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
  48 /* Session management structure */
  49 static struct {
  50         bool list_events;
  51         bool force_add;
  52         bool show_lines;
  53         bool show_vars;
  54         bool show_ext_vars;
  55         bool show_funcs;
  56         bool mod_events;
  57         bool uprobes;
  58         int nevents;
  59         struct perf_probe_event events[MAX_PROBES];
  60         struct strlist *dellist;
  61         struct line_range line_range;
  62         char *target;
  63         int max_probe_points;
  64         struct strfilter *filter;
  65 } params;
  66
  67 /* Parse an event definition. Note that any error must die. */
  68 static int parse_probe_event(const char *str)
  69 {
  70         struct perf_probe_event *pev = &params.events[params.nevents];
  71         int ret;
  72
  73         pr_debug("probe-definition(%d): %s\n", params.nevents, str);
  74         if (++params.nevents == MAX_PROBES) {
  75                 pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
  76                 return -1;
  77         }
  78
  79         pev->uprobes = params.uprobes;
  80
  81         /* Parse a perf-probe command into event */
  82         ret = parse_perf_probe_command(str, pev);
  83         pr_debug("%d arguments\n", pev->nargs);
  84
  85         return ret;
  86 }
  87
  88 static int set_target(const char *ptr)
  89 {
  90         int found = 0;
  91         const char *buf;
  92
  93         /*
  94          * The first argument after options can be an absolute path
  95          * to an executable / library or kernel module.
  96          *
  97          * TODO: Support relative path, and $PATH, $LD_LIBRARY_PATH,
  98          * short module name.
  99          */
 100         if (!params.target && ptr && *ptr == '/') {
 101                 params.target = strdup(ptr);
 102                 if (!params.target)
 103                         return -ENOMEM;
 104
 105                 found = 1;
 106                 buf = ptr + (strlen(ptr) - 3);
 107
 108                 if (strcmp(buf, ".ko"))
 109                         params.uprobes = true;
 110
 111         }
 112
 113         return found;
 114 }
 115
 116 static int parse_probe_event_argv(int argc, const char **argv)
 117 {
 118         int i, len, ret, found_target;
 119         char *buf;
 120
 121         found_target = set_target(argv[0]);
 122         if (found_target < 0)
 123                 return found_target;
 124
 125         if (found_target && argc == 1)
 126                 return 0;
 127
 128         /* Bind up rest arguments */
 129         len = 0;
 130         for (i = 0; i < argc; i++) {
 131                 if (i == 0 && found_target)
 132                         continue;
 133
 134                 len += strlen(argv[i]) + 1;
 135         }
 136         buf = zalloc(len + 1);
 137         if (buf == NULL)
 138                 return -ENOMEM;
 139         len = 0;
 140         for (i = 0; i < argc; i++) {
 141                 if (i == 0 && found_target)
 142                         continue;
 143
 144                 len += sprintf(&buf[len], "%s ", argv[i]);
 145         }
 146         params.mod_events = true;
 147         ret = parse_probe_event(buf);
 148         free(buf);
 149         return ret;
 150 }
 151
 152 static int opt_add_probe_event(const struct option *opt __maybe_unused,
 153                               const char *str, int unset __maybe_unused)
 154 {
 155         if (str) {
 156                 params.mod_events = true;
 157                 return parse_probe_event(str);
 158         } else
 159                 return 0;
 160 }
 161
 162 static int opt_del_probe_event(const struct option *opt __maybe_unused,
 163                                const char *str, int unset __maybe_unused)
 164 {
 165         if (str) {
 166                 params.mod_events = true;
 167                 if (!params.dellist)
 168                         params.dellist = strlist__new(true, NULL);
 169                 strlist__add(params.dellist, str);
 170         }
 171         return 0;
 172 }
 173
 174 static int opt_set_target(const struct option *opt, const char *str,
 175                         int unset __maybe_unused)
 176 {
 177         int ret = -ENOENT;
 178         char *tmp;
 179
 180         if  (str && !params.target) {
 181                 if (!strcmp(opt->long_name, "exec"))
 182                         params.uprobes = true;
 183 #ifdef HAVE_DWARF_SUPPORT
 184                 else if (!strcmp(opt->long_name, "module"))
 185                         params.uprobes = false;
 186 #endif
 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                 params.target = tmp;
 203                 ret = 0;
 204         }
 205
 206         return ret;
 207 }
 208
 209 #ifdef HAVE_DWARF_SUPPORT
 210 static int opt_show_lines(const struct option *opt __maybe_unused,
 211                           const char *str, int unset __maybe_unused)
 212 {
 213         int ret = 0;
 214
 215         if (!str)
 216                 return 0;
 217
 218         if (params.show_lines) {
 219                 pr_warning("Warning: more than one --line options are"
 220                            " detected. Only the first one is valid.\n");
 221                 return 0;
 222         }
 223
 224         params.show_lines = true;
 225         ret = parse_line_range_desc(str, &params.line_range);
 226
 227         return ret;
 228 }
 229
 230 static int opt_show_vars(const struct option *opt __maybe_unused,
 231                          const char *str, int unset __maybe_unused)
 232 {
 233         struct perf_probe_event *pev = &params.events[params.nevents];
 234         int ret;
 235
 236         if (!str)
 237                 return 0;
 238
 239         ret = parse_probe_event(str);
 240         if (!ret && pev->nargs != 0) {
 241                 pr_err("  Error: '--vars' doesn't accept arguments.\n");
 242                 return -EINVAL;
 243         }
 244         params.show_vars = true;
 245
 246         return ret;
 247 }
 248 #endif
 249
 250 static int opt_set_filter(const struct option *opt __maybe_unused,
 251                           const char *str, int unset __maybe_unused)
 252 {
 253         const char *err;
 254
 255         if (str) {
 256                 pr_debug2("Set filter: %s\n", str);
 257                 if (params.filter)
 258                         strfilter__delete(params.filter);
 259                 params.filter = strfilter__new(str, &err);
 260                 if (!params.filter) {
 261                         pr_err("Filter parse error at %td.\n", err - str + 1);
 262                         pr_err("Source: \"%s\"\n", str);
 263                         pr_err("         %*c\n", (int)(err - str + 1), '^');
 264                         return -EINVAL;
 265                 }
 266         }
 267
 268         return 0;
 269 }
 270
 271 static int init_params(void)
 272 {
 273         return line_range__init(&params.line_range);
 274 }
 275
 276 static void cleanup_params(void)
 277 {
 278         int i;
 279
 280         for (i = 0; i < params.nevents; i++)
 281                 clear_perf_probe_event(params.events + i);
 282         if (params.dellist)
 283                 strlist__delete(params.dellist);
 284         line_range__clear(&params.line_range);
 285         free(params.target);
 286         if (params.filter)
 287                 strfilter__delete(params.filter);
 288         memset(&params, 0, sizeof(params));
 289 }
 290
 291 static void pr_err_with_code(const char *msg, int err)
 292 {
 293         pr_err("%s", msg);
 294         pr_debug(" Reason: %s (Code: %d)", strerror(-err), err);
 295         pr_err("\n");
 296 }
 297
 298 static int
 299 __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 300 {
 301         const char * const probe_usage[] = {
 302                 "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
 303                 "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
 304                 "perf probe [<options>] --del '[GROUP:]EVENT' ...",
 305                 "perf probe --list",
 306 #ifdef HAVE_DWARF_SUPPORT
 307                 "perf probe [<options>] --line 'LINEDESC'",
 308                 "perf probe [<options>] --vars 'PROBEPOINT'",
 309 #endif
 310                 NULL
 311 };
 312         const struct option options[] = {
 313         OPT_INCR('v', "verbose", &verbose,
 314                     "be more verbose (show parsed arguments, etc)"),
 315         OPT_BOOLEAN('l', "list", &params.list_events,
 316                     "list up current probe events"),
 317         OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
 318                 opt_del_probe_event),
 319         OPT_CALLBACK('a', "add", NULL,
 320 #ifdef HAVE_DWARF_SUPPORT
 321                 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
 322                 " [[NAME=]ARG ...]",
 323 #else
 324                 "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
 325 #endif
 326                 "probe point definition, where\n"
 327                 "\t\tGROUP:\tGroup name (optional)\n"
 328                 "\t\tEVENT:\tEvent name\n"
 329                 "\t\tFUNC:\tFunction name\n"
 330                 "\t\tOFF:\tOffset from function entry (in byte)\n"
 331                 "\t\t%return:\tPut the probe at function return\n"
 332 #ifdef HAVE_DWARF_SUPPORT
 333                 "\t\tSRC:\tSource code path\n"
 334                 "\t\tRL:\tRelative line number from function entry.\n"
 335                 "\t\tAL:\tAbsolute line number in file.\n"
 336                 "\t\tPT:\tLazy expression of line code.\n"
 337                 "\t\tARG:\tProbe argument (local variable name or\n"
 338                 "\t\t\tkprobe-tracer argument format.)\n",
 339 #else
 340                 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
 341 #endif
 342                 opt_add_probe_event),
 343         OPT_BOOLEAN('f', "force", &params.force_add, "forcibly add events"
 344                     " with existing name"),
 345 #ifdef HAVE_DWARF_SUPPORT
 346         OPT_CALLBACK('L', "line", NULL,
 347                      "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
 348                      "Show source code lines.", opt_show_lines),
 349         OPT_CALLBACK('V', "vars", NULL,
 350                      "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
 351                      "Show accessible variables on PROBEDEF", opt_show_vars),
 352         OPT_BOOLEAN('\0', "externs", &params.show_ext_vars,
 353                     "Show external variables too (with --vars only)"),
 354         OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
 355                    "file", "vmlinux pathname"),
 356         OPT_STRING('s', "source", &symbol_conf.source_prefix,
 357                    "directory", "path to kernel source"),
 358         OPT_CALLBACK('m', "module", NULL, "modname|path",
 359                 "target module name (for online) or path (for offline)",
 360                 opt_set_target),
 361 #endif
 362         OPT__DRY_RUN(&probe_event_dry_run),
 363         OPT_INTEGER('\0', "max-probes", &params.max_probe_points,
 364                  "Set how many probe points can be found for a probe."),
 365         OPT_BOOLEAN('F', "funcs", &params.show_funcs,
 366                     "Show potential probe-able functions."),
 367         OPT_CALLBACK('\0', "filter", NULL,
 368                      "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
 369                      "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
 370                      "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
 371                      opt_set_filter),
 372         OPT_CALLBACK('x', "exec", NULL, "executable|path",
 373                         "target executable name or path", opt_set_target),
 374         OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
 375                     "Disable symbol demangling"),
 376         OPT_END()
 377         };
 378         int ret;
 379
 380         argc = parse_options(argc, argv, options, probe_usage,
 381                              PARSE_OPT_STOP_AT_NON_OPTION);
 382         if (argc > 0) {
 383                 if (strcmp(argv[0], "-") == 0) {
 384                         pr_warning("  Error: '-' is not supported.\n");
 385                         usage_with_options(probe_usage, options);
 386                 }
 387                 ret = parse_probe_event_argv(argc, argv);
 388                 if (ret < 0) {
 389                         pr_err_with_code("  Error: Command Parse Error.", ret);
 390                         return ret;
 391                 }
 392         }
 393
 394         if (params.max_probe_points == 0)
 395                 params.max_probe_points = MAX_PROBES;
 396
 397         if ((!params.nevents && !params.dellist && !params.list_events &&
 398              !params.show_lines && !params.show_funcs))
 399                 usage_with_options(probe_usage, options);
 400
 401         /*
 402          * Only consider the user's kernel image path if given.
 403          */
 404         symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
 405
 406         if (params.list_events) {
 407                 if (params.mod_events) {
 408                         pr_err("  Error: Don't use --list with --add/--del.\n");
 409                         usage_with_options(probe_usage, options);
 410                 }
 411                 if (params.show_lines) {
 412                         pr_err("  Error: Don't use --list with --line.\n");
 413                         usage_with_options(probe_usage, options);
 414                 }
 415                 if (params.show_vars) {
 416                         pr_err(" Error: Don't use --list with --vars.\n");
 417                         usage_with_options(probe_usage, options);
 418                 }
 419                 if (params.show_funcs) {
 420                         pr_err("  Error: Don't use --list with --funcs.\n");
 421                         usage_with_options(probe_usage, options);
 422                 }
 423                 if (params.uprobes) {
 424                         pr_warning("  Error: Don't use --list with --exec.\n");
 425                         usage_with_options(probe_usage, options);
 426                 }
 427                 ret = show_perf_probe_events();
 428                 if (ret < 0)
 429                         pr_err_with_code("  Error: Failed to show event list.", ret);
 430                 return ret;
 431         }
 432         if (params.show_funcs) {
 433                 if (params.nevents != 0 || params.dellist) {
 434                         pr_err("  Error: Don't use --funcs with"
 435                                " --add/--del.\n");
 436                         usage_with_options(probe_usage, options);
 437                 }
 438                 if (params.show_lines) {
 439                         pr_err("  Error: Don't use --funcs with --line.\n");
 440                         usage_with_options(probe_usage, options);
 441                 }
 442                 if (params.show_vars) {
 443                         pr_err("  Error: Don't use --funcs with --vars.\n");
 444                         usage_with_options(probe_usage, options);
 445                 }
 446                 if (!params.filter)
 447                         params.filter = strfilter__new(DEFAULT_FUNC_FILTER,
 448                                                        NULL);
 449                 ret = show_available_funcs(params.target, params.filter,
 450                                         params.uprobes);
 451                 strfilter__delete(params.filter);
 452                 params.filter = NULL;
 453                 if (ret < 0)
 454                         pr_err_with_code("  Error: Failed to show functions.", ret);
 455                 return ret;
 456         }
 457
 458 #ifdef HAVE_DWARF_SUPPORT
 459         if (params.show_lines) {
 460                 if (params.mod_events) {
 461                         pr_err("  Error: Don't use --line with"
 462                                " --add/--del.\n");
 463                         usage_with_options(probe_usage, options);
 464                 }
 465                 if (params.show_vars) {
 466                         pr_err(" Error: Don't use --line with --vars.\n");
 467                         usage_with_options(probe_usage, options);
 468                 }
 469
 470                 ret = show_line_range(&params.line_range, params.target);
 471                 if (ret < 0)
 472                         pr_err_with_code("  Error: Failed to show lines.", ret);
 473                 return ret;
 474         }
 475         if (params.show_vars) {
 476                 if (params.mod_events) {
 477                         pr_err("  Error: Don't use --vars with"
 478                                " --add/--del.\n");
 479                         usage_with_options(probe_usage, options);
 480                 }
 481                 if (!params.filter)
 482                         params.filter = strfilter__new(DEFAULT_VAR_FILTER,
 483                                                        NULL);
 484
 485                 ret = show_available_vars(params.events, params.nevents,
 486                                           params.max_probe_points,
 487                                           params.target,
 488                                           params.filter,
 489                                           params.show_ext_vars);
 490                 strfilter__delete(params.filter);
 491                 params.filter = NULL;
 492                 if (ret < 0)
 493                         pr_err_with_code("  Error: Failed to show vars.", ret);
 494                 return ret;
 495         }
 496 #endif
 497
 498         if (params.dellist) {
 499                 ret = del_perf_probe_events(params.dellist);
 500                 if (ret < 0) {
 501                         pr_err_with_code("  Error: Failed to delete events.", ret);
 502                         return ret;
 503                 }
 504         }
 505
 506         if (params.nevents) {
 507                 ret = add_perf_probe_events(params.events, params.nevents,
 508                                             params.max_probe_points,
 509                                             params.target,
 510                                             params.force_add);
 511                 if (ret < 0) {
 512                         pr_err_with_code("  Error: Failed to add events.", ret);
 513                         return ret;
 514                 }
 515         }
 516         return 0;
 517 }
 518
 519 int cmd_probe(int argc, const char **argv, const char *prefix)
 520 {
 521         int ret;
 522
 523         ret = init_params();
 524         if (!ret) {
 525                 ret = __cmd_probe(argc, argv, prefix);
 526                 cleanup_params();
 527         }
 528
 529         return ret;
 530 }