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 #define _GNU_SOURCE
  24 #include <sys/utsname.h>
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27 #include <fcntl.h>
  28 #include <errno.h>
  29 #include <stdio.h>
  30 #include <unistd.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33
  34 #undef _GNU_SOURCE
  35 #include "perf.h"
  36 #include "builtin.h"
  37 #include "util/util.h"
  38 #include "util/strlist.h"
  39 #include "util/strfilter.h"
  40 #include "util/symbol.h"
  41 #include "util/debug.h"
  42 #include "util/debugfs.h"
  43 #include "util/parse-options.h"
  44 #include "util/probe-finder.h"
  45 #include "util/probe-event.h"
  46
  47 #define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"
  48 #define DEFAULT_FUNC_FILTER "!_*"
  49 #define MAX_PATH_LEN 256
  50
  51 /* Session management structure */
  52 static struct {
  53         bool list_events;
  54         bool force_add;
  55         bool show_lines;
  56         bool show_vars;
  57         bool show_ext_vars;
  58         bool show_funcs;
  59         bool mod_events;
  60         int nevents;
  61         struct perf_probe_event events[MAX_PROBES];
  62         struct strlist *dellist;
  63         struct line_range line_range;
  64         const char *target_module;
  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         /* 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 parse_probe_event_argv(int argc, const char **argv)
  89 {
  90         int i, len, ret;
  91         char *buf;
  92
  93         /* Bind up rest arguments */
  94         len = 0;
  95         for (i = 0; i < argc; i++)
  96                 len += strlen(argv[i]) + 1;
  97         buf = zalloc(len + 1);
  98         if (buf == NULL)
  99                 return -ENOMEM;
 100         len = 0;
 101         for (i = 0; i < argc; i++)
 102                 len += sprintf(&buf[len], "%s ", argv[i]);
 103         params.mod_events = true;
 104         ret = parse_probe_event(buf);
 105         free(buf);
 106         return ret;
 107 }
 108
 109 static int opt_add_probe_event(const struct option *opt __used,
 110                               const char *str, int unset __used)
 111 {
 112         if (str) {
 113                 params.mod_events = true;
 114                 return parse_probe_event(str);
 115         } else
 116                 return 0;
 117 }
 118
 119 static int opt_del_probe_event(const struct option *opt __used,
 120                                const char *str, int unset __used)
 121 {
 122         if (str) {
 123                 params.mod_events = true;
 124                 if (!params.dellist)
 125                         params.dellist = strlist__new(true, NULL);
 126                 strlist__add(params.dellist, str);
 127         }
 128         return 0;
 129 }
 130
 131 #ifdef DWARF_SUPPORT
 132 static int opt_show_lines(const struct option *opt __used,
 133                           const char *str, int unset __used)
 134 {
 135         int ret = 0;
 136
 137         if (!str)
 138                 return 0;
 139
 140         if (params.show_lines) {
 141                 pr_warning("Warning: more than one --line options are"
 142                            " detected. Only the first one is valid.\n");
 143                 return 0;
 144         }
 145
 146         params.show_lines = true;
 147         ret = parse_line_range_desc(str, &params.line_range);
 148         INIT_LIST_HEAD(&params.line_range.line_list);
 149
 150         return ret;
 151 }
 152
 153 static int opt_show_vars(const struct option *opt __used,
 154                          const char *str, int unset __used)
 155 {
 156         struct perf_probe_event *pev = &params.events[params.nevents];
 157         int ret;
 158
 159         if (!str)
 160                 return 0;
 161
 162         ret = parse_probe_event(str);
 163         if (!ret && pev->nargs != 0) {
 164                 pr_err("  Error: '--vars' doesn't accept arguments.\n");
 165                 return -EINVAL;
 166         }
 167         params.show_vars = true;
 168
 169         return ret;
 170 }
 171 #endif
 172
 173 static int opt_set_filter(const struct option *opt __used,
 174                           const char *str, int unset __used)
 175 {
 176         const char *err;
 177
 178         if (str) {
 179                 pr_debug2("Set filter: %s\n", str);
 180                 if (params.filter)
 181                         strfilter__delete(params.filter);
 182                 params.filter = strfilter__new(str, &err);
 183                 if (!params.filter) {
 184                         pr_err("Filter parse error at %td.\n", err - str + 1);
 185                         pr_err("Source: \"%s\"\n", str);
 186                         pr_err("         %*c\n", (int)(err - str + 1), '^');
 187                         return -EINVAL;
 188                 }
 189         }
 190
 191         return 0;
 192 }
 193
 194 static const char * const probe_usage[] = {
 195         "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
 196         "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
 197         "perf probe [<options>] --del '[GROUP:]EVENT' ...",
 198         "perf probe --list",
 199 #ifdef DWARF_SUPPORT
 200         "perf probe [<options>] --line 'LINEDESC'",
 201         "perf probe [<options>] --vars 'PROBEPOINT'",
 202 #endif
 203         NULL
 204 };
 205
 206 static const struct option options[] = {
 207         OPT_INCR('v', "verbose", &verbose,
 208                     "be more verbose (show parsed arguments, etc)"),
 209         OPT_BOOLEAN('l', "list", &params.list_events,
 210                     "list up current probe events"),
 211         OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
 212                 opt_del_probe_event),
 213         OPT_CALLBACK('a', "add", NULL,
 214 #ifdef DWARF_SUPPORT
 215                 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
 216                 " [[NAME=]ARG ...]",
 217 #else
 218                 "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
 219 #endif
 220                 "probe point definition, where\n"
 221                 "\t\tGROUP:\tGroup name (optional)\n"
 222                 "\t\tEVENT:\tEvent name\n"
 223                 "\t\tFUNC:\tFunction name\n"
 224                 "\t\tOFF:\tOffset from function entry (in byte)\n"
 225                 "\t\t%return:\tPut the probe at function return\n"
 226 #ifdef DWARF_SUPPORT
 227                 "\t\tSRC:\tSource code path\n"
 228                 "\t\tRL:\tRelative line number from function entry.\n"
 229                 "\t\tAL:\tAbsolute line number in file.\n"
 230                 "\t\tPT:\tLazy expression of line code.\n"
 231                 "\t\tARG:\tProbe argument (local variable name or\n"
 232                 "\t\t\tkprobe-tracer argument format.)\n",
 233 #else
 234                 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
 235 #endif
 236                 opt_add_probe_event),
 237         OPT_BOOLEAN('f', "force", &params.force_add, "forcibly add events"
 238                     " with existing name"),
 239 #ifdef DWARF_SUPPORT
 240         OPT_CALLBACK('L', "line", NULL,
 241                      "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
 242                      "Show source code lines.", opt_show_lines),
 243         OPT_CALLBACK('V', "vars", NULL,
 244                      "FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
 245                      "Show accessible variables on PROBEDEF", opt_show_vars),
 246         OPT_BOOLEAN('\0', "externs", &params.show_ext_vars,
 247                     "Show external variables too (with --vars only)"),
 248         OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
 249                    "file", "vmlinux pathname"),
 250         OPT_STRING('s', "source", &symbol_conf.source_prefix,
 251                    "directory", "path to kernel source"),
 252         OPT_STRING('m', "module", &params.target_module,
 253                    "modname|path",
 254                    "target module name (for online) or path (for offline)"),
 255 #endif
 256         OPT__DRY_RUN(&probe_event_dry_run),
 257         OPT_INTEGER('\0', "max-probes", &params.max_probe_points,
 258                  "Set how many probe points can be found for a probe."),
 259         OPT_BOOLEAN('F', "funcs", &params.show_funcs,
 260                     "Show potential probe-able functions."),
 261         OPT_CALLBACK('\0', "filter", NULL,
 262                      "[!]FILTER", "Set a filter (with --vars/funcs only)\n"
 263                      "\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
 264                      "\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
 265                      opt_set_filter),
 266         OPT_END()
 267 };
 268
 269 int cmd_probe(int argc, const char **argv, const char *prefix __used)
 270 {
 271         int ret;
 272
 273         argc = parse_options(argc, argv, options, probe_usage,
 274                              PARSE_OPT_STOP_AT_NON_OPTION);
 275         if (argc > 0) {
 276                 if (strcmp(argv[0], "-") == 0) {
 277                         pr_warning("  Error: '-' is not supported.\n");
 278                         usage_with_options(probe_usage, options);
 279                 }
 280                 ret = parse_probe_event_argv(argc, argv);
 281                 if (ret < 0) {
 282                         pr_err("  Error: Parse Error.  (%d)\n", ret);
 283                         return ret;
 284                 }
 285         }
 286
 287         if (params.max_probe_points == 0)
 288                 params.max_probe_points = MAX_PROBES;
 289
 290         if ((!params.nevents && !params.dellist && !params.list_events &&
 291              !params.show_lines && !params.show_funcs))
 292                 usage_with_options(probe_usage, options);
 293
 294         /*
 295          * Only consider the user's kernel image path if given.
 296          */
 297         symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
 298
 299         if (params.list_events) {
 300                 if (params.mod_events) {
 301                         pr_err("  Error: Don't use --list with --add/--del.\n");
 302                         usage_with_options(probe_usage, options);
 303                 }
 304                 if (params.show_lines) {
 305                         pr_err("  Error: Don't use --list with --line.\n");
 306                         usage_with_options(probe_usage, options);
 307                 }
 308                 if (params.show_vars) {
 309                         pr_err(" Error: Don't use --list with --vars.\n");
 310                         usage_with_options(probe_usage, options);
 311                 }
 312                 if (params.show_funcs) {
 313                         pr_err("  Error: Don't use --list with --funcs.\n");
 314                         usage_with_options(probe_usage, options);
 315                 }
 316                 ret = show_perf_probe_events();
 317                 if (ret < 0)
 318                         pr_err("  Error: Failed to show event list. (%d)\n",
 319                                ret);
 320                 return ret;
 321         }
 322         if (params.show_funcs) {
 323                 if (params.nevents != 0 || params.dellist) {
 324                         pr_err("  Error: Don't use --funcs with"
 325                                " --add/--del.\n");
 326                         usage_with_options(probe_usage, options);
 327                 }
 328                 if (params.show_lines) {
 329                         pr_err("  Error: Don't use --funcs with --line.\n");
 330                         usage_with_options(probe_usage, options);
 331                 }
 332                 if (params.show_vars) {
 333                         pr_err("  Error: Don't use --funcs with --vars.\n");
 334                         usage_with_options(probe_usage, options);
 335                 }
 336                 if (!params.filter)
 337                         params.filter = strfilter__new(DEFAULT_FUNC_FILTER,
 338                                                        NULL);
 339                 ret = show_available_funcs(params.target_module,
 340                                            params.filter);
 341                 strfilter__delete(params.filter);
 342                 if (ret < 0)
 343                         pr_err("  Error: Failed to show functions."
 344                                " (%d)\n", ret);
 345                 return ret;
 346         }
 347
 348 #ifdef DWARF_SUPPORT
 349         if (params.show_lines) {
 350                 if (params.mod_events) {
 351                         pr_err("  Error: Don't use --line with"
 352                                " --add/--del.\n");
 353                         usage_with_options(probe_usage, options);
 354                 }
 355                 if (params.show_vars) {
 356                         pr_err(" Error: Don't use --line with --vars.\n");
 357                         usage_with_options(probe_usage, options);
 358                 }
 359
 360                 ret = show_line_range(&params.line_range, params.target_module);
 361                 if (ret < 0)
 362                         pr_err("  Error: Failed to show lines. (%d)\n", ret);
 363                 return ret;
 364         }
 365         if (params.show_vars) {
 366                 if (params.mod_events) {
 367                         pr_err("  Error: Don't use --vars with"
 368                                " --add/--del.\n");
 369                         usage_with_options(probe_usage, options);
 370                 }
 371                 if (!params.filter)
 372                         params.filter = strfilter__new(DEFAULT_VAR_FILTER,
 373                                                        NULL);
 374
 375                 ret = show_available_vars(params.events, params.nevents,
 376                                           params.max_probe_points,
 377                                           params.target_module,
 378                                           params.filter,
 379                                           params.show_ext_vars);
 380                 strfilter__delete(params.filter);
 381                 if (ret < 0)
 382                         pr_err("  Error: Failed to show vars. (%d)\n", ret);
 383                 return ret;
 384         }
 385 #endif
 386
 387         if (params.dellist) {
 388                 ret = del_perf_probe_events(params.dellist);
 389                 strlist__delete(params.dellist);
 390                 if (ret < 0) {
 391                         pr_err("  Error: Failed to delete events. (%d)\n", ret);
 392                         return ret;
 393                 }
 394         }
 395
 396         if (params.nevents) {
 397                 ret = add_perf_probe_events(params.events, params.nevents,
 398                                             params.max_probe_points,
 399                                             params.target_module,
 400                                             params.force_add);
 401                 if (ret < 0) {
 402                         pr_err("  Error: Failed to add events. (%d)\n", ret);
 403                         return ret;
 404                 }
 405         }
 406         return 0;
 407 }