tools/perf/builtin-probe.c

   1 /*
   2  * builtin-probe.c
   3  *
   4  * Builtin probe command: Set up probe events by C expression
   5  *
   6  * Written by Masami Hiramatsu <mhiramat@redhat.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  21  *
  22  */
  23 #include <sys/utsname.h>
  24 #include <sys/types.h>
  25 #include <sys/stat.h>
  26 #include <fcntl.h>
  27 #include <errno.h>
  28 #include <stdio.h>
  29 #include <unistd.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32
  33 #include "perf.h"
  34 #include "builtin.h"
  35 #include "util/util.h"
  36 #include "util/strlist.h"
  37 #include "util/strfilter.h"
  38 #include "util/symbol.h"
  39 #include "util/debug.h"
  40 #include <subcmd/parse-options.h>
  41 #include "util/probe-finder.h"
  42 #include "util/probe-event.h"
  43 #include "util/probe-file.h"
  44
  45 #define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"
  46 #define DEFAULT_FUNC_FILTER "!_*"
  47 #define DEFAULT_LIST_FILTER "*:*"
  48
  49 /* Session management structure */
  50 static struct {
  51         int command;    /* Command short_name */
  52         bool list_events;
  53         bool uprobes;
  54         bool quiet;
  55         bool target_used;
  56         int nevents;
  57         struct perf_probe_event events[MAX_PROBES];
  58         struct line_range line_range;
  59         char *target;
  60         struct strfilter *filter;
  61 } params;
  62
  63 /* Parse an event definition. Note that any error must die. */
  64 static int parse_probe_event(const char *str)
  65 {
  66         struct perf_probe_event *pev = &params.events[params.nevents];
  67         int ret;
  68
  69         pr_debug("probe-definition(%d): %s\n", params.nevents, str);
  70         if (++params.nevents == MAX_PROBES) {
  71                 pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
  72                 return -1;
  73         }
  74
  75         pev->uprobes = params.uprobes;
  76         if (params.target) {
  77                 pev->target = strdup(params.target);
  78                 if (!pev->target)
  79                         return -ENOMEM;
  80                 params.target_used = true;
  81         }
  82
  83         /* Parse a perf-probe command into event */
  84         ret = parse_perf_probe_command(str, pev);
  85         pr_debug("%d arguments\n", pev->nargs);
  86
  87         return ret;
  88 }
  89
  90 static int params_add_filter(const char *str)
  91 {
  92         const char *err = NULL;
  93         int ret = 0;
  94
  95         pr_debug2("Add filter: %s\n", str);
  96         if (!params.filter) {
  97                 params.filter = strfilter__new(str, &err);
  98                 if (!params.filter)
  99                         ret = err ? -EINVAL : -ENOMEM;
 100         } else
 101                 ret = strfilter__or(params.filter, str, &err);
 102
 103         if (ret == -EINVAL) {
 104                 pr_err("Filter parse error at %td.\n", err - str + 1);
 105                 pr_err("Source: \"%s\"\n", str);
 106                 pr_err("         %*c\n", (int)(err - str + 1), '^');
 107         }
 108
 109         return ret;
 110 }
 111
 112 static int set_target(const char *ptr)
 113 {
 114         int found = 0;
 115         const char *buf;
 116
 117         /*
 118          * The first argument after options can be an absolute path
 119          * to an executable / library or kernel module.
 120          *
 121          * TODO: Support relative path, and $PATH, $LD_LIBRARY_PATH,
 122          * short module name.
 123          */
 124         if (!params.target && ptr && *ptr == '/') {
 125                 params.target = strdup(ptr);
 126                 if (!params.target)
 127                         return -ENOMEM;
 128                 params.target_used = false;
 129
 130                 found = 1;
 131                 buf = ptr + (strlen(ptr) - 3);
 132
 133                 if (strcmp(buf, ".ko"))
 134                         params.uprobes = true;
 135
 136         }
 137
 138         return found;
 139 }
 140
 141 static int parse_probe_event_argv(int argc, const char **argv)
 142 {
 143         int i, len, ret, found_target;
 144         char *buf;
 145
 146         found_target = set_target(argv[0]);
 147         if (found_target < 0)
 148                 return found_target;
 149
 150         if (found_target && argc == 1)
 151                 return 0;
 152
 153         /* Bind up rest arguments */
 154         len = 0;
 155         for (i = 0; i < argc; i++) {
 156                 if (i == 0 && found_target)
 157                         continue;
 158
 159                 len += strlen(argv[i]) + 1;
 160         }
 161         buf = zalloc(len + 1);
 162         if (buf == NULL)
 163                 return -ENOMEM;
 164         len = 0;
 165         for (i = 0; i < argc; i++) {
 166                 if (i == 0 && found_target)
 167                         continue;
 168
 169                 len += sprintf(&buf[len], "%s ", argv[i]);
 170         }
 171         ret = parse_probe_event(buf);
 172         free(buf);
 173         return ret;
 174 }
 175
 176 static int opt_set_target(const struct option *opt, const char *str,
 177                         int unset __maybe_unused)
 178 {
 179         int ret = -ENOENT;
 180         char *tmp;
 181
 182         if  (str) {
 183                 if (!strcmp(opt->long_name, "exec"))
 184                         params.uprobes = true;
 185                 else if (!strcmp(opt->long_name, "module"))
 186                         params.uprobes = false;
 187                 else
 188                         return ret;
 189
 190                 /* Expand given path to absolute path, except for modulename */
 191                 if (params.uprobes || strchr(str, '/')) {
 192                         tmp = realpath(str, NULL);
 193                         if (!tmp) {
 194                                 pr_warning("Failed to get the absolute path of %s: %m\n", str);
 195                                 return ret;
 196                         }
 197                 } else {
 198                         tmp = strdup(str);
 199                         if (!tmp)
 200                                 return -ENOMEM;
 201                 }
 202                 free(params.target);
 203                 params.target = tmp;
 204                 params.target_used = false;
 205                 ret = 0;
 206         }
 207
 208         return ret;
 209 }
 210
 211 /* Command option callbacks */
 212
 213 #ifdef HAVE_DWARF_SUPPORT
 214 static int opt_show_lines(const struct option *opt,
 215                           const char *str, int unset __maybe_unused)
 216 {
 217         int ret = 0;
 218
 219         if (!str)
 220                 return 0;
 221
 222         if (params.command == 'L') {
 223                 pr_warning("Warning: more than one --line options are"
 224                            " detected. Only the first one is valid.\n");
 225                 return 0;
 226         }
 227
 228         params.command = opt->short_name;
 229         ret = parse_line_range_desc(str, &params.line_range);
 230
 231         return ret;
 232 }
 233
 234 static int opt_show_vars(const struct option *opt,
 235                          const char *str, int unset __maybe_unused)
 236 {
 237         struct perf_probe_event *pev = &params.events[params.nevents];
 238         int ret;
 239
 240         if (!str)
 241                 return 0;
 242
 243         ret = parse_probe_event(str);
 244         if (!ret && pev->nargs != 0) {
 245                 pr_err("  Error: '--vars' doesn't accept arguments.\n");
 246                 return -EINVAL;
 247         }
 248         params.command = opt->short_name;
 249
 250         return ret;
 251 }
 252 #else
 253 # define opt_show_lines NULL
 254 # define opt_show_vars NULL
 255 #endif
 256 static int opt_add_probe_event(const struct option *opt,
 257                               const char *str, int unset __maybe_unused)
 258 {
 259         if (str) {
 260                 params.command = opt->short_name;
 261                 return parse_probe_event(str);
 262         }
 263
 264         return 0;
 265 }
 266
 267 static int opt_set_filter_with_command(const struct option *opt,
 268                                        const char *str, int unset)
 269 {
 270         if (!unset)
 271                 params.command = opt->short_name;
 272
 273         if (str)
 274                 return params_add_filter(str);
 275
 276         return 0;
 277 }
 278
 279 static int opt_set_filter(const struct option *opt __maybe_unused,
 280                           const char *str, int unset __maybe_unused)
 281 {
 282         if (str)
 283                 return params_add_filter(str);
 284
 285         return 0;
 286 }
 287
 288 static int init_params(void)
 289 {
 290         return line_range__init(&params.line_range);
 291 }
 292
 293 static void cleanup_params(void)
 294 {
 295         int i;
 296
 297         for (i = 0; i < params.nevents; i++)
 298                 clear_perf_probe_event(params.events + i);
 299         line_range__clear(&params.line_range);
 300         free(params.target);
 301         strfilter__delete(params.filter);
 302         memset(&params, 0, sizeof(params));
 303 }
 304
 305 static void pr_err_with_code(const char *msg, int err)
 306 {
 307         char sbuf[STRERR_BUFSIZE];
 308
 309         pr_err("%s", msg);
 310         pr_debug(" Reason: %s (Code: %d)",
 311                  strerror_r(-err, sbuf, sizeof(sbuf)), err);
 312         pr_err("\n");
 313 }
 314
 315 static int perf_add_probe_events(struct perf_probe_event *pevs, int npevs)
 316 {
 317         int ret;
 318         int i, k;
 319         const char *event = NULL, *group = NULL;
 320
 321         ret = init_probe_symbol_maps(pevs->uprobes);
 322         if (ret < 0)
 323                 return ret;
 324
 325         ret = convert_perf_probe_events(pevs, npevs);
 326         if (ret < 0)
 327                 goto out_cleanup;
 328
 329         ret = apply_perf_probe_events(pevs, npevs);
 330         if (ret < 0)
 331                 goto out_cleanup;
 332
 333         for (i = k = 0; i < npevs; i++)
 334                 k += pevs[i].ntevs;
 335
 336         pr_info("Added new event%s\n", (k > 1) ? "s:" : ":");
 337         for (i = 0; i < npevs; i++) {
 338                 struct perf_probe_event *pev = &pevs[i];
 339
 340                 for (k = 0; k < pev->ntevs; k++) {
 341                         struct probe_trace_event *tev = &pev->tevs[k];
 342
 343                         /* We use tev's name for showing new events */
 344                         show_perf_probe_event(tev->group, tev->event, pev,
 345                                               tev->point.module, false);
 346
 347                         /* Save the last valid name */
 348                         event = tev->event;
 349                         group = tev->group;
 350                 }
 351         }
 352
 353         /* Note that it is possible to skip all events because of blacklist */
 354         if (event) {
 355                 /* Show how to use the event. */
 356                 pr_info("\nYou can now use it in all perf tools, such as:\n\n");
 357                 pr_info("\tperf record -e %s:%s -aR sleep 1\n\n", group, event);
 358         }
 359
 360 out_cleanup:
 361         cleanup_perf_probe_events(pevs, npevs);
 362         exit_probe_symbol_maps();
 363         return ret;
 364 }
 365
 366 static int perf_del_probe_events(struct strfilter *filter)
 367 {
 368         int ret, ret2, ufd = -1, kfd = -1;
 369         char *str = strfilter__string(filter);
 370         struct strlist *klist = NULL, *ulist = NULL;
 371         struct str_node *ent;
 372
 373         if (!str)
 374                 return -EINVAL;
 375
 376         pr_debug("Delete filter: \'%s\'\n", str);
 377
 378         /* Get current event names */
 379         ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
 380         if (ret < 0)
 381                 goto out;
 382
 383         klist = strlist__new(NULL, NULL);
 384         ulist = strlist__new(NULL, NULL);
 385         if (!klist || !ulist) {
 386                 ret = -ENOMEM;
 387                 goto out;
 388         }
 389
 390         ret = probe_file__get_events(kfd, filter, klist);
 391         if (ret == 0) {
 392                 strlist__for_each(ent, klist)
 393                         pr_info("Removed event: %s\n", ent->s);
 394
 395                 ret = probe_file__del_strlist(kfd, klist);
 396                 if (ret < 0)
 397                         goto error;
 398         }
 399
 400         ret2 = probe_file__get_events(ufd, filter, ulist);
 401         if (ret2 == 0) {
 402                 strlist__for_each(ent, ulist)
 403                         pr_info("Removed event: %s\n", ent->s);
 404
 405                 ret2 = probe_file__del_strlist(ufd, ulist);
 406                 if (ret2 < 0)
 407                         goto error;
 408         }
 409
 410         if (ret == -ENOENT && ret2 == -ENOENT)
 411                 pr_debug("\"%s\" does not hit any event.\n", str);
 412                 /* Note that this is silently ignored */
 413         ret = 0;
 414
 415 error:
 416         if (kfd >= 0)
 417                 close(kfd);
 418         if (ufd >= 0)
 419                 close(ufd);
 420 out:
 421         strlist__delete(klist);
 422         strlist__delete(ulist);
 423         free(str);
 424
 425         return ret;
 426 }
 427
 428 static int
 429 __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 430 {
 431         const char * const probe_usage[] = {
 432                 "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
 433                 "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
 434                 "perf probe [<options>] --del '[GROUP:]EVENT' ...",
 435                 "perf probe --list [GROUP:]EVENT ...",
 436 #ifdef HAVE_DWARF_SUPPORT
 437                 "perf probe [<options>] --line 'LINEDESC'",
 438                 "perf probe [<options>] --vars 'PROBEPOINT'",
 439 #endif
 440                 "perf probe [<options>] --funcs",
 441                 NULL
 442         };
 443         struct option options[] = {
 444         OPT_INCR('v', "verbose", &verbose,
 445                     "be more verbose (show parsed arguments, etc)"),
 446         OPT_BOOLEAN('q', "quiet", &params.quiet,
 447                     "be quiet (do not show any mesages)"),
 448         OPT_CALLBACK_DEFAULT('l', "list", NULL, "[GROUP:]EVENT",
 449                              "list up probe events",
 450                              opt_set_filter_with_command, DEFAULT_LIST_FILTER),
 451         OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
 452                      opt_set_filter_with_command),
 453         OPT_CALLBACK('a', "add", NULL,
 454 #ifdef HAVE_DWARF_SUPPORT
 455                 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
 456                 " [[NAME=]ARG ...]",
 457 #else
 458                 "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
 459 #endif
 460                 "probe point definition, where\n"
 461                 "\t\tGROUP:\tGroup name (optional)\n"
 462                 "\t\tEVENT:\tEvent name\n"
 463                 "\t\tFUNC:\tFunction name\n"
 464                 "\t\tOFF:\tOffset from function entry (in byte)\n"
 465                 "\t\t%return:\tPut the probe at function return\n"
 466 #ifdef HAVE_DWARF_SUPPORT
 467                 "\t\tSRC:\tSource code path\n"
 468                 "\t\tRL:\tRelative line number from function entry.\n"
 469                 "\t\tAL:\tAbsolute line number in file.\n"
 470                 "\t\tPT:\tLazy expression of line code.\n"
 471                 "\t\tARG:\tProbe argument (local variable name or\n"
 472                 "\t\t\tkprobe-tracer argument format.)\n",
 473 #else
 474                 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
 475 #endif
 476                 opt_add_probe_event),
 477         OPT_BOOLEAN('f', "force", &probe_conf.force_add, "forcibly add events"
 478                     " with existing name"),
 479         OPT_CALLBACK('L', "line", NULL,
 480                      "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
 481                      "Show source code lines.", opt_show_lines),
 482         OPT_CALLBACK('V', "vars", NULL,
 483                      "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
 484                      "Show accessible variables on PROBEDEF", opt_show_vars),
 485         OPT_BOOLEAN('\0', "externs", &probe_conf.show_ext_vars,
 486                     "Show external variables too (with --vars only)"),
 487         OPT_BOOLEAN('\0', "range", &probe_conf.show_location_range,
 488                 "Show variables location range in scope (with --vars only)"),
 489         OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
 490                    "file", "vmlinux pathname"),
 491         OPT_STRING('s', "source", &symbol_conf.source_prefix,
 492                    "directory", "path to kernel source"),
 493         OPT_BOOLEAN('\0', "no-inlines", &probe_conf.no_inlines,
 494                 "Don't search inlined functions"),
 495         OPT__DRY_RUN(&probe_event_dry_run),
 496         OPT_INTEGER('\0', "max-probes", &probe_conf.max_probes,
 497                  "Set how many probe points can be found for a probe."),
 498         OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",
 499                              "Show potential probe-able functions.",
 500                              opt_set_filter_with_command, DEFAULT_FUNC_FILTER),
 501         OPT_CALLBACK('\0', "filter", NULL,
 502                      "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
 503                      "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
 504                      "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
 505                      opt_set_filter),
 506         OPT_CALLBACK('x', "exec", NULL, "executable|path",
 507                         "target executable name or path", opt_set_target),
 508         OPT_CALLBACK('m', "module", NULL, "modname|path",
 509                 "target module name (for online) or path (for offline)",
 510                 opt_set_target),
 511         OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
 512                     "Enable symbol demangling"),
 513         OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
 514                     "Enable kernel symbol demangling"),
 515         OPT_END()
 516         };
 517         int ret;
 518
 519         set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);
 520         set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);
 521         set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);
 522 #ifdef HAVE_DWARF_SUPPORT
 523         set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);
 524         set_option_flag(options, 'V', "vars", PARSE_OPT_EXCLUSIVE);
 525 #else
 526 # define set_nobuild(s, l, c) set_option_nobuild(options, s, l, "NO_DWARF=1", c)
 527         set_nobuild('L', "line", false);
 528         set_nobuild('V', "vars", false);
 529         set_nobuild('\0', "externs", false);
 530         set_nobuild('\0', "range", false);
 531         set_nobuild('k', "vmlinux", true);
 532         set_nobuild('s', "source", true);
 533         set_nobuild('\0', "no-inlines", true);
 534 # undef set_nobuild
 535 #endif
 536         set_option_flag(options, 'F', "funcs", PARSE_OPT_EXCLUSIVE);
 537
 538         argc = parse_options(argc, argv, options, probe_usage,
 539                              PARSE_OPT_STOP_AT_NON_OPTION);
 540         if (argc > 0) {
 541                 if (strcmp(argv[0], "-") == 0) {
 542                         usage_with_options_msg(probe_usage, options,
 543                                 "'-' is not supported.\n");
 544                 }
 545                 if (params.command && params.command != 'a') {
 546                         usage_with_options_msg(probe_usage, options,
 547                                 "another command except --add is set.\n");
 548                 }
 549                 ret = parse_probe_event_argv(argc, argv);
 550                 if (ret < 0) {
 551                         pr_err_with_code("  Error: Command Parse Error.", ret);
 552                         return ret;
 553                 }
 554                 params.command = 'a';
 555         }
 556
 557         if (params.quiet) {
 558                 if (verbose != 0) {
 559                         pr_err("  Error: -v and -q are exclusive.\n");
 560                         return -EINVAL;
 561                 }
 562                 verbose = -1;
 563         }
 564
 565         if (probe_conf.max_probes == 0)
 566                 probe_conf.max_probes = MAX_PROBES;
 567
 568         /*
 569          * Only consider the user's kernel image path if given.
 570          */
 571         symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
 572
 573         switch (params.command) {
 574         case 'l':
 575                 if (params.uprobes) {
 576                         pr_err("  Error: Don't use --list with --exec.\n");
 577                         parse_options_usage(probe_usage, options, "l", true);
 578                         parse_options_usage(NULL, options, "x", true);
 579                         return -EINVAL;
 580                 }
 581                 ret = show_perf_probe_events(params.filter);
 582                 if (ret < 0)
 583                         pr_err_with_code("  Error: Failed to show event list.", ret);
 584                 return ret;
 585         case 'F':
 586                 ret = show_available_funcs(params.target, params.filter,
 587                                         params.uprobes);
 588                 if (ret < 0)
 589                         pr_err_with_code("  Error: Failed to show functions.", ret);
 590                 return ret;
 591 #ifdef HAVE_DWARF_SUPPORT
 592         case 'L':
 593                 ret = show_line_range(&params.line_range, params.target,
 594                                       params.uprobes);
 595                 if (ret < 0)
 596                         pr_err_with_code("  Error: Failed to show lines.", ret);
 597                 return ret;
 598         case 'V':
 599                 if (!params.filter)
 600                         params.filter = strfilter__new(DEFAULT_VAR_FILTER,
 601                                                        NULL);
 602
 603                 ret = show_available_vars(params.events, params.nevents,
 604                                           params.filter);
 605                 if (ret < 0)
 606                         pr_err_with_code("  Error: Failed to show vars.", ret);
 607                 return ret;
 608 #endif
 609         case 'd':
 610                 ret = perf_del_probe_events(params.filter);
 611                 if (ret < 0) {
 612                         pr_err_with_code("  Error: Failed to delete events.", ret);
 613                         return ret;
 614                 }
 615                 break;
 616         case 'a':
 617                 /* Ensure the last given target is used */
 618                 if (params.target && !params.target_used) {
 619                         pr_err("  Error: -x/-m must follow the probe definitions.\n");
 620                         parse_options_usage(probe_usage, options, "m", true);
 621                         parse_options_usage(NULL, options, "x", true);
 622                         return -EINVAL;
 623                 }
 624
 625                 ret = perf_add_probe_events(params.events, params.nevents);
 626                 if (ret < 0) {
 627                         pr_err_with_code("  Error: Failed to add events.", ret);
 628                         return ret;
 629                 }
 630                 break;
 631         default:
 632                 usage_with_options(probe_usage, options);
 633         }
 634         return 0;
 635 }
 636
 637 int cmd_probe(int argc, const char **argv, const char *prefix)
 638 {
 639         int ret;
 640
 641         ret = init_params();
 642         if (!ret) {
 643                 ret = __cmd_probe(argc, argv, prefix);
 644                 cleanup_params();
 645         }
 646
 647         return ret < 0 ? ret : 0;
 648 }