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
22static bool no_buildid_cache;
23
24int 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
50static 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
71struct 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
82int 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
97int 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
115int 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 */
130static 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
148static 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
158char *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
175static 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
198static 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
239int 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
256static 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
266static int machine__hit_all_dsos(struct machine *machine)
267{
268	return __dsos__hit_all(&machine->dsos.head);
269}
270
271int 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
291void disable_buildid_cache(void)
292{
293	no_buildid_cache = true;
294}
295
296static 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
318int 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
348out:
349	free(dir_name);
350	if (ret)
351		strlist__delete(list);
352	else
353		*result = list;
354
355	return ret;
356}
357
358int 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;
407out_free:
408	if (!is_kallsyms)
409		free(realname);
410	free(filename);
411	free(dir_name);
412	free(linkname);
413	return err;
414}
415
416static 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
427bool 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
439int 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;
471out_free:
472	free(filename);
473	free(linkname);
474	return err;
475}
476
477static 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
493static 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
506static int machine__cache_build_ids(struct machine *machine)
507{
508	return __dsos__cache_build_ids(&machine->dsos.head, machine);
509}
510
511int 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
531static 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
536bool 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