1 /*
2 * build-id.c
3 *
4 * build-id support
5 *
6 * Copyright (C) 2009, 2010 Red Hat Inc.
7 * Copyright (C) 2009, 2010 Arnaldo Carvalho de Melo <acme@redhat.com>
8 */
9 #include "util.h"
10 #include <stdio.h>
11 #include "build-id.h"
12 #include "event.h"
13 #include "symbol.h"
14 #include <linux/kernel.h>
15 #include "debug.h"
16 #include "session.h"
17 #include "tool.h"
18 #include "header.h"
19 #include "vdso.h"
20
21
22 static bool no_buildid_cache;
23
build_id__mark_dso_hit(struct perf_tool * tool __maybe_unused,union perf_event * event,struct perf_sample * sample,struct perf_evsel * evsel __maybe_unused,struct machine * machine)24 int build_id__mark_dso_hit(struct perf_tool *tool __maybe_unused,
25 union perf_event *event,
26 struct perf_sample *sample,
27 struct perf_evsel *evsel __maybe_unused,
28 struct machine *machine)
29 {
30 struct addr_location al;
31 u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
32 struct thread *thread = machine__findnew_thread(machine, sample->pid,
33 sample->tid);
34
35 if (thread == NULL) {
36 pr_err("problem processing %d event, skipping it.\n",
37 event->header.type);
38 return -1;
39 }
40
41 thread__find_addr_map(thread, cpumode, MAP__FUNCTION, sample->ip, &al);
42
43 if (al.map != NULL)
44 al.map->dso->hit = 1;
45
46 thread__put(thread);
47 return 0;
48 }
49
perf_event__exit_del_thread(struct perf_tool * tool __maybe_unused,union perf_event * event,struct perf_sample * sample __maybe_unused,struct machine * machine)50 static int perf_event__exit_del_thread(struct perf_tool *tool __maybe_unused,
51 union perf_event *event,
52 struct perf_sample *sample
53 __maybe_unused,
54 struct machine *machine)
55 {
56 struct thread *thread = machine__findnew_thread(machine,
57 event->fork.pid,
58 event->fork.tid);
59
60 dump_printf("(%d:%d):(%d:%d)\n", event->fork.pid, event->fork.tid,
61 event->fork.ppid, event->fork.ptid);
62
63 if (thread) {
64 machine__remove_thread(machine, thread);
65 thread__put(thread);
66 }
67
68 return 0;
69 }
70
71 struct perf_tool build_id__mark_dso_hit_ops = {
72 .sample = build_id__mark_dso_hit,
73 .mmap = perf_event__process_mmap,
74 .mmap2 = perf_event__process_mmap2,
75 .fork = perf_event__process_fork,
76 .exit = perf_event__exit_del_thread,
77 .attr = perf_event__process_attr,
78 .build_id = perf_event__process_build_id,
79 .ordered_events = true,
80 };
81
build_id__sprintf(const u8 * build_id,int len,char * bf)82 int build_id__sprintf(const u8 *build_id, int len, char *bf)
83 {
84 char *bid = bf;
85 const u8 *raw = build_id;
86 int i;
87
88 for (i = 0; i < len; ++i) {
89 sprintf(bid, "%02x", *raw);
90 ++raw;
91 bid += 2;
92 }
93
94 return (bid - bf) + 1;
95 }
96
sysfs__sprintf_build_id(const char * root_dir,char * sbuild_id)97 int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id)
98 {
99 char notes[PATH_MAX];
100 u8 build_id[BUILD_ID_SIZE];
101 int ret;
102
103 if (!root_dir)
104 root_dir = "";
105
106 scnprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir);
107
108 ret = sysfs__read_build_id(notes, build_id, sizeof(build_id));
109 if (ret < 0)
110 return ret;
111
112 return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
113 }
114
filename__sprintf_build_id(const char * pathname,char * sbuild_id)115 int filename__sprintf_build_id(const char *pathname, char *sbuild_id)
116 {
117 u8 build_id[BUILD_ID_SIZE];
118 int ret;
119
120 ret = filename__read_build_id(pathname, build_id, sizeof(build_id));
121 if (ret < 0)
122 return ret;
123 else if (ret != sizeof(build_id))
124 return -EINVAL;
125
126 return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
127 }
128
129 /* asnprintf consolidates asprintf and snprintf */
asnprintf(char ** strp,size_t size,const char * fmt,...)130 static int asnprintf(char **strp, size_t size, const char *fmt, ...)
131 {
132 va_list ap;
133 int ret;
134
135 if (!strp)
136 return -EINVAL;
137
138 va_start(ap, fmt);
139 if (*strp)
140 ret = vsnprintf(*strp, size, fmt, ap);
141 else
142 ret = vasprintf(strp, fmt, ap);
143 va_end(ap);
144
145 return ret;
146 }
147
build_id__filename(const char * sbuild_id,char * bf,size_t size)148 static char *build_id__filename(const char *sbuild_id, char *bf, size_t size)
149 {
150 char *tmp = bf;
151 int ret = asnprintf(&bf, size, "%s/.build-id/%.2s/%s", buildid_dir,
152 sbuild_id, sbuild_id + 2);
153 if (ret < 0 || (tmp && size < (unsigned int)ret))
154 return NULL;
155 return bf;
156 }
157
dso__build_id_filename(const struct dso * dso,char * bf,size_t size)158 char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size)
159 {
160 char build_id_hex[SBUILD_ID_SIZE];
161
162 if (!dso->has_build_id)
163 return NULL;
164
165 build_id__sprintf(dso->build_id, sizeof(dso->build_id), build_id_hex);
166 return build_id__filename(build_id_hex, bf, size);
167 }
168
169 #define dsos__for_each_with_build_id(pos, head) \
170 list_for_each_entry(pos, head, node) \
171 if (!pos->has_build_id) \
172 continue; \
173 else
174
write_buildid(const char * name,size_t name_len,u8 * build_id,pid_t pid,u16 misc,int fd)175 static int write_buildid(const char *name, size_t name_len, u8 *build_id,
176 pid_t pid, u16 misc, int fd)
177 {
178 int err;
179 struct build_id_event b;
180 size_t len;
181
182 len = name_len + 1;
183 len = PERF_ALIGN(len, NAME_ALIGN);
184
185 memset(&b, 0, sizeof(b));
186 memcpy(&b.build_id, build_id, BUILD_ID_SIZE);
187 b.pid = pid;
188 b.header.misc = misc;
189 b.header.size = sizeof(b) + len;
190
191 err = writen(fd, &b, sizeof(b));
192 if (err < 0)
193 return err;
194
195 return write_padded(fd, name, name_len + 1, len);
196 }
197
machine__write_buildid_table(struct machine * machine,int fd)198 static int machine__write_buildid_table(struct machine *machine, int fd)
199 {
200 int err = 0;
201 char nm[PATH_MAX];
202 struct dso *pos;
203 u16 kmisc = PERF_RECORD_MISC_KERNEL,
204 umisc = PERF_RECORD_MISC_USER;
205
206 if (!machine__is_host(machine)) {
207 kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
208 umisc = PERF_RECORD_MISC_GUEST_USER;
209 }
210
211 dsos__for_each_with_build_id(pos, &machine->dsos.head) {
212 const char *name;
213 size_t name_len;
214
215 if (!pos->hit)
216 continue;
217
218 if (dso__is_vdso(pos)) {
219 name = pos->short_name;
220 name_len = pos->short_name_len + 1;
221 } else if (dso__is_kcore(pos)) {
222 machine__mmap_name(machine, nm, sizeof(nm));
223 name = nm;
224 name_len = strlen(nm) + 1;
225 } else {
226 name = pos->long_name;
227 name_len = pos->long_name_len + 1;
228 }
229
230 err = write_buildid(name, name_len, pos->build_id, machine->pid,
231 pos->kernel ? kmisc : umisc, fd);
232 if (err)
233 break;
234 }
235
236 return err;
237 }
238
perf_session__write_buildid_table(struct perf_session * session,int fd)239 int perf_session__write_buildid_table(struct perf_session *session, int fd)
240 {
241 struct rb_node *nd;
242 int err = machine__write_buildid_table(&session->machines.host, fd);
243
244 if (err)
245 return err;
246
247 for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
248 struct machine *pos = rb_entry(nd, struct machine, rb_node);
249 err = machine__write_buildid_table(pos, fd);
250 if (err)
251 break;
252 }
253 return err;
254 }
255
__dsos__hit_all(struct list_head * head)256 static int __dsos__hit_all(struct list_head *head)
257 {
258 struct dso *pos;
259
260 list_for_each_entry(pos, head, node)
261 pos->hit = true;
262
263 return 0;
264 }
265
machine__hit_all_dsos(struct machine * machine)266 static int machine__hit_all_dsos(struct machine *machine)
267 {
268 return __dsos__hit_all(&machine->dsos.head);
269 }
270
dsos__hit_all(struct perf_session * session)271 int dsos__hit_all(struct perf_session *session)
272 {
273 struct rb_node *nd;
274 int err;
275
276 err = machine__hit_all_dsos(&session->machines.host);
277 if (err)
278 return err;
279
280 for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
281 struct machine *pos = rb_entry(nd, struct machine, rb_node);
282
283 err = machine__hit_all_dsos(pos);
284 if (err)
285 return err;
286 }
287
288 return 0;
289 }
290
disable_buildid_cache(void)291 void disable_buildid_cache(void)
292 {
293 no_buildid_cache = true;
294 }
295
build_id_cache__dirname_from_path(const char * name,bool is_kallsyms,bool is_vdso)296 static char *build_id_cache__dirname_from_path(const char *name,
297 bool is_kallsyms, bool is_vdso)
298 {
299 char *realname = (char *)name, *filename;
300 bool slash = is_kallsyms || is_vdso;
301
302 if (!slash) {
303 realname = realpath(name, NULL);
304 if (!realname)
305 return NULL;
306 }
307
308 if (asprintf(&filename, "%s%s%s", buildid_dir, slash ? "/" : "",
309 is_vdso ? DSO__NAME_VDSO : realname) < 0)
310 filename = NULL;
311
312 if (!slash)
313 free(realname);
314
315 return filename;
316 }
317
build_id_cache__list_build_ids(const char * pathname,struct strlist ** result)318 int build_id_cache__list_build_ids(const char *pathname,
319 struct strlist **result)
320 {
321 struct strlist *list;
322 char *dir_name;
323 DIR *dir;
324 struct dirent *d;
325 int ret = 0;
326
327 list = strlist__new(NULL, NULL);
328 dir_name = build_id_cache__dirname_from_path(pathname, false, false);
329 if (!list || !dir_name) {
330 ret = -ENOMEM;
331 goto out;
332 }
333
334 /* List up all dirents */
335 dir = opendir(dir_name);
336 if (!dir) {
337 ret = -errno;
338 goto out;
339 }
340
341 while ((d = readdir(dir)) != NULL) {
342 if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
343 continue;
344 strlist__add(list, d->d_name);
345 }
346 closedir(dir);
347
348 out:
349 free(dir_name);
350 if (ret)
351 strlist__delete(list);
352 else
353 *result = list;
354
355 return ret;
356 }
357
build_id_cache__add_s(const char * sbuild_id,const char * name,bool is_kallsyms,bool is_vdso)358 int build_id_cache__add_s(const char *sbuild_id, const char *name,
359 bool is_kallsyms, bool is_vdso)
360 {
361 const size_t size = PATH_MAX;
362 char *realname = NULL, *filename = NULL, *dir_name = NULL,
363 *linkname = zalloc(size), *targetname, *tmp;
364 int err = -1;
365
366 if (!is_kallsyms) {
367 realname = realpath(name, NULL);
368 if (!realname)
369 goto out_free;
370 }
371
372 dir_name = build_id_cache__dirname_from_path(name, is_kallsyms, is_vdso);
373 if (!dir_name)
374 goto out_free;
375
376 if (mkdir_p(dir_name, 0755))
377 goto out_free;
378
379 if (asprintf(&filename, "%s/%s", dir_name, sbuild_id) < 0) {
380 filename = NULL;
381 goto out_free;
382 }
383
384 if (access(filename, F_OK)) {
385 if (is_kallsyms) {
386 if (copyfile("/proc/kallsyms", filename))
387 goto out_free;
388 } else if (link(realname, filename) && errno != EEXIST &&
389 copyfile(name, filename))
390 goto out_free;
391 }
392
393 if (!build_id__filename(sbuild_id, linkname, size))
394 goto out_free;
395 tmp = strrchr(linkname, '/');
396 *tmp = '\0';
397
398 if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
399 goto out_free;
400
401 *tmp = '/';
402 targetname = filename + strlen(buildid_dir) - 5;
403 memcpy(targetname, "../..", 5);
404
405 if (symlink(targetname, linkname) == 0)
406 err = 0;
407 out_free:
408 if (!is_kallsyms)
409 free(realname);
410 free(filename);
411 free(dir_name);
412 free(linkname);
413 return err;
414 }
415
build_id_cache__add_b(const u8 * build_id,size_t build_id_size,const char * name,bool is_kallsyms,bool is_vdso)416 static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
417 const char *name, bool is_kallsyms,
418 bool is_vdso)
419 {
420 char sbuild_id[SBUILD_ID_SIZE];
421
422 build_id__sprintf(build_id, build_id_size, sbuild_id);
423
424 return build_id_cache__add_s(sbuild_id, name, is_kallsyms, is_vdso);
425 }
426
build_id_cache__cached(const char * sbuild_id)427 bool build_id_cache__cached(const char *sbuild_id)
428 {
429 bool ret = false;
430 char *filename = build_id__filename(sbuild_id, NULL, 0);
431
432 if (filename && !access(filename, F_OK))
433 ret = true;
434 free(filename);
435
436 return ret;
437 }
438
build_id_cache__remove_s(const char * sbuild_id)439 int build_id_cache__remove_s(const char *sbuild_id)
440 {
441 const size_t size = PATH_MAX;
442 char *filename = zalloc(size),
443 *linkname = zalloc(size), *tmp;
444 int err = -1;
445
446 if (filename == NULL || linkname == NULL)
447 goto out_free;
448
449 if (!build_id__filename(sbuild_id, linkname, size))
450 goto out_free;
451
452 if (access(linkname, F_OK))
453 goto out_free;
454
455 if (readlink(linkname, filename, size - 1) < 0)
456 goto out_free;
457
458 if (unlink(linkname))
459 goto out_free;
460
461 /*
462 * Since the link is relative, we must make it absolute:
463 */
464 tmp = strrchr(linkname, '/') + 1;
465 snprintf(tmp, size - (tmp - linkname), "%s", filename);
466
467 if (unlink(linkname))
468 goto out_free;
469
470 err = 0;
471 out_free:
472 free(filename);
473 free(linkname);
474 return err;
475 }
476
dso__cache_build_id(struct dso * dso,struct machine * machine)477 static int dso__cache_build_id(struct dso *dso, struct machine *machine)
478 {
479 bool is_kallsyms = dso->kernel && dso->long_name[0] != '/';
480 bool is_vdso = dso__is_vdso(dso);
481 const char *name = dso->long_name;
482 char nm[PATH_MAX];
483
484 if (dso__is_kcore(dso)) {
485 is_kallsyms = true;
486 machine__mmap_name(machine, nm, sizeof(nm));
487 name = nm;
488 }
489 return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id), name,
490 is_kallsyms, is_vdso);
491 }
492
__dsos__cache_build_ids(struct list_head * head,struct machine * machine)493 static int __dsos__cache_build_ids(struct list_head *head,
494 struct machine *machine)
495 {
496 struct dso *pos;
497 int err = 0;
498
499 dsos__for_each_with_build_id(pos, head)
500 if (dso__cache_build_id(pos, machine))
501 err = -1;
502
503 return err;
504 }
505
machine__cache_build_ids(struct machine * machine)506 static int machine__cache_build_ids(struct machine *machine)
507 {
508 return __dsos__cache_build_ids(&machine->dsos.head, machine);
509 }
510
perf_session__cache_build_ids(struct perf_session * session)511 int perf_session__cache_build_ids(struct perf_session *session)
512 {
513 struct rb_node *nd;
514 int ret;
515
516 if (no_buildid_cache)
517 return 0;
518
519 if (mkdir(buildid_dir, 0755) != 0 && errno != EEXIST)
520 return -1;
521
522 ret = machine__cache_build_ids(&session->machines.host);
523
524 for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
525 struct machine *pos = rb_entry(nd, struct machine, rb_node);
526 ret |= machine__cache_build_ids(pos);
527 }
528 return ret ? -1 : 0;
529 }
530
machine__read_build_ids(struct machine * machine,bool with_hits)531 static bool machine__read_build_ids(struct machine *machine, bool with_hits)
532 {
533 return __dsos__read_build_ids(&machine->dsos.head, with_hits);
534 }
535
perf_session__read_build_ids(struct perf_session * session,bool with_hits)536 bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
537 {
538 struct rb_node *nd;
539 bool ret = machine__read_build_ids(&session->machines.host, with_hits);
540
541 for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
542 struct machine *pos = rb_entry(nd, struct machine, rb_node);
543 ret |= machine__read_build_ids(pos, with_hits);
544 }
545
546 return ret;
547 }
548