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         char sbuf[STRERR_BUFSIZE];
 294
 295         pr_err("%s", msg);
 296         pr_debug(" Reason: %s (Code: %d)",
 297                  strerror_r(-err, sbuf, sizeof(sbuf)), err);
 298         pr_err("\n");
 299 }
 300
 301 static int
 302 __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 303 {
 304         const char * const probe_usage[] = {
 305                 "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
 306                 "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
 307                 "perf probe [<options>] --del '[GROUP:]EVENT' ...",
 308                 "perf probe --list",
 309 #ifdef HAVE_DWARF_SUPPORT
 310                 "perf probe [<options>] --line 'LINEDESC'",
 311                 "perf probe [<options>] --vars 'PROBEPOINT'",
 312 #endif
 313                 NULL
 314 };
 315         const struct option options[] = {
 316         OPT_INCR('v', "verbose", &verbose,
 317                     "be more verbose (show parsed arguments, etc)"),
 318         OPT_BOOLEAN('l', "list", &params.list_events,
 319                     "list up current probe events"),
 320         OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
 321                 opt_del_probe_event),
 322         OPT_CALLBACK('a', "add", NULL,
 323 #ifdef HAVE_DWARF_SUPPORT
 324                 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
 325                 " [[NAME=]ARG ...]",
 326 #else
 327                 "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
 328 #endif
 329                 "probe point definition, where\n"
 330                 "\t\tGROUP:\tGroup name (optional)\n"
 331                 "\t\tEVENT:\tEvent name\n"
 332                 "\t\tFUNC:\tFunction name\n"
 333                 "\t\tOFF:\tOffset from function entry (in byte)\n"
 334                 "\t\t%return:\tPut the probe at function return\n"
 335 #ifdef HAVE_DWARF_SUPPORT
 336                 "\t\tSRC:\tSource code path\n"
 337                 "\t\tRL:\tRelative line number from function entry.\n"
 338                 "\t\tAL:\tAbsolute line number in file.\n"
 339                 "\t\tPT:\tLazy expression of line code.\n"
 340                 "\t\tARG:\tProbe argument (local variable name or\n"
 341                 "\t\t\tkprobe-tracer argument format.)\n",
 342 #else
 343                 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
 344 #endif
 345                 opt_add_probe_event),
 346         OPT_BOOLEAN('f', "force", &params.force_add, "forcibly add events"
 347                     " with existing name"),
 348 #ifdef HAVE_DWARF_SUPPORT
 349         OPT_CALLBACK('L', "line", NULL,
 350                      "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
 351                      "Show source code lines.", opt_show_lines),
 352         OPT_CALLBACK('V', "vars", NULL,
 353                      "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
 354                      "Show accessible variables on PROBEDEF", opt_show_vars),
 355         OPT_BOOLEAN('\0', "externs", &params.show_ext_vars,
 356                     "Show external variables too (with --vars only)"),
 357         OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
 358                    "file", "vmlinux pathname"),
 359         OPT_STRING('s', "source", &symbol_conf.source_prefix,
 360                    "directory", "path to kernel source"),
 361         OPT_CALLBACK('m', "module", NULL, "modname|path",
 362                 "target module name (for online) or path (for offline)",
 363                 opt_set_target),
 364 #endif
 365         OPT__DRY_RUN(&probe_event_dry_run),
 366         OPT_INTEGER('\0', "max-probes", &params.max_probe_points,
 367                  "Set how many probe points can be found for a probe."),
 368         OPT_BOOLEAN('F', "funcs", &params.show_funcs,
 369                     "Show potential probe-able functions."),
 370         OPT_CALLBACK('\0', "filter", NULL,
 371                      "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
 372                      "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
 373                      "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
 374                      opt_set_filter),
 375         OPT_CALLBACK('x', "exec", NULL, "executable|path",
 376                         "target executable name or path", opt_set_target),
 377         OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
 378                     "Disable symbol demangling"),
 379         OPT_END()
 380         };
 381         int ret;
 382
 383         argc = parse_options(argc, argv, options, probe_usage,
 384                              PARSE_OPT_STOP_AT_NON_OPTION);
 385         if (argc > 0) {
 386                 if (strcmp(argv[0], "-") == 0) {
 387                         pr_warning("  Error: '-' is not supported.\n");
 388                         usage_with_options(probe_usage, options);
 389                 }
 390                 ret = parse_probe_event_argv(argc, argv);
 391                 if (ret < 0) {
 392                         pr_err_with_code("  Error: Command Parse Error.", ret);
 393                         return ret;
 394                 }
 395         }
 396
 397         if (params.max_probe_points == 0)
 398                 params.max_probe_points = MAX_PROBES;
 399
 400         if ((!params.nevents && !params.dellist && !params.list_events &&
 401              !params.show_lines && !params.show_funcs))
 402                 usage_with_options(probe_usage, options);
 403
 404         /*
 405          * Only consider the user's kernel image path if given.
 406          */
 407         symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
 408
 409         if (params.list_events) {
 410                 if (params.mod_events) {
 411                         pr_err("  Error: Don't use --list with --add/--del.\n");
 412                         usage_with_options(probe_usage, options);
 413                 }
 414                 if (params.show_lines) {
 415                         pr_err("  Error: Don't use --list with --line.\n");
 416                         usage_with_options(probe_usage, options);
 417                 }
 418                 if (params.show_vars) {
 419                         pr_err(" Error: Don't use --list with --vars.\n");
 420                         usage_with_options(probe_usage, options);
 421                 }
 422                 if (params.show_funcs) {
 423                         pr_err("  Error: Don't use --list with --funcs.\n");
 424                         usage_with_options(probe_usage, options);
 425                 }
 426                 if (params.uprobes) {
 427                         pr_warning("  Error: Don't use --list with --exec.\n");
 428                         usage_with_options(probe_usage, options);
 429                 }
 430                 ret = show_perf_probe_events();
 431                 if (ret < 0)
 432                         pr_err_with_code("  Error: Failed to show event list.", ret);
 433                 return ret;
 434         }
 435         if (params.show_funcs) {
 436                 if (params.nevents != 0 || params.dellist) {
 437                         pr_err("  Error: Don't use --funcs with"
 438                                " --add/--del.\n");
 439                         usage_with_options(probe_usage, options);
 440                 }
 441                 if (params.show_lines) {
 442                         pr_err("  Error: Don't use --funcs with --line.\n");
 443                         usage_with_options(probe_usage, options);
 444                 }
 445                 if (params.show_vars) {
 446                         pr_err("  Error: Don't use --funcs with --vars.\n");
 447                         usage_with_options(probe_usage, options);
 448                 }
 449                 if (!params.filter)
 450                         params.filter = strfilter__new(DEFAULT_FUNC_FILTER,
 451                                                        NULL);
 452                 ret = show_available_funcs(params.target, params.filter,
 453                                         params.uprobes);
 454                 strfilter__delete(params.filter);
 455                 params.filter = NULL;
 456                 if (ret < 0)
 457                         pr_err_with_code("  Error: Failed to show functions.", ret);
 458                 return ret;
 459         }
 460
 461 #ifdef HAVE_DWARF_SUPPORT
 462         if (params.show_lines) {
 463                 if (params.mod_events) {
 464                         pr_err("  Error: Don't use --line with"
 465                                " --add/--del.\n");
 466                         usage_with_options(probe_usage, options);
 467                 }
 468                 if (params.show_vars) {
 469                         pr_err(" Error: Don't use --line with --vars.\n");
 470                         usage_with_options(probe_usage, options);
 471                 }
 472
 473                 ret = show_line_range(&params.line_range, params.target);
 474                 if (ret < 0)
 475                         pr_err_with_code("  Error: Failed to show lines.", ret);
 476                 return ret;
 477         }
 478         if (params.show_vars) {
 479                 if (params.mod_events) {
 480                         pr_err("  Error: Don't use --vars with"
 481                                " --add/--del.\n");
 482                         usage_with_options(probe_usage, options);
 483                 }
 484                 if (!params.filter)
 485                         params.filter = strfilter__new(DEFAULT_VAR_FILTER,
 486                                                        NULL);
 487
 488                 ret = show_available_vars(params.events, params.nevents,
 489                                           params.max_probe_points,
 490                                           params.target,
 491                                           params.filter,
 492                                           params.show_ext_vars);
 493                 strfilter__delete(params.filter);
 494                 params.filter = NULL;
 495                 if (ret < 0)
 496                         pr_err_with_code("  Error: Failed to show vars.", ret);
 497                 return ret;
 498         }
 499 #endif
 500
 501         if (params.dellist) {
 502                 ret = del_perf_probe_events(params.dellist);
 503                 if (ret < 0) {
 504                         pr_err_with_code("  Error: Failed to delete events.", ret);
 505                         return ret;
 506                 }
 507         }
 508
 509         if (params.nevents) {
 510                 ret = add_perf_probe_events(params.events, params.nevents,
 511                                             params.max_probe_points,
 512                                             params.target,
 513                                             params.force_add);
 514                 if (ret < 0) {
 515                         pr_err_with_code("  Error: Failed to add events.", ret);
 516                         return ret;
 517                 }
 518         }
 519         return 0;
 520 }
 521
 522 int cmd_probe(int argc, const char **argv, const char *prefix)
 523 {
 524         int ret;
 525
 526         ret = init_params();
 527         if (!ret) {
 528                 ret = __cmd_probe(argc, argv, prefix);
 529                 cleanup_params();
 530         }
 531
 532         return ret;
 533 }