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         bool target_used;
  60         int nevents;
  61         struct perf_probe_event events[MAX_PROBES];
  62         struct strlist *dellist;
  63         struct line_range line_range;
  64         char *target;
  65         int max_probe_points;
  66         struct strfilter *filter;
  67 } params;
  68
  69 /* Parse an event definition. Note that any error must die. */
  70 static int parse_probe_event(const char *str)
  71 {
  72         struct perf_probe_event *pev = &params.events[params.nevents];
  73         int ret;
  74
  75         pr_debug("probe-definition(%d): %s\n", params.nevents, str);
  76         if (++params.nevents == MAX_PROBES) {
  77                 pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
  78                 return -1;
  79         }
  80
  81         pev->uprobes = params.uprobes;
  82         if (params.target) {
  83                 pev->target = strdup(params.target);
  84                 if (!pev->target)
  85                         return -ENOMEM;
  86                 params.target_used = true;
  87         }
  88
  89         /* Parse a perf-probe command into event */
  90         ret = parse_perf_probe_command(str, pev);
  91         pr_debug("%d arguments\n", pev->nargs);
  92
  93         return ret;
  94 }
  95
  96 static int set_target(const char *ptr)
  97 {
  98         int found = 0;
  99         const char *buf;
 100
 101         /*
 102          * The first argument after options can be an absolute path
 103          * to an executable / library or kernel module.
 104          *
 105          * TODO: Support relative path, and $PATH, $LD_LIBRARY_PATH,
 106          * short module name.
 107          */
 108         if (!params.target && ptr && *ptr == '/') {
 109                 params.target = strdup(ptr);
 110                 if (!params.target)
 111                         return -ENOMEM;
 112                 params.target_used = false;
 113
 114                 found = 1;
 115                 buf = ptr + (strlen(ptr) - 3);
 116
 117                 if (strcmp(buf, ".ko"))
 118                         params.uprobes = true;
 119
 120         }
 121
 122         return found;
 123 }
 124
 125 static int parse_probe_event_argv(int argc, const char **argv)
 126 {
 127         int i, len, ret, found_target;
 128         char *buf;
 129
 130         found_target = set_target(argv[0]);
 131         if (found_target < 0)
 132                 return found_target;
 133
 134         if (found_target && argc == 1)
 135                 return 0;
 136
 137         /* Bind up rest arguments */
 138         len = 0;
 139         for (i = 0; i < argc; i++) {
 140                 if (i == 0 && found_target)
 141                         continue;
 142
 143                 len += strlen(argv[i]) + 1;
 144         }
 145         buf = zalloc(len + 1);
 146         if (buf == NULL)
 147                 return -ENOMEM;
 148         len = 0;
 149         for (i = 0; i < argc; i++) {
 150                 if (i == 0 && found_target)
 151                         continue;
 152
 153                 len += sprintf(&buf[len], "%s ", argv[i]);
 154         }
 155         params.mod_events = true;
 156         ret = parse_probe_event(buf);
 157         free(buf);
 158         return ret;
 159 }
 160
 161 static int opt_add_probe_event(const struct option *opt __maybe_unused,
 162                               const char *str, int unset __maybe_unused)
 163 {
 164         if (str) {
 165                 params.mod_events = true;
 166                 return parse_probe_event(str);
 167         } else
 168                 return 0;
 169 }
 170
 171 static int opt_del_probe_event(const struct option *opt __maybe_unused,
 172                                const char *str, int unset __maybe_unused)
 173 {
 174         if (str) {
 175                 params.mod_events = true;
 176                 if (!params.dellist)
 177                         params.dellist = strlist__new(true, NULL);
 178                 strlist__add(params.dellist, str);
 179         }
 180         return 0;
 181 }
 182
 183 static int opt_set_target(const struct option *opt, const char *str,
 184                         int unset __maybe_unused)
 185 {
 186         int ret = -ENOENT;
 187         char *tmp;
 188
 189         if  (str) {
 190                 if (!strcmp(opt->long_name, "exec"))
 191                         params.uprobes = true;
 192 #ifdef HAVE_DWARF_SUPPORT
 193                 else if (!strcmp(opt->long_name, "module"))
 194                         params.uprobes = false;
 195 #endif
 196                 else
 197                         return ret;
 198
 199                 /* Expand given path to absolute path, except for modulename */
 200                 if (params.uprobes || strchr(str, '/')) {
 201                         tmp = realpath(str, NULL);
 202                         if (!tmp) {
 203                                 pr_warning("Failed to get the absolute path of %s: %m\n", str);
 204                                 return ret;
 205                         }
 206                 } else {
 207                         tmp = strdup(str);
 208                         if (!tmp)
 209                                 return -ENOMEM;
 210                 }
 211                 free(params.target);
 212                 params.target = tmp;
 213                 params.target_used = false;
 214                 ret = 0;
 215         }
 216
 217         return ret;
 218 }
 219
 220 #ifdef HAVE_DWARF_SUPPORT
 221 static int opt_show_lines(const struct option *opt __maybe_unused,
 222                           const char *str, int unset __maybe_unused)
 223 {
 224         int ret = 0;
 225
 226         if (!str)
 227                 return 0;
 228
 229         if (params.show_lines) {
 230                 pr_warning("Warning: more than one --line options are"
 231                            " detected. Only the first one is valid.\n");
 232                 return 0;
 233         }
 234
 235         params.show_lines = true;
 236         ret = parse_line_range_desc(str, &params.line_range);
 237
 238         return ret;
 239 }
 240
 241 static int opt_show_vars(const struct option *opt __maybe_unused,
 242                          const char *str, int unset __maybe_unused)
 243 {
 244         struct perf_probe_event *pev = &params.events[params.nevents];
 245         int ret;
 246
 247         if (!str)
 248                 return 0;
 249
 250         ret = parse_probe_event(str);
 251         if (!ret && pev->nargs != 0) {
 252                 pr_err("  Error: '--vars' doesn't accept arguments.\n");
 253                 return -EINVAL;
 254         }
 255         params.show_vars = true;
 256
 257         return ret;
 258 }
 259 #endif
 260
 261 static int opt_set_filter(const struct option *opt __maybe_unused,
 262                           const char *str, int unset __maybe_unused)
 263 {
 264         const char *err;
 265
 266         if (str) {
 267                 pr_debug2("Set filter: %s\n", str);
 268                 if (params.filter)
 269                         strfilter__delete(params.filter);
 270                 params.filter = strfilter__new(str, &err);
 271                 if (!params.filter) {
 272                         pr_err("Filter parse error at %td.\n", err - str + 1);
 273                         pr_err("Source: \"%s\"\n", str);
 274                         pr_err("         %*c\n", (int)(err - str + 1), '^');
 275                         return -EINVAL;
 276                 }
 277         }
 278
 279         return 0;
 280 }
 281
 282 static int init_params(void)
 283 {
 284         return line_range__init(&params.line_range);
 285 }
 286
 287 static void cleanup_params(void)
 288 {
 289         int i;
 290
 291         for (i = 0; i < params.nevents; i++)
 292                 clear_perf_probe_event(params.events + i);
 293         if (params.dellist)
 294                 strlist__delete(params.dellist);
 295         line_range__clear(&params.line_range);
 296         free(params.target);
 297         if (params.filter)
 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
 313 __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 314 {
 315         const char * const probe_usage[] = {
 316                 "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
 317                 "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
 318                 "perf probe [<options>] --del '[GROUP:]EVENT' ...",
 319                 "perf probe --list",
 320 #ifdef HAVE_DWARF_SUPPORT
 321                 "perf probe [<options>] --line 'LINEDESC'",
 322                 "perf probe [<options>] --vars 'PROBEPOINT'",
 323 #endif
 324                 NULL
 325 };
 326         struct option options[] = {
 327         OPT_INCR('v', "verbose", &verbose,
 328                     "be more verbose (show parsed arguments, etc)"),
 329         OPT_BOOLEAN('q', "quiet", &params.quiet,
 330                     "be quiet (do not show any mesages)"),
 331         OPT_BOOLEAN('l', "list", &params.list_events,
 332                     "list up current probe events"),
 333         OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
 334                 opt_del_probe_event),
 335         OPT_CALLBACK('a', "add", NULL,
 336 #ifdef HAVE_DWARF_SUPPORT
 337                 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
 338                 " [[NAME=]ARG ...]",
 339 #else
 340                 "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
 341 #endif
 342                 "probe point definition, where\n"
 343                 "\t\tGROUP:\tGroup name (optional)\n"
 344                 "\t\tEVENT:\tEvent name\n"
 345                 "\t\tFUNC:\tFunction name\n"
 346                 "\t\tOFF:\tOffset from function entry (in byte)\n"
 347                 "\t\t%return:\tPut the probe at function return\n"
 348 #ifdef HAVE_DWARF_SUPPORT
 349                 "\t\tSRC:\tSource code path\n"
 350                 "\t\tRL:\tRelative line number from function entry.\n"
 351                 "\t\tAL:\tAbsolute line number in file.\n"
 352                 "\t\tPT:\tLazy expression of line code.\n"
 353                 "\t\tARG:\tProbe argument (local variable name or\n"
 354                 "\t\t\tkprobe-tracer argument format.)\n",
 355 #else
 356                 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
 357 #endif
 358                 opt_add_probe_event),
 359         OPT_BOOLEAN('f', "force", &params.force_add, "forcibly add events"
 360                     " with existing name"),
 361 #ifdef HAVE_DWARF_SUPPORT
 362         OPT_CALLBACK('L', "line", NULL,
 363                      "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
 364                      "Show source code lines.", opt_show_lines),
 365         OPT_CALLBACK('V', "vars", NULL,
 366                      "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
 367                      "Show accessible variables on PROBEDEF", opt_show_vars),
 368         OPT_BOOLEAN('\0', "externs", &params.show_ext_vars,
 369                     "Show external variables too (with --vars only)"),
 370         OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
 371                    "file", "vmlinux pathname"),
 372         OPT_STRING('s', "source", &symbol_conf.source_prefix,
 373                    "directory", "path to kernel source"),
 374         OPT_CALLBACK('m', "module", NULL, "modname|path",
 375                 "target module name (for online) or path (for offline)",
 376                 opt_set_target),
 377 #endif
 378         OPT__DRY_RUN(&probe_event_dry_run),
 379         OPT_INTEGER('\0', "max-probes", &params.max_probe_points,
 380                  "Set how many probe points can be found for a probe."),
 381         OPT_BOOLEAN('F', "funcs", &params.show_funcs,
 382                     "Show potential probe-able functions."),
 383         OPT_CALLBACK('\0', "filter", NULL,
 384                      "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
 385                      "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
 386                      "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
 387                      opt_set_filter),
 388         OPT_CALLBACK('x', "exec", NULL, "executable|path",
 389                         "target executable name or path", opt_set_target),
 390         OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
 391                     "Enable symbol demangling"),
 392         OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
 393                     "Enable kernel symbol demangling"),
 394         OPT_END()
 395         };
 396         int ret;
 397
 398         set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);
 399         set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);
 400         set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);
 401 #ifdef HAVE_DWARF_SUPPORT
 402         set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);
 403         set_option_flag(options, 'V', "vars", PARSE_OPT_EXCLUSIVE);
 404 #endif
 405
 406         argc = parse_options(argc, argv, options, probe_usage,
 407                              PARSE_OPT_STOP_AT_NON_OPTION);
 408         if (argc > 0) {
 409                 if (strcmp(argv[0], "-") == 0) {
 410                         pr_warning("  Error: '-' is not supported.\n");
 411                         usage_with_options(probe_usage, options);
 412                 }
 413                 ret = parse_probe_event_argv(argc, argv);
 414                 if (ret < 0) {
 415                         pr_err_with_code("  Error: Command Parse Error.", ret);
 416                         return ret;
 417                 }
 418         }
 419
 420         if (params.quiet) {
 421                 if (verbose != 0) {
 422                         pr_err("  Error: -v and -q are exclusive.\n");
 423                         return -EINVAL;
 424                 }
 425                 verbose = -1;
 426         }
 427
 428         if (params.max_probe_points == 0)
 429                 params.max_probe_points = MAX_PROBES;
 430
 431         if ((!params.nevents && !params.dellist && !params.list_events &&
 432              !params.show_lines && !params.show_funcs))
 433                 usage_with_options(probe_usage, options);
 434
 435         /*
 436          * Only consider the user's kernel image path if given.
 437          */
 438         symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
 439
 440         if (params.list_events) {
 441                 if (params.uprobes) {
 442                         pr_warning("  Error: Don't use --list with --exec.\n");
 443                         usage_with_options(probe_usage, options);
 444                 }
 445                 ret = show_perf_probe_events();
 446                 if (ret < 0)
 447                         pr_err_with_code("  Error: Failed to show event list.", ret);
 448                 return ret;
 449         }
 450         if (params.show_funcs) {
 451                 if (!params.filter)
 452                         params.filter = strfilter__new(DEFAULT_FUNC_FILTER,
 453                                                        NULL);
 454                 ret = show_available_funcs(params.target, params.filter,
 455                                         params.uprobes);
 456                 strfilter__delete(params.filter);
 457                 params.filter = NULL;
 458                 if (ret < 0)
 459                         pr_err_with_code("  Error: Failed to show functions.", ret);
 460                 return ret;
 461         }
 462
 463 #ifdef HAVE_DWARF_SUPPORT
 464         if (params.show_lines) {
 465                 ret = show_line_range(&params.line_range, params.target,
 466                                       params.uprobes);
 467                 if (ret < 0)
 468                         pr_err_with_code("  Error: Failed to show lines.", ret);
 469                 return ret;
 470         }
 471         if (params.show_vars) {
 472                 if (!params.filter)
 473                         params.filter = strfilter__new(DEFAULT_VAR_FILTER,
 474                                                        NULL);
 475
 476                 ret = show_available_vars(params.events, params.nevents,
 477                                           params.max_probe_points,
 478                                           params.target,
 479                                           params.filter,
 480                                           params.show_ext_vars);
 481                 strfilter__delete(params.filter);
 482                 params.filter = NULL;
 483                 if (ret < 0)
 484                         pr_err_with_code("  Error: Failed to show vars.", ret);
 485                 return ret;
 486         }
 487 #endif
 488
 489         if (params.dellist) {
 490                 ret = del_perf_probe_events(params.dellist);
 491                 if (ret < 0) {
 492                         pr_err_with_code("  Error: Failed to delete events.", ret);
 493                         return ret;
 494                 }
 495         }
 496
 497         if (params.nevents) {
 498                 /* Ensure the last given target is used */
 499                 if (params.target && !params.target_used) {
 500                         pr_warning("  Error: -x/-m must follow the probe definitions.\n");
 501                         usage_with_options(probe_usage, options);
 502                 }
 503
 504                 ret = add_perf_probe_events(params.events, params.nevents,
 505                                             params.max_probe_points,
 506                                             params.force_add);
 507                 if (ret < 0) {
 508                         pr_err_with_code("  Error: Failed to add events.", ret);
 509                         return ret;
 510                 }
 511         }
 512         return 0;
 513 }
 514
 515 int cmd_probe(int argc, const char **argv, const char *prefix)
 516 {
 517         int ret;
 518
 519         ret = init_params();
 520         if (!ret) {
 521                 ret = __cmd_probe(argc, argv, prefix);
 522                 cleanup_params();
 523         }
 524
 525         return ret;
 526 }