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