ipv6: fix race condition regarding dst->expires and dst->from.
[pandora-kernel.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/exec_cmd.h"
12 #include "util/cache.h"
13 #include "util/quote.h"
14 #include "util/run-command.h"
15 #include "util/parse-events.h"
16 #include "util/debugfs.h"
17 #include <pthread.h>
18
19 const char perf_usage_string[] =
20         "perf [--version] [--help] COMMAND [ARGS]";
21
22 const char perf_more_info_string[] =
23         "See 'perf help COMMAND' for more information on a specific command.";
24
25 int use_browser = -1;
26 static int use_pager = -1;
27 const char *input_name;
28
29 struct cmd_struct {
30         const char *cmd;
31         int (*fn)(int, const char **, const char *);
32         int option;
33 };
34
35 static struct cmd_struct commands[] = {
36         { "buildid-cache", cmd_buildid_cache, 0 },
37         { "buildid-list", cmd_buildid_list, 0 },
38         { "diff",       cmd_diff,       0 },
39         { "evlist",     cmd_evlist,     0 },
40         { "help",       cmd_help,       0 },
41         { "list",       cmd_list,       0 },
42         { "record",     cmd_record,     0 },
43         { "report",     cmd_report,     0 },
44         { "bench",      cmd_bench,      0 },
45         { "stat",       cmd_stat,       0 },
46         { "timechart",  cmd_timechart,  0 },
47         { "top",        cmd_top,        0 },
48         { "annotate",   cmd_annotate,   0 },
49         { "version",    cmd_version,    0 },
50         { "script",     cmd_script,     0 },
51         { "sched",      cmd_sched,      0 },
52 #ifdef LIBELF_SUPPORT
53         { "probe",      cmd_probe,      0 },
54 #endif
55         { "kmem",       cmd_kmem,       0 },
56         { "lock",       cmd_lock,       0 },
57         { "kvm",        cmd_kvm,        0 },
58         { "test",       cmd_test,       0 },
59 #ifdef LIBAUDIT_SUPPORT
60         { "trace",      cmd_trace,      0 },
61 #endif
62         { "inject",     cmd_inject,     0 },
63 };
64
65 struct pager_config {
66         const char *cmd;
67         int val;
68 };
69
70 static int pager_command_config(const char *var, const char *value, void *data)
71 {
72         struct pager_config *c = data;
73         if (!prefixcmp(var, "pager.") && !strcmp(var + 6, c->cmd))
74                 c->val = perf_config_bool(var, value);
75         return 0;
76 }
77
78 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
79 int check_pager_config(const char *cmd)
80 {
81         struct pager_config c;
82         c.cmd = cmd;
83         c.val = -1;
84         perf_config(pager_command_config, &c);
85         return c.val;
86 }
87
88 static int browser_command_config(const char *var, const char *value, void *data)
89 {
90         struct pager_config *c = data;
91         if (!prefixcmp(var, "tui.") && !strcmp(var + 4, c->cmd))
92                 c->val = perf_config_bool(var, value);
93         if (!prefixcmp(var, "gtk.") && !strcmp(var + 4, c->cmd))
94                 c->val = perf_config_bool(var, value) ? 2 : 0;
95         return 0;
96 }
97
98 /*
99  * returns 0 for "no tui", 1 for "use tui", 2 for "use gtk",
100  * and -1 for "not specified"
101  */
102 static int check_browser_config(const char *cmd)
103 {
104         struct pager_config c;
105         c.cmd = cmd;
106         c.val = -1;
107         perf_config(browser_command_config, &c);
108         return c.val;
109 }
110
111 static void commit_pager_choice(void)
112 {
113         switch (use_pager) {
114         case 0:
115                 setenv("PERF_PAGER", "cat", 1);
116                 break;
117         case 1:
118                 /* setup_pager(); */
119                 break;
120         default:
121                 break;
122         }
123 }
124
125 static int handle_options(const char ***argv, int *argc, int *envchanged)
126 {
127         int handled = 0;
128
129         while (*argc > 0) {
130                 const char *cmd = (*argv)[0];
131                 if (cmd[0] != '-')
132                         break;
133
134                 /*
135                  * For legacy reasons, the "version" and "help"
136                  * commands can be written with "--" prepended
137                  * to make them look like flags.
138                  */
139                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
140                         break;
141
142                 /*
143                  * Check remaining flags.
144                  */
145                 if (!prefixcmp(cmd, CMD_EXEC_PATH)) {
146                         cmd += strlen(CMD_EXEC_PATH);
147                         if (*cmd == '=')
148                                 perf_set_argv_exec_path(cmd + 1);
149                         else {
150                                 puts(perf_exec_path());
151                                 exit(0);
152                         }
153                 } else if (!strcmp(cmd, "--html-path")) {
154                         puts(system_path(PERF_HTML_PATH));
155                         exit(0);
156                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
157                         use_pager = 1;
158                 } else if (!strcmp(cmd, "--no-pager")) {
159                         use_pager = 0;
160                         if (envchanged)
161                                 *envchanged = 1;
162                 } else if (!strcmp(cmd, "--perf-dir")) {
163                         if (*argc < 2) {
164                                 fprintf(stderr, "No directory given for --perf-dir.\n");
165                                 usage(perf_usage_string);
166                         }
167                         setenv(PERF_DIR_ENVIRONMENT, (*argv)[1], 1);
168                         if (envchanged)
169                                 *envchanged = 1;
170                         (*argv)++;
171                         (*argc)--;
172                         handled++;
173                 } else if (!prefixcmp(cmd, CMD_PERF_DIR)) {
174                         setenv(PERF_DIR_ENVIRONMENT, cmd + strlen(CMD_PERF_DIR), 1);
175                         if (envchanged)
176                                 *envchanged = 1;
177                 } else if (!strcmp(cmd, "--work-tree")) {
178                         if (*argc < 2) {
179                                 fprintf(stderr, "No directory given for --work-tree.\n");
180                                 usage(perf_usage_string);
181                         }
182                         setenv(PERF_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
183                         if (envchanged)
184                                 *envchanged = 1;
185                         (*argv)++;
186                         (*argc)--;
187                 } else if (!prefixcmp(cmd, CMD_WORK_TREE)) {
188                         setenv(PERF_WORK_TREE_ENVIRONMENT, cmd + strlen(CMD_WORK_TREE), 1);
189                         if (envchanged)
190                                 *envchanged = 1;
191                 } else if (!strcmp(cmd, "--debugfs-dir")) {
192                         if (*argc < 2) {
193                                 fprintf(stderr, "No directory given for --debugfs-dir.\n");
194                                 usage(perf_usage_string);
195                         }
196                         debugfs_set_path((*argv)[1]);
197                         if (envchanged)
198                                 *envchanged = 1;
199                         (*argv)++;
200                         (*argc)--;
201                 } else if (!prefixcmp(cmd, CMD_DEBUGFS_DIR)) {
202                         debugfs_set_path(cmd + strlen(CMD_DEBUGFS_DIR));
203                         fprintf(stderr, "dir: %s\n", debugfs_mountpoint);
204                         if (envchanged)
205                                 *envchanged = 1;
206                 } else if (!strcmp(cmd, "--list-cmds")) {
207                         unsigned int i;
208
209                         for (i = 0; i < ARRAY_SIZE(commands); i++) {
210                                 struct cmd_struct *p = commands+i;
211                                 printf("%s ", p->cmd);
212                         }
213                         exit(0);
214                 } else {
215                         fprintf(stderr, "Unknown option: %s\n", cmd);
216                         usage(perf_usage_string);
217                 }
218
219                 (*argv)++;
220                 (*argc)--;
221                 handled++;
222         }
223         return handled;
224 }
225
226 static int handle_alias(int *argcp, const char ***argv)
227 {
228         int envchanged = 0, ret = 0, saved_errno = errno;
229         int count, option_count;
230         const char **new_argv;
231         const char *alias_command;
232         char *alias_string;
233
234         alias_command = (*argv)[0];
235         alias_string = alias_lookup(alias_command);
236         if (alias_string) {
237                 if (alias_string[0] == '!') {
238                         if (*argcp > 1) {
239                                 struct strbuf buf;
240
241                                 strbuf_init(&buf, PATH_MAX);
242                                 strbuf_addstr(&buf, alias_string);
243                                 sq_quote_argv(&buf, (*argv) + 1, PATH_MAX);
244                                 free(alias_string);
245                                 alias_string = buf.buf;
246                         }
247                         ret = system(alias_string + 1);
248                         if (ret >= 0 && WIFEXITED(ret) &&
249                             WEXITSTATUS(ret) != 127)
250                                 exit(WEXITSTATUS(ret));
251                         die("Failed to run '%s' when expanding alias '%s'",
252                             alias_string + 1, alias_command);
253                 }
254                 count = split_cmdline(alias_string, &new_argv);
255                 if (count < 0)
256                         die("Bad alias.%s string", alias_command);
257                 option_count = handle_options(&new_argv, &count, &envchanged);
258                 if (envchanged)
259                         die("alias '%s' changes environment variables\n"
260                                  "You can use '!perf' in the alias to do this.",
261                                  alias_command);
262                 memmove(new_argv - option_count, new_argv,
263                                 count * sizeof(char *));
264                 new_argv -= option_count;
265
266                 if (count < 1)
267                         die("empty alias for %s", alias_command);
268
269                 if (!strcmp(alias_command, new_argv[0]))
270                         die("recursive alias: %s", alias_command);
271
272                 new_argv = realloc(new_argv, sizeof(char *) *
273                                     (count + *argcp + 1));
274                 /* insert after command name */
275                 memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
276                 new_argv[count + *argcp] = NULL;
277
278                 *argv = new_argv;
279                 *argcp += count - 1;
280
281                 ret = 1;
282         }
283
284         errno = saved_errno;
285
286         return ret;
287 }
288
289 const char perf_version_string[] = PERF_VERSION;
290
291 #define RUN_SETUP       (1<<0)
292 #define USE_PAGER       (1<<1)
293 /*
294  * require working tree to be present -- anything uses this needs
295  * RUN_SETUP for reading from the configuration file.
296  */
297 #define NEED_WORK_TREE  (1<<2)
298
299 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
300 {
301         int status;
302         struct stat st;
303         const char *prefix;
304
305         prefix = NULL;
306         if (p->option & RUN_SETUP)
307                 prefix = NULL; /* setup_perf_directory(); */
308
309         if (use_browser == -1)
310                 use_browser = check_browser_config(p->cmd);
311
312         if (use_pager == -1 && p->option & RUN_SETUP)
313                 use_pager = check_pager_config(p->cmd);
314         if (use_pager == -1 && p->option & USE_PAGER)
315                 use_pager = 1;
316         commit_pager_choice();
317
318         status = p->fn(argc, argv, prefix);
319         exit_browser(status);
320
321         if (status)
322                 return status & 0xff;
323
324         /* Somebody closed stdout? */
325         if (fstat(fileno(stdout), &st))
326                 return 0;
327         /* Ignore write errors for pipes and sockets.. */
328         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
329                 return 0;
330
331         /* Check for ENOSPC and EIO errors.. */
332         if (fflush(stdout))
333                 die("write failure on standard output: %s", strerror(errno));
334         if (ferror(stdout))
335                 die("unknown write failure on standard output");
336         if (fclose(stdout))
337                 die("close failed on standard output: %s", strerror(errno));
338         return 0;
339 }
340
341 static void handle_internal_command(int argc, const char **argv)
342 {
343         const char *cmd = argv[0];
344         unsigned int i;
345         static const char ext[] = STRIP_EXTENSION;
346
347         if (sizeof(ext) > 1) {
348                 i = strlen(argv[0]) - strlen(ext);
349                 if (i > 0 && !strcmp(argv[0] + i, ext)) {
350                         char *argv0 = strdup(argv[0]);
351                         argv[0] = cmd = argv0;
352                         argv0[i] = '\0';
353                 }
354         }
355
356         /* Turn "perf cmd --help" into "perf help cmd" */
357         if (argc > 1 && !strcmp(argv[1], "--help")) {
358                 argv[1] = argv[0];
359                 argv[0] = cmd = "help";
360         }
361
362         for (i = 0; i < ARRAY_SIZE(commands); i++) {
363                 struct cmd_struct *p = commands+i;
364                 if (strcmp(p->cmd, cmd))
365                         continue;
366                 exit(run_builtin(p, argc, argv));
367         }
368 }
369
370 static void execv_dashed_external(const char **argv)
371 {
372         struct strbuf cmd = STRBUF_INIT;
373         const char *tmp;
374         int status;
375
376         strbuf_addf(&cmd, "perf-%s", argv[0]);
377
378         /*
379          * argv[0] must be the perf command, but the argv array
380          * belongs to the caller, and may be reused in
381          * subsequent loop iterations. Save argv[0] and
382          * restore it on error.
383          */
384         tmp = argv[0];
385         argv[0] = cmd.buf;
386
387         /*
388          * if we fail because the command is not found, it is
389          * OK to return. Otherwise, we just pass along the status code.
390          */
391         status = run_command_v_opt(argv, 0);
392         if (status != -ERR_RUN_COMMAND_EXEC) {
393                 if (IS_RUN_COMMAND_ERR(status))
394                         die("unable to run '%s'", argv[0]);
395                 exit(-status);
396         }
397         errno = ENOENT; /* as if we called execvp */
398
399         argv[0] = tmp;
400
401         strbuf_release(&cmd);
402 }
403
404 static int run_argv(int *argcp, const char ***argv)
405 {
406         int done_alias = 0;
407
408         while (1) {
409                 /* See if it's an internal command */
410                 handle_internal_command(*argcp, *argv);
411
412                 /* .. then try the external ones */
413                 execv_dashed_external(*argv);
414
415                 /* It could be an alias -- this works around the insanity
416                  * of overriding "perf log" with "perf show" by having
417                  * alias.log = show
418                  */
419                 if (done_alias || !handle_alias(argcp, argv))
420                         break;
421                 done_alias = 1;
422         }
423
424         return done_alias;
425 }
426
427 static void pthread__block_sigwinch(void)
428 {
429         sigset_t set;
430
431         sigemptyset(&set);
432         sigaddset(&set, SIGWINCH);
433         pthread_sigmask(SIG_BLOCK, &set, NULL);
434 }
435
436 void pthread__unblock_sigwinch(void)
437 {
438         sigset_t set;
439
440         sigemptyset(&set);
441         sigaddset(&set, SIGWINCH);
442         pthread_sigmask(SIG_UNBLOCK, &set, NULL);
443 }
444
445 int main(int argc, const char **argv)
446 {
447         const char *cmd;
448
449         page_size = sysconf(_SC_PAGE_SIZE);
450
451         cmd = perf_extract_argv0_path(argv[0]);
452         if (!cmd)
453                 cmd = "perf-help";
454         /* get debugfs mount point from /proc/mounts */
455         debugfs_mount(NULL);
456         /*
457          * "perf-xxxx" is the same as "perf xxxx", but we obviously:
458          *
459          *  - cannot take flags in between the "perf" and the "xxxx".
460          *  - cannot execute it externally (since it would just do
461          *    the same thing over again)
462          *
463          * So we just directly call the internal command handler, and
464          * die if that one cannot handle it.
465          */
466         if (!prefixcmp(cmd, "perf-")) {
467                 cmd += 5;
468                 argv[0] = cmd;
469                 handle_internal_command(argc, argv);
470                 die("cannot handle %s internally", cmd);
471         }
472
473         /* Look for flags.. */
474         argv++;
475         argc--;
476         handle_options(&argv, &argc, NULL);
477         commit_pager_choice();
478         set_buildid_dir();
479
480         if (argc > 0) {
481                 if (!prefixcmp(argv[0], "--"))
482                         argv[0] += 2;
483         } else {
484                 /* The user didn't specify a command; give them help */
485                 printf("\n usage: %s\n\n", perf_usage_string);
486                 list_common_cmds_help();
487                 printf("\n %s\n\n", perf_more_info_string);
488                 exit(1);
489         }
490         cmd = argv[0];
491
492         test_attr__init();
493
494         /*
495          * We use PATH to find perf commands, but we prepend some higher
496          * precedence paths: the "--exec-path" option, the PERF_EXEC_PATH
497          * environment, and the $(perfexecdir) from the Makefile at build
498          * time.
499          */
500         setup_path();
501         /*
502          * Block SIGWINCH notifications so that the thread that wants it can
503          * unblock and get syscalls like select interrupted instead of waiting
504          * forever while the signal goes to some other non interested thread.
505          */
506         pthread__block_sigwinch();
507
508         while (1) {
509                 static int done_help;
510                 static int was_alias;
511
512                 was_alias = run_argv(&argc, &argv);
513                 if (errno != ENOENT)
514                         break;
515
516                 if (was_alias) {
517                         fprintf(stderr, "Expansion of alias '%s' failed; "
518                                 "'%s' is not a perf-command\n",
519                                 cmd, argv[0]);
520                         exit(1);
521                 }
522                 if (!done_help) {
523                         cmd = argv[0] = help_unknown_cmd(cmd);
524                         done_help = 1;
525                 } else
526                         break;
527         }
528
529         fprintf(stderr, "Failed to run command '%s': %s\n",
530                 cmd, strerror(errno));
531
532         return 1;
533 }