trace_output.c 27 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881882883884885886887888889890891892893894895896897898899900901902903904905906907908909910911912913914915916917918919920921922923924925926927928929930931932933934935936937938939940941942943944945946947948949950951952953954955956957958959960961962963964965966967968969970971972973974975976977978979980981982983984985986987988989990991992993994995996997998999100010011002100310041005100610071008100910101011101210131014101510161017101810191020102110221023102410251026102710281029103010311032103310341035103610371038103910401041104210431044104510461047104810491050105110521053105410551056105710581059106010611062106310641065106610671068106910701071107210731074107510761077107810791080108110821083108410851086108710881089109010911092109310941095109610971098109911001101110211031104110511061107110811091110111111121113111411151116111711181119112011211122112311241125112611271128112911301131113211331134113511361137113811391140114111421143114411451146114711481149115011511152115311541155115611571158115911601161116211631164116511661167116811691170117111721173117411751176117711781179118011811182118311841185118611871188118911901191119211931194119511961197119811991200120112021203120412051206120712081209121012111212121312141215121612171218121912201221122212231224122512261227122812291230123112321233123412351236123712381239124012411242124312441245124612471248124912501251125212531254125512561257125812591260126112621263126412651266126712681269127012711272127312741275127612771278127912801281128212831284128512861287128812891290129112921293129412951296129712981299130013011302130313041305130613071308
  1. /*
  2. * trace_output.c
  3. *
  4. * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
  5. *
  6. */
  7. #include <linux/module.h>
  8. #include <linux/mutex.h>
  9. #include <linux/ftrace.h>
  10. #include "trace_output.h"
  11. /* must be a power of 2 */
  12. #define EVENT_HASHSIZE 128
  13. DECLARE_RWSEM(trace_event_mutex);
  14. static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
  15. static int next_event_type = __TRACE_LAST_TYPE + 1;
  16. int trace_print_seq(struct seq_file *m, struct trace_seq *s)
  17. {
  18. int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
  19. int ret;
  20. ret = seq_write(m, s->buffer, len);
  21. /*
  22. * Only reset this buffer if we successfully wrote to the
  23. * seq_file buffer.
  24. */
  25. if (!ret)
  26. trace_seq_init(s);
  27. return ret;
  28. }
  29. enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
  30. {
  31. struct trace_seq *s = &iter->seq;
  32. struct trace_entry *entry = iter->ent;
  33. struct bprint_entry *field;
  34. int ret;
  35. trace_assign_type(field, entry);
  36. ret = trace_seq_bprintf(s, field->fmt, field->buf);
  37. if (!ret)
  38. return TRACE_TYPE_PARTIAL_LINE;
  39. return TRACE_TYPE_HANDLED;
  40. }
  41. enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
  42. {
  43. struct trace_seq *s = &iter->seq;
  44. struct trace_entry *entry = iter->ent;
  45. struct print_entry *field;
  46. int ret;
  47. trace_assign_type(field, entry);
  48. ret = trace_seq_printf(s, "%s", field->buf);
  49. if (!ret)
  50. return TRACE_TYPE_PARTIAL_LINE;
  51. return TRACE_TYPE_HANDLED;
  52. }
  53. /**
  54. * trace_seq_printf - sequence printing of trace information
  55. * @s: trace sequence descriptor
  56. * @fmt: printf format string
  57. *
  58. * It returns 0 if the trace oversizes the buffer's free
  59. * space, 1 otherwise.
  60. *
  61. * The tracer may use either sequence operations or its own
  62. * copy to user routines. To simplify formating of a trace
  63. * trace_seq_printf is used to store strings into a special
  64. * buffer (@s). Then the output may be either used by
  65. * the sequencer or pulled into another buffer.
  66. */
  67. int
  68. trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
  69. {
  70. int len = (PAGE_SIZE - 1) - s->len;
  71. va_list ap;
  72. int ret;
  73. if (s->full || !len)
  74. return 0;
  75. va_start(ap, fmt);
  76. ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
  77. va_end(ap);
  78. /* If we can't write it all, don't bother writing anything */
  79. if (ret >= len) {
  80. s->full = 1;
  81. return 0;
  82. }
  83. s->len += ret;
  84. return 1;
  85. }
  86. EXPORT_SYMBOL_GPL(trace_seq_printf);
  87. /**
  88. * trace_seq_vprintf - sequence printing of trace information
  89. * @s: trace sequence descriptor
  90. * @fmt: printf format string
  91. *
  92. * The tracer may use either sequence operations or its own
  93. * copy to user routines. To simplify formating of a trace
  94. * trace_seq_printf is used to store strings into a special
  95. * buffer (@s). Then the output may be either used by
  96. * the sequencer or pulled into another buffer.
  97. */
  98. int
  99. trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
  100. {
  101. int len = (PAGE_SIZE - 1) - s->len;
  102. int ret;
  103. if (s->full || !len)
  104. return 0;
  105. ret = vsnprintf(s->buffer + s->len, len, fmt, args);
  106. /* If we can't write it all, don't bother writing anything */
  107. if (ret >= len) {
  108. s->full = 1;
  109. return 0;
  110. }
  111. s->len += ret;
  112. return len;
  113. }
  114. EXPORT_SYMBOL_GPL(trace_seq_vprintf);
  115. int trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
  116. {
  117. int len = (PAGE_SIZE - 1) - s->len;
  118. int ret;
  119. if (s->full || !len)
  120. return 0;
  121. ret = bstr_printf(s->buffer + s->len, len, fmt, binary);
  122. /* If we can't write it all, don't bother writing anything */
  123. if (ret >= len) {
  124. s->full = 1;
  125. return 0;
  126. }
  127. s->len += ret;
  128. return len;
  129. }
  130. /**
  131. * trace_seq_puts - trace sequence printing of simple string
  132. * @s: trace sequence descriptor
  133. * @str: simple string to record
  134. *
  135. * The tracer may use either the sequence operations or its own
  136. * copy to user routines. This function records a simple string
  137. * into a special buffer (@s) for later retrieval by a sequencer
  138. * or other mechanism.
  139. */
  140. int trace_seq_puts(struct trace_seq *s, const char *str)
  141. {
  142. int len = strlen(str);
  143. if (s->full)
  144. return 0;
  145. if (len > ((PAGE_SIZE - 1) - s->len)) {
  146. s->full = 1;
  147. return 0;
  148. }
  149. memcpy(s->buffer + s->len, str, len);
  150. s->len += len;
  151. return len;
  152. }
  153. int trace_seq_putc(struct trace_seq *s, unsigned char c)
  154. {
  155. if (s->full)
  156. return 0;
  157. if (s->len >= (PAGE_SIZE - 1)) {
  158. s->full = 1;
  159. return 0;
  160. }
  161. s->buffer[s->len++] = c;
  162. return 1;
  163. }
  164. EXPORT_SYMBOL(trace_seq_putc);
  165. int trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len)
  166. {
  167. if (s->full)
  168. return 0;
  169. if (len > ((PAGE_SIZE - 1) - s->len)) {
  170. s->full = 1;
  171. return 0;
  172. }
  173. memcpy(s->buffer + s->len, mem, len);
  174. s->len += len;
  175. return len;
  176. }
  177. int trace_seq_putmem_hex(struct trace_seq *s, const void *mem, size_t len)
  178. {
  179. unsigned char hex[HEX_CHARS];
  180. const unsigned char *data = mem;
  181. int i, j;
  182. if (s->full)
  183. return 0;
  184. #ifdef __BIG_ENDIAN
  185. for (i = 0, j = 0; i < len; i++) {
  186. #else
  187. for (i = len-1, j = 0; i >= 0; i--) {
  188. #endif
  189. hex[j++] = hex_asc_hi(data[i]);
  190. hex[j++] = hex_asc_lo(data[i]);
  191. }
  192. hex[j++] = ' ';
  193. return trace_seq_putmem(s, hex, j);
  194. }
  195. void *trace_seq_reserve(struct trace_seq *s, size_t len)
  196. {
  197. void *ret;
  198. if (s->full)
  199. return NULL;
  200. if (len > ((PAGE_SIZE - 1) - s->len)) {
  201. s->full = 1;
  202. return NULL;
  203. }
  204. ret = s->buffer + s->len;
  205. s->len += len;
  206. return ret;
  207. }
  208. int trace_seq_path(struct trace_seq *s, struct path *path)
  209. {
  210. unsigned char *p;
  211. if (s->full)
  212. return 0;
  213. if (s->len >= (PAGE_SIZE - 1)) {
  214. s->full = 1;
  215. return 0;
  216. }
  217. p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len);
  218. if (!IS_ERR(p)) {
  219. p = mangle_path(s->buffer + s->len, p, "\n");
  220. if (p) {
  221. s->len = p - s->buffer;
  222. return 1;
  223. }
  224. } else {
  225. s->buffer[s->len++] = '?';
  226. return 1;
  227. }
  228. s->full = 1;
  229. return 0;
  230. }
  231. const char *
  232. ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
  233. unsigned long flags,
  234. const struct trace_print_flags *flag_array)
  235. {
  236. unsigned long mask;
  237. const char *str;
  238. const char *ret = p->buffer + p->len;
  239. int i;
  240. for (i = 0; flag_array[i].name && flags; i++) {
  241. mask = flag_array[i].mask;
  242. if ((flags & mask) != mask)
  243. continue;
  244. str = flag_array[i].name;
  245. flags &= ~mask;
  246. if (p->len && delim)
  247. trace_seq_puts(p, delim);
  248. trace_seq_puts(p, str);
  249. }
  250. /* check for left over flags */
  251. if (flags) {
  252. if (p->len && delim)
  253. trace_seq_puts(p, delim);
  254. trace_seq_printf(p, "0x%lx", flags);
  255. }
  256. trace_seq_putc(p, 0);
  257. return ret;
  258. }
  259. EXPORT_SYMBOL(ftrace_print_flags_seq);
  260. const char *
  261. ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
  262. const struct trace_print_flags *symbol_array)
  263. {
  264. int i;
  265. const char *ret = p->buffer + p->len;
  266. for (i = 0; symbol_array[i].name; i++) {
  267. if (val != symbol_array[i].mask)
  268. continue;
  269. trace_seq_puts(p, symbol_array[i].name);
  270. break;
  271. }
  272. if (!p->len)
  273. trace_seq_printf(p, "0x%lx", val);
  274. trace_seq_putc(p, 0);
  275. return ret;
  276. }
  277. EXPORT_SYMBOL(ftrace_print_symbols_seq);
  278. #if BITS_PER_LONG == 32
  279. const char *
  280. ftrace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
  281. const struct trace_print_flags_u64 *symbol_array)
  282. {
  283. int i;
  284. const char *ret = p->buffer + p->len;
  285. for (i = 0; symbol_array[i].name; i++) {
  286. if (val != symbol_array[i].mask)
  287. continue;
  288. trace_seq_puts(p, symbol_array[i].name);
  289. break;
  290. }
  291. if (!p->len)
  292. trace_seq_printf(p, "0x%llx", val);
  293. trace_seq_putc(p, 0);
  294. return ret;
  295. }
  296. EXPORT_SYMBOL(ftrace_print_symbols_seq_u64);
  297. #endif
  298. const char *
  299. ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
  300. {
  301. int i;
  302. const char *ret = p->buffer + p->len;
  303. for (i = 0; i < buf_len; i++)
  304. trace_seq_printf(p, "%s%2.2x", i == 0 ? "" : " ", buf[i]);
  305. trace_seq_putc(p, 0);
  306. return ret;
  307. }
  308. EXPORT_SYMBOL(ftrace_print_hex_seq);
  309. #ifdef CONFIG_KRETPROBES
  310. static inline const char *kretprobed(const char *name)
  311. {
  312. static const char tramp_name[] = "kretprobe_trampoline";
  313. int size = sizeof(tramp_name);
  314. if (strncmp(tramp_name, name, size) == 0)
  315. return "[unknown/kretprobe'd]";
  316. return name;
  317. }
  318. #else
  319. static inline const char *kretprobed(const char *name)
  320. {
  321. return name;
  322. }
  323. #endif /* CONFIG_KRETPROBES */
  324. static int
  325. seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
  326. {
  327. #ifdef CONFIG_KALLSYMS
  328. char str[KSYM_SYMBOL_LEN];
  329. const char *name;
  330. kallsyms_lookup(address, NULL, NULL, NULL, str);
  331. name = kretprobed(str);
  332. return trace_seq_printf(s, fmt, name);
  333. #endif
  334. return 1;
  335. }
  336. static int
  337. seq_print_sym_offset(struct trace_seq *s, const char *fmt,
  338. unsigned long address)
  339. {
  340. #ifdef CONFIG_KALLSYMS
  341. char str[KSYM_SYMBOL_LEN];
  342. const char *name;
  343. sprint_symbol(str, address);
  344. name = kretprobed(str);
  345. return trace_seq_printf(s, fmt, name);
  346. #endif
  347. return 1;
  348. }
  349. #ifndef CONFIG_64BIT
  350. # define IP_FMT "%08lx"
  351. #else
  352. # define IP_FMT "%016lx"
  353. #endif
  354. int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
  355. unsigned long ip, unsigned long sym_flags)
  356. {
  357. struct file *file = NULL;
  358. unsigned long vmstart = 0;
  359. int ret = 1;
  360. if (s->full)
  361. return 0;
  362. if (mm) {
  363. const struct vm_area_struct *vma;
  364. down_read(&mm->mmap_sem);
  365. vma = find_vma(mm, ip);
  366. if (vma) {
  367. file = vma->vm_file;
  368. vmstart = vma->vm_start;
  369. }
  370. if (file) {
  371. ret = trace_seq_path(s, &file->f_path);
  372. if (ret)
  373. ret = trace_seq_printf(s, "[+0x%lx]",
  374. ip - vmstart);
  375. }
  376. up_read(&mm->mmap_sem);
  377. }
  378. if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
  379. ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
  380. return ret;
  381. }
  382. int
  383. seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
  384. unsigned long sym_flags)
  385. {
  386. struct mm_struct *mm = NULL;
  387. int ret = 1;
  388. unsigned int i;
  389. if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
  390. struct task_struct *task;
  391. /*
  392. * we do the lookup on the thread group leader,
  393. * since individual threads might have already quit!
  394. */
  395. rcu_read_lock();
  396. task = find_task_by_vpid(entry->tgid);
  397. if (task)
  398. mm = get_task_mm(task);
  399. rcu_read_unlock();
  400. }
  401. for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
  402. unsigned long ip = entry->caller[i];
  403. if (ip == ULONG_MAX || !ret)
  404. break;
  405. if (ret)
  406. ret = trace_seq_puts(s, " => ");
  407. if (!ip) {
  408. if (ret)
  409. ret = trace_seq_puts(s, "??");
  410. if (ret)
  411. ret = trace_seq_puts(s, "\n");
  412. continue;
  413. }
  414. if (!ret)
  415. break;
  416. if (ret)
  417. ret = seq_print_user_ip(s, mm, ip, sym_flags);
  418. ret = trace_seq_puts(s, "\n");
  419. }
  420. if (mm)
  421. mmput(mm);
  422. return ret;
  423. }
  424. int
  425. seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
  426. {
  427. int ret;
  428. if (!ip)
  429. return trace_seq_printf(s, "0");
  430. if (sym_flags & TRACE_ITER_SYM_OFFSET)
  431. ret = seq_print_sym_offset(s, "%s", ip);
  432. else
  433. ret = seq_print_sym_short(s, "%s", ip);
  434. if (!ret)
  435. return 0;
  436. if (sym_flags & TRACE_ITER_SYM_ADDR)
  437. ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
  438. return ret;
  439. }
  440. /**
  441. * trace_print_lat_fmt - print the irq, preempt and lockdep fields
  442. * @s: trace seq struct to write to
  443. * @entry: The trace entry field from the ring buffer
  444. *
  445. * Prints the generic fields of irqs off, in hard or softirq, preempt
  446. * count.
  447. */
  448. int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
  449. {
  450. char hardsoft_irq;
  451. char need_resched;
  452. char irqs_off;
  453. int hardirq;
  454. int softirq;
  455. int ret;
  456. hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
  457. softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
  458. irqs_off =
  459. (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
  460. (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' :
  461. '.';
  462. need_resched =
  463. (entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.';
  464. hardsoft_irq =
  465. (hardirq && softirq) ? 'H' :
  466. hardirq ? 'h' :
  467. softirq ? 's' :
  468. '.';
  469. if (!trace_seq_printf(s, "%c%c%c",
  470. irqs_off, need_resched, hardsoft_irq))
  471. return 0;
  472. if (entry->preempt_count)
  473. ret = trace_seq_printf(s, "%x", entry->preempt_count);
  474. else
  475. ret = trace_seq_putc(s, '.');
  476. return ret;
  477. }
  478. static int
  479. lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
  480. {
  481. char comm[TASK_COMM_LEN];
  482. trace_find_cmdline(entry->pid, comm);
  483. if (!trace_seq_printf(s, "%8.8s-%-5d %3d",
  484. comm, entry->pid, cpu))
  485. return 0;
  486. return trace_print_lat_fmt(s, entry);
  487. }
  488. static unsigned long preempt_mark_thresh = 100;
  489. static int
  490. lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
  491. unsigned long rel_usecs)
  492. {
  493. return trace_seq_printf(s, " %4lldus%c: ", abs_usecs,
  494. rel_usecs > preempt_mark_thresh ? '!' :
  495. rel_usecs > 1 ? '+' : ' ');
  496. }
  497. int trace_print_context(struct trace_iterator *iter)
  498. {
  499. struct trace_seq *s = &iter->seq;
  500. struct trace_entry *entry = iter->ent;
  501. unsigned long long t = ns2usecs(iter->ts);
  502. unsigned long usec_rem = do_div(t, USEC_PER_SEC);
  503. unsigned long secs = (unsigned long)t;
  504. char comm[TASK_COMM_LEN];
  505. trace_find_cmdline(entry->pid, comm);
  506. return trace_seq_printf(s, "%16s-%-5d [%03d] %5lu.%06lu: ",
  507. comm, entry->pid, iter->cpu, secs, usec_rem);
  508. }
  509. int trace_print_lat_context(struct trace_iterator *iter)
  510. {
  511. u64 next_ts;
  512. int ret;
  513. struct trace_seq *s = &iter->seq;
  514. struct trace_entry *entry = iter->ent,
  515. *next_entry = trace_find_next_entry(iter, NULL,
  516. &next_ts);
  517. unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
  518. unsigned long abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
  519. unsigned long rel_usecs;
  520. if (!next_entry)
  521. next_ts = iter->ts;
  522. rel_usecs = ns2usecs(next_ts - iter->ts);
  523. if (verbose) {
  524. char comm[TASK_COMM_LEN];
  525. trace_find_cmdline(entry->pid, comm);
  526. ret = trace_seq_printf(s, "%16s %5d %3d %d %08x %08lx [%08llx]"
  527. " %ld.%03ldms (+%ld.%03ldms): ", comm,
  528. entry->pid, iter->cpu, entry->flags,
  529. entry->preempt_count, iter->idx,
  530. ns2usecs(iter->ts),
  531. abs_usecs / USEC_PER_MSEC,
  532. abs_usecs % USEC_PER_MSEC,
  533. rel_usecs / USEC_PER_MSEC,
  534. rel_usecs % USEC_PER_MSEC);
  535. } else {
  536. ret = lat_print_generic(s, entry, iter->cpu);
  537. if (ret)
  538. ret = lat_print_timestamp(s, abs_usecs, rel_usecs);
  539. }
  540. return ret;
  541. }
  542. static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
  543. static int task_state_char(unsigned long state)
  544. {
  545. int bit = state ? __ffs(state) + 1 : 0;
  546. return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
  547. }
  548. /**
  549. * ftrace_find_event - find a registered event
  550. * @type: the type of event to look for
  551. *
  552. * Returns an event of type @type otherwise NULL
  553. * Called with trace_event_read_lock() held.
  554. */
  555. struct trace_event *ftrace_find_event(int type)
  556. {
  557. struct trace_event *event;
  558. struct hlist_node *n;
  559. unsigned key;
  560. key = type & (EVENT_HASHSIZE - 1);
  561. hlist_for_each_entry(event, n, &event_hash[key], node) {
  562. if (event->type == type)
  563. return event;
  564. }
  565. return NULL;
  566. }
  567. static LIST_HEAD(ftrace_event_list);
  568. static int trace_search_list(struct list_head **list)
  569. {
  570. struct trace_event *e;
  571. int last = __TRACE_LAST_TYPE;
  572. if (list_empty(&ftrace_event_list)) {
  573. *list = &ftrace_event_list;
  574. return last + 1;
  575. }
  576. /*
  577. * We used up all possible max events,
  578. * lets see if somebody freed one.
  579. */
  580. list_for_each_entry(e, &ftrace_event_list, list) {
  581. if (e->type != last + 1)
  582. break;
  583. last++;
  584. }
  585. /* Did we used up all 65 thousand events??? */
  586. if ((last + 1) > FTRACE_MAX_EVENT)
  587. return 0;
  588. *list = &e->list;
  589. return last + 1;
  590. }
  591. void trace_event_read_lock(void)
  592. {
  593. down_read(&trace_event_mutex);
  594. }
  595. void trace_event_read_unlock(void)
  596. {
  597. up_read(&trace_event_mutex);
  598. }
  599. /**
  600. * register_ftrace_event - register output for an event type
  601. * @event: the event type to register
  602. *
  603. * Event types are stored in a hash and this hash is used to
  604. * find a way to print an event. If the @event->type is set
  605. * then it will use that type, otherwise it will assign a
  606. * type to use.
  607. *
  608. * If you assign your own type, please make sure it is added
  609. * to the trace_type enum in trace.h, to avoid collisions
  610. * with the dynamic types.
  611. *
  612. * Returns the event type number or zero on error.
  613. */
  614. int register_ftrace_event(struct trace_event *event)
  615. {
  616. unsigned key;
  617. int ret = 0;
  618. down_write(&trace_event_mutex);
  619. if (WARN_ON(!event))
  620. goto out;
  621. if (WARN_ON(!event->funcs))
  622. goto out;
  623. INIT_LIST_HEAD(&event->list);
  624. if (!event->type) {
  625. struct list_head *list = NULL;
  626. if (next_event_type > FTRACE_MAX_EVENT) {
  627. event->type = trace_search_list(&list);
  628. if (!event->type)
  629. goto out;
  630. } else {
  631. event->type = next_event_type++;
  632. list = &ftrace_event_list;
  633. }
  634. if (WARN_ON(ftrace_find_event(event->type)))
  635. goto out;
  636. list_add_tail(&event->list, list);
  637. } else if (event->type > __TRACE_LAST_TYPE) {
  638. printk(KERN_WARNING "Need to add type to trace.h\n");
  639. WARN_ON(1);
  640. goto out;
  641. } else {
  642. /* Is this event already used */
  643. if (ftrace_find_event(event->type))
  644. goto out;
  645. }
  646. if (event->funcs->trace == NULL)
  647. event->funcs->trace = trace_nop_print;
  648. if (event->funcs->raw == NULL)
  649. event->funcs->raw = trace_nop_print;
  650. if (event->funcs->hex == NULL)
  651. event->funcs->hex = trace_nop_print;
  652. if (event->funcs->binary == NULL)
  653. event->funcs->binary = trace_nop_print;
  654. key = event->type & (EVENT_HASHSIZE - 1);
  655. hlist_add_head(&event->node, &event_hash[key]);
  656. ret = event->type;
  657. out:
  658. up_write(&trace_event_mutex);
  659. return ret;
  660. }
  661. EXPORT_SYMBOL_GPL(register_ftrace_event);
  662. /*
  663. * Used by module code with the trace_event_mutex held for write.
  664. */
  665. int __unregister_ftrace_event(struct trace_event *event)
  666. {
  667. hlist_del(&event->node);
  668. list_del(&event->list);
  669. return 0;
  670. }
  671. /**
  672. * unregister_ftrace_event - remove a no longer used event
  673. * @event: the event to remove
  674. */
  675. int unregister_ftrace_event(struct trace_event *event)
  676. {
  677. down_write(&trace_event_mutex);
  678. __unregister_ftrace_event(event);
  679. up_write(&trace_event_mutex);
  680. return 0;
  681. }
  682. EXPORT_SYMBOL_GPL(unregister_ftrace_event);
  683. /*
  684. * Standard events
  685. */
  686. enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
  687. struct trace_event *event)
  688. {
  689. if (!trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type))
  690. return TRACE_TYPE_PARTIAL_LINE;
  691. return TRACE_TYPE_HANDLED;
  692. }
  693. /* TRACE_FN */
  694. static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,
  695. struct trace_event *event)
  696. {
  697. struct ftrace_entry *field;
  698. struct trace_seq *s = &iter->seq;
  699. trace_assign_type(field, iter->ent);
  700. if (!seq_print_ip_sym(s, field->ip, flags))
  701. goto partial;
  702. if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
  703. if (!trace_seq_printf(s, " <-"))
  704. goto partial;
  705. if (!seq_print_ip_sym(s,
  706. field->parent_ip,
  707. flags))
  708. goto partial;
  709. }
  710. if (!trace_seq_printf(s, "\n"))
  711. goto partial;
  712. return TRACE_TYPE_HANDLED;
  713. partial:
  714. return TRACE_TYPE_PARTIAL_LINE;
  715. }
  716. static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
  717. struct trace_event *event)
  718. {
  719. struct ftrace_entry *field;
  720. trace_assign_type(field, iter->ent);
  721. if (!trace_seq_printf(&iter->seq, "%lx %lx\n",
  722. field->ip,
  723. field->parent_ip))
  724. return TRACE_TYPE_PARTIAL_LINE;
  725. return TRACE_TYPE_HANDLED;
  726. }
  727. static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
  728. struct trace_event *event)
  729. {
  730. struct ftrace_entry *field;
  731. struct trace_seq *s = &iter->seq;
  732. trace_assign_type(field, iter->ent);
  733. SEQ_PUT_HEX_FIELD_RET(s, field->ip);
  734. SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
  735. return TRACE_TYPE_HANDLED;
  736. }
  737. static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
  738. struct trace_event *event)
  739. {
  740. struct ftrace_entry *field;
  741. struct trace_seq *s = &iter->seq;
  742. trace_assign_type(field, iter->ent);
  743. SEQ_PUT_FIELD_RET(s, field->ip);
  744. SEQ_PUT_FIELD_RET(s, field->parent_ip);
  745. return TRACE_TYPE_HANDLED;
  746. }
  747. static struct trace_event_functions trace_fn_funcs = {
  748. .trace = trace_fn_trace,
  749. .raw = trace_fn_raw,
  750. .hex = trace_fn_hex,
  751. .binary = trace_fn_bin,
  752. };
  753. static struct trace_event trace_fn_event = {
  754. .type = TRACE_FN,
  755. .funcs = &trace_fn_funcs,
  756. };
  757. /* TRACE_CTX an TRACE_WAKE */
  758. static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
  759. char *delim)
  760. {
  761. struct ctx_switch_entry *field;
  762. char comm[TASK_COMM_LEN];
  763. int S, T;
  764. trace_assign_type(field, iter->ent);
  765. T = task_state_char(field->next_state);
  766. S = task_state_char(field->prev_state);
  767. trace_find_cmdline(field->next_pid, comm);
  768. if (!trace_seq_printf(&iter->seq,
  769. " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
  770. field->prev_pid,
  771. field->prev_prio,
  772. S, delim,
  773. field->next_cpu,
  774. field->next_pid,
  775. field->next_prio,
  776. T, comm))
  777. return TRACE_TYPE_PARTIAL_LINE;
  778. return TRACE_TYPE_HANDLED;
  779. }
  780. static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
  781. struct trace_event *event)
  782. {
  783. return trace_ctxwake_print(iter, "==>");
  784. }
  785. static enum print_line_t trace_wake_print(struct trace_iterator *iter,
  786. int flags, struct trace_event *event)
  787. {
  788. return trace_ctxwake_print(iter, " +");
  789. }
  790. static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
  791. {
  792. struct ctx_switch_entry *field;
  793. int T;
  794. trace_assign_type(field, iter->ent);
  795. if (!S)
  796. S = task_state_char(field->prev_state);
  797. T = task_state_char(field->next_state);
  798. if (!trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
  799. field->prev_pid,
  800. field->prev_prio,
  801. S,
  802. field->next_cpu,
  803. field->next_pid,
  804. field->next_prio,
  805. T))
  806. return TRACE_TYPE_PARTIAL_LINE;
  807. return TRACE_TYPE_HANDLED;
  808. }
  809. static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
  810. struct trace_event *event)
  811. {
  812. return trace_ctxwake_raw(iter, 0);
  813. }
  814. static enum print_line_t trace_wake_raw(struct trace_iterator *iter, int flags,
  815. struct trace_event *event)
  816. {
  817. return trace_ctxwake_raw(iter, '+');
  818. }
  819. static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
  820. {
  821. struct ctx_switch_entry *field;
  822. struct trace_seq *s = &iter->seq;
  823. int T;
  824. trace_assign_type(field, iter->ent);
  825. if (!S)
  826. S = task_state_char(field->prev_state);
  827. T = task_state_char(field->next_state);
  828. SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
  829. SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
  830. SEQ_PUT_HEX_FIELD_RET(s, S);
  831. SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
  832. SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
  833. SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
  834. SEQ_PUT_HEX_FIELD_RET(s, T);
  835. return TRACE_TYPE_HANDLED;
  836. }
  837. static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
  838. struct trace_event *event)
  839. {
  840. return trace_ctxwake_hex(iter, 0);
  841. }
  842. static enum print_line_t trace_wake_hex(struct trace_iterator *iter, int flags,
  843. struct trace_event *event)
  844. {
  845. return trace_ctxwake_hex(iter, '+');
  846. }
  847. static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
  848. int flags, struct trace_event *event)
  849. {
  850. struct ctx_switch_entry *field;
  851. struct trace_seq *s = &iter->seq;
  852. trace_assign_type(field, iter->ent);
  853. SEQ_PUT_FIELD_RET(s, field->prev_pid);
  854. SEQ_PUT_FIELD_RET(s, field->prev_prio);
  855. SEQ_PUT_FIELD_RET(s, field->prev_state);
  856. SEQ_PUT_FIELD_RET(s, field->next_pid);
  857. SEQ_PUT_FIELD_RET(s, field->next_prio);
  858. SEQ_PUT_FIELD_RET(s, field->next_state);
  859. return TRACE_TYPE_HANDLED;
  860. }
  861. static struct trace_event_functions trace_ctx_funcs = {
  862. .trace = trace_ctx_print,
  863. .raw = trace_ctx_raw,
  864. .hex = trace_ctx_hex,
  865. .binary = trace_ctxwake_bin,
  866. };
  867. static struct trace_event trace_ctx_event = {
  868. .type = TRACE_CTX,
  869. .funcs = &trace_ctx_funcs,
  870. };
  871. static struct trace_event_functions trace_wake_funcs = {
  872. .trace = trace_wake_print,
  873. .raw = trace_wake_raw,
  874. .hex = trace_wake_hex,
  875. .binary = trace_ctxwake_bin,
  876. };
  877. static struct trace_event trace_wake_event = {
  878. .type = TRACE_WAKE,
  879. .funcs = &trace_wake_funcs,
  880. };
  881. /* TRACE_STACK */
  882. static enum print_line_t trace_stack_print(struct trace_iterator *iter,
  883. int flags, struct trace_event *event)
  884. {
  885. struct stack_entry *field;
  886. struct trace_seq *s = &iter->seq;
  887. int i;
  888. trace_assign_type(field, iter->ent);
  889. if (!trace_seq_puts(s, "<stack trace>\n"))
  890. goto partial;
  891. for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
  892. if (!field->caller[i] || (field->caller[i] == ULONG_MAX))
  893. break;
  894. if (!trace_seq_puts(s, " => "))
  895. goto partial;
  896. if (!seq_print_ip_sym(s, field->caller[i], flags))
  897. goto partial;
  898. if (!trace_seq_puts(s, "\n"))
  899. goto partial;
  900. }
  901. return TRACE_TYPE_HANDLED;
  902. partial:
  903. return TRACE_TYPE_PARTIAL_LINE;
  904. }
  905. static struct trace_event_functions trace_stack_funcs = {
  906. .trace = trace_stack_print,
  907. };
  908. static struct trace_event trace_stack_event = {
  909. .type = TRACE_STACK,
  910. .funcs = &trace_stack_funcs,
  911. };
  912. /* TRACE_USER_STACK */
  913. static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
  914. int flags, struct trace_event *event)
  915. {
  916. struct userstack_entry *field;
  917. struct trace_seq *s = &iter->seq;
  918. trace_assign_type(field, iter->ent);
  919. if (!trace_seq_puts(s, "<user stack trace>\n"))
  920. goto partial;
  921. if (!seq_print_userip_objs(field, s, flags))
  922. goto partial;
  923. return TRACE_TYPE_HANDLED;
  924. partial:
  925. return TRACE_TYPE_PARTIAL_LINE;
  926. }
  927. static struct trace_event_functions trace_user_stack_funcs = {
  928. .trace = trace_user_stack_print,
  929. };
  930. static struct trace_event trace_user_stack_event = {
  931. .type = TRACE_USER_STACK,
  932. .funcs = &trace_user_stack_funcs,
  933. };
  934. /* TRACE_BPRINT */
  935. static enum print_line_t
  936. trace_bprint_print(struct trace_iterator *iter, int flags,
  937. struct trace_event *event)
  938. {
  939. struct trace_entry *entry = iter->ent;
  940. struct trace_seq *s = &iter->seq;
  941. struct bprint_entry *field;
  942. trace_assign_type(field, entry);
  943. if (!seq_print_ip_sym(s, field->ip, flags))
  944. goto partial;
  945. if (!trace_seq_puts(s, ": "))
  946. goto partial;
  947. if (!trace_seq_bprintf(s, field->fmt, field->buf))
  948. goto partial;
  949. return TRACE_TYPE_HANDLED;
  950. partial:
  951. return TRACE_TYPE_PARTIAL_LINE;
  952. }
  953. static enum print_line_t
  954. trace_bprint_raw(struct trace_iterator *iter, int flags,
  955. struct trace_event *event)
  956. {
  957. struct bprint_entry *field;
  958. struct trace_seq *s = &iter->seq;
  959. trace_assign_type(field, iter->ent);
  960. if (!trace_seq_printf(s, ": %lx : ", field->ip))
  961. goto partial;
  962. if (!trace_seq_bprintf(s, field->fmt, field->buf))
  963. goto partial;
  964. return TRACE_TYPE_HANDLED;
  965. partial:
  966. return TRACE_TYPE_PARTIAL_LINE;
  967. }
  968. static struct trace_event_functions trace_bprint_funcs = {
  969. .trace = trace_bprint_print,
  970. .raw = trace_bprint_raw,
  971. };
  972. static struct trace_event trace_bprint_event = {
  973. .type = TRACE_BPRINT,
  974. .funcs = &trace_bprint_funcs,
  975. };
  976. /* TRACE_PRINT */
  977. static enum print_line_t trace_print_print(struct trace_iterator *iter,
  978. int flags, struct trace_event *event)
  979. {
  980. struct print_entry *field;
  981. struct trace_seq *s = &iter->seq;
  982. trace_assign_type(field, iter->ent);
  983. if (!seq_print_ip_sym(s, field->ip, flags))
  984. goto partial;
  985. if (!trace_seq_printf(s, ": %s", field->buf))
  986. goto partial;
  987. return TRACE_TYPE_HANDLED;
  988. partial:
  989. return TRACE_TYPE_PARTIAL_LINE;
  990. }
  991. static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
  992. struct trace_event *event)
  993. {
  994. struct print_entry *field;
  995. trace_assign_type(field, iter->ent);
  996. if (!trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf))
  997. goto partial;
  998. return TRACE_TYPE_HANDLED;
  999. partial:
  1000. return TRACE_TYPE_PARTIAL_LINE;
  1001. }
  1002. static struct trace_event_functions trace_print_funcs = {
  1003. .trace = trace_print_print,
  1004. .raw = trace_print_raw,
  1005. };
  1006. static struct trace_event trace_print_event = {
  1007. .type = TRACE_PRINT,
  1008. .funcs = &trace_print_funcs,
  1009. };
  1010. static struct trace_event *events[] __initdata = {
  1011. &trace_fn_event,
  1012. &trace_ctx_event,
  1013. &trace_wake_event,
  1014. &trace_stack_event,
  1015. &trace_user_stack_event,
  1016. &trace_bprint_event,
  1017. &trace_print_event,
  1018. NULL
  1019. };
  1020. __init static int init_events(void)
  1021. {
  1022. struct trace_event *event;
  1023. int i, ret;
  1024. for (i = 0; events[i]; i++) {
  1025. event = events[i];
  1026. ret = register_ftrace_event(event);
  1027. if (!ret) {
  1028. printk(KERN_WARNING "event %d failed to register\n",
  1029. event->type);
  1030. WARN_ON_ONCE(1);
  1031. }
  1032. }
  1033. return 0;
  1034. }
  1035. device_initcall(init_events);