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         bool quiet;
  59         int nevents;
  60         struct perf_probe_event events[MAX_PROBES];
  61         struct strlist *dellist;
  62         struct line_range line_range;
  63         char *target;
  64         int max_probe_points;
  65         struct strfilter *filter;
  66 } params;
  67
  68 /* Parse an event definition. Note that any error must die. */
  69 static int parse_probe_event(const char *str)
  70 {
  71         struct perf_probe_event *pev = &params.events[params.nevents];
  72         int ret;
  73
  74         pr_debug("probe-definition(%d): %s\n", params.nevents, str);
  75         if (++params.nevents == MAX_PROBES) {
  76                 pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
  77                 return -1;
  78         }
  79
  80         pev->uprobes = params.uprobes;
  81
  82         /* Parse a perf-probe command into event */
  83         ret = parse_perf_probe_command(str, pev);
  84         pr_debug("%d arguments\n", pev->nargs);
  85
  86         return ret;
  87 }
  88
  89 static int set_target(const char *ptr)
  90 {
  91         int found = 0;
  92         const char *buf;
  93
  94         /*
  95          * The first argument after options can be an absolute path
  96          * to an executable / library or kernel module.
  97          *
  98          * TODO: Support relative path, and $PATH, $LD_LIBRARY_PATH,
  99          * short module name.
 100          */
 101         if (!params.target && ptr && *ptr == '/') {
 102                 params.target = strdup(ptr);
 103                 if (!params.target)
 104                         return -ENOMEM;
 105
 106                 found = 1;
 107                 buf = ptr + (strlen(ptr) - 3);
 108
 109                 if (strcmp(buf, ".ko"))
 110                         params.uprobes = true;
 111
 112         }
 113
 114         return found;
 115 }
 116
 117 static int parse_probe_event_argv(int argc, const char **argv)
 118 {
 119         int i, len, ret, found_target;
 120         char *buf;
 121
 122         found_target = set_target(argv[0]);
 123         if (found_target < 0)
 124                 return found_target;
 125
 126         if (found_target && argc == 1)
 127                 return 0;
 128
 129         /* Bind up rest arguments */
 130         len = 0;
 131         for (i = 0; i < argc; i++) {
 132                 if (i == 0 && found_target)
 133                         continue;
 134
 135                 len += strlen(argv[i]) + 1;
 136         }
 137         buf = zalloc(len + 1);
 138         if (buf == NULL)
 139                 return -ENOMEM;
 140         len = 0;
 141         for (i = 0; i < argc; i++) {
 142                 if (i == 0 && found_target)
 143                         continue;
 144
 145                 len += sprintf(&buf[len], "%s ", argv[i]);
 146         }
 147         params.mod_events = true;
 148         ret = parse_probe_event(buf);
 149         free(buf);
 150         return ret;
 151 }
 152
 153 static int opt_add_probe_event(const struct option *opt __maybe_unused,
 154                               const char *str, int unset __maybe_unused)
 155 {
 156         if (str) {
 157                 params.mod_events = true;
 158                 return parse_probe_event(str);
 159         } else
 160                 return 0;
 161 }
 162
 163 static int opt_del_probe_event(const struct option *opt __maybe_unused,
 164                                const char *str, int unset __maybe_unused)
 165 {
 166         if (str) {
 167                 params.mod_events = true;
 168                 if (!params.dellist)
 169                         params.dellist = strlist__new(true, NULL);
 170                 strlist__add(params.dellist, str);
 171         }
 172         return 0;
 173 }
 174
 175 static int opt_set_target(const struct option *opt, const char *str,
 176                         int unset __maybe_unused)
 177 {
 178         int ret = -ENOENT;
 179         char *tmp;
 180
 181         if  (str && !params.target) {
 182                 if (!strcmp(opt->long_name, "exec"))
 183                         params.uprobes = true;
 184 #ifdef HAVE_DWARF_SUPPORT
 185                 else if (!strcmp(opt->long_name, "module"))
 186                         params.uprobes = false;
 187 #endif
 188                 else
 189                         return ret;
 190
 191                 /* Expand given path to absolute path, except for modulename */
 192                 if (params.uprobes || strchr(str, '/')) {
 193                         tmp = realpath(str, NULL);
 194                         if (!tmp) {
 195                                 pr_warning("Failed to get the absolute path of %s: %m\n", str);
 196                                 return ret;
 197                         }
 198                 } else {
 199                         tmp = strdup(str);
 200                         if (!tmp)
 201                                 return -ENOMEM;
 202                 }
 203                 params.target = tmp;
 204                 ret = 0;
 205         }
 206
 207         return ret;
 208 }
 209
 210 #ifdef HAVE_DWARF_SUPPORT
 211 static int opt_show_lines(const struct option *opt __maybe_unused,
 212                           const char *str, int unset __maybe_unused)
 213 {
 214         int ret = 0;
 215
 216         if (!str)
 217                 return 0;
 218
 219         if (params.show_lines) {
 220                 pr_warning("Warning: more than one --line options are"
 221                            " detected. Only the first one is valid.\n");
 222                 return 0;
 223         }
 224
 225         params.show_lines = true;
 226         ret = parse_line_range_desc(str, &params.line_range);
 227
 228         return ret;
 229 }
 230
 231 static int opt_show_vars(const struct option *opt __maybe_unused,
 232                          const char *str, int unset __maybe_unused)
 233 {
 234         struct perf_probe_event *pev = &params.events[params.nevents];
 235         int ret;
 236
 237         if (!str)
 238                 return 0;
 239
 240         ret = parse_probe_event(str);
 241         if (!ret && pev->nargs != 0) {
 242                 pr_err("  Error: '--vars' doesn't accept arguments.\n");
 243                 return -EINVAL;
 244         }
 245         params.show_vars = true;
 246
 247         return ret;
 248 }
 249 #endif
 250
 251 static int opt_set_filter(const struct option *opt __maybe_unused,
 252                           const char *str, int unset __maybe_unused)
 253 {
 254         const char *err;
 255
 256         if (str) {
 257                 pr_debug2("Set filter: %s\n", str);
 258                 if (params.filter)
 259                         strfilter__delete(params.filter);
 260                 params.filter = strfilter__new(str, &err);
 261                 if (!params.filter) {
 262                         pr_err("Filter parse error at %td.\n", err - str + 1);
 263                         pr_err("Source: \"%s\"\n", str);
 264                         pr_err("         %*c\n", (int)(err - str + 1), '^');
 265                         return -EINVAL;
 266                 }
 267         }
 268
 269         return 0;
 270 }
 271
 272 static int init_params(void)
 273 {
 274         return line_range__init(&params.line_range);
 275 }
 276
 277 static void cleanup_params(void)
 278 {
 279         int i;
 280
 281         for (i = 0; i < params.nevents; i++)
 282                 clear_perf_probe_event(params.events + i);
 283         if (params.dellist)
 284                 strlist__delete(params.dellist);
 285         line_range__clear(&params.line_range);
 286         free(params.target);
 287         if (params.filter)
 288                 strfilter__delete(params.filter);
 289         memset(&params, 0, sizeof(params));
 290 }
 291
 292 static void pr_err_with_code(const char *msg, int err)
 293 {
 294         char sbuf[STRERR_BUFSIZE];
 295
 296         pr_err("%s", msg);
 297         pr_debug(" Reason: %s (Code: %d)",
 298                  strerror_r(-err, sbuf, sizeof(sbuf)), err);
 299         pr_err("\n");
 300 }
 301
 302 static int
 303 __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 304 {
 305         const char * const probe_usage[] = {
 306                 "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
 307                 "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
 308                 "perf probe [<options>] --del '[GROUP:]EVENT' ...",
 309                 "perf probe --list",
 310 #ifdef HAVE_DWARF_SUPPORT
 311                 "perf probe [<options>] --line 'LINEDESC'",
 312                 "perf probe [<options>] --vars 'PROBEPOINT'",
 313 #endif
 314                 NULL
 315 };
 316         struct option options[] = {
 317         OPT_INCR('v', "verbose", &verbose,
 318                     "be more verbose (show parsed arguments, etc)"),
 319         OPT_BOOLEAN('q', "quiet", &params.quiet,
 320                     "be quiet (do not show any mesages)"),
 321         OPT_BOOLEAN('l', "list", &params.list_events,
 322                     "list up current probe events"),
 323         OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
 324                 opt_del_probe_event),
 325         OPT_CALLBACK('a', "add", NULL,
 326 #ifdef HAVE_DWARF_SUPPORT
 327                 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
 328                 " [[NAME=]ARG ...]",
 329 #else
 330                 "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
 331 #endif
 332                 "probe point definition, where\n"
 333                 "\t\tGROUP:\tGroup name (optional)\n"
 334                 "\t\tEVENT:\tEvent name\n"
 335                 "\t\tFUNC:\tFunction name\n"
 336                 "\t\tOFF:\tOffset from function entry (in byte)\n"
 337                 "\t\t%return:\tPut the probe at function return\n"
 338 #ifdef HAVE_DWARF_SUPPORT
 339                 "\t\tSRC:\tSource code path\n"
 340                 "\t\tRL:\tRelative line number from function entry.\n"
 341                 "\t\tAL:\tAbsolute line number in file.\n"
 342                 "\t\tPT:\tLazy expression of line code.\n"
 343                 "\t\tARG:\tProbe argument (local variable name or\n"
 344                 "\t\t\tkprobe-tracer argument format.)\n",
 345 #else
 346                 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
 347 #endif
 348                 opt_add_probe_event),
 349         OPT_BOOLEAN('f', "force", &params.force_add, "forcibly add events"
 350                     " with existing name"),
 351 #ifdef HAVE_DWARF_SUPPORT
 352         OPT_CALLBACK('L', "line", NULL,
 353                      "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
 354                      "Show source code lines.", opt_show_lines),
 355         OPT_CALLBACK('V', "vars", NULL,
 356                      "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
 357                      "Show accessible variables on PROBEDEF", opt_show_vars),
 358         OPT_BOOLEAN('\0', "externs", &params.show_ext_vars,
 359                     "Show external variables too (with --vars only)"),
 360         OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
 361                    "file", "vmlinux pathname"),
 362         OPT_STRING('s', "source", &symbol_conf.source_prefix,
 363                    "directory", "path to kernel source"),
 364         OPT_CALLBACK('m', "module", NULL, "modname|path",
 365                 "target module name (for online) or path (for offline)",
 366                 opt_set_target),
 367 #endif
 368         OPT__DRY_RUN(&probe_event_dry_run),
 369         OPT_INTEGER('\0', "max-probes", &params.max_probe_points,
 370                  "Set how many probe points can be found for a probe."),
 371         OPT_BOOLEAN('F', "funcs", &params.show_funcs,
 372                     "Show potential probe-able functions."),
 373         OPT_CALLBACK('\0', "filter", NULL,
 374                      "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
 375                      "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
 376                      "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
 377                      opt_set_filter),
 378         OPT_CALLBACK('x', "exec", NULL, "executable|path",
 379                         "target executable name or path", opt_set_target),
 380         OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
 381                     "Enable symbol demangling"),
 382         OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
 383                     "Enable kernel symbol demangling"),
 384         OPT_END()
 385         };
 386         int ret;
 387
 388         set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);
 389         set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);
 390         set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);
 391 #ifdef HAVE_DWARF_SUPPORT
 392         set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);
 393         set_option_flag(options, 'V', "vars", PARSE_OPT_EXCLUSIVE);
 394 #endif
 395
 396         argc = parse_options(argc, argv, options, probe_usage,
 397                              PARSE_OPT_STOP_AT_NON_OPTION);
 398         if (argc > 0) {
 399                 if (strcmp(argv[0], "-") == 0) {
 400                         pr_warning("  Error: '-' is not supported.\n");
 401                         usage_with_options(probe_usage, options);
 402                 }
 403                 ret = parse_probe_event_argv(argc, argv);
 404                 if (ret < 0) {
 405                         pr_err_with_code("  Error: Command Parse Error.", ret);
 406                         return ret;
 407                 }
 408         }
 409
 410         if (params.quiet) {
 411                 if (verbose != 0) {
 412                         pr_err("  Error: -v and -q are exclusive.\n");
 413                         return -EINVAL;
 414                 }
 415                 verbose = -1;
 416         }
 417
 418         if (params.max_probe_points == 0)
 419                 params.max_probe_points = MAX_PROBES;
 420
 421         if ((!params.nevents && !params.dellist && !params.list_events &&
 422              !params.show_lines && !params.show_funcs))
 423                 usage_with_options(probe_usage, options);
 424
 425         /*
 426          * Only consider the user's kernel image path if given.
 427          */
 428         symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
 429
 430         if (params.list_events) {
 431                 if (params.uprobes) {
 432                         pr_warning("  Error: Don't use --list with --exec.\n");
 433                         usage_with_options(probe_usage, options);
 434                 }
 435                 ret = show_perf_probe_events();
 436                 if (ret < 0)
 437                         pr_err_with_code("  Error: Failed to show event list.", ret);
 438                 return ret;
 439         }
 440         if (params.show_funcs) {
 441                 if (!params.filter)
 442                         params.filter = strfilter__new(DEFAULT_FUNC_FILTER,
 443                                                        NULL);
 444                 ret = show_available_funcs(params.target, params.filter,
 445                                         params.uprobes);
 446                 strfilter__delete(params.filter);
 447                 params.filter = NULL;
 448                 if (ret < 0)
 449                         pr_err_with_code("  Error: Failed to show functions.", ret);
 450                 return ret;
 451         }
 452
 453 #ifdef HAVE_DWARF_SUPPORT
 454         if (params.show_lines) {
 455                 ret = show_line_range(&params.line_range, params.target,
 456                                       params.uprobes);
 457                 if (ret < 0)
 458                         pr_err_with_code("  Error: Failed to show lines.", ret);
 459                 return ret;
 460         }
 461         if (params.show_vars) {
 462                 if (!params.filter)
 463                         params.filter = strfilter__new(DEFAULT_VAR_FILTER,
 464                                                        NULL);
 465
 466                 ret = show_available_vars(params.events, params.nevents,
 467                                           params.max_probe_points,
 468                                           params.target,
 469                                           params.filter,
 470                                           params.show_ext_vars);
 471                 strfilter__delete(params.filter);
 472                 params.filter = NULL;
 473                 if (ret < 0)
 474                         pr_err_with_code("  Error: Failed to show vars.", ret);
 475                 return ret;
 476         }
 477 #endif
 478
 479         if (params.dellist) {
 480                 ret = del_perf_probe_events(params.dellist);
 481                 if (ret < 0) {
 482                         pr_err_with_code("  Error: Failed to delete events.", ret);
 483                         return ret;
 484                 }
 485         }
 486
 487         if (params.nevents) {
 488                 ret = add_perf_probe_events(params.events, params.nevents,
 489                                             params.max_probe_points,
 490                                             params.target,
 491                                             params.force_add);
 492                 if (ret < 0) {
 493                         pr_err_with_code("  Error: Failed to add events.", ret);
 494                         return ret;
 495                 }
 496         }
 497         return 0;
 498 }
 499
 500 int cmd_probe(int argc, const char **argv, const char *prefix)
 501 {
 502         int ret;
 503
 504         ret = init_params();
 505         if (!ret) {
 506                 ret = __cmd_probe(argc, argv, prefix);
 507                 cleanup_params();
 508         }
 509
 510         return ret;
 511 }