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 <api/fs/debugfs.h>
  41 #include "util/parse-options.h"
  42 #include "util/probe-finder.h"
  43 #include "util/probe-event.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 #ifdef HAVE_DWARF_SUPPORT
 186                 else if (!strcmp(opt->long_name, "module"))
 187                         params.uprobes = false;
 188 #endif
 189                 else
 190                         return ret;
 191
 192                 /* Expand given path to absolute path, except for modulename */
 193                 if (params.uprobes || strchr(str, '/')) {
 194                         tmp = realpath(str, NULL);
 195                         if (!tmp) {
 196                                 pr_warning("Failed to get the absolute path of %s: %m\n", str);
 197                                 return ret;
 198                         }
 199                 } else {
 200                         tmp = strdup(str);
 201                         if (!tmp)
 202                                 return -ENOMEM;
 203                 }
 204                 free(params.target);
 205                 params.target = tmp;
 206                 params.target_used = false;
 207                 ret = 0;
 208         }
 209
 210         return ret;
 211 }
 212
 213 /* Command option callbacks */
 214
 215 #ifdef HAVE_DWARF_SUPPORT
 216 static int opt_show_lines(const struct option *opt,
 217                           const char *str, int unset __maybe_unused)
 218 {
 219         int ret = 0;
 220
 221         if (!str)
 222                 return 0;
 223
 224         if (params.command == 'L') {
 225                 pr_warning("Warning: more than one --line options are"
 226                            " detected. Only the first one is valid.\n");
 227                 return 0;
 228         }
 229
 230         params.command = opt->short_name;
 231         ret = parse_line_range_desc(str, &params.line_range);
 232
 233         return ret;
 234 }
 235
 236 static int opt_show_vars(const struct option *opt,
 237                          const char *str, int unset __maybe_unused)
 238 {
 239         struct perf_probe_event *pev = &params.events[params.nevents];
 240         int ret;
 241
 242         if (!str)
 243                 return 0;
 244
 245         ret = parse_probe_event(str);
 246         if (!ret && pev->nargs != 0) {
 247                 pr_err("  Error: '--vars' doesn't accept arguments.\n");
 248                 return -EINVAL;
 249         }
 250         params.command = opt->short_name;
 251
 252         return ret;
 253 }
 254 #endif
 255 static int opt_add_probe_event(const struct option *opt,
 256                               const char *str, int unset __maybe_unused)
 257 {
 258         if (str) {
 259                 params.command = opt->short_name;
 260                 return parse_probe_event(str);
 261         }
 262
 263         return 0;
 264 }
 265
 266 static int opt_set_filter_with_command(const struct option *opt,
 267                                        const char *str, int unset)
 268 {
 269         if (!unset)
 270                 params.command = opt->short_name;
 271
 272         if (str)
 273                 return params_add_filter(str);
 274
 275         return 0;
 276 }
 277
 278 static int opt_set_filter(const struct option *opt __maybe_unused,
 279                           const char *str, int unset __maybe_unused)
 280 {
 281         if (str)
 282                 return params_add_filter(str);
 283
 284         return 0;
 285 }
 286
 287 static int init_params(void)
 288 {
 289         return line_range__init(&params.line_range);
 290 }
 291
 292 static void cleanup_params(void)
 293 {
 294         int i;
 295
 296         for (i = 0; i < params.nevents; i++)
 297                 clear_perf_probe_event(params.events + i);
 298         line_range__clear(&params.line_range);
 299         free(params.target);
 300         if (params.filter)
 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
 316 __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 317 {
 318         const char * const probe_usage[] = {
 319                 "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
 320                 "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
 321                 "perf probe [<options>] --del '[GROUP:]EVENT' ...",
 322                 "perf probe --list [GROUP:]EVENT ...",
 323 #ifdef HAVE_DWARF_SUPPORT
 324                 "perf probe [<options>] --line 'LINEDESC'",
 325                 "perf probe [<options>] --vars 'PROBEPOINT'",
 326 #endif
 327                 "perf probe [<options>] --funcs",
 328                 NULL
 329         };
 330         struct option options[] = {
 331         OPT_INCR('v', "verbose", &verbose,
 332                     "be more verbose (show parsed arguments, etc)"),
 333         OPT_BOOLEAN('q', "quiet", &params.quiet,
 334                     "be quiet (do not show any mesages)"),
 335         OPT_CALLBACK_DEFAULT('l', "list", NULL, "[GROUP:]EVENT",
 336                              "list up probe events",
 337                              opt_set_filter_with_command, DEFAULT_LIST_FILTER),
 338         OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
 339                      opt_set_filter_with_command),
 340         OPT_CALLBACK('a', "add", NULL,
 341 #ifdef HAVE_DWARF_SUPPORT
 342                 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
 343                 " [[NAME=]ARG ...]",
 344 #else
 345                 "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
 346 #endif
 347                 "probe point definition, where\n"
 348                 "\t\tGROUP:\tGroup name (optional)\n"
 349                 "\t\tEVENT:\tEvent name\n"
 350                 "\t\tFUNC:\tFunction name\n"
 351                 "\t\tOFF:\tOffset from function entry (in byte)\n"
 352                 "\t\t%return:\tPut the probe at function return\n"
 353 #ifdef HAVE_DWARF_SUPPORT
 354                 "\t\tSRC:\tSource code path\n"
 355                 "\t\tRL:\tRelative line number from function entry.\n"
 356                 "\t\tAL:\tAbsolute line number in file.\n"
 357                 "\t\tPT:\tLazy expression of line code.\n"
 358                 "\t\tARG:\tProbe argument (local variable name or\n"
 359                 "\t\t\tkprobe-tracer argument format.)\n",
 360 #else
 361                 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
 362 #endif
 363                 opt_add_probe_event),
 364         OPT_BOOLEAN('f', "force", &probe_conf.force_add, "forcibly add events"
 365                     " with existing name"),
 366 #ifdef HAVE_DWARF_SUPPORT
 367         OPT_CALLBACK('L', "line", NULL,
 368                      "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
 369                      "Show source code lines.", opt_show_lines),
 370         OPT_CALLBACK('V', "vars", NULL,
 371                      "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
 372                      "Show accessible variables on PROBEDEF", opt_show_vars),
 373         OPT_BOOLEAN('\0', "externs", &probe_conf.show_ext_vars,
 374                     "Show external variables too (with --vars only)"),
 375         OPT_BOOLEAN('\0', "range", &probe_conf.show_location_range,
 376                 "Show variables location range in scope (with --vars only)"),
 377         OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
 378                    "file", "vmlinux pathname"),
 379         OPT_STRING('s', "source", &symbol_conf.source_prefix,
 380                    "directory", "path to kernel source"),
 381         OPT_CALLBACK('m', "module", NULL, "modname|path",
 382                 "target module name (for online) or path (for offline)",
 383                 opt_set_target),
 384         OPT_BOOLEAN('\0', "no-inlines", &probe_conf.no_inlines,
 385                 "Don't search inlined functions"),
 386 #endif
 387         OPT__DRY_RUN(&probe_event_dry_run),
 388         OPT_INTEGER('\0', "max-probes", &probe_conf.max_probes,
 389                  "Set how many probe points can be found for a probe."),
 390         OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",
 391                              "Show potential probe-able functions.",
 392                              opt_set_filter_with_command, DEFAULT_FUNC_FILTER),
 393         OPT_CALLBACK('\0', "filter", NULL,
 394                      "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
 395                      "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
 396                      "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
 397                      opt_set_filter),
 398         OPT_CALLBACK('x', "exec", NULL, "executable|path",
 399                         "target executable name or path", opt_set_target),
 400         OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
 401                     "Enable symbol demangling"),
 402         OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
 403                     "Enable kernel symbol demangling"),
 404         OPT_END()
 405         };
 406         int ret;
 407
 408         set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);
 409         set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);
 410         set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);
 411 #ifdef HAVE_DWARF_SUPPORT
 412         set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);
 413         set_option_flag(options, 'V', "vars", PARSE_OPT_EXCLUSIVE);
 414 #endif
 415         set_option_flag(options, 'F', "funcs", PARSE_OPT_EXCLUSIVE);
 416
 417         argc = parse_options(argc, argv, options, probe_usage,
 418                              PARSE_OPT_STOP_AT_NON_OPTION);
 419         if (argc > 0) {
 420                 if (strcmp(argv[0], "-") == 0) {
 421                         pr_warning("  Error: '-' is not supported.\n");
 422                         usage_with_options(probe_usage, options);
 423                 }
 424                 if (params.command && params.command != 'a') {
 425                         pr_warning("  Error: another command except --add is set.\n");
 426                         usage_with_options(probe_usage, options);
 427                 }
 428                 ret = parse_probe_event_argv(argc, argv);
 429                 if (ret < 0) {
 430                         pr_err_with_code("  Error: Command Parse Error.", ret);
 431                         return ret;
 432                 }
 433                 params.command = 'a';
 434         }
 435
 436         if (params.quiet) {
 437                 if (verbose != 0) {
 438                         pr_err("  Error: -v and -q are exclusive.\n");
 439                         return -EINVAL;
 440                 }
 441                 verbose = -1;
 442         }
 443
 444         if (probe_conf.max_probes == 0)
 445                 probe_conf.max_probes = MAX_PROBES;
 446
 447         /*
 448          * Only consider the user's kernel image path if given.
 449          */
 450         symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
 451
 452         switch (params.command) {
 453         case 'l':
 454                 if (params.uprobes) {
 455                         pr_warning("  Error: Don't use --list with --exec.\n");
 456                         usage_with_options(probe_usage, options);
 457                 }
 458                 ret = show_perf_probe_events(params.filter);
 459                 if (ret < 0)
 460                         pr_err_with_code("  Error: Failed to show event list.", ret);
 461                 return ret;
 462         case 'F':
 463                 ret = show_available_funcs(params.target, params.filter,
 464                                         params.uprobes);
 465                 if (ret < 0)
 466                         pr_err_with_code("  Error: Failed to show functions.", ret);
 467                 return ret;
 468 #ifdef HAVE_DWARF_SUPPORT
 469         case 'L':
 470                 ret = show_line_range(&params.line_range, params.target,
 471                                       params.uprobes);
 472                 if (ret < 0)
 473                         pr_err_with_code("  Error: Failed to show lines.", ret);
 474                 return ret;
 475         case 'V':
 476                 if (!params.filter)
 477                         params.filter = strfilter__new(DEFAULT_VAR_FILTER,
 478                                                        NULL);
 479
 480                 ret = show_available_vars(params.events, params.nevents,
 481                                           params.filter);
 482                 if (ret < 0)
 483                         pr_err_with_code("  Error: Failed to show vars.", ret);
 484                 return ret;
 485 #endif
 486         case 'd':
 487                 ret = del_perf_probe_events(params.filter);
 488                 if (ret < 0) {
 489                         pr_err_with_code("  Error: Failed to delete events.", ret);
 490                         return ret;
 491                 }
 492                 break;
 493         case 'a':
 494                 /* Ensure the last given target is used */
 495                 if (params.target && !params.target_used) {
 496                         pr_warning("  Error: -x/-m must follow the probe definitions.\n");
 497                         usage_with_options(probe_usage, options);
 498                 }
 499
 500                 ret = add_perf_probe_events(params.events, params.nevents);
 501                 if (ret < 0) {
 502                         pr_err_with_code("  Error: Failed to add events.", ret);
 503                         return ret;
 504                 }
 505                 break;
 506         default:
 507                 usage_with_options(probe_usage, options);
 508         }
 509         return 0;
 510 }
 511
 512 int cmd_probe(int argc, const char **argv, const char *prefix)
 513 {
 514         int ret;
 515
 516         ret = init_params();
 517         if (!ret) {
 518                 ret = __cmd_probe(argc, argv, prefix);
 519                 cleanup_params();
 520         }
 521
 522         return ret < 0 ? ret : 0;
 523 }