[deliverable/linux.git] / tools / perf / util / build-id.c

/*
 * build-id.c
 *
 * build-id support
 *
 * Copyright (C) 2009, 2010 Red Hat Inc.
 * Copyright (C) 2009, 2010 Arnaldo Carvalho de Melo <acme@redhat.com>
 */
#include "util.h"
#include <stdio.h>
#include "build-id.h"
#include "event.h"
#include "symbol.h"
#include <linux/kernel.h>
#include "debug.h"
#include "session.h"
#include "tool.h"
#include "header.h"
#include "vdso.h"


static bool no_buildid_cache;

int 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)
{
	struct addr_location al;
	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
	struct thread *thread = machine__findnew_thread(machine, sample->pid,
							sample->tid);

	if (thread == NULL) {
		pr_err("problem processing %d event, skipping it.\n",
			event->header.type);
		return -1;
	}

	thread__find_addr_map(thread, cpumode, MAP__FUNCTION, sample->ip, &al);

	if (al.map != NULL)
		al.map->dso->hit = 1;

	return 0;
}

static int perf_event__exit_del_thread(struct perf_tool *tool __maybe_unused,
				       union perf_event *event,
				       struct perf_sample *sample
				       __maybe_unused,
				       struct machine *machine)
{
	struct thread *thread = machine__findnew_thread(machine,
							event->fork.pid,
							event->fork.tid);

	dump_printf("(%d:%d):(%d:%d)\n", event->fork.pid, event->fork.tid,
		    event->fork.ppid, event->fork.ptid);

	if (thread) {
		rb_erase(&thread->rb_node, &machine->threads);
		machine->last_match = NULL;
		thread__delete(thread);
	}

	return 0;
}

struct perf_tool build_id__mark_dso_hit_ops = {
	.sample	= build_id__mark_dso_hit,
	.mmap	= perf_event__process_mmap,
	.mmap2	= perf_event__process_mmap2,
	.fork	= perf_event__process_fork,
	.exit	= perf_event__exit_del_thread,
	.attr		 = perf_event__process_attr,
	.build_id	 = perf_event__process_build_id,
};

int build_id__sprintf(const u8 *build_id, int len, char *bf)
{
	char *bid = bf;
	const u8 *raw = build_id;
	int i;

	for (i = 0; i < len; ++i) {
		sprintf(bid, "%02x", *raw);
		++raw;
		bid += 2;
	}

	return raw - build_id;
}

char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size)
{
	char build_id_hex[BUILD_ID_SIZE * 2 + 1];

	if (!dso->has_build_id)
		return NULL;

	build_id__sprintf(dso->build_id, sizeof(dso->build_id), build_id_hex);
	if (bf == NULL) {
		if (asprintf(&bf, "%s/.build-id/%.2s/%s", buildid_dir,
			     build_id_hex, build_id_hex + 2) < 0)
			return NULL;
	} else
		snprintf(bf, size, "%s/.build-id/%.2s/%s", buildid_dir,
			 build_id_hex, build_id_hex + 2);
	return bf;
}

#define dsos__for_each_with_build_id(pos, head)	\
	list_for_each_entry(pos, head, node)	\
		if (!pos->has_build_id)		\
			continue;		\
		else

static int write_buildid(const char *name, size_t name_len, u8 *build_id,
			 pid_t pid, u16 misc, int fd)
{
	int err;
	struct build_id_event b;
	size_t len;

	len = name_len + 1;
	len = PERF_ALIGN(len, NAME_ALIGN);

	memset(&b, 0, sizeof(b));
	memcpy(&b.build_id, build_id, BUILD_ID_SIZE);
	b.pid = pid;
	b.header.misc = misc;
	b.header.size = sizeof(b) + len;

	err = writen(fd, &b, sizeof(b));
	if (err < 0)
		return err;

	return write_padded(fd, name, name_len + 1, len);
}

static int __dsos__write_buildid_table(struct list_head *head,
				       struct machine *machine,
				       pid_t pid, u16 misc, int fd)
{
	char nm[PATH_MAX];
	struct dso *pos;

	dsos__for_each_with_build_id(pos, head) {
		int err;
		const char *name;
		size_t name_len;

		if (!pos->hit)
			continue;

		if (dso__is_vdso(pos)) {
			name = pos->short_name;
			name_len = pos->short_name_len + 1;
		} else if (dso__is_kcore(pos)) {
			machine__mmap_name(machine, nm, sizeof(nm));
			name = nm;
			name_len = strlen(nm) + 1;
		} else {
			name = pos->long_name;
			name_len = pos->long_name_len + 1;
		}

		err = write_buildid(name, name_len, pos->build_id,
				    pid, misc, fd);
		if (err)
			return err;
	}

	return 0;
}

static int machine__write_buildid_table(struct machine *machine, int fd)
{
	int err;
	u16 kmisc = PERF_RECORD_MISC_KERNEL,
	    umisc = PERF_RECORD_MISC_USER;

	if (!machine__is_host(machine)) {
		kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
		umisc = PERF_RECORD_MISC_GUEST_USER;
	}

	err = __dsos__write_buildid_table(&machine->kernel_dsos.head, machine,
					  machine->pid, kmisc, fd);
	if (err == 0)
		err = __dsos__write_buildid_table(&machine->user_dsos.head,
						  machine, machine->pid, umisc,
						  fd);
	return err;
}

int perf_session__write_buildid_table(struct perf_session *session, int fd)
{
	struct rb_node *nd;
	int err = machine__write_buildid_table(&session->machines.host, fd);

	if (err)
		return err;

	for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
		struct machine *pos = rb_entry(nd, struct machine, rb_node);
		err = machine__write_buildid_table(pos, fd);
		if (err)
			break;
	}
	return err;
}

static int __dsos__hit_all(struct list_head *head)
{
	struct dso *pos;

	list_for_each_entry(pos, head, node)
		pos->hit = true;

	return 0;
}

static int machine__hit_all_dsos(struct machine *machine)
{
	int err;

	err = __dsos__hit_all(&machine->kernel_dsos.head);
	if (err)
		return err;

	return __dsos__hit_all(&machine->user_dsos.head);
}

int dsos__hit_all(struct perf_session *session)
{
	struct rb_node *nd;
	int err;

	err = machine__hit_all_dsos(&session->machines.host);
	if (err)
		return err;

	for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
		struct machine *pos = rb_entry(nd, struct machine, rb_node);

		err = machine__hit_all_dsos(pos);
		if (err)
			return err;
	}

	return 0;
}

void disable_buildid_cache(void)
{
	no_buildid_cache = true;
}

int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
			  const char *name, bool is_kallsyms, bool is_vdso)
{
	const size_t size = PATH_MAX;
	char *realname, *filename = zalloc(size),
	     *linkname = zalloc(size), *targetname;
	int len, err = -1;
	bool slash = is_kallsyms || is_vdso;

	if (is_kallsyms) {
		if (symbol_conf.kptr_restrict) {
			pr_debug("Not caching a kptr_restrict'ed /proc/kallsyms\n");
			err = 0;
			goto out_free;
		}
		realname = (char *) name;
	} else
		realname = realpath(name, NULL);

	if (realname == NULL || filename == NULL || linkname == NULL)
		goto out_free;

	len = scnprintf(filename, size, "%s%s%s",
		       debugdir, slash ? "/" : "",
		       is_vdso ? DSO__NAME_VDSO : realname);
	if (mkdir_p(filename, 0755))
		goto out_free;

	snprintf(filename + len, size - len, "/%s", sbuild_id);

	if (access(filename, F_OK)) {
		if (is_kallsyms) {
			 if (copyfile("/proc/kallsyms", filename))
				goto out_free;
		} else if (link(realname, filename) && copyfile(name, filename))
			goto out_free;
	}

	len = scnprintf(linkname, size, "%s/.build-id/%.2s",
		       debugdir, sbuild_id);

	if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
		goto out_free;

	snprintf(linkname + len, size - len, "/%s", sbuild_id + 2);
	targetname = filename + strlen(debugdir) - 5;
	memcpy(targetname, "../..", 5);

	if (symlink(targetname, linkname) == 0)
		err = 0;
out_free:
	if (!is_kallsyms)
		free(realname);
	free(filename);
	free(linkname);
	return err;
}

static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
				 const char *name, const char *debugdir,
				 bool is_kallsyms, bool is_vdso)
{
	char sbuild_id[BUILD_ID_SIZE * 2 + 1];

	build_id__sprintf(build_id, build_id_size, sbuild_id);

	return build_id_cache__add_s(sbuild_id, debugdir, name,
				     is_kallsyms, is_vdso);
}

int build_id_cache__remove_s(const char *sbuild_id, const char *debugdir)
{
	const size_t size = PATH_MAX;
	char *filename = zalloc(size),
	     *linkname = zalloc(size);
	int err = -1;

	if (filename == NULL || linkname == NULL)
		goto out_free;

	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
		 debugdir, sbuild_id, sbuild_id + 2);

	if (access(linkname, F_OK))
		goto out_free;

	if (readlink(linkname, filename, size - 1) < 0)
		goto out_free;

	if (unlink(linkname))
		goto out_free;

	/*
	 * Since the link is relative, we must make it absolute:
	 */
	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
		 debugdir, sbuild_id, filename);

	if (unlink(linkname))
		goto out_free;

	err = 0;
out_free:
	free(filename);
	free(linkname);
	return err;
}

static int dso__cache_build_id(struct dso *dso, struct machine *machine,
			       const char *debugdir)
{
	bool is_kallsyms = dso->kernel && dso->long_name[0] != '/';
	bool is_vdso = dso__is_vdso(dso);
	const char *name = dso->long_name;
	char nm[PATH_MAX];

	if (dso__is_kcore(dso)) {
		is_kallsyms = true;
		machine__mmap_name(machine, nm, sizeof(nm));
		name = nm;
	}
	return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id), name,
				     debugdir, is_kallsyms, is_vdso);
}

static int __dsos__cache_build_ids(struct list_head *head,
				   struct machine *machine, const char *debugdir)
{
	struct dso *pos;
	int err = 0;

	dsos__for_each_with_build_id(pos, head)
		if (dso__cache_build_id(pos, machine, debugdir))
			err = -1;

	return err;
}

static int machine__cache_build_ids(struct machine *machine, const char *debugdir)
{
	int ret = __dsos__cache_build_ids(&machine->kernel_dsos.head, machine,
					  debugdir);
	ret |= __dsos__cache_build_ids(&machine->user_dsos.head, machine,
				       debugdir);
	return ret;
}

int perf_session__cache_build_ids(struct perf_session *session)
{
	struct rb_node *nd;
	int ret;
	char debugdir[PATH_MAX];

	if (no_buildid_cache)
		return 0;

	snprintf(debugdir, sizeof(debugdir), "%s", buildid_dir);

	if (mkdir(debugdir, 0755) != 0 && errno != EEXIST)
		return -1;

	ret = machine__cache_build_ids(&session->machines.host, debugdir);

	for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
		struct machine *pos = rb_entry(nd, struct machine, rb_node);
		ret |= machine__cache_build_ids(pos, debugdir);
	}
	return ret ? -1 : 0;
}

static bool machine__read_build_ids(struct machine *machine, bool with_hits)
{
	bool ret;

	ret  = __dsos__read_build_ids(&machine->kernel_dsos.head, with_hits);
	ret |= __dsos__read_build_ids(&machine->user_dsos.head, with_hits);
	return ret;
}

bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
{
	struct rb_node *nd;
	bool ret = machine__read_build_ids(&session->machines.host, with_hits);

	for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
		struct machine *pos = rb_entry(nd, struct machine, rb_node);
		ret |= machine__read_build_ids(pos, with_hits);
	}

	return ret;
}
Commit	Line	Data
7b2567c1 ACM	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	*/
b36f19d5 ACM	9	#include "util.h"
b36f19d5 ACM	10	#include <stdio.h>
7b2567c1 ACM	11	#include "build-id.h"
	12	#include "event.h"
	13	#include "symbol.h"
	14	#include <linux/kernel.h>
591765fd	15	#include "debug.h"
d20deb64	16	#include "session.h"
45694aa7	17	#include "tool.h"
e195fac8 NK	18	#include "header.h"
e195fac8 NK	19	#include "vdso.h"
7b2567c1	20
73c5d224 NK	21
	22	static bool no_buildid_cache;
	23
54a3cf59 AV	24	int build_id__mark_dso_hit(struct perf_tool *tool __maybe_unused,
54a3cf59 AV	25	union perf_event *event,
ef89325f	26	struct perf_sample *sample,
54a3cf59 AV	27	struct perf_evsel *evsel __maybe_unused,
54a3cf59 AV	28	struct machine *machine)
7b2567c1 ACM	29	{
	30	struct addr_location al;
	31	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
ef89325f	32	struct thread *thread = machine__findnew_thread(machine, sample->pid,
13ce34df	33	sample->tid);
7b2567c1 ACM	34
	35	if (thread == NULL) {
	36	pr_err("problem processing %d event, skipping it.\n",
	37	event->header.type);
	38	return -1;
	39	}
	40
bb871a9c	41	thread__find_addr_map(thread, cpumode, MAP__FUNCTION, sample->ip, &al);
7b2567c1 ACM	42
	43	if (al.map != NULL)
	44	al.map->dso->hit = 1;
	45
	46	return 0;
	47	}
	48
1d037ca1	49	static int perf_event__exit_del_thread(struct perf_tool *tool __maybe_unused,
d20deb64	50	union perf_event *event,
1d037ca1 IT	51	struct perf_sample *sample
1d037ca1 IT	52	__maybe_unused,
743eb868	53	struct machine *machine)
591765fd	54	{
314add6b AH	55	struct thread *thread = machine__findnew_thread(machine,
	56	event->fork.pid,
	57	event->fork.tid);
591765fd	58
8115d60c ACM	59	dump_printf("(%d:%d):(%d:%d)\n", event->fork.pid, event->fork.tid,
8115d60c ACM	60	event->fork.ppid, event->fork.ptid);
591765fd ACM	61
591765fd ACM	62	if (thread) {
743eb868 ACM	63	rb_erase(&thread->rb_node, &machine->threads);
743eb868 ACM	64	machine->last_match = NULL;
591765fd ACM	65	thread__delete(thread);
	66	}
	67
	68	return 0;
	69	}
	70
45694aa7	71	struct perf_tool build_id__mark_dso_hit_ops = {
7b2567c1	72	.sample = build_id__mark_dso_hit,
8115d60c	73	.mmap = perf_event__process_mmap,
5c5e854b	74	.mmap2 = perf_event__process_mmap2,
f62d3f0f	75	.fork = perf_event__process_fork,
8115d60c	76	.exit = perf_event__exit_del_thread,
299c3452 SE	77	.attr = perf_event__process_attr,
299c3452 SE	78	.build_id = perf_event__process_build_id,
7b2567c1	79	};
b36f19d5	80
ebb296c2 JO	81	int build_id__sprintf(const u8 build_id, int len, char bf)
	82	{
	83	char *bid = bf;
	84	const u8 *raw = build_id;
	85	int i;
	86
	87	for (i = 0; i < len; ++i) {
	88	sprintf(bid, "%02x", *raw);
	89	++raw;
	90	bid += 2;
	91	}
	92
	93	return raw - build_id;
	94	}
	95
3344996e	96	char dso__build_id_filename(const struct dso dso, char *bf, size_t size)
b36f19d5 ACM	97	{
b36f19d5 ACM	98	char build_id_hex[BUILD_ID_SIZE * 2 + 1];
b36f19d5	99
c824c433	100	if (!dso->has_build_id)
b36f19d5 ACM	101	return NULL;
b36f19d5 ACM	102
c824c433	103	build_id__sprintf(dso->build_id, sizeof(dso->build_id), build_id_hex);
b36f19d5	104	if (bf == NULL) {
45de34bb SE	105	if (asprintf(&bf, "%s/.build-id/%.2s/%s", buildid_dir,
45de34bb SE	106	build_id_hex, build_id_hex + 2) < 0)
b36f19d5 ACM	107	return NULL;
b36f19d5 ACM	108	} else
45de34bb SE	109	snprintf(bf, size, "%s/.build-id/%.2s/%s", buildid_dir,
45de34bb SE	110	build_id_hex, build_id_hex + 2);
b36f19d5 ACM	111	return bf;
b36f19d5 ACM	112	}
e195fac8 NK	113
	114	#define dsos__for_each_with_build_id(pos, head) \
	115	list_for_each_entry(pos, head, node) \
	116	if (!pos->has_build_id) \
	117	continue; \
	118	else
	119
	120	static int write_buildid(const char name, size_t name_len, u8 build_id,
	121	pid_t pid, u16 misc, int fd)
	122	{
	123	int err;
	124	struct build_id_event b;
	125	size_t len;
	126
	127	len = name_len + 1;
	128	len = PERF_ALIGN(len, NAME_ALIGN);
	129
	130	memset(&b, 0, sizeof(b));
	131	memcpy(&b.build_id, build_id, BUILD_ID_SIZE);
	132	b.pid = pid;
	133	b.header.misc = misc;
	134	b.header.size = sizeof(b) + len;
	135
	136	err = writen(fd, &b, sizeof(b));
	137	if (err < 0)
	138	return err;
	139
	140	return write_padded(fd, name, name_len + 1, len);
	141	}
	142
	143	static int __dsos__write_buildid_table(struct list_head *head,
	144	struct machine *machine,
	145	pid_t pid, u16 misc, int fd)
	146	{
	147	char nm[PATH_MAX];
	148	struct dso *pos;
	149
	150	dsos__for_each_with_build_id(pos, head) {
	151	int err;
	152	const char *name;
	153	size_t name_len;
	154
	155	if (!pos->hit)
	156	continue;
	157
	158	if (dso__is_vdso(pos)) {
	159	name = pos->short_name;
	160	name_len = pos->short_name_len + 1;
	161	} else if (dso__is_kcore(pos)) {
	162	machine__mmap_name(machine, nm, sizeof(nm));
	163	name = nm;
	164	name_len = strlen(nm) + 1;
	165	} else {
	166	name = pos->long_name;
	167	name_len = pos->long_name_len + 1;
	168	}
	169
	170	err = write_buildid(name, name_len, pos->build_id,
	171	pid, misc, fd);
	172	if (err)
	173	return err;
	174	}
	175
	176	return 0;
177	}
178
179	static int machine__write_buildid_table(struct machine *machine, int fd)
180	{
181	int err;
182	u16 kmisc = PERF_RECORD_MISC_KERNEL,
183	umisc = PERF_RECORD_MISC_USER;
184
185	if (!machine__is_host(machine)) {
186	kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
187	umisc = PERF_RECORD_MISC_GUEST_USER;
188	}
189
190	err = __dsos__write_buildid_table(&machine->kernel_dsos.head, machine,
191	machine->pid, kmisc, fd);
192	if (err == 0)
193	err = __dsos__write_buildid_table(&machine->user_dsos.head,
194	machine, machine->pid, umisc,
195	fd);
196	return err;
197	}
198
199	int perf_session__write_buildid_table(struct perf_session *session, int fd)
200	{
201	struct rb_node *nd;
202	int err = machine__write_buildid_table(&session->machines.host, fd);
203
204	if (err)
205	return err;
206
207	for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
208	struct machine *pos = rb_entry(nd, struct machine, rb_node);
209	err = machine__write_buildid_table(pos, fd);
210	if (err)
211	break;
212	}
213	return err;
214	}
215
216	static int __dsos__hit_all(struct list_head *head)
217	{
218	struct dso *pos;
219
220	list_for_each_entry(pos, head, node)
221	pos->hit = true;
222
223	return 0;
224	}
225
226	static int machine__hit_all_dsos(struct machine *machine)
227	{
228	int err;
229
230	err = __dsos__hit_all(&machine->kernel_dsos.head);
231	if (err)
232	return err;
233
234	return __dsos__hit_all(&machine->user_dsos.head);
235	}
236
237	int dsos__hit_all(struct perf_session *session)
238	{
239	struct rb_node *nd;
240	int err;
241
242	err = machine__hit_all_dsos(&session->machines.host);
243	if (err)
244	return err;
245
246	for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
247	struct machine *pos = rb_entry(nd, struct machine, rb_node);
248
249	err = machine__hit_all_dsos(pos);
250	if (err)
251	return err;
252	}
253
254	return 0;
255	}
256
73c5d224 NK	257	void disable_buildid_cache(void)
	258	{
	259	no_buildid_cache = true;
	260	}
	261
e195fac8 NK	262	int build_id_cache__add_s(const char sbuild_id, const char debugdir,
	263	const char *name, bool is_kallsyms, bool is_vdso)
	264	{
	265	const size_t size = PATH_MAX;
	266	char realname, filename = zalloc(size),
	267	linkname = zalloc(size), targetname;
	268	int len, err = -1;
	269	bool slash = is_kallsyms \|\| is_vdso;
	270
	271	if (is_kallsyms) {
	272	if (symbol_conf.kptr_restrict) {
	273	pr_debug("Not caching a kptr_restrict'ed /proc/kallsyms\n");
	274	err = 0;
	275	goto out_free;
	276	}
	277	realname = (char *) name;
	278	} else
	279	realname = realpath(name, NULL);
	280
	281	if (realname == NULL \|\| filename == NULL \|\| linkname == NULL)
	282	goto out_free;
	283
	284	len = scnprintf(filename, size, "%s%s%s",
	285	debugdir, slash ? "/" : "",
	286	is_vdso ? DSO__NAME_VDSO : realname);
	287	if (mkdir_p(filename, 0755))
	288	goto out_free;
	289
	290	snprintf(filename + len, size - len, "/%s", sbuild_id);
	291
	292	if (access(filename, F_OK)) {
	293	if (is_kallsyms) {
	294	if (copyfile("/proc/kallsyms", filename))
	295	goto out_free;
	296	} else if (link(realname, filename) && copyfile(name, filename))
	297	goto out_free;
	298	}
	299
	300	len = scnprintf(linkname, size, "%s/.build-id/%.2s",
	301	debugdir, sbuild_id);
	302
	303	if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
	304	goto out_free;
	305
	306	snprintf(linkname + len, size - len, "/%s", sbuild_id + 2);
	307	targetname = filename + strlen(debugdir) - 5;
	308	memcpy(targetname, "../..", 5);
	309
	310	if (symlink(targetname, linkname) == 0)
	311	err = 0;
	312	out_free:
	313	if (!is_kallsyms)
	314	free(realname);
	315	free(filename);
	316	free(linkname);
	317	return err;
	318	}
	319
	320	static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
	321	const char name, const char debugdir,
	322	bool is_kallsyms, bool is_vdso)
	323	{
	324	char sbuild_id[BUILD_ID_SIZE * 2 + 1];
	325
326	build_id__sprintf(build_id, build_id_size, sbuild_id);
327
328	return build_id_cache__add_s(sbuild_id, debugdir, name,
329	is_kallsyms, is_vdso);
330	}
331
332	int build_id_cache__remove_s(const char sbuild_id, const char debugdir)
333	{
334	const size_t size = PATH_MAX;
335	char *filename = zalloc(size),
336	*linkname = zalloc(size);
337	int err = -1;
338
339	if (filename == NULL \|\| linkname == NULL)
340	goto out_free;
341
342	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
343	debugdir, sbuild_id, sbuild_id + 2);
344
345	if (access(linkname, F_OK))
346	goto out_free;
347
348	if (readlink(linkname, filename, size - 1) < 0)
349	goto out_free;
350
351	if (unlink(linkname))
352	goto out_free;
353
354	/*
355	* Since the link is relative, we must make it absolute:
356	*/
357	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
358	debugdir, sbuild_id, filename);
359
360	if (unlink(linkname))
361	goto out_free;
362
363	err = 0;
364	out_free:
365	free(filename);
366	free(linkname);
367	return err;
368	}
369
370	static int dso__cache_build_id(struct dso dso, struct machine machine,
371	const char *debugdir)
372	{
373	bool is_kallsyms = dso->kernel && dso->long_name[0] != '/';
374	bool is_vdso = dso__is_vdso(dso);
375	const char *name = dso->long_name;
376	char nm[PATH_MAX];
377
378	if (dso__is_kcore(dso)) {
379	is_kallsyms = true;
380	machine__mmap_name(machine, nm, sizeof(nm));
381	name = nm;
382	}
383	return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id), name,
384	debugdir, is_kallsyms, is_vdso);
385	}
386
387	static int __dsos__cache_build_ids(struct list_head *head,
388	struct machine machine, const char debugdir)
389	{
390	struct dso *pos;
391	int err = 0;
392
393	dsos__for_each_with_build_id(pos, head)
394	if (dso__cache_build_id(pos, machine, debugdir))
395	err = -1;
396
397	return err;
398	}
399
400	static int machine__cache_build_ids(struct machine machine, const char debugdir)
401	{
402	int ret = __dsos__cache_build_ids(&machine->kernel_dsos.head, machine,
403	debugdir);
404	ret \|= __dsos__cache_build_ids(&machine->user_dsos.head, machine,
405	debugdir);
406	return ret;
407	}
408
409	int perf_session__cache_build_ids(struct perf_session *session)
410	{
411	struct rb_node *nd;
412	int ret;
413	char debugdir[PATH_MAX];
414
73c5d224 NK	415	if (no_buildid_cache)
	416	return 0;
	417
e195fac8 NK	418	snprintf(debugdir, sizeof(debugdir), "%s", buildid_dir);
	419
	420	if (mkdir(debugdir, 0755) != 0 && errno != EEXIST)
	421	return -1;
	422
	423	ret = machine__cache_build_ids(&session->machines.host, debugdir);
	424
	425	for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
	426	struct machine *pos = rb_entry(nd, struct machine, rb_node);
	427	ret \|= machine__cache_build_ids(pos, debugdir);
	428	}
	429	return ret ? -1 : 0;
	430	}
	431
	432	static bool machine__read_build_ids(struct machine *machine, bool with_hits)
	433	{
	434	bool ret;
	435
	436	ret = __dsos__read_build_ids(&machine->kernel_dsos.head, with_hits);
	437	ret \|= __dsos__read_build_ids(&machine->user_dsos.head, with_hits);
	438	return ret;
	439	}
	440
	441	bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
	442	{
	443	struct rb_node *nd;
	444	bool ret = machine__read_build_ids(&session->machines.host, with_hits);
	445
	446	for (nd = rb_first(&session->machines.guests); nd; nd = rb_next(nd)) {
	447	struct machine *pos = rb_entry(nd, struct machine, rb_node);
	448	ret \|= machine__read_build_ids(pos, with_hits);
	449	}
	450
	451	return ret;
	452	}