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/symbol.h"
  40 #include "util/debug.h"
  41 #include "util/debugfs.h"
  42 #include "util/parse-options.h"
  43 #include "util/probe-finder.h"
  44 #include "util/probe-event.h"
  45
  46 #define MAX_PATH_LEN 256
  47
  48 /* Session management structure */
  49 static struct {
  50         bool list_events;
  51         bool force_add;
  52         bool show_lines;
  53         int nevents;
  54         struct perf_probe_event events[MAX_PROBES];
  55         struct strlist *dellist;
  56         struct line_range line_range;
  57         int max_probe_points;
  58 } params;
  59
  60
  61 /* Parse an event definition. Note that any error must die. */
  62 static int parse_probe_event(const char *str)
  63 {
  64         struct perf_probe_event *pev = &params.events[params.nevents];
  65         int ret;
  66
  67         pr_debug("probe-definition(%d): %s\n", params.nevents, str);
  68         if (++params.nevents == MAX_PROBES) {
  69                 pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
  70                 return -1;
  71         }
  72
  73         /* Parse a perf-probe command into event */
  74         ret = parse_perf_probe_command(str, pev);
  75         pr_debug("%d arguments\n", pev->nargs);
  76
  77         return ret;
  78 }
  79
  80 static int parse_probe_event_argv(int argc, const char **argv)
  81 {
  82         int i, len, ret;
  83         char *buf;
  84
  85         /* Bind up rest arguments */
  86         len = 0;
  87         for (i = 0; i < argc; i++)
  88                 len += strlen(argv[i]) + 1;
  89         buf = zalloc(len + 1);
  90         if (buf == NULL)
  91                 return -ENOMEM;
  92         len = 0;
  93         for (i = 0; i < argc; i++)
  94                 len += sprintf(&buf[len], "%s ", argv[i]);
  95         ret = parse_probe_event(buf);
  96         free(buf);
  97         return ret;
  98 }
  99
 100 static int opt_add_probe_event(const struct option *opt __used,
 101                               const char *str, int unset __used)
 102 {
 103         if (str)
 104                 return parse_probe_event(str);
 105         else
 106                 return 0;
 107 }
 108
 109 static int opt_del_probe_event(const struct option *opt __used,
 110                                const char *str, int unset __used)
 111 {
 112         if (str) {
 113                 if (!params.dellist)
 114                         params.dellist = strlist__new(true, NULL);
 115                 strlist__add(params.dellist, str);
 116         }
 117         return 0;
 118 }
 119
 120 #ifdef DWARF_SUPPORT
 121 static int opt_show_lines(const struct option *opt __used,
 122                           const char *str, int unset __used)
 123 {
 124         int ret = 0;
 125
 126         if (str)
 127                 ret = parse_line_range_desc(str, &params.line_range);
 128         INIT_LIST_HEAD(&params.line_range.line_list);
 129         params.show_lines = true;
 130
 131         return ret;
 132 }
 133 #endif
 134
 135 static const char * const probe_usage[] = {
 136         "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
 137         "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
 138         "perf probe [<options>] --del '[GROUP:]EVENT' ...",
 139         "perf probe --list",
 140 #ifdef DWARF_SUPPORT
 141         "perf probe --line 'LINEDESC'",
 142 #endif
 143         NULL
 144 };
 145
 146 static const struct option options[] = {
 147         OPT_INCR('v', "verbose", &verbose,
 148                     "be more verbose (show parsed arguments, etc)"),
 149         OPT_BOOLEAN('l', "list", &params.list_events,
 150                     "list up current probe events"),
 151         OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
 152                 opt_del_probe_event),
 153         OPT_CALLBACK('a', "add", NULL,
 154 #ifdef DWARF_SUPPORT
 155                 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
 156                 " [[NAME=]ARG ...]",
 157 #else
 158                 "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
 159 #endif
 160                 "probe point definition, where\n"
 161                 "\t\tGROUP:\tGroup name (optional)\n"
 162                 "\t\tEVENT:\tEvent name\n"
 163                 "\t\tFUNC:\tFunction name\n"
 164                 "\t\tOFF:\tOffset from function entry (in byte)\n"
 165                 "\t\t%return:\tPut the probe at function return\n"
 166 #ifdef DWARF_SUPPORT
 167                 "\t\tSRC:\tSource code path\n"
 168                 "\t\tRL:\tRelative line number from function entry.\n"
 169                 "\t\tAL:\tAbsolute line number in file.\n"
 170                 "\t\tPT:\tLazy expression of line code.\n"
 171                 "\t\tARG:\tProbe argument (local variable name or\n"
 172                 "\t\t\tkprobe-tracer argument format.)\n",
 173 #else
 174                 "\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
 175 #endif
 176                 opt_add_probe_event),
 177         OPT_BOOLEAN('f', "force", &params.force_add, "forcibly add events"
 178                     " with existing name"),
 179 #ifdef DWARF_SUPPORT
 180         OPT_CALLBACK('L', "line", NULL,
 181                      "FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
 182                      "Show source code lines.", opt_show_lines),
 183         OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
 184                    "file", "vmlinux pathname"),
 185         OPT_STRING('s', "source", &symbol_conf.source_prefix,
 186                    "directory", "path to kernel source"),
 187 #endif
 188         OPT__DRY_RUN(&probe_event_dry_run),
 189         OPT_INTEGER('\0', "max-probes", &params.max_probe_points,
 190                  "Set how many probe points can be found for a probe."),
 191         OPT_END()
 192 };
 193
 194 int cmd_probe(int argc, const char **argv, const char *prefix __used)
 195 {
 196         int ret;
 197
 198         argc = parse_options(argc, argv, options, probe_usage,
 199                              PARSE_OPT_STOP_AT_NON_OPTION);
 200         if (argc > 0) {
 201                 if (strcmp(argv[0], "-") == 0) {
 202                         pr_warning("  Error: '-' is not supported.\n");
 203                         usage_with_options(probe_usage, options);
 204                 }
 205                 ret = parse_probe_event_argv(argc, argv);
 206                 if (ret < 0) {
 207                         pr_err("  Error: Parse Error.  (%d)\n", ret);
 208                         return ret;
 209                 }
 210         }
 211
 212         if (params.max_probe_points == 0)
 213                 params.max_probe_points = MAX_PROBES;
 214
 215         if ((!params.nevents && !params.dellist && !params.list_events &&
 216              !params.show_lines))
 217                 usage_with_options(probe_usage, options);
 218
 219         if (params.list_events) {
 220                 if (params.nevents != 0 || params.dellist) {
 221                         pr_err("  Error: Don't use --list with --add/--del.\n");
 222                         usage_with_options(probe_usage, options);
 223                 }
 224                 if (params.show_lines) {
 225                         pr_err("  Error: Don't use --list with --line.\n");
 226                         usage_with_options(probe_usage, options);
 227                 }
 228                 ret = show_perf_probe_events();
 229                 if (ret < 0)
 230                         pr_err("  Error: Failed to show event list. (%d)\n",
 231                                ret);
 232                 return ret;
 233         }
 234
 235 #ifdef DWARF_SUPPORT
 236         if (params.show_lines) {
 237                 if (params.nevents != 0 || params.dellist) {
 238                         pr_warning("  Error: Don't use --line with"
 239                                    " --add/--del.\n");
 240                         usage_with_options(probe_usage, options);
 241                 }
 242
 243                 ret = show_line_range(&params.line_range);
 244                 if (ret < 0)
 245                         pr_err("  Error: Failed to show lines. (%d)\n", ret);
 246                 return ret;
 247         }
 248 #endif
 249
 250         if (params.dellist) {
 251                 ret = del_perf_probe_events(params.dellist);
 252                 strlist__delete(params.dellist);
 253                 if (ret < 0) {
 254                         pr_err("  Error: Failed to delete events. (%d)\n", ret);
 255                         return ret;
 256                 }
 257         }
 258
 259         if (params.nevents) {
 260                 ret = add_perf_probe_events(params.events, params.nevents,
 261                                             params.force_add,
 262                                             params.max_probe_points);
 263                 if (ret < 0) {
 264                         pr_err("  Error: Failed to add events. (%d)\n", ret);
 265                         return ret;
 266                 }
 267         }
 268         return 0;
 269 }