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