)
 425 {
 426         int ret, ret2, ufd = -1, kfd = -1;
 427         char *str = strfilter__string(filter);
 428         struct strlist *klist = NULL, *ulist = NULL;
 429         struct str_node *ent;
 430
 431         if (!str)
 432                 return -EINVAL;
 433
 434         pr_debug("Delete filter: \'%s\'\n", str);
 435
 436         if (probe_conf.cache)
 437                 return del_perf_probe_caches(filter);
 438
 439         /* Get current event names */
 440         ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
 441         if (ret < 0)
 442                 goto out;
 443
 444         klist = strlist__new(NULL, NULL);
 445         ulist = strlist__new(NULL, NULL);
 446         if (!klist || !ulist) {
 447                 ret = -ENOMEM;
 448                 goto out;
 449         }
 450
 451         ret = probe_file__get_events(kfd, filter, klist);
 452         if (ret == 0) {
 453                 strlist__for_each_entry(ent, klist)
 454                         pr_info("Removed event: %s\n", ent->s);
 455
 456                 ret = probe_file__del_strlist(kfd, klist);
 457                 if (ret < 0)
 458                         goto error;
 459         } else if (ret == -ENOMEM)
 460                 goto error;
 461
 462         ret2 = probe_file__get_events(ufd, filter, ulist);
 463         if (ret2 == 0) {
 464                 strlist__for_each_entry(ent, ulist)
 465                         pr_info("Removed event: %s\n", ent->s);
 466
 467                 ret2 = probe_file__del_strlist(ufd, ulist);
 468                 if (ret2 < 0)
 469                         goto error;
 470         } else if (ret2 == -ENOMEM)
 471                 goto error;
 472
 473         if (ret == -ENOENT && ret2 == -ENOENT)
 474                 pr_warning("\"%s\" does not hit any event.\n", str);
 475         else
 476                 ret = 0;
 477
 478 error:
 479         if (kfd >= 0)
 480                 close(kfd);
 481         if (ufd >= 0)
 482                 close(ufd);
 483 out:
 484         strlist__delete(klist);
 485         strlist__delete(ulist);
 486         free(str);
 487
 488         return ret;
 489 }
 490
 491 #ifdef HAVE_DWARF_SUPPORT
 492 #define PROBEDEF_STR    \
 493         "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT [[NAME=]ARG ...]"
 494 #else
 495 #define PROBEDEF_STR    "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]"
 496 #endif
 497
 498
 499 static int
 500 __cmd_probe(int argc, const char **argv)
 501 {
 502         const char * const probe_usage[] = {
 503                 "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
 504                 "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
 505                 "perf probe [<options>] --del '[GROUP:]EVENT' ...",
 506                 "perf probe --list [GROUP:]EVENT ...",
 507 #ifdef HAVE_DWARF_SUPPORT
 508                 "perf probe [<options>] --line 'LINEDESC'",
 509                 "perf probe [<options>] --vars 'PROBEPOINT'",
 510 #endif
 511                 "perf probe [<options>] --funcs",
 512                 NULL
 513         };
 514         struct option options[] = {
 515         OPT_INCR('v', "verbose", &verbose,
 516                     "be more verbose (show parsed arguments, etc)"),
 517         OPT_BOOLEAN('q', "quiet", &params.quiet,
 518                     "be quiet (do not show any messages)"),
 519         OPT_CALLBACK_DEFAULT('l', "list", NULL, "[GROUP:]EVENT",
 520                              "list up probe events",
 521                              opt_set_filter_with_command, DEFAULT_LIST_FILTER),
 522         OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
 523                      opt_set_filter_with_command),
 524         OPT_CALLBACK('a', "add", NULL, PROBEDEF_STR,
 525                 "probe point definition, where\n"
 526                 "\t\tGROUP:\tGroup name (optional)\n"
 527                 "\t\tEVENT:\tEvent name\n"
 528                 "\t\tFUNC:\tFunction name\n"
 529                 "\t\tOFF:\tOffset from function entry (in byte)\n"
 530                 "\t\t%return:\tPut the probe at function return\n"
 531 #ifdef HAVE_DWARF_SUPPORT
 532                 "\t\tSRC:\tSource code path\n"
 533                 "\t\tRL:\tRelative line number from function entry.\n"
 534                 "\t\tAL:\tAbsolute line number in file.\n"
 535                 "\t\tPT:\tLazy expression of line code.\n"
 536                 "\t\tARG:\tProbe argument (local variable name or\n"
 537                 "\t\t\tkprobe-tracer argument format.)\n",
 538 #else
 539                 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
 540 #endif
 541                 opt_add_probe_event),
 542         OPT_CALLBACK('D', "definition", NULL, PROBEDEF_STR,
 543                 "Show trace event definition of given traceevent for k/uprobe_events.",
 544                 opt_add_probe_event),
 545         OPT_BOOLEAN('f', "force", &probe_conf.force_add, "forcibly add events"
 546                     " with existing name"),
 547         OPT_CALLBACK('L', "line", NULL,
 548                      "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
 549                      "Show source code lines.", opt_show_lines),
 550         OPT_CALLBACK('V', "vars", NULL,
 551                      "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
 552                      "Show accessible variables on PROBEDEF", opt_show_vars),
 553         OPT_BOOLEAN('\0', "externs", &probe_conf.show_ext_vars,
 554                     "Show external variables too (with --vars only)"),
 555         OPT_BOOLEAN('\0', "range", &probe_conf.show_location_range,
 556                 "Show variables location range in scope (with --vars only)"),
 557         OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
 558                    "file", "vmlinux pathname"),
 559         OPT_STRING('s', "source", &symbol_conf.source_prefix,
 560                    "directory", "path to kernel source"),
 561         OPT_BOOLEAN('\0', "no-inlines", &probe_conf.no_inlines,
 562                 "Don't search inlined functions"),
 563         OPT__DRY_RUN(&probe_event_dry_run),
 564         OPT_INTEGER('\0', "max-probes", &probe_conf.max_probes,
 565                  "Set how many probe points can be found for a probe."),
 566         OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",
 567                              "Show potential probe-able functions.",
 568                              opt_set_filter_with_command, DEFAULT_FUNC_FILTER),
 569         OPT_CALLBACK('\0', "filter", NULL,
 570                      "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
 571                      "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
 572                      "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
 573                      opt_set_filter),
 574         OPT_CALLBACK('x', "exec", NULL, "executable|path",
 575                         "target executable name or path", opt_set_target),
 576         OPT_CALLBACK('m', "module", NULL, "modname|path",
 577                 "target module name (for online) or path (for offline)",
 578                 opt_set_target),
 579         OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
 580                     "Enable symbol demangling"),
 581         OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
 582                     "Enable kernel symbol demangling"),
 583         OPT_BOOLEAN(0, "cache", &probe_conf.cache, "Manipulate probe cache"),
 584         OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
 585                    "Look for files with symbols relative to this directory"),
 586         OPT_CALLBACK(0, "target-ns", NULL, "pid",
 587                      "target pid for namespace contexts", opt_set_target_ns),
 588         OPT_BOOLEAN(0, "bootconfig", &probe_conf.bootconfig,
 589                     "Output probe definition with bootconfig format"),
 590         OPT_END()
 591         };
 592         int ret;
 593
 594         set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);
 595         set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);
 596         set_option_flag(options, 'D', "definition", PARSE_OPT_EXCLUSIVE);
 597         set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);
 598 #ifdef HAVE_DWARF_SUPPORT
 599         set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);
 600         set_option_flag(options, 'V', "vars", PARSE_OPT_EXCLUSIVE);
 601 #else
 602 # define set_nobuild(s, l, c) set_option_nobuild(options, s, l, "NO_DWARF=1", c)
 603         set_nobuild('L', "line", false);
 604         set_nobuild('V', "vars", false);
 605         set_nobuild('\0', "externs", false);
 606         set_nobuild('\0', "range", false);
 607         set_nobuild('k', "vmlinux", true);
 608         set_nobuild('s', "source", true);
 609         set_nobuild('\0', "no-inlines", true);
 610 # undef set_nobuild
 611 #endif
 612         set_option_flag(options, 'F', "funcs", PARSE_OPT_EXCLUSIVE);
 613
 614         argc = parse_options(argc, argv, options, probe_usage,
 615                              PARSE_OPT_STOP_AT_NON_OPTION);
 616         if (argc > 0) {
 617                 if (strcmp(argv[0], "-") == 0) {
 618                         usage_with_options_msg(probe_usage, options,
 619                                 "'-' is not supported.\n");
 620                 }
 621                 if (params.command && params.command != 'a') {
 622                         usage_with_options_msg(probe_usage, options,
 623                                 "another command except --add is set.\n");
 624                 }
 625                 ret = parse_probe_event_argv(argc, argv);
 626                 if (ret < 0) {
 627                         pr_err_with_code("  Error: Command Parse Error.", ret);
 628                         return ret;
 629                 }
 630                 params.command = 'a';
 631         }
 632
 633         ret = symbol__validate_sym_arguments();
 634         if (ret)
 635                 return ret;
 636
 637         if (params.quiet) {
 638                 if (verbose != 0) {
 639                         pr_err("  Error: -v and -q are exclusive.\n");
 640                         return -EINVAL;
 641                 }
 642                 verbose = -1;
 643         }
 644
 645         if (probe_conf.max_probes == 0)
 646                 probe_conf.max_probes = MAX_PROBES;
 647
 648         /*
 649          * Only consider the user's kernel image path if given.
 650          */
 651         symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
 652
 653         /*
 654          * Except for --list, --del and --add, other command doesn't depend
 655          * nor change running kernel. So if user gives offline vmlinux,
 656          * ignore its buildid.
 657          */
 658         if (!strchr("lda", params.command) && symbol_conf.vmlinux_name)
 659                 symbol_conf.ignore_vmlinux_buildid = true;
 660
 661         switch (params.command) {
 662         case 'l':
 663                 if (params.uprobes) {
 664                         pr_err("  Error: Don't use --list with --exec.\n");
 665                         parse_options_usage(probe_usage, options, "l", true);
 666                         parse_options_usage(NULL, options, "x", true);
 667                         return -EINVAL;
 668                 }
 669                 ret = show_perf_probe_events(params.filter);
 670                 if (ret < 0)
 671                         pr_err_with_code("  Error: Failed to show event list.", ret);
 672                 return ret;
 673         case 'F':
 674                 ret = show_available_funcs(params.target, params.nsi,
 675                                            params.filter, params.uprobes);
 676                 if (ret < 0)
 677                         pr_err_with_code("  Error: Failed to show functions.", ret);
 678                 return ret;
 679 #ifdef HAVE_DWARF_SUPPORT
 680         case 'L':
 681                 ret = show_line_range(&params.line_range, params.target,
 682                                       params.nsi, params.uprobes);
 683                 if (ret < 0)
 684                         pr_err_with_code("  Error: Failed to show lines.", ret);
 685                 return ret;
 686         case 'V':
 687                 if (!params.filter)
 688                         params.filter = strfilter__new(DEFAULT_VAR_FILTER,
 689                                                        NULL);
 690
 691                 ret = show_available_vars(params.events, params.nevents,
 692                                           params.filter);
 693                 if (ret < 0)
 694                         pr_err_with_code("  Error: Failed to show vars.", ret);
 695                 return ret;
 696 #endif
 697         case 'd':
 698                 ret = perf_del_probe_events(params.filter);
 699                 if (ret < 0) {
 700                         pr_err_with_code("  Error: Failed to delete events.", ret);
 701                         return ret;
 702                 }
 703                 break;
 704         case 'D':
 705                 if (probe_conf.bootconfig && params.uprobes) {
 706                         pr_err("  Error: --bootconfig doesn't support uprobes.\n");
 707                         return -EINVAL;
 708                 }
 709                 __fallthrough;
 710         case 'a':
 711
 712                 /* Ensure the last given target is used */
 713                 if (params.target && !params.target_used) {
 714                         pr_err("  Error: -x/-m must follow the probe definitions.\n");
 715                         parse_options_usage(probe_usage, options, "m", true);
 716                         parse_options_usage(NULL, options, "x", true);
 717                         return -EINVAL;
 718                 }
 719
 720                 ret = perf_add_probe_events(params.events, params.nevents);
 721                 if (ret < 0) {
 722
 723                         /*
 724                          * When perf_add_probe_events() fails it calls
 725                          * cleanup_perf_probe_events(pevs, npevs), i.e.
 726                          * cleanup_perf_probe_events(params.events, params.nevents), which
 727                          * will call clear_perf_probe_event(), so set nevents to zero
 728                          * to avoid cleanup_params() to call clear_perf_probe_event() again
 729                          * on the same pevs.
 730                          */
 731                         params.nevents = 0;
 732                         pr_err_with_code("  Error: Failed to add events.", ret);
 733                         return ret;
 734                 }
 735                 break;
 736         default:
 737                 usage_with_options(probe_usage, options);
 738         }
 739         return 0;
 740 }
 741
 742 int cmd_probe(int argc, const char **argv)
 743 {
 744         int ret;
 745
 746         ret = init_params();
 747         if (!ret) {
 748                 ret = __cmd_probe(argc, argv);
 749                 cleanup_params();
 750         }
 751
 752         return ret < 0 ? ret : 0;
 753 }