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   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 need_dwarf;
  52         bool list_events;
  53         bool force_add;
  54         bool show_lines;
  55         int nr_probe;
  56         struct probe_point probes[MAX_PROBES];
  57         struct strlist *dellist;
  58         struct line_range line_range;
  59 } session;
  60
  61
  62 /* Parse an event definition. Note that any error must die. */
  63 static void parse_probe_event(const char *str)
  64 {
  65         struct probe_point *pp = &session.probes[session.nr_probe];
  66
  67         pr_debug("probe-definition(%d): %s\n", session.nr_probe, str);
  68         if (++session.nr_probe == MAX_PROBES)
  69                 die("Too many probes (> %d) are specified.", MAX_PROBES);
  70
  71         /* Parse perf-probe event into probe_point */
  72         parse_perf_probe_event(str, pp, &session.need_dwarf);
  73
  74         pr_debug("%d arguments\n", pp->nr_args);
  75 }
  76
  77 static void parse_probe_event_argv(int argc, const char **argv)
  78 {
  79         int i, len;
  80         char *buf;
  81
  82         /* Bind up rest arguments */
  83         len = 0;
  84         for (i = 0; i < argc; i++)
  85                 len += strlen(argv[i]) + 1;
  86         buf = xzalloc(len + 1);
  87         len = 0;
  88         for (i = 0; i < argc; i++)
  89                 len += sprintf(&buf[len], "%s ", argv[i]);
  90         parse_probe_event(buf);
  91         free(buf);
  92 }
  93
  94 static int opt_add_probe_event(const struct option *opt __used,
  95                               const char *str, int unset __used)
  96 {
  97         if (str)
  98                 parse_probe_event(str);
  99         return 0;
 100 }
 101
 102 static int opt_del_probe_event(const struct option *opt __used,
 103                                const char *str, int unset __used)
 104 {
 105         if (str) {
 106                 if (!session.dellist)
 107                         session.dellist = strlist__new(true, NULL);
 108                 strlist__add(session.dellist, str);
 109         }
 110         return 0;
 111 }
 112
 113 #ifndef NO_DWARF_SUPPORT
 114 static int opt_show_lines(const struct option *opt __used,
 115                           const char *str, int unset __used)
 116 {
 117         if (str)
 118                 parse_line_range_desc(str, &session.line_range);
 119         INIT_LIST_HEAD(&session.line_range.line_list);
 120         session.show_lines = true;
 121         return 0;
 122 }
 123 #endif
 124
 125 static const char * const probe_usage[] = {
 126         "perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
 127         "perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
 128         "perf probe [<options>] --del '[GROUP:]EVENT' ...",
 129         "perf probe --list",
 130 #ifndef NO_DWARF_SUPPORT
 131         "perf probe --line 'LINEDESC'",
 132 #endif
 133         NULL
 134 };
 135
 136 static const struct option options[] = {
 137         OPT_BOOLEAN('v', "verbose", &verbose,
 138                     "be more verbose (show parsed arguments, etc)"),
 139 #ifndef NO_DWARF_SUPPORT
 140         OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
 141                    "file", "vmlinux pathname"),
 142 #endif
 143         OPT_BOOLEAN('l', "list", &session.list_events,
 144                     "list up current probe events"),
 145         OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
 146                 opt_del_probe_event),
 147         OPT_CALLBACK('a', "add", NULL,
 148 #ifdef NO_DWARF_SUPPORT
 149                 "[EVENT=]FUNC[+OFF|%return] [ARG ...]",
 150 #else
 151                 "[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
 152                 " [ARG ...]",
 153 #endif
 154                 "probe point definition, where\n"
 155                 "\t\tGROUP:\tGroup name (optional)\n"
 156                 "\t\tEVENT:\tEvent name\n"
 157                 "\t\tFUNC:\tFunction name\n"
 158                 "\t\tOFF:\tOffset from function entry (in byte)\n"
 159                 "\t\t%return:\tPut the probe at function return\n"
 160 #ifdef NO_DWARF_SUPPORT
 161                 "\t\tARG:\tProbe argument (only \n"
 162 #else
 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 #endif
 169                 "\t\t\tkprobe-tracer argument format.)\n",
 170                 opt_add_probe_event),
 171         OPT_BOOLEAN('f', "force", &session.force_add, "forcibly add events"
 172                     " with existing name"),
 173 #ifndef NO_DWARF_SUPPORT
 174         OPT_CALLBACK('L', "line", NULL,
 175                      "FUNC[:RLN[+NUM|:RLN2]]|SRC:ALN[+NUM|:ALN2]",
 176                      "Show source code lines.", opt_show_lines),
 177 #endif
 178         OPT_END()
 179 };
 180
 181 int cmd_probe(int argc, const char **argv, const char *prefix __used)
 182 {
 183         argc = parse_options(argc, argv, options, probe_usage,
 184                              PARSE_OPT_STOP_AT_NON_OPTION);
 185         if (argc > 0) {
 186                 if (strcmp(argv[0], "-") == 0) {
 187                         pr_warning("  Error: '-' is not supported.\n");
 188                         usage_with_options(probe_usage, options);
 189                 }
 190                 parse_probe_event_argv(argc, argv);
 191         }
 192
 193         if ((!session.nr_probe && !session.dellist && !session.list_events &&
 194              !session.show_lines))
 195                 usage_with_options(probe_usage, options);
 196
 197         if (debugfs_valid_mountpoint(debugfs_path) < 0)
 198                 die("Failed to find debugfs path.");
 199
 200         if (session.list_events) {
 201                 if (session.nr_probe != 0 || session.dellist) {
 202                         pr_warning("  Error: Don't use --list with"
 203                                    " --add/--del.\n");
 204                         usage_with_options(probe_usage, options);
 205                 }
 206                 if (session.show_lines) {
 207                         pr_warning("  Error: Don't use --list with --line.\n");
 208                         usage_with_options(probe_usage, options);
 209                 }
 210                 show_perf_probe_events();
 211                 return 0;
 212         }
 213
 214 #ifndef NO_DWARF_SUPPORT
 215         if (session.show_lines) {
 216                 if (session.nr_probe != 0 || session.dellist) {
 217                         pr_warning("  Error: Don't use --line with"
 218                                    " --add/--del.\n");
 219                         usage_with_options(probe_usage, options);
 220                 }
 221
 222                 show_line_range(&session.line_range);
 223                 return 0;
 224         }
 225 #endif
 226
 227         if (session.dellist) {
 228                 del_trace_kprobe_events(session.dellist);
 229                 strlist__delete(session.dellist);
 230                 if (session.nr_probe == 0)
 231                         return 0;
 232         }
 233
 234         add_trace_kprobe_events(session.probes, session.nr_probe,
 235                                 session.force_add, session.need_dwarf);
 236         return 0;
 237 }
 238