cfg80211: handle failed skb allocation
[cascardo/linux.git] / tools / perf / perf.c
1 /*
2  * perf.c
3  *
4  * Performance analysis utility.
5  *
6  * This is the main hub from which the sub-commands (perf stat,
7  * perf top, perf record, perf report, etc.) are started.
8  */
9 #include "builtin.h"
10
11 #include "util/env.h"
12 #include <subcmd/exec-cmd.h>
13 #include "util/cache.h"
14 #include "util/quote.h"
15 #include <subcmd/run-command.h>
16 #include "util/parse-events.h"
17 #include <subcmd/parse-options.h>
18 #include "util/bpf-loader.h"
19 #include "util/debug.h"
20 #include <api/fs/fs.h>
21 #include <api/fs/tracing_path.h>
22 #include <pthread.h>
23 #include <stdlib.h>
24 #include <time.h>
25
26 const char perf_usage_string[] =
27         "perf [--version] [--help] [OPTIONS] COMMAND [ARGS]";
28
29 const char perf_more_info_string[] =
30         "See 'perf help COMMAND' for more information on a specific command.";
31
32 int use_browser = -1;
33 static int use_pager = -1;
34 const char *input_name;
35
36 struct cmd_struct {
37         const char *cmd;
38         int (*fn)(int, const char **, const char *);
39         int option;
40 };
41
42 static struct cmd_struct commands[] = {
43         { "buildid-cache", cmd_buildid_cache, 0 },
44         { "buildid-list", cmd_buildid_list, 0 },
45         { "config",     cmd_config,     0 },
46         { "diff",       cmd_diff,       0 },
47         { "evlist",     cmd_evlist,     0 },
48         { "help",       cmd_help,       0 },
49         { "list",       cmd_list,       0 },
50         { "record",     cmd_record,     0 },
51         { "report",     cmd_report,     0 },
52         { "bench",      cmd_bench,      0 },
53         { "stat",       cmd_stat,       0 },
54         { "timechart",  cmd_timechart,  0 },
55         { "top",        cmd_top,        0 },
56         { "annotate",   cmd_annotate,   0 },
57         { "version",    cmd_version,    0 },
58         { "script",     cmd_script,     0 },
59         { "sched",      cmd_sched,      0 },
60 #ifdef HAVE_LIBELF_SUPPORT
61         { "probe",      cmd_probe,      0 },
62 #endif
63         { "kmem",       cmd_kmem,       0 },
64         { "lock",       cmd_lock,       0 },
65         { "kvm",        cmd_kvm,        0 },
66         { "test",       cmd_test,       0 },
67 #ifdef HAVE_LIBAUDIT_SUPPORT
68         { "trace",      cmd_trace,      0 },
69 #endif
70         { "inject",     cmd_inject,     0 },
71         { "mem",        cmd_mem,        0 },
72         { "data",       cmd_data,       0 },
73 };
74
75 struct pager_config {
76         const char *cmd;
77         int val;
78 };
79
80 static int pager_command_config(const char *var, const char *value, void *data)
81 {
82         struct pager_config *c = data;
83         if (!prefixcmp(var, "pager.") && !strcmp(var + 6, c->cmd))
84                 c->val = perf_config_bool(var, value);
85         return 0;
86 }
87
88 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
89 int check_pager_config(const char *cmd)
90 {
91         struct pager_config c;
92         c.cmd = cmd;
93         c.val = -1;
94         perf_config(pager_command_config, &c);
95         return c.val;
96 }
97
98 static int browser_command_config(const char *var, const char *value, void *data)
99 {
100         struct pager_config *c = data;
101         if (!prefixcmp(var, "tui.") && !strcmp(var + 4, c->cmd))
102                 c->val = perf_config_bool(var, value);
103         if (!prefixcmp(var, "gtk.") && !strcmp(var + 4, c->cmd))
104                 c->val = perf_config_bool(var, value) ? 2 : 0;
105         return 0;
106 }
107
108 /*
109  * returns 0 for "no tui", 1 for "use tui", 2 for "use gtk",
110  * and -1 for "not specified"
111  */
112 static int check_browser_config(const char *cmd)
113 {
114         struct pager_config c;
115         c.cmd = cmd;
116         c.val = -1;
117         perf_config(browser_command_config, &c);
118         return c.val;
119 }
120
121 static void commit_pager_choice(void)
122 {
123         switch (use_pager) {
124         case 0:
125                 setenv(PERF_PAGER_ENVIRONMENT, "cat", 1);
126                 break;
127         case 1:
128                 /* setup_pager(); */
129                 break;
130         default:
131                 break;
132         }
133 }
134
135 struct option options[] = {
136         OPT_ARGUMENT("help", "help"),
137         OPT_ARGUMENT("version", "version"),
138         OPT_ARGUMENT("exec-path", "exec-path"),
139         OPT_ARGUMENT("html-path", "html-path"),
140         OPT_ARGUMENT("paginate", "paginate"),
141         OPT_ARGUMENT("no-pager", "no-pager"),
142         OPT_ARGUMENT("perf-dir", "perf-dir"),
143         OPT_ARGUMENT("work-tree", "work-tree"),
144         OPT_ARGUMENT("debugfs-dir", "debugfs-dir"),
145         OPT_ARGUMENT("buildid-dir", "buildid-dir"),
146         OPT_ARGUMENT("list-cmds", "list-cmds"),
147         OPT_ARGUMENT("list-opts", "list-opts"),
148         OPT_ARGUMENT("debug", "debug"),
149         OPT_END()
150 };
151
152 static int handle_options(const char ***argv, int *argc, int *envchanged)
153 {
154         int handled = 0;
155
156         while (*argc > 0) {
157                 const char *cmd = (*argv)[0];
158                 if (cmd[0] != '-')
159                         break;
160
161                 /*
162                  * For legacy reasons, the "version" and "help"
163                  * commands can be written with "--" prepended
164                  * to make them look like flags.
165                  */
166                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
167                         break;
168
169                 /*
170                  * Shortcut for '-h' and '-v' options to invoke help
171                  * and version command.
172                  */
173                 if (!strcmp(cmd, "-h")) {
174                         (*argv)[0] = "--help";
175                         break;
176                 }
177
178                 if (!strcmp(cmd, "-v")) {
179                         (*argv)[0] = "--version";
180                         break;
181                 }
182
183                 /*
184                  * Check remaining flags.
185                  */
186                 if (!prefixcmp(cmd, CMD_EXEC_PATH)) {
187                         cmd += strlen(CMD_EXEC_PATH);
188                         if (*cmd == '=')
189                                 set_argv_exec_path(cmd + 1);
190                         else {
191                                 puts(get_argv_exec_path());
192                                 exit(0);
193                         }
194                 } else if (!strcmp(cmd, "--html-path")) {
195                         puts(system_path(PERF_HTML_PATH));
196                         exit(0);
197                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
198                         use_pager = 1;
199                 } else if (!strcmp(cmd, "--no-pager")) {
200                         use_pager = 0;
201                         if (envchanged)
202                                 *envchanged = 1;
203                 } else if (!strcmp(cmd, "--perf-dir")) {
204                         if (*argc < 2) {
205                                 fprintf(stderr, "No directory given for --perf-dir.\n");
206                                 usage(perf_usage_string);
207                         }
208                         setenv(PERF_DIR_ENVIRONMENT, (*argv)[1], 1);
209                         if (envchanged)
210                                 *envchanged = 1;
211                         (*argv)++;
212                         (*argc)--;
213                         handled++;
214                 } else if (!prefixcmp(cmd, CMD_PERF_DIR)) {
215                         setenv(PERF_DIR_ENVIRONMENT, cmd + strlen(CMD_PERF_DIR), 1);
216                         if (envchanged)
217                                 *envchanged = 1;
218                 } else if (!strcmp(cmd, "--work-tree")) {
219                         if (*argc < 2) {
220                                 fprintf(stderr, "No directory given for --work-tree.\n");
221                                 usage(perf_usage_string);
222                         }
223                         setenv(PERF_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
224                         if (envchanged)
225                                 *envchanged = 1;
226                         (*argv)++;
227                         (*argc)--;
228                 } else if (!prefixcmp(cmd, CMD_WORK_TREE)) {
229                         setenv(PERF_WORK_TREE_ENVIRONMENT, cmd + strlen(CMD_WORK_TREE), 1);
230                         if (envchanged)
231                                 *envchanged = 1;
232                 } else if (!strcmp(cmd, "--debugfs-dir")) {
233                         if (*argc < 2) {
234                                 fprintf(stderr, "No directory given for --debugfs-dir.\n");
235                                 usage(perf_usage_string);
236                         }
237                         tracing_path_set((*argv)[1]);
238                         if (envchanged)
239                                 *envchanged = 1;
240                         (*argv)++;
241                         (*argc)--;
242                 } else if (!strcmp(cmd, "--buildid-dir")) {
243                         if (*argc < 2) {
244                                 fprintf(stderr, "No directory given for --buildid-dir.\n");
245                                 usage(perf_usage_string);
246                         }
247                         set_buildid_dir((*argv)[1]);
248                         if (envchanged)
249                                 *envchanged = 1;
250                         (*argv)++;
251                         (*argc)--;
252                 } else if (!prefixcmp(cmd, CMD_DEBUGFS_DIR)) {
253                         tracing_path_set(cmd + strlen(CMD_DEBUGFS_DIR));
254                         fprintf(stderr, "dir: %s\n", tracing_path);
255                         if (envchanged)
256                                 *envchanged = 1;
257                 } else if (!strcmp(cmd, "--list-cmds")) {
258                         unsigned int i;
259
260                         for (i = 0; i < ARRAY_SIZE(commands); i++) {
261                                 struct cmd_struct *p = commands+i;
262                                 printf("%s ", p->cmd);
263                         }
264                         putchar('\n');
265                         exit(0);
266                 } else if (!strcmp(cmd, "--list-opts")) {
267                         unsigned int i;
268
269                         for (i = 0; i < ARRAY_SIZE(options)-1; i++) {
270                                 struct option *p = options+i;
271                                 printf("--%s ", p->long_name);
272                         }
273                         putchar('\n');
274                         exit(0);
275                 } else if (!strcmp(cmd, "--debug")) {
276                         if (*argc < 2) {
277                                 fprintf(stderr, "No variable specified for --debug.\n");
278                                 usage(perf_usage_string);
279                         }
280                         if (perf_debug_option((*argv)[1]))
281                                 usage(perf_usage_string);
282
283                         (*argv)++;
284                         (*argc)--;
285                 } else {
286                         fprintf(stderr, "Unknown option: %s\n", cmd);
287                         usage(perf_usage_string);
288                 }
289
290                 (*argv)++;
291                 (*argc)--;
292                 handled++;
293         }
294         return handled;
295 }
296
297 static int handle_alias(int *argcp, const char ***argv)
298 {
299         int envchanged = 0, ret = 0, saved_errno = errno;
300         int count, option_count;
301         const char **new_argv;
302         const char *alias_command;
303         char *alias_string;
304
305         alias_command = (*argv)[0];
306         alias_string = alias_lookup(alias_command);
307         if (alias_string) {
308                 if (alias_string[0] == '!') {
309                         if (*argcp > 1) {
310                                 struct strbuf buf;
311
312                                 if (strbuf_init(&buf, PATH_MAX) < 0 ||
313                                     strbuf_addstr(&buf, alias_string) < 0 ||
314                                     sq_quote_argv(&buf, (*argv) + 1,
315                                                   PATH_MAX) < 0)
316                                         die("Failed to allocate memory.");
317                                 free(alias_string);
318                                 alias_string = buf.buf;
319                         }
320                         ret = system(alias_string + 1);
321                         if (ret >= 0 && WIFEXITED(ret) &&
322                             WEXITSTATUS(ret) != 127)
323                                 exit(WEXITSTATUS(ret));
324                         die("Failed to run '%s' when expanding alias '%s'",
325                             alias_string + 1, alias_command);
326                 }
327                 count = split_cmdline(alias_string, &new_argv);
328                 if (count < 0)
329                         die("Bad alias.%s string", alias_command);
330                 option_count = handle_options(&new_argv, &count, &envchanged);
331                 if (envchanged)
332                         die("alias '%s' changes environment variables\n"
333                                  "You can use '!perf' in the alias to do this.",
334                                  alias_command);
335                 memmove(new_argv - option_count, new_argv,
336                                 count * sizeof(char *));
337                 new_argv -= option_count;
338
339                 if (count < 1)
340                         die("empty alias for %s", alias_command);
341
342                 if (!strcmp(alias_command, new_argv[0]))
343                         die("recursive alias: %s", alias_command);
344
345                 new_argv = realloc(new_argv, sizeof(char *) *
346                                     (count + *argcp + 1));
347                 /* insert after command name */
348                 memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
349                 new_argv[count + *argcp] = NULL;
350
351                 *argv = new_argv;
352                 *argcp += count - 1;
353
354                 ret = 1;
355         }
356
357         errno = saved_errno;
358
359         return ret;
360 }
361
362 const char perf_version_string[] = PERF_VERSION;
363
364 #define RUN_SETUP       (1<<0)
365 #define USE_PAGER       (1<<1)
366 /*
367  * require working tree to be present -- anything uses this needs
368  * RUN_SETUP for reading from the configuration file.
369  */
370 #define NEED_WORK_TREE  (1<<2)
371
372 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
373 {
374         int status;
375         struct stat st;
376         const char *prefix;
377         char sbuf[STRERR_BUFSIZE];
378
379         prefix = NULL;
380         if (p->option & RUN_SETUP)
381                 prefix = NULL; /* setup_perf_directory(); */
382
383         if (use_browser == -1)
384                 use_browser = check_browser_config(p->cmd);
385
386         if (use_pager == -1 && p->option & RUN_SETUP)
387                 use_pager = check_pager_config(p->cmd);
388         if (use_pager == -1 && p->option & USE_PAGER)
389                 use_pager = 1;
390         commit_pager_choice();
391
392         perf_env__set_cmdline(&perf_env, argc, argv);
393         status = p->fn(argc, argv, prefix);
394         exit_browser(status);
395         perf_env__exit(&perf_env);
396         bpf__clear();
397
398         if (status)
399                 return status & 0xff;
400
401         /* Somebody closed stdout? */
402         if (fstat(fileno(stdout), &st))
403                 return 0;
404         /* Ignore write errors for pipes and sockets.. */
405         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
406                 return 0;
407
408         status = 1;
409         /* Check for ENOSPC and EIO errors.. */
410         if (fflush(stdout)) {
411                 fprintf(stderr, "write failure on standard output: %s",
412                         strerror_r(errno, sbuf, sizeof(sbuf)));
413                 goto out;
414         }
415         if (ferror(stdout)) {
416                 fprintf(stderr, "unknown write failure on standard output");
417                 goto out;
418         }
419         if (fclose(stdout)) {
420                 fprintf(stderr, "close failed on standard output: %s",
421                         strerror_r(errno, sbuf, sizeof(sbuf)));
422                 goto out;
423         }
424         status = 0;
425 out:
426         return status;
427 }
428
429 static void handle_internal_command(int argc, const char **argv)
430 {
431         const char *cmd = argv[0];
432         unsigned int i;
433         static const char ext[] = STRIP_EXTENSION;
434
435         if (sizeof(ext) > 1) {
436                 i = strlen(argv[0]) - strlen(ext);
437                 if (i > 0 && !strcmp(argv[0] + i, ext)) {
438                         char *argv0 = strdup(argv[0]);
439                         argv[0] = cmd = argv0;
440                         argv0[i] = '\0';
441                 }
442         }
443
444         /* Turn "perf cmd --help" into "perf help cmd" */
445         if (argc > 1 && !strcmp(argv[1], "--help")) {
446                 argv[1] = argv[0];
447                 argv[0] = cmd = "help";
448         }
449
450         for (i = 0; i < ARRAY_SIZE(commands); i++) {
451                 struct cmd_struct *p = commands+i;
452                 if (strcmp(p->cmd, cmd))
453                         continue;
454                 exit(run_builtin(p, argc, argv));
455         }
456 }
457
458 static void execv_dashed_external(const char **argv)
459 {
460         char *cmd;
461         const char *tmp;
462         int status;
463
464         if (asprintf(&cmd, "perf-%s", argv[0]) < 0)
465                 goto do_die;
466
467         /*
468          * argv[0] must be the perf command, but the argv array
469          * belongs to the caller, and may be reused in
470          * subsequent loop iterations. Save argv[0] and
471          * restore it on error.
472          */
473         tmp = argv[0];
474         argv[0] = cmd;
475
476         /*
477          * if we fail because the command is not found, it is
478          * OK to return. Otherwise, we just pass along the status code.
479          */
480         status = run_command_v_opt(argv, 0);
481         if (status != -ERR_RUN_COMMAND_EXEC) {
482                 if (IS_RUN_COMMAND_ERR(status)) {
483 do_die:
484                         die("unable to run '%s'", argv[0]);
485                 }
486                 exit(-status);
487         }
488         errno = ENOENT; /* as if we called execvp */
489
490         argv[0] = tmp;
491         zfree(&cmd);
492 }
493
494 static int run_argv(int *argcp, const char ***argv)
495 {
496         int done_alias = 0;
497
498         while (1) {
499                 /* See if it's an internal command */
500                 handle_internal_command(*argcp, *argv);
501
502                 /* .. then try the external ones */
503                 execv_dashed_external(*argv);
504
505                 /* It could be an alias -- this works around the insanity
506                  * of overriding "perf log" with "perf show" by having
507                  * alias.log = show
508                  */
509                 if (done_alias || !handle_alias(argcp, argv))
510                         break;
511                 done_alias = 1;
512         }
513
514         return done_alias;
515 }
516
517 static void pthread__block_sigwinch(void)
518 {
519         sigset_t set;
520
521         sigemptyset(&set);
522         sigaddset(&set, SIGWINCH);
523         pthread_sigmask(SIG_BLOCK, &set, NULL);
524 }
525
526 void pthread__unblock_sigwinch(void)
527 {
528         sigset_t set;
529
530         sigemptyset(&set);
531         sigaddset(&set, SIGWINCH);
532         pthread_sigmask(SIG_UNBLOCK, &set, NULL);
533 }
534
535 int main(int argc, const char **argv)
536 {
537         const char *cmd;
538         char sbuf[STRERR_BUFSIZE];
539         int value;
540
541         /* libsubcmd init */
542         exec_cmd_init("perf", PREFIX, PERF_EXEC_PATH, EXEC_PATH_ENVIRONMENT);
543         pager_init(PERF_PAGER_ENVIRONMENT);
544
545         /* The page_size is placed in util object. */
546         page_size = sysconf(_SC_PAGE_SIZE);
547         cacheline_size = sysconf(_SC_LEVEL1_DCACHE_LINESIZE);
548
549         if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0)
550                 sysctl_perf_event_max_stack = value;
551
552         cmd = extract_argv0_path(argv[0]);
553         if (!cmd)
554                 cmd = "perf-help";
555
556         srandom(time(NULL));
557
558         perf_config(perf_default_config, NULL);
559         set_buildid_dir(NULL);
560
561         /* get debugfs/tracefs mount point from /proc/mounts */
562         tracing_path_mount();
563
564         /*
565          * "perf-xxxx" is the same as "perf xxxx", but we obviously:
566          *
567          *  - cannot take flags in between the "perf" and the "xxxx".
568          *  - cannot execute it externally (since it would just do
569          *    the same thing over again)
570          *
571          * So we just directly call the internal command handler, and
572          * die if that one cannot handle it.
573          */
574         if (!prefixcmp(cmd, "perf-")) {
575                 cmd += 5;
576                 argv[0] = cmd;
577                 handle_internal_command(argc, argv);
578                 fprintf(stderr, "cannot handle %s internally", cmd);
579                 goto out;
580         }
581         if (!prefixcmp(cmd, "trace")) {
582 #ifdef HAVE_LIBAUDIT_SUPPORT
583                 setup_path();
584                 argv[0] = "trace";
585                 return cmd_trace(argc, argv, NULL);
586 #else
587                 fprintf(stderr,
588                         "trace command not available: missing audit-libs devel package at build time.\n");
589                 goto out;
590 #endif
591         }
592         /* Look for flags.. */
593         argv++;
594         argc--;
595         handle_options(&argv, &argc, NULL);
596         commit_pager_choice();
597
598         if (argc > 0) {
599                 if (!prefixcmp(argv[0], "--"))
600                         argv[0] += 2;
601         } else {
602                 /* The user didn't specify a command; give them help */
603                 printf("\n usage: %s\n\n", perf_usage_string);
604                 list_common_cmds_help();
605                 printf("\n %s\n\n", perf_more_info_string);
606                 goto out;
607         }
608         cmd = argv[0];
609
610         test_attr__init();
611
612         /*
613          * We use PATH to find perf commands, but we prepend some higher
614          * precedence paths: the "--exec-path" option, the PERF_EXEC_PATH
615          * environment, and the $(perfexecdir) from the Makefile at build
616          * time.
617          */
618         setup_path();
619         /*
620          * Block SIGWINCH notifications so that the thread that wants it can
621          * unblock and get syscalls like select interrupted instead of waiting
622          * forever while the signal goes to some other non interested thread.
623          */
624         pthread__block_sigwinch();
625
626         perf_debug_setup();
627
628         while (1) {
629                 static int done_help;
630                 int was_alias = run_argv(&argc, &argv);
631
632                 if (errno != ENOENT)
633                         break;
634
635                 if (was_alias) {
636                         fprintf(stderr, "Expansion of alias '%s' failed; "
637                                 "'%s' is not a perf-command\n",
638                                 cmd, argv[0]);
639                         goto out;
640                 }
641                 if (!done_help) {
642                         cmd = argv[0] = help_unknown_cmd(cmd);
643                         done_help = 1;
644                 } else
645                         break;
646         }
647
648         fprintf(stderr, "Failed to run command '%s': %s\n",
649                 cmd, strerror_r(errno, sbuf, sizeof(sbuf)));
650 out:
651         return 1;
652 }