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