trace-event-read.c 8.1 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Copyright (C) 2009, Steven Rostedt <srostedt@redhat.com>
  4. */
  5. #include <dirent.h>
  6. #include <stdio.h>
  7. #include <stdlib.h>
  8. #include <string.h>
  9. #include <stdarg.h>
  10. #include <sys/types.h>
  11. #include <sys/stat.h>
  12. #include <sys/wait.h>
  13. #include <sys/mman.h>
  14. #include <fcntl.h>
  15. #include <unistd.h>
  16. #include <errno.h>
  17. #include "trace-event.h"
  18. #include "debug.h"
  19. static int input_fd;
  20. static ssize_t trace_data_size;
  21. static bool repipe;
  22. static int __do_read(int fd, void *buf, int size)
  23. {
  24. int rsize = size;
  25. while (size) {
  26. int ret = read(fd, buf, size);
  27. if (ret <= 0)
  28. return -1;
  29. if (repipe) {
  30. int retw = write(STDOUT_FILENO, buf, ret);
  31. if (retw <= 0 || retw != ret) {
  32. pr_debug("repiping input file");
  33. return -1;
  34. }
  35. }
  36. size -= ret;
  37. buf += ret;
  38. }
  39. return rsize;
  40. }
  41. static int do_read(void *data, int size)
  42. {
  43. int r;
  44. r = __do_read(input_fd, data, size);
  45. if (r <= 0) {
  46. pr_debug("reading input file (size expected=%d received=%d)",
  47. size, r);
  48. return -1;
  49. }
  50. trace_data_size += r;
  51. return r;
  52. }
  53. /* If it fails, the next read will report it */
  54. static void skip(int size)
  55. {
  56. char buf[BUFSIZ];
  57. int r;
  58. while (size) {
  59. r = size > BUFSIZ ? BUFSIZ : size;
  60. do_read(buf, r);
  61. size -= r;
  62. }
  63. }
  64. static unsigned int read4(struct tep_handle *pevent)
  65. {
  66. unsigned int data;
  67. if (do_read(&data, 4) < 0)
  68. return 0;
  69. return tep_read_number(pevent, &data, 4);
  70. }
  71. static unsigned long long read8(struct tep_handle *pevent)
  72. {
  73. unsigned long long data;
  74. if (do_read(&data, 8) < 0)
  75. return 0;
  76. return tep_read_number(pevent, &data, 8);
  77. }
  78. static char *read_string(void)
  79. {
  80. char buf[BUFSIZ];
  81. char *str = NULL;
  82. int size = 0;
  83. off_t r;
  84. char c;
  85. for (;;) {
  86. r = read(input_fd, &c, 1);
  87. if (r < 0) {
  88. pr_debug("reading input file");
  89. goto out;
  90. }
  91. if (!r) {
  92. pr_debug("no data");
  93. goto out;
  94. }
  95. if (repipe) {
  96. int retw = write(STDOUT_FILENO, &c, 1);
  97. if (retw <= 0 || retw != r) {
  98. pr_debug("repiping input file string");
  99. goto out;
  100. }
  101. }
  102. buf[size++] = c;
  103. if (!c)
  104. break;
  105. }
  106. trace_data_size += size;
  107. str = malloc(size);
  108. if (str)
  109. memcpy(str, buf, size);
  110. out:
  111. return str;
  112. }
  113. static int read_proc_kallsyms(struct tep_handle *pevent)
  114. {
  115. unsigned int size;
  116. size = read4(pevent);
  117. if (!size)
  118. return 0;
  119. /*
  120. * Just skip it, now that we configure libtraceevent to use the
  121. * tools/perf/ symbol resolver.
  122. *
  123. * We need to skip it so that we can continue parsing old perf.data
  124. * files, that contains this /proc/kallsyms payload.
  125. *
  126. * Newer perf.data files will have just the 4-bytes zeros "kallsyms
  127. * payload", so that older tools can continue reading it and interpret
  128. * it as "no kallsyms payload is present".
  129. */
  130. lseek(input_fd, size, SEEK_CUR);
  131. trace_data_size += size;
  132. return 0;
  133. }
  134. static int read_ftrace_printk(struct tep_handle *pevent)
  135. {
  136. unsigned int size;
  137. char *buf;
  138. /* it can have 0 size */
  139. size = read4(pevent);
  140. if (!size)
  141. return 0;
  142. buf = malloc(size + 1);
  143. if (buf == NULL)
  144. return -1;
  145. if (do_read(buf, size) < 0) {
  146. free(buf);
  147. return -1;
  148. }
  149. buf[size] = '\0';
  150. parse_ftrace_printk(pevent, buf, size);
  151. free(buf);
  152. return 0;
  153. }
  154. static int read_header_files(struct tep_handle *pevent)
  155. {
  156. unsigned long long size;
  157. char *header_page;
  158. char buf[BUFSIZ];
  159. int ret = 0;
  160. if (do_read(buf, 12) < 0)
  161. return -1;
  162. if (memcmp(buf, "header_page", 12) != 0) {
  163. pr_debug("did not read header page");
  164. return -1;
  165. }
  166. size = read8(pevent);
  167. header_page = malloc(size);
  168. if (header_page == NULL)
  169. return -1;
  170. if (do_read(header_page, size) < 0) {
  171. pr_debug("did not read header page");
  172. free(header_page);
  173. return -1;
  174. }
  175. if (!tep_parse_header_page(pevent, header_page, size,
  176. tep_get_long_size(pevent))) {
  177. /*
  178. * The commit field in the page is of type long,
  179. * use that instead, since it represents the kernel.
  180. */
  181. tep_set_long_size(pevent, tep_get_header_page_size(pevent));
  182. }
  183. free(header_page);
  184. if (do_read(buf, 13) < 0)
  185. return -1;
  186. if (memcmp(buf, "header_event", 13) != 0) {
  187. pr_debug("did not read header event");
  188. return -1;
  189. }
  190. size = read8(pevent);
  191. skip(size);
  192. return ret;
  193. }
  194. static int read_ftrace_file(struct tep_handle *pevent, unsigned long long size)
  195. {
  196. int ret;
  197. char *buf;
  198. buf = malloc(size);
  199. if (buf == NULL) {
  200. pr_debug("memory allocation failure\n");
  201. return -1;
  202. }
  203. ret = do_read(buf, size);
  204. if (ret < 0) {
  205. pr_debug("error reading ftrace file.\n");
  206. goto out;
  207. }
  208. ret = parse_ftrace_file(pevent, buf, size);
  209. if (ret < 0)
  210. pr_debug("error parsing ftrace file.\n");
  211. out:
  212. free(buf);
  213. return ret;
  214. }
  215. static int read_event_file(struct tep_handle *pevent, char *sys,
  216. unsigned long long size)
  217. {
  218. int ret;
  219. char *buf;
  220. buf = malloc(size);
  221. if (buf == NULL) {
  222. pr_debug("memory allocation failure\n");
  223. return -1;
  224. }
  225. ret = do_read(buf, size);
  226. if (ret < 0)
  227. goto out;
  228. ret = parse_event_file(pevent, buf, size, sys);
  229. if (ret < 0)
  230. pr_debug("error parsing event file.\n");
  231. out:
  232. free(buf);
  233. return ret;
  234. }
  235. static int read_ftrace_files(struct tep_handle *pevent)
  236. {
  237. unsigned long long size;
  238. int count;
  239. int i;
  240. int ret;
  241. count = read4(pevent);
  242. for (i = 0; i < count; i++) {
  243. size = read8(pevent);
  244. ret = read_ftrace_file(pevent, size);
  245. if (ret)
  246. return ret;
  247. }
  248. return 0;
  249. }
  250. static int read_event_files(struct tep_handle *pevent)
  251. {
  252. unsigned long long size;
  253. char *sys;
  254. int systems;
  255. int count;
  256. int i,x;
  257. int ret;
  258. systems = read4(pevent);
  259. for (i = 0; i < systems; i++) {
  260. sys = read_string();
  261. if (sys == NULL)
  262. return -1;
  263. count = read4(pevent);
  264. for (x=0; x < count; x++) {
  265. size = read8(pevent);
  266. ret = read_event_file(pevent, sys, size);
  267. if (ret) {
  268. free(sys);
  269. return ret;
  270. }
  271. }
  272. free(sys);
  273. }
  274. return 0;
  275. }
  276. static int read_saved_cmdline(struct tep_handle *pevent)
  277. {
  278. unsigned long long size;
  279. char *buf;
  280. int ret;
  281. /* it can have 0 size */
  282. size = read8(pevent);
  283. if (!size)
  284. return 0;
  285. buf = malloc(size + 1);
  286. if (buf == NULL) {
  287. pr_debug("memory allocation failure\n");
  288. return -1;
  289. }
  290. ret = do_read(buf, size);
  291. if (ret < 0) {
  292. pr_debug("error reading saved cmdlines\n");
  293. goto out;
  294. }
  295. buf[ret] = '\0';
  296. parse_saved_cmdline(pevent, buf, size);
  297. ret = 0;
  298. out:
  299. free(buf);
  300. return ret;
  301. }
  302. ssize_t trace_report(int fd, struct trace_event *tevent, bool __repipe)
  303. {
  304. char buf[BUFSIZ];
  305. char test[] = { 23, 8, 68 };
  306. char *version;
  307. int show_version = 0;
  308. int show_funcs = 0;
  309. int show_printk = 0;
  310. ssize_t size = -1;
  311. int file_bigendian;
  312. int host_bigendian;
  313. int file_long_size;
  314. int file_page_size;
  315. struct tep_handle *pevent = NULL;
  316. int err;
  317. repipe = __repipe;
  318. input_fd = fd;
  319. if (do_read(buf, 3) < 0)
  320. return -1;
  321. if (memcmp(buf, test, 3) != 0) {
  322. pr_debug("no trace data in the file");
  323. return -1;
  324. }
  325. if (do_read(buf, 7) < 0)
  326. return -1;
  327. if (memcmp(buf, "tracing", 7) != 0) {
  328. pr_debug("not a trace file (missing 'tracing' tag)");
  329. return -1;
  330. }
  331. version = read_string();
  332. if (version == NULL)
  333. return -1;
  334. if (show_version)
  335. printf("version = %s\n", version);
  336. if (do_read(buf, 1) < 0) {
  337. free(version);
  338. return -1;
  339. }
  340. file_bigendian = buf[0];
  341. host_bigendian = bigendian();
  342. if (trace_event__init(tevent)) {
  343. pr_debug("trace_event__init failed");
  344. goto out;
  345. }
  346. pevent = tevent->pevent;
  347. tep_set_flag(pevent, TEP_NSEC_OUTPUT);
  348. tep_set_file_bigendian(pevent, file_bigendian);
  349. tep_set_local_bigendian(pevent, host_bigendian);
  350. if (do_read(buf, 1) < 0)
  351. goto out;
  352. file_long_size = buf[0];
  353. file_page_size = read4(pevent);
  354. if (!file_page_size)
  355. goto out;
  356. tep_set_long_size(pevent, file_long_size);
  357. tep_set_page_size(pevent, file_page_size);
  358. err = read_header_files(pevent);
  359. if (err)
  360. goto out;
  361. err = read_ftrace_files(pevent);
  362. if (err)
  363. goto out;
  364. err = read_event_files(pevent);
  365. if (err)
  366. goto out;
  367. err = read_proc_kallsyms(pevent);
  368. if (err)
  369. goto out;
  370. err = read_ftrace_printk(pevent);
  371. if (err)
  372. goto out;
  373. if (atof(version) >= 0.6) {
  374. err = read_saved_cmdline(pevent);
  375. if (err)
  376. goto out;
  377. }
  378. size = trace_data_size;
  379. repipe = false;
  380. if (show_funcs) {
  381. tep_print_funcs(pevent);
  382. } else if (show_printk) {
  383. tep_print_printk(pevent);
  384. }
  385. pevent = NULL;
  386. out:
  387. if (pevent)
  388. trace_event__cleanup(tevent);
  389. free(version);
  390. return size;
  391. }