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 "util/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 #endif
 253 static int opt_add_probe_event(const struct option *opt,
 254                               const char *str, int unset __maybe_unused)
 255 {
 256         if (str) {
 257                 params.command = opt->short_name;
 258                 return parse_probe_event(str);
 259         }
 260
 261         return 0;
 262 }
 263
 264 static int opt_set_filter_with_command(const struct option *opt,
 265                                        const char *str, int unset)
 266 {
 267         if (!unset)
 268                 params.command = opt->short_name;
 269
 270         if (str)
 271                 return params_add_filter(str);
 272
 273         return 0;
 274 }
 275
 276 static int opt_set_filter(const struct option *opt __maybe_unused,
 277                           const char *str, int unset __maybe_unused)
 278 {
 279         if (str)
 280                 return params_add_filter(str);
 281
 282         return 0;
 283 }
 284
 285 static int init_params(void)
 286 {
 287         return line_range__init(&params.line_range);
 288 }
 289
 290 static void cleanup_params(void)
 291 {
 292         int i;
 293
 294         for (i = 0; i < params.nevents; i++)
 295                 clear_perf_probe_event(params.events + i);
 296         line_range__clear(&params.line_range);
 297         free(params.target);
 298         strfilter__delete(params.filter);
 299         memset(&params, 0, sizeof(params));
 300 }
 301
 302 static void pr_err_with_code(const char *msg, int err)
 303 {
 304         char sbuf[STRERR_BUFSIZE];
 305
 306         pr_err("%s", msg);
 307         pr_debug(" Reason: %s (Code: %d)",
 308                  strerror_r(-err, sbuf, sizeof(sbuf)), err);
 309         pr_err("\n");
 310 }
 311
 312 static int perf_add_probe_events(struct perf_probe_event *pevs, int npevs)
 313 {
 314         int ret;
 315         int i, k;
 316         const char *event = NULL, *group = NULL;
 317
 318         ret = init_probe_symbol_maps(pevs->uprobes);
 319         if (ret < 0)
 320                 return ret;
 321
 322         ret = convert_perf_probe_events(pevs, npevs);
 323         if (ret < 0)
 324                 goto out_cleanup;
 325
 326         ret = apply_perf_probe_events(pevs, npevs);
 327         if (ret < 0)
 328                 goto out_cleanup;
 329
 330         for (i = k = 0; i < npevs; i++)
 331                 k += pevs[i].ntevs;
 332
 333         pr_info("Added new event%s\n", (k > 1) ? "s:" : ":");
 334         for (i = 0; i < npevs; i++) {
 335                 struct perf_probe_event *pev = &pevs[i];
 336
 337                 for (k = 0; k < pev->ntevs; k++) {
 338                         struct probe_trace_event *tev = &pev->tevs[k];
 339
 340                         /* We use tev's name for showing new events */
 341                         show_perf_probe_event(tev->group, tev->event, pev,
 342                                               tev->point.module, false);
 343
 344                         /* Save the last valid name */
 345                         event = tev->event;
 346                         group = tev->group;
 347                 }
 348         }
 349
 350         /* Note that it is possible to skip all events because of blacklist */
 351         if (event) {
 352                 /* Show how to use the event. */
 353                 pr_info("\nYou can now use it in all perf tools, such as:\n\n");
 354                 pr_info("\tperf record -e %s:%s -aR sleep 1\n\n", group, event);
 355         }
 356
 357 out_cleanup:
 358         cleanup_perf_probe_events(pevs, npevs);
 359         exit_probe_symbol_maps();
 360         return ret;
 361 }
 362
 363 static int perf_del_probe_events(struct strfilter *filter)
 364 {
 365         int ret, ret2, ufd = -1, kfd = -1;
 366         char *str = strfilter__string(filter);
 367         struct strlist *klist = NULL, *ulist = NULL;
 368         struct str_node *ent;
 369
 370         if (!str)
 371                 return -EINVAL;
 372
 373         pr_debug("Delete filter: \'%s\'\n", str);
 374
 375         /* Get current event names */
 376         ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
 377         if (ret < 0)
 378                 goto out;
 379
 380         klist = strlist__new(NULL, NULL);
 381         ulist = strlist__new(NULL, NULL);
 382         if (!klist || !ulist) {
 383                 ret = -ENOMEM;
 384                 goto out;
 385         }
 386
 387         ret = probe_file__get_events(kfd, filter, klist);
 388         if (ret == 0) {
 389                 strlist__for_each(ent, klist)
 390                         pr_info("Removed event: %s\n", ent->s);
 391
 392                 ret = probe_file__del_strlist(kfd, klist);
 393                 if (ret < 0)
 394                         goto error;
 395         }
 396
 397         ret2 = probe_file__get_events(ufd, filter, ulist);
 398         if (ret2 == 0) {
 399                 strlist__for_each(ent, ulist)
 400                         pr_info("Removed event: %s\n", ent->s);
 401
 402                 ret2 = probe_file__del_strlist(ufd, ulist);
 403                 if (ret2 < 0)
 404                         goto error;
 405         }
 406
 407         if (ret == -ENOENT && ret2 == -ENOENT)
 408                 pr_debug("\"%s\" does not hit any event.\n", str);
 409                 /* Note that this is silently ignored */
 410         ret = 0;
 411
 412 error:
 413         if (kfd >= 0)
 414                 close(kfd);
 415         if (ufd >= 0)
 416                 close(ufd);
 417 out:
 418         strlist__delete(klist);
 419         strlist__delete(ulist);
 420         free(str);
 421
 422         return ret;
 423 }
 424
 425 static int
 426 __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 427 {
 428         const char * const probe_usage[] = {
 429                 "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
 430                 "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
 431                 "perf probe [<options>] --del '[GROUP:]EVENT' ...",
 432                 "perf probe --list [GROUP:]EVENT ...",
 433 #ifdef HAVE_DWARF_SUPPORT
 434                 "perf probe [<options>] --line 'LINEDESC'",
 435                 "perf probe [<options>] --vars 'PROBEPOINT'",
 436 #endif
 437                 "perf probe [<options>] --funcs",
 438                 NULL
 439         };
 440         struct option options[] = {
 441         OPT_INCR('v', "verbose", &verbose,
 442                     "be more verbose (show parsed arguments, etc)"),
 443         OPT_BOOLEAN('q', "quiet", &params.quiet,
 444                     "be quiet (do not show any mesages)"),
 445         OPT_CALLBACK_DEFAULT('l', "list", NULL, "[GROUP:]EVENT",
 446                              "list up probe events",
 447                              opt_set_filter_with_command, DEFAULT_LIST_FILTER),
 448         OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
 449                      opt_set_filter_with_command),
 450         OPT_CALLBACK('a', "add", NULL,
 451 #ifdef HAVE_DWARF_SUPPORT
 452                 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
 453                 " [[NAME=]ARG ...]",
 454 #else
 455                 "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
 456 #endif
 457                 "probe point definition, where\n"
 458                 "\t\tGROUP:\tGroup name (optional)\n"
 459                 "\t\tEVENT:\tEvent name\n"
 460                 "\t\tFUNC:\tFunction name\n"
 461                 "\t\tOFF:\tOffset from function entry (in byte)\n"
 462                 "\t\t%return:\tPut the probe at function return\n"
 463 #ifdef HAVE_DWARF_SUPPORT
 464                 "\t\tSRC:\tSource code path\n"
 465                 "\t\tRL:\tRelative line number from function entry.\n"
 466                 "\t\tAL:\tAbsolute line number in file.\n"
 467                 "\t\tPT:\tLazy expression of line code.\n"
 468                 "\t\tARG:\tProbe argument (local variable name or\n"
 469                 "\t\t\tkprobe-tracer argument format.)\n",
 470 #else
 471                 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
 472 #endif
 473                 opt_add_probe_event),
 474         OPT_BOOLEAN('f', "force", &probe_conf.force_add, "forcibly add events"
 475                     " with existing name"),
 476 #ifdef HAVE_DWARF_SUPPORT
 477         OPT_CALLBACK('L', "line", NULL,
 478                      "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
 479                      "Show source code lines.", opt_show_lines),
 480         OPT_CALLBACK('V', "vars", NULL,
 481                      "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
 482                      "Show accessible variables on PROBEDEF", opt_show_vars),
 483         OPT_BOOLEAN('\0', "externs", &probe_conf.show_ext_vars,
 484                     "Show external variables too (with --vars only)"),
 485         OPT_BOOLEAN('\0', "range", &probe_conf.show_location_range,
 486                 "Show variables location range in scope (with --vars only)"),
 487         OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
 488                    "file", "vmlinux pathname"),
 489         OPT_STRING('s', "source", &symbol_conf.source_prefix,
 490                    "directory", "path to kernel source"),
 491         OPT_BOOLEAN('\0', "no-inlines", &probe_conf.no_inlines,
 492                 "Don't search inlined functions"),
 493 #endif
 494         OPT__DRY_RUN(&probe_event_dry_run),
 495         OPT_INTEGER('\0', "max-probes", &probe_conf.max_probes,
 496                  "Set how many probe points can be found for a probe."),
 497         OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",
 498                              "Show potential probe-able functions.",
 499                              opt_set_filter_with_command, DEFAULT_FUNC_FILTER),
 500         OPT_CALLBACK('\0', "filter", NULL,
 501                      "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
 502                      "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
 503                      "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
 504                      opt_set_filter),
 505         OPT_CALLBACK('x', "exec", NULL, "executable|path",
 506                         "target executable name or path", opt_set_target),
 507         OPT_CALLBACK('m', "module", NULL, "modname|path",
 508                 "target module name (for online) or path (for offline)",
 509                 opt_set_target),
 510         OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
 511                     "Enable symbol demangling"),
 512         OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
 513                     "Enable kernel symbol demangling"),
 514         OPT_END()
 515         };
 516         int ret;
 517
 518         set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);
 519         set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);
 520         set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);
 521 #ifdef HAVE_DWARF_SUPPORT
 522         set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);
 523         set_option_flag(options, 'V', "vars", PARSE_OPT_EXCLUSIVE);
 524 #endif
 525         set_option_flag(options, 'F', "funcs", PARSE_OPT_EXCLUSIVE);
 526
 527         argc = parse_options(argc, argv, options, probe_usage,
 528                              PARSE_OPT_STOP_AT_NON_OPTION);
 529         if (argc > 0) {
 530                 if (strcmp(argv[0], "-") == 0) {
 531                         usage_with_options_msg(probe_usage, options,
 532                                 "'-' is not supported.\n");
 533                 }
 534                 if (params.command && params.command != 'a') {
 535                         usage_with_options_msg(probe_usage, options,
 536                                 "another command except --add is set.\n");
 537                 }
 538                 ret = parse_probe_event_argv(argc, argv);
 539                 if (ret < 0) {
 540                         pr_err_with_code("  Error: Command Parse Error.", ret);
 541                         return ret;
 542                 }
 543                 params.command = 'a';
 544         }
 545
 546         if (params.quiet) {
 547                 if (verbose != 0) {
 548                         pr_err("  Error: -v and -q are exclusive.\n");
 549                         return -EINVAL;
 550                 }
 551                 verbose = -1;
 552         }
 553
 554         if (probe_conf.max_probes == 0)
 555                 probe_conf.max_probes = MAX_PROBES;
 556
 557         /*
 558          * Only consider the user's kernel image path if given.
 559          */
 560         symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
 561
 562         switch (params.command) {
 563         case 'l':
 564                 if (params.uprobes) {
 565                         pr_err("  Error: Don't use --list with --exec.\n");
 566                         parse_options_usage(probe_usage, options, "l", true);
 567                         parse_options_usage(NULL, options, "x", true);
 568                         return -EINVAL;
 569                 }
 570                 ret = show_perf_probe_events(params.filter);
 571                 if (ret < 0)
 572                         pr_err_with_code("  Error: Failed to show event list.", ret);
 573                 return ret;
 574         case 'F':
 575                 ret = show_available_funcs(params.target, params.filter,
 576                                         params.uprobes);
 577                 if (ret < 0)
 578                         pr_err_with_code("  Error: Failed to show functions.", ret);
 579                 return ret;
 580 #ifdef HAVE_DWARF_SUPPORT
 581         case 'L':
 582                 ret = show_line_range(&params.line_range, params.target,
 583                                       params.uprobes);
 584                 if (ret < 0)
 585                         pr_err_with_code("  Error: Failed to show lines.", ret);
 586                 return ret;
 587         case 'V':
 588                 if (!params.filter)
 589                         params.filter = strfilter__new(DEFAULT_VAR_FILTER,
 590                                                        NULL);
 591
 592                 ret = show_available_vars(params.events, params.nevents,
 593                                           params.filter);
 594                 if (ret < 0)
 595                         pr_err_with_code("  Error: Failed to show vars.", ret);
 596                 return ret;
 597 #endif
 598         case 'd':
 599                 ret = perf_del_probe_events(params.filter);
 600                 if (ret < 0) {
 601                         pr_err_with_code("  Error: Failed to delete events.", ret);
 602                         return ret;
 603                 }
 604                 break;
 605         case 'a':
 606                 /* Ensure the last given target is used */
 607                 if (params.target && !params.target_used) {
 608                         pr_err("  Error: -x/-m must follow the probe definitions.\n");
 609                         parse_options_usage(probe_usage, options, "m", true);
 610                         parse_options_usage(NULL, options, "x", true);
 611                         return -EINVAL;
 612                 }
 613
 614                 ret = perf_add_probe_events(params.events, params.nevents);
 615                 if (ret < 0) {
 616                         pr_err_with_code("  Error: Failed to add events.", ret);
 617                         return ret;
 618                 }
 619                 break;
 620         default:
 621                 usage_with_options(probe_usage, options);
 622         }
 623         return 0;
 624 }
 625
 626 int cmd_probe(int argc, const char **argv, const char *prefix)
 627 {
 628         int ret;
 629
 630         ret = init_params();
 631         if (!ret) {
 632                 ret = __cmd_probe(argc, argv, prefix);
 633                 cleanup_params();
 634         }
 635
 636         return ret < 0 ? ret : 0;
 637 }