xref: /linux/tools/perf/util/header.c (revision 25aee3debe0464f6c680173041fa3de30ec9ff54)
1 #define _FILE_OFFSET_BITS 64
2 
3 #include "util.h"
4 #include <sys/types.h>
5 #include <byteswap.h>
6 #include <unistd.h>
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include <linux/list.h>
10 #include <linux/kernel.h>
11 #include <linux/bitops.h>
12 #include <sys/utsname.h>
13 
14 #include "evlist.h"
15 #include "evsel.h"
16 #include "header.h"
17 #include "../perf.h"
18 #include "trace-event.h"
19 #include "session.h"
20 #include "symbol.h"
21 #include "debug.h"
22 #include "cpumap.h"
23 
24 static bool no_buildid_cache = false;
25 
26 static int event_count;
27 static struct perf_trace_event_type *events;
28 
29 static u32 header_argc;
30 static const char **header_argv;
31 
32 int perf_header__push_event(u64 id, const char *name)
33 {
34 	struct perf_trace_event_type *nevents;
35 
36 	if (strlen(name) > MAX_EVENT_NAME)
37 		pr_warning("Event %s will be truncated\n", name);
38 
39 	nevents = realloc(events, (event_count + 1) * sizeof(*events));
40 	if (nevents == NULL)
41 		return -ENOMEM;
42 	events = nevents;
43 
44 	memset(&events[event_count], 0, sizeof(struct perf_trace_event_type));
45 	events[event_count].event_id = id;
46 	strncpy(events[event_count].name, name, MAX_EVENT_NAME - 1);
47 	event_count++;
48 	return 0;
49 }
50 
51 char *perf_header__find_event(u64 id)
52 {
53 	int i;
54 	for (i = 0 ; i < event_count; i++) {
55 		if (events[i].event_id == id)
56 			return events[i].name;
57 	}
58 	return NULL;
59 }
60 
61 /*
62  * magic2 = "PERFILE2"
63  * must be a numerical value to let the endianness
64  * determine the memory layout. That way we are able
65  * to detect endianness when reading the perf.data file
66  * back.
67  *
68  * we check for legacy (PERFFILE) format.
69  */
70 static const char *__perf_magic1 = "PERFFILE";
71 static const u64 __perf_magic2    = 0x32454c4946524550ULL;
72 static const u64 __perf_magic2_sw = 0x50455246494c4532ULL;
73 
74 #define PERF_MAGIC	__perf_magic2
75 
76 struct perf_file_attr {
77 	struct perf_event_attr	attr;
78 	struct perf_file_section	ids;
79 };
80 
81 void perf_header__set_feat(struct perf_header *header, int feat)
82 {
83 	set_bit(feat, header->adds_features);
84 }
85 
86 void perf_header__clear_feat(struct perf_header *header, int feat)
87 {
88 	clear_bit(feat, header->adds_features);
89 }
90 
91 bool perf_header__has_feat(const struct perf_header *header, int feat)
92 {
93 	return test_bit(feat, header->adds_features);
94 }
95 
96 static int do_write(int fd, const void *buf, size_t size)
97 {
98 	while (size) {
99 		int ret = write(fd, buf, size);
100 
101 		if (ret < 0)
102 			return -errno;
103 
104 		size -= ret;
105 		buf += ret;
106 	}
107 
108 	return 0;
109 }
110 
111 #define NAME_ALIGN 64
112 
113 static int write_padded(int fd, const void *bf, size_t count,
114 			size_t count_aligned)
115 {
116 	static const char zero_buf[NAME_ALIGN];
117 	int err = do_write(fd, bf, count);
118 
119 	if (!err)
120 		err = do_write(fd, zero_buf, count_aligned - count);
121 
122 	return err;
123 }
124 
125 static int do_write_string(int fd, const char *str)
126 {
127 	u32 len, olen;
128 	int ret;
129 
130 	olen = strlen(str) + 1;
131 	len = ALIGN(olen, NAME_ALIGN);
132 
133 	/* write len, incl. \0 */
134 	ret = do_write(fd, &len, sizeof(len));
135 	if (ret < 0)
136 		return ret;
137 
138 	return write_padded(fd, str, olen, len);
139 }
140 
141 static char *do_read_string(int fd, struct perf_header *ph)
142 {
143 	ssize_t sz, ret;
144 	u32 len;
145 	char *buf;
146 
147 	sz = read(fd, &len, sizeof(len));
148 	if (sz < (ssize_t)sizeof(len))
149 		return NULL;
150 
151 	if (ph->needs_swap)
152 		len = bswap_32(len);
153 
154 	buf = malloc(len);
155 	if (!buf)
156 		return NULL;
157 
158 	ret = read(fd, buf, len);
159 	if (ret == (ssize_t)len) {
160 		/*
161 		 * strings are padded by zeroes
162 		 * thus the actual strlen of buf
163 		 * may be less than len
164 		 */
165 		return buf;
166 	}
167 
168 	free(buf);
169 	return NULL;
170 }
171 
172 int
173 perf_header__set_cmdline(int argc, const char **argv)
174 {
175 	int i;
176 
177 	header_argc = (u32)argc;
178 
179 	/* do not include NULL termination */
180 	header_argv = calloc(argc, sizeof(char *));
181 	if (!header_argv)
182 		return -ENOMEM;
183 
184 	/*
185 	 * must copy argv contents because it gets moved
186 	 * around during option parsing
187 	 */
188 	for (i = 0; i < argc ; i++)
189 		header_argv[i] = argv[i];
190 
191 	return 0;
192 }
193 
194 #define dsos__for_each_with_build_id(pos, head)	\
195 	list_for_each_entry(pos, head, node)	\
196 		if (!pos->has_build_id)		\
197 			continue;		\
198 		else
199 
200 static int __dsos__write_buildid_table(struct list_head *head, pid_t pid,
201 				u16 misc, int fd)
202 {
203 	struct dso *pos;
204 
205 	dsos__for_each_with_build_id(pos, head) {
206 		int err;
207 		struct build_id_event b;
208 		size_t len;
209 
210 		if (!pos->hit)
211 			continue;
212 		len = pos->long_name_len + 1;
213 		len = ALIGN(len, NAME_ALIGN);
214 		memset(&b, 0, sizeof(b));
215 		memcpy(&b.build_id, pos->build_id, sizeof(pos->build_id));
216 		b.pid = pid;
217 		b.header.misc = misc;
218 		b.header.size = sizeof(b) + len;
219 		err = do_write(fd, &b, sizeof(b));
220 		if (err < 0)
221 			return err;
222 		err = write_padded(fd, pos->long_name,
223 				   pos->long_name_len + 1, len);
224 		if (err < 0)
225 			return err;
226 	}
227 
228 	return 0;
229 }
230 
231 static int machine__write_buildid_table(struct machine *machine, int fd)
232 {
233 	int err;
234 	u16 kmisc = PERF_RECORD_MISC_KERNEL,
235 	    umisc = PERF_RECORD_MISC_USER;
236 
237 	if (!machine__is_host(machine)) {
238 		kmisc = PERF_RECORD_MISC_GUEST_KERNEL;
239 		umisc = PERF_RECORD_MISC_GUEST_USER;
240 	}
241 
242 	err = __dsos__write_buildid_table(&machine->kernel_dsos, machine->pid,
243 					  kmisc, fd);
244 	if (err == 0)
245 		err = __dsos__write_buildid_table(&machine->user_dsos,
246 						  machine->pid, umisc, fd);
247 	return err;
248 }
249 
250 static int dsos__write_buildid_table(struct perf_header *header, int fd)
251 {
252 	struct perf_session *session = container_of(header,
253 			struct perf_session, header);
254 	struct rb_node *nd;
255 	int err = machine__write_buildid_table(&session->host_machine, fd);
256 
257 	if (err)
258 		return err;
259 
260 	for (nd = rb_first(&session->machines); nd; nd = rb_next(nd)) {
261 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
262 		err = machine__write_buildid_table(pos, fd);
263 		if (err)
264 			break;
265 	}
266 	return err;
267 }
268 
269 int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
270 			  const char *name, bool is_kallsyms)
271 {
272 	const size_t size = PATH_MAX;
273 	char *realname, *filename = zalloc(size),
274 	     *linkname = zalloc(size), *targetname;
275 	int len, err = -1;
276 
277 	if (is_kallsyms) {
278 		if (symbol_conf.kptr_restrict) {
279 			pr_debug("Not caching a kptr_restrict'ed /proc/kallsyms\n");
280 			return 0;
281 		}
282 		realname = (char *)name;
283 	} else
284 		realname = realpath(name, NULL);
285 
286 	if (realname == NULL || filename == NULL || linkname == NULL)
287 		goto out_free;
288 
289 	len = scnprintf(filename, size, "%s%s%s",
290 		       debugdir, is_kallsyms ? "/" : "", realname);
291 	if (mkdir_p(filename, 0755))
292 		goto out_free;
293 
294 	snprintf(filename + len, size - len, "/%s", sbuild_id);
295 
296 	if (access(filename, F_OK)) {
297 		if (is_kallsyms) {
298 			 if (copyfile("/proc/kallsyms", filename))
299 				goto out_free;
300 		} else if (link(realname, filename) && copyfile(name, filename))
301 			goto out_free;
302 	}
303 
304 	len = scnprintf(linkname, size, "%s/.build-id/%.2s",
305 		       debugdir, sbuild_id);
306 
307 	if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
308 		goto out_free;
309 
310 	snprintf(linkname + len, size - len, "/%s", sbuild_id + 2);
311 	targetname = filename + strlen(debugdir) - 5;
312 	memcpy(targetname, "../..", 5);
313 
314 	if (symlink(targetname, linkname) == 0)
315 		err = 0;
316 out_free:
317 	if (!is_kallsyms)
318 		free(realname);
319 	free(filename);
320 	free(linkname);
321 	return err;
322 }
323 
324 static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
325 				 const char *name, const char *debugdir,
326 				 bool is_kallsyms)
327 {
328 	char sbuild_id[BUILD_ID_SIZE * 2 + 1];
329 
330 	build_id__sprintf(build_id, build_id_size, sbuild_id);
331 
332 	return build_id_cache__add_s(sbuild_id, debugdir, name, is_kallsyms);
333 }
334 
335 int build_id_cache__remove_s(const char *sbuild_id, const char *debugdir)
336 {
337 	const size_t size = PATH_MAX;
338 	char *filename = zalloc(size),
339 	     *linkname = zalloc(size);
340 	int err = -1;
341 
342 	if (filename == NULL || linkname == NULL)
343 		goto out_free;
344 
345 	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
346 		 debugdir, sbuild_id, sbuild_id + 2);
347 
348 	if (access(linkname, F_OK))
349 		goto out_free;
350 
351 	if (readlink(linkname, filename, size - 1) < 0)
352 		goto out_free;
353 
354 	if (unlink(linkname))
355 		goto out_free;
356 
357 	/*
358 	 * Since the link is relative, we must make it absolute:
359 	 */
360 	snprintf(linkname, size, "%s/.build-id/%.2s/%s",
361 		 debugdir, sbuild_id, filename);
362 
363 	if (unlink(linkname))
364 		goto out_free;
365 
366 	err = 0;
367 out_free:
368 	free(filename);
369 	free(linkname);
370 	return err;
371 }
372 
373 static int dso__cache_build_id(struct dso *dso, const char *debugdir)
374 {
375 	bool is_kallsyms = dso->kernel && dso->long_name[0] != '/';
376 
377 	return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id),
378 				     dso->long_name, debugdir, is_kallsyms);
379 }
380 
381 static int __dsos__cache_build_ids(struct list_head *head, const char *debugdir)
382 {
383 	struct dso *pos;
384 	int err = 0;
385 
386 	dsos__for_each_with_build_id(pos, head)
387 		if (dso__cache_build_id(pos, debugdir))
388 			err = -1;
389 
390 	return err;
391 }
392 
393 static int machine__cache_build_ids(struct machine *machine, const char *debugdir)
394 {
395 	int ret = __dsos__cache_build_ids(&machine->kernel_dsos, debugdir);
396 	ret |= __dsos__cache_build_ids(&machine->user_dsos, debugdir);
397 	return ret;
398 }
399 
400 static int perf_session__cache_build_ids(struct perf_session *session)
401 {
402 	struct rb_node *nd;
403 	int ret;
404 	char debugdir[PATH_MAX];
405 
406 	snprintf(debugdir, sizeof(debugdir), "%s", buildid_dir);
407 
408 	if (mkdir(debugdir, 0755) != 0 && errno != EEXIST)
409 		return -1;
410 
411 	ret = machine__cache_build_ids(&session->host_machine, debugdir);
412 
413 	for (nd = rb_first(&session->machines); nd; nd = rb_next(nd)) {
414 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
415 		ret |= machine__cache_build_ids(pos, debugdir);
416 	}
417 	return ret ? -1 : 0;
418 }
419 
420 static bool machine__read_build_ids(struct machine *machine, bool with_hits)
421 {
422 	bool ret = __dsos__read_build_ids(&machine->kernel_dsos, with_hits);
423 	ret |= __dsos__read_build_ids(&machine->user_dsos, with_hits);
424 	return ret;
425 }
426 
427 static bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
428 {
429 	struct rb_node *nd;
430 	bool ret = machine__read_build_ids(&session->host_machine, with_hits);
431 
432 	for (nd = rb_first(&session->machines); nd; nd = rb_next(nd)) {
433 		struct machine *pos = rb_entry(nd, struct machine, rb_node);
434 		ret |= machine__read_build_ids(pos, with_hits);
435 	}
436 
437 	return ret;
438 }
439 
440 static int write_tracing_data(int fd, struct perf_header *h __used,
441 			    struct perf_evlist *evlist)
442 {
443 	return read_tracing_data(fd, &evlist->entries);
444 }
445 
446 
447 static int write_build_id(int fd, struct perf_header *h,
448 			  struct perf_evlist *evlist __used)
449 {
450 	struct perf_session *session;
451 	int err;
452 
453 	session = container_of(h, struct perf_session, header);
454 
455 	if (!perf_session__read_build_ids(session, true))
456 		return -1;
457 
458 	err = dsos__write_buildid_table(h, fd);
459 	if (err < 0) {
460 		pr_debug("failed to write buildid table\n");
461 		return err;
462 	}
463 	if (!no_buildid_cache)
464 		perf_session__cache_build_ids(session);
465 
466 	return 0;
467 }
468 
469 static int write_hostname(int fd, struct perf_header *h __used,
470 			  struct perf_evlist *evlist __used)
471 {
472 	struct utsname uts;
473 	int ret;
474 
475 	ret = uname(&uts);
476 	if (ret < 0)
477 		return -1;
478 
479 	return do_write_string(fd, uts.nodename);
480 }
481 
482 static int write_osrelease(int fd, struct perf_header *h __used,
483 			   struct perf_evlist *evlist __used)
484 {
485 	struct utsname uts;
486 	int ret;
487 
488 	ret = uname(&uts);
489 	if (ret < 0)
490 		return -1;
491 
492 	return do_write_string(fd, uts.release);
493 }
494 
495 static int write_arch(int fd, struct perf_header *h __used,
496 		      struct perf_evlist *evlist __used)
497 {
498 	struct utsname uts;
499 	int ret;
500 
501 	ret = uname(&uts);
502 	if (ret < 0)
503 		return -1;
504 
505 	return do_write_string(fd, uts.machine);
506 }
507 
508 static int write_version(int fd, struct perf_header *h __used,
509 			 struct perf_evlist *evlist __used)
510 {
511 	return do_write_string(fd, perf_version_string);
512 }
513 
514 static int write_cpudesc(int fd, struct perf_header *h __used,
515 		       struct perf_evlist *evlist __used)
516 {
517 #ifndef CPUINFO_PROC
518 #define CPUINFO_PROC NULL
519 #endif
520 	FILE *file;
521 	char *buf = NULL;
522 	char *s, *p;
523 	const char *search = CPUINFO_PROC;
524 	size_t len = 0;
525 	int ret = -1;
526 
527 	if (!search)
528 		return -1;
529 
530 	file = fopen("/proc/cpuinfo", "r");
531 	if (!file)
532 		return -1;
533 
534 	while (getline(&buf, &len, file) > 0) {
535 		ret = strncmp(buf, search, strlen(search));
536 		if (!ret)
537 			break;
538 	}
539 
540 	if (ret)
541 		goto done;
542 
543 	s = buf;
544 
545 	p = strchr(buf, ':');
546 	if (p && *(p+1) == ' ' && *(p+2))
547 		s = p + 2;
548 	p = strchr(s, '\n');
549 	if (p)
550 		*p = '\0';
551 
552 	/* squash extra space characters (branding string) */
553 	p = s;
554 	while (*p) {
555 		if (isspace(*p)) {
556 			char *r = p + 1;
557 			char *q = r;
558 			*p = ' ';
559 			while (*q && isspace(*q))
560 				q++;
561 			if (q != (p+1))
562 				while ((*r++ = *q++));
563 		}
564 		p++;
565 	}
566 	ret = do_write_string(fd, s);
567 done:
568 	free(buf);
569 	fclose(file);
570 	return ret;
571 }
572 
573 static int write_nrcpus(int fd, struct perf_header *h __used,
574 			struct perf_evlist *evlist __used)
575 {
576 	long nr;
577 	u32 nrc, nra;
578 	int ret;
579 
580 	nr = sysconf(_SC_NPROCESSORS_CONF);
581 	if (nr < 0)
582 		return -1;
583 
584 	nrc = (u32)(nr & UINT_MAX);
585 
586 	nr = sysconf(_SC_NPROCESSORS_ONLN);
587 	if (nr < 0)
588 		return -1;
589 
590 	nra = (u32)(nr & UINT_MAX);
591 
592 	ret = do_write(fd, &nrc, sizeof(nrc));
593 	if (ret < 0)
594 		return ret;
595 
596 	return do_write(fd, &nra, sizeof(nra));
597 }
598 
599 static int write_event_desc(int fd, struct perf_header *h __used,
600 			    struct perf_evlist *evlist)
601 {
602 	struct perf_evsel *attr;
603 	u32 nre = 0, nri, sz;
604 	int ret;
605 
606 	list_for_each_entry(attr, &evlist->entries, node)
607 		nre++;
608 
609 	/*
610 	 * write number of events
611 	 */
612 	ret = do_write(fd, &nre, sizeof(nre));
613 	if (ret < 0)
614 		return ret;
615 
616 	/*
617 	 * size of perf_event_attr struct
618 	 */
619 	sz = (u32)sizeof(attr->attr);
620 	ret = do_write(fd, &sz, sizeof(sz));
621 	if (ret < 0)
622 		return ret;
623 
624 	list_for_each_entry(attr, &evlist->entries, node) {
625 
626 		ret = do_write(fd, &attr->attr, sz);
627 		if (ret < 0)
628 			return ret;
629 		/*
630 		 * write number of unique id per event
631 		 * there is one id per instance of an event
632 		 *
633 		 * copy into an nri to be independent of the
634 		 * type of ids,
635 		 */
636 		nri = attr->ids;
637 		ret = do_write(fd, &nri, sizeof(nri));
638 		if (ret < 0)
639 			return ret;
640 
641 		/*
642 		 * write event string as passed on cmdline
643 		 */
644 		ret = do_write_string(fd, perf_evsel__name(attr));
645 		if (ret < 0)
646 			return ret;
647 		/*
648 		 * write unique ids for this event
649 		 */
650 		ret = do_write(fd, attr->id, attr->ids * sizeof(u64));
651 		if (ret < 0)
652 			return ret;
653 	}
654 	return 0;
655 }
656 
657 static int write_cmdline(int fd, struct perf_header *h __used,
658 			 struct perf_evlist *evlist __used)
659 {
660 	char buf[MAXPATHLEN];
661 	char proc[32];
662 	u32 i, n;
663 	int ret;
664 
665 	/*
666 	 * actual atual path to perf binary
667 	 */
668 	sprintf(proc, "/proc/%d/exe", getpid());
669 	ret = readlink(proc, buf, sizeof(buf));
670 	if (ret <= 0)
671 		return -1;
672 
673 	/* readlink() does not add null termination */
674 	buf[ret] = '\0';
675 
676 	/* account for binary path */
677 	n = header_argc + 1;
678 
679 	ret = do_write(fd, &n, sizeof(n));
680 	if (ret < 0)
681 		return ret;
682 
683 	ret = do_write_string(fd, buf);
684 	if (ret < 0)
685 		return ret;
686 
687 	for (i = 0 ; i < header_argc; i++) {
688 		ret = do_write_string(fd, header_argv[i]);
689 		if (ret < 0)
690 			return ret;
691 	}
692 	return 0;
693 }
694 
695 #define CORE_SIB_FMT \
696 	"/sys/devices/system/cpu/cpu%d/topology/core_siblings_list"
697 #define THRD_SIB_FMT \
698 	"/sys/devices/system/cpu/cpu%d/topology/thread_siblings_list"
699 
700 struct cpu_topo {
701 	u32 core_sib;
702 	u32 thread_sib;
703 	char **core_siblings;
704 	char **thread_siblings;
705 };
706 
707 static int build_cpu_topo(struct cpu_topo *tp, int cpu)
708 {
709 	FILE *fp;
710 	char filename[MAXPATHLEN];
711 	char *buf = NULL, *p;
712 	size_t len = 0;
713 	u32 i = 0;
714 	int ret = -1;
715 
716 	sprintf(filename, CORE_SIB_FMT, cpu);
717 	fp = fopen(filename, "r");
718 	if (!fp)
719 		return -1;
720 
721 	if (getline(&buf, &len, fp) <= 0)
722 		goto done;
723 
724 	fclose(fp);
725 
726 	p = strchr(buf, '\n');
727 	if (p)
728 		*p = '\0';
729 
730 	for (i = 0; i < tp->core_sib; i++) {
731 		if (!strcmp(buf, tp->core_siblings[i]))
732 			break;
733 	}
734 	if (i == tp->core_sib) {
735 		tp->core_siblings[i] = buf;
736 		tp->core_sib++;
737 		buf = NULL;
738 		len = 0;
739 	}
740 
741 	sprintf(filename, THRD_SIB_FMT, cpu);
742 	fp = fopen(filename, "r");
743 	if (!fp)
744 		goto done;
745 
746 	if (getline(&buf, &len, fp) <= 0)
747 		goto done;
748 
749 	p = strchr(buf, '\n');
750 	if (p)
751 		*p = '\0';
752 
753 	for (i = 0; i < tp->thread_sib; i++) {
754 		if (!strcmp(buf, tp->thread_siblings[i]))
755 			break;
756 	}
757 	if (i == tp->thread_sib) {
758 		tp->thread_siblings[i] = buf;
759 		tp->thread_sib++;
760 		buf = NULL;
761 	}
762 	ret = 0;
763 done:
764 	if(fp)
765 		fclose(fp);
766 	free(buf);
767 	return ret;
768 }
769 
770 static void free_cpu_topo(struct cpu_topo *tp)
771 {
772 	u32 i;
773 
774 	if (!tp)
775 		return;
776 
777 	for (i = 0 ; i < tp->core_sib; i++)
778 		free(tp->core_siblings[i]);
779 
780 	for (i = 0 ; i < tp->thread_sib; i++)
781 		free(tp->thread_siblings[i]);
782 
783 	free(tp);
784 }
785 
786 static struct cpu_topo *build_cpu_topology(void)
787 {
788 	struct cpu_topo *tp;
789 	void *addr;
790 	u32 nr, i;
791 	size_t sz;
792 	long ncpus;
793 	int ret = -1;
794 
795 	ncpus = sysconf(_SC_NPROCESSORS_CONF);
796 	if (ncpus < 0)
797 		return NULL;
798 
799 	nr = (u32)(ncpus & UINT_MAX);
800 
801 	sz = nr * sizeof(char *);
802 
803 	addr = calloc(1, sizeof(*tp) + 2 * sz);
804 	if (!addr)
805 		return NULL;
806 
807 	tp = addr;
808 
809 	addr += sizeof(*tp);
810 	tp->core_siblings = addr;
811 	addr += sz;
812 	tp->thread_siblings = addr;
813 
814 	for (i = 0; i < nr; i++) {
815 		ret = build_cpu_topo(tp, i);
816 		if (ret < 0)
817 			break;
818 	}
819 	if (ret) {
820 		free_cpu_topo(tp);
821 		tp = NULL;
822 	}
823 	return tp;
824 }
825 
826 static int write_cpu_topology(int fd, struct perf_header *h __used,
827 			  struct perf_evlist *evlist __used)
828 {
829 	struct cpu_topo *tp;
830 	u32 i;
831 	int ret;
832 
833 	tp = build_cpu_topology();
834 	if (!tp)
835 		return -1;
836 
837 	ret = do_write(fd, &tp->core_sib, sizeof(tp->core_sib));
838 	if (ret < 0)
839 		goto done;
840 
841 	for (i = 0; i < tp->core_sib; i++) {
842 		ret = do_write_string(fd, tp->core_siblings[i]);
843 		if (ret < 0)
844 			goto done;
845 	}
846 	ret = do_write(fd, &tp->thread_sib, sizeof(tp->thread_sib));
847 	if (ret < 0)
848 		goto done;
849 
850 	for (i = 0; i < tp->thread_sib; i++) {
851 		ret = do_write_string(fd, tp->thread_siblings[i]);
852 		if (ret < 0)
853 			break;
854 	}
855 done:
856 	free_cpu_topo(tp);
857 	return ret;
858 }
859 
860 
861 
862 static int write_total_mem(int fd, struct perf_header *h __used,
863 			  struct perf_evlist *evlist __used)
864 {
865 	char *buf = NULL;
866 	FILE *fp;
867 	size_t len = 0;
868 	int ret = -1, n;
869 	uint64_t mem;
870 
871 	fp = fopen("/proc/meminfo", "r");
872 	if (!fp)
873 		return -1;
874 
875 	while (getline(&buf, &len, fp) > 0) {
876 		ret = strncmp(buf, "MemTotal:", 9);
877 		if (!ret)
878 			break;
879 	}
880 	if (!ret) {
881 		n = sscanf(buf, "%*s %"PRIu64, &mem);
882 		if (n == 1)
883 			ret = do_write(fd, &mem, sizeof(mem));
884 	}
885 	free(buf);
886 	fclose(fp);
887 	return ret;
888 }
889 
890 static int write_topo_node(int fd, int node)
891 {
892 	char str[MAXPATHLEN];
893 	char field[32];
894 	char *buf = NULL, *p;
895 	size_t len = 0;
896 	FILE *fp;
897 	u64 mem_total, mem_free, mem;
898 	int ret = -1;
899 
900 	sprintf(str, "/sys/devices/system/node/node%d/meminfo", node);
901 	fp = fopen(str, "r");
902 	if (!fp)
903 		return -1;
904 
905 	while (getline(&buf, &len, fp) > 0) {
906 		/* skip over invalid lines */
907 		if (!strchr(buf, ':'))
908 			continue;
909 		if (sscanf(buf, "%*s %*d %s %"PRIu64, field, &mem) != 2)
910 			goto done;
911 		if (!strcmp(field, "MemTotal:"))
912 			mem_total = mem;
913 		if (!strcmp(field, "MemFree:"))
914 			mem_free = mem;
915 	}
916 
917 	fclose(fp);
918 
919 	ret = do_write(fd, &mem_total, sizeof(u64));
920 	if (ret)
921 		goto done;
922 
923 	ret = do_write(fd, &mem_free, sizeof(u64));
924 	if (ret)
925 		goto done;
926 
927 	ret = -1;
928 	sprintf(str, "/sys/devices/system/node/node%d/cpulist", node);
929 
930 	fp = fopen(str, "r");
931 	if (!fp)
932 		goto done;
933 
934 	if (getline(&buf, &len, fp) <= 0)
935 		goto done;
936 
937 	p = strchr(buf, '\n');
938 	if (p)
939 		*p = '\0';
940 
941 	ret = do_write_string(fd, buf);
942 done:
943 	free(buf);
944 	fclose(fp);
945 	return ret;
946 }
947 
948 static int write_numa_topology(int fd, struct perf_header *h __used,
949 			  struct perf_evlist *evlist __used)
950 {
951 	char *buf = NULL;
952 	size_t len = 0;
953 	FILE *fp;
954 	struct cpu_map *node_map = NULL;
955 	char *c;
956 	u32 nr, i, j;
957 	int ret = -1;
958 
959 	fp = fopen("/sys/devices/system/node/online", "r");
960 	if (!fp)
961 		return -1;
962 
963 	if (getline(&buf, &len, fp) <= 0)
964 		goto done;
965 
966 	c = strchr(buf, '\n');
967 	if (c)
968 		*c = '\0';
969 
970 	node_map = cpu_map__new(buf);
971 	if (!node_map)
972 		goto done;
973 
974 	nr = (u32)node_map->nr;
975 
976 	ret = do_write(fd, &nr, sizeof(nr));
977 	if (ret < 0)
978 		goto done;
979 
980 	for (i = 0; i < nr; i++) {
981 		j = (u32)node_map->map[i];
982 		ret = do_write(fd, &j, sizeof(j));
983 		if (ret < 0)
984 			break;
985 
986 		ret = write_topo_node(fd, i);
987 		if (ret < 0)
988 			break;
989 	}
990 done:
991 	free(buf);
992 	fclose(fp);
993 	free(node_map);
994 	return ret;
995 }
996 
997 /*
998  * default get_cpuid(): nothing gets recorded
999  * actual implementation must be in arch/$(ARCH)/util/header.c
1000  */
1001 int __attribute__((weak)) get_cpuid(char *buffer __used, size_t sz __used)
1002 {
1003 	return -1;
1004 }
1005 
1006 static int write_cpuid(int fd, struct perf_header *h __used,
1007 		       struct perf_evlist *evlist __used)
1008 {
1009 	char buffer[64];
1010 	int ret;
1011 
1012 	ret = get_cpuid(buffer, sizeof(buffer));
1013 	if (!ret)
1014 		goto write_it;
1015 
1016 	return -1;
1017 write_it:
1018 	return do_write_string(fd, buffer);
1019 }
1020 
1021 static int write_branch_stack(int fd __used, struct perf_header *h __used,
1022 		       struct perf_evlist *evlist __used)
1023 {
1024 	return 0;
1025 }
1026 
1027 static void print_hostname(struct perf_header *ph, int fd, FILE *fp)
1028 {
1029 	char *str = do_read_string(fd, ph);
1030 	fprintf(fp, "# hostname : %s\n", str);
1031 	free(str);
1032 }
1033 
1034 static void print_osrelease(struct perf_header *ph, int fd, FILE *fp)
1035 {
1036 	char *str = do_read_string(fd, ph);
1037 	fprintf(fp, "# os release : %s\n", str);
1038 	free(str);
1039 }
1040 
1041 static void print_arch(struct perf_header *ph, int fd, FILE *fp)
1042 {
1043 	char *str = do_read_string(fd, ph);
1044 	fprintf(fp, "# arch : %s\n", str);
1045 	free(str);
1046 }
1047 
1048 static void print_cpudesc(struct perf_header *ph, int fd, FILE *fp)
1049 {
1050 	char *str = do_read_string(fd, ph);
1051 	fprintf(fp, "# cpudesc : %s\n", str);
1052 	free(str);
1053 }
1054 
1055 static void print_nrcpus(struct perf_header *ph, int fd, FILE *fp)
1056 {
1057 	ssize_t ret;
1058 	u32 nr;
1059 
1060 	ret = read(fd, &nr, sizeof(nr));
1061 	if (ret != (ssize_t)sizeof(nr))
1062 		nr = -1; /* interpreted as error */
1063 
1064 	if (ph->needs_swap)
1065 		nr = bswap_32(nr);
1066 
1067 	fprintf(fp, "# nrcpus online : %u\n", nr);
1068 
1069 	ret = read(fd, &nr, sizeof(nr));
1070 	if (ret != (ssize_t)sizeof(nr))
1071 		nr = -1; /* interpreted as error */
1072 
1073 	if (ph->needs_swap)
1074 		nr = bswap_32(nr);
1075 
1076 	fprintf(fp, "# nrcpus avail : %u\n", nr);
1077 }
1078 
1079 static void print_version(struct perf_header *ph, int fd, FILE *fp)
1080 {
1081 	char *str = do_read_string(fd, ph);
1082 	fprintf(fp, "# perf version : %s\n", str);
1083 	free(str);
1084 }
1085 
1086 static void print_cmdline(struct perf_header *ph, int fd, FILE *fp)
1087 {
1088 	ssize_t ret;
1089 	char *str;
1090 	u32 nr, i;
1091 
1092 	ret = read(fd, &nr, sizeof(nr));
1093 	if (ret != (ssize_t)sizeof(nr))
1094 		return;
1095 
1096 	if (ph->needs_swap)
1097 		nr = bswap_32(nr);
1098 
1099 	fprintf(fp, "# cmdline : ");
1100 
1101 	for (i = 0; i < nr; i++) {
1102 		str = do_read_string(fd, ph);
1103 		fprintf(fp, "%s ", str);
1104 		free(str);
1105 	}
1106 	fputc('\n', fp);
1107 }
1108 
1109 static void print_cpu_topology(struct perf_header *ph, int fd, FILE *fp)
1110 {
1111 	ssize_t ret;
1112 	u32 nr, i;
1113 	char *str;
1114 
1115 	ret = read(fd, &nr, sizeof(nr));
1116 	if (ret != (ssize_t)sizeof(nr))
1117 		return;
1118 
1119 	if (ph->needs_swap)
1120 		nr = bswap_32(nr);
1121 
1122 	for (i = 0; i < nr; i++) {
1123 		str = do_read_string(fd, ph);
1124 		fprintf(fp, "# sibling cores   : %s\n", str);
1125 		free(str);
1126 	}
1127 
1128 	ret = read(fd, &nr, sizeof(nr));
1129 	if (ret != (ssize_t)sizeof(nr))
1130 		return;
1131 
1132 	if (ph->needs_swap)
1133 		nr = bswap_32(nr);
1134 
1135 	for (i = 0; i < nr; i++) {
1136 		str = do_read_string(fd, ph);
1137 		fprintf(fp, "# sibling threads : %s\n", str);
1138 		free(str);
1139 	}
1140 }
1141 
1142 static void print_event_desc(struct perf_header *ph, int fd, FILE *fp)
1143 {
1144 	struct perf_event_attr attr;
1145 	uint64_t id;
1146 	void *buf = NULL;
1147 	char *str;
1148 	u32 nre, sz, nr, i, j;
1149 	ssize_t ret;
1150 	size_t msz;
1151 
1152 	/* number of events */
1153 	ret = read(fd, &nre, sizeof(nre));
1154 	if (ret != (ssize_t)sizeof(nre))
1155 		goto error;
1156 
1157 	if (ph->needs_swap)
1158 		nre = bswap_32(nre);
1159 
1160 	ret = read(fd, &sz, sizeof(sz));
1161 	if (ret != (ssize_t)sizeof(sz))
1162 		goto error;
1163 
1164 	if (ph->needs_swap)
1165 		sz = bswap_32(sz);
1166 
1167 	memset(&attr, 0, sizeof(attr));
1168 
1169 	/* buffer to hold on file attr struct */
1170 	buf = malloc(sz);
1171 	if (!buf)
1172 		goto error;
1173 
1174 	msz = sizeof(attr);
1175 	if (sz < msz)
1176 		msz = sz;
1177 
1178 	for (i = 0 ; i < nre; i++) {
1179 
1180 		/*
1181 		 * must read entire on-file attr struct to
1182 		 * sync up with layout.
1183 		 */
1184 		ret = read(fd, buf, sz);
1185 		if (ret != (ssize_t)sz)
1186 			goto error;
1187 
1188 		if (ph->needs_swap)
1189 			perf_event__attr_swap(buf);
1190 
1191 		memcpy(&attr, buf, msz);
1192 
1193 		ret = read(fd, &nr, sizeof(nr));
1194 		if (ret != (ssize_t)sizeof(nr))
1195 			goto error;
1196 
1197 		if (ph->needs_swap)
1198 			nr = bswap_32(nr);
1199 
1200 		str = do_read_string(fd, ph);
1201 		fprintf(fp, "# event : name = %s, ", str);
1202 		free(str);
1203 
1204 		fprintf(fp, "type = %d, config = 0x%"PRIx64
1205 			    ", config1 = 0x%"PRIx64", config2 = 0x%"PRIx64,
1206 				attr.type,
1207 				(u64)attr.config,
1208 				(u64)attr.config1,
1209 				(u64)attr.config2);
1210 
1211 		fprintf(fp, ", excl_usr = %d, excl_kern = %d",
1212 				attr.exclude_user,
1213 				attr.exclude_kernel);
1214 
1215 		fprintf(fp, ", excl_host = %d, excl_guest = %d",
1216 				attr.exclude_host,
1217 				attr.exclude_guest);
1218 
1219 		fprintf(fp, ", precise_ip = %d", attr.precise_ip);
1220 
1221 		if (nr)
1222 			fprintf(fp, ", id = {");
1223 
1224 		for (j = 0 ; j < nr; j++) {
1225 			ret = read(fd, &id, sizeof(id));
1226 			if (ret != (ssize_t)sizeof(id))
1227 				goto error;
1228 
1229 			if (ph->needs_swap)
1230 				id = bswap_64(id);
1231 
1232 			if (j)
1233 				fputc(',', fp);
1234 
1235 			fprintf(fp, " %"PRIu64, id);
1236 		}
1237 		if (nr && j == nr)
1238 			fprintf(fp, " }");
1239 		fputc('\n', fp);
1240 	}
1241 	free(buf);
1242 	return;
1243 error:
1244 	fprintf(fp, "# event desc: not available or unable to read\n");
1245 }
1246 
1247 static void print_total_mem(struct perf_header *h __used, int fd, FILE *fp)
1248 {
1249 	uint64_t mem;
1250 	ssize_t ret;
1251 
1252 	ret = read(fd, &mem, sizeof(mem));
1253 	if (ret != sizeof(mem))
1254 		goto error;
1255 
1256 	if (h->needs_swap)
1257 		mem = bswap_64(mem);
1258 
1259 	fprintf(fp, "# total memory : %"PRIu64" kB\n", mem);
1260 	return;
1261 error:
1262 	fprintf(fp, "# total memory : unknown\n");
1263 }
1264 
1265 static void print_numa_topology(struct perf_header *h __used, int fd, FILE *fp)
1266 {
1267 	ssize_t ret;
1268 	u32 nr, c, i;
1269 	char *str;
1270 	uint64_t mem_total, mem_free;
1271 
1272 	/* nr nodes */
1273 	ret = read(fd, &nr, sizeof(nr));
1274 	if (ret != (ssize_t)sizeof(nr))
1275 		goto error;
1276 
1277 	if (h->needs_swap)
1278 		nr = bswap_32(nr);
1279 
1280 	for (i = 0; i < nr; i++) {
1281 
1282 		/* node number */
1283 		ret = read(fd, &c, sizeof(c));
1284 		if (ret != (ssize_t)sizeof(c))
1285 			goto error;
1286 
1287 		if (h->needs_swap)
1288 			c = bswap_32(c);
1289 
1290 		ret = read(fd, &mem_total, sizeof(u64));
1291 		if (ret != sizeof(u64))
1292 			goto error;
1293 
1294 		ret = read(fd, &mem_free, sizeof(u64));
1295 		if (ret != sizeof(u64))
1296 			goto error;
1297 
1298 		if (h->needs_swap) {
1299 			mem_total = bswap_64(mem_total);
1300 			mem_free = bswap_64(mem_free);
1301 		}
1302 
1303 		fprintf(fp, "# node%u meminfo  : total = %"PRIu64" kB,"
1304 			    " free = %"PRIu64" kB\n",
1305 			c,
1306 			mem_total,
1307 			mem_free);
1308 
1309 		str = do_read_string(fd, h);
1310 		fprintf(fp, "# node%u cpu list : %s\n", c, str);
1311 		free(str);
1312 	}
1313 	return;
1314 error:
1315 	fprintf(fp, "# numa topology : not available\n");
1316 }
1317 
1318 static void print_cpuid(struct perf_header *ph, int fd, FILE *fp)
1319 {
1320 	char *str = do_read_string(fd, ph);
1321 	fprintf(fp, "# cpuid : %s\n", str);
1322 	free(str);
1323 }
1324 
1325 static void print_branch_stack(struct perf_header *ph __used, int fd __used,
1326 			       FILE *fp)
1327 {
1328 	fprintf(fp, "# contains samples with branch stack\n");
1329 }
1330 
1331 static int __event_process_build_id(struct build_id_event *bev,
1332 				    char *filename,
1333 				    struct perf_session *session)
1334 {
1335 	int err = -1;
1336 	struct list_head *head;
1337 	struct machine *machine;
1338 	u16 misc;
1339 	struct dso *dso;
1340 	enum dso_kernel_type dso_type;
1341 
1342 	machine = perf_session__findnew_machine(session, bev->pid);
1343 	if (!machine)
1344 		goto out;
1345 
1346 	misc = bev->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
1347 
1348 	switch (misc) {
1349 	case PERF_RECORD_MISC_KERNEL:
1350 		dso_type = DSO_TYPE_KERNEL;
1351 		head = &machine->kernel_dsos;
1352 		break;
1353 	case PERF_RECORD_MISC_GUEST_KERNEL:
1354 		dso_type = DSO_TYPE_GUEST_KERNEL;
1355 		head = &machine->kernel_dsos;
1356 		break;
1357 	case PERF_RECORD_MISC_USER:
1358 	case PERF_RECORD_MISC_GUEST_USER:
1359 		dso_type = DSO_TYPE_USER;
1360 		head = &machine->user_dsos;
1361 		break;
1362 	default:
1363 		goto out;
1364 	}
1365 
1366 	dso = __dsos__findnew(head, filename);
1367 	if (dso != NULL) {
1368 		char sbuild_id[BUILD_ID_SIZE * 2 + 1];
1369 
1370 		dso__set_build_id(dso, &bev->build_id);
1371 
1372 		if (filename[0] == '[')
1373 			dso->kernel = dso_type;
1374 
1375 		build_id__sprintf(dso->build_id, sizeof(dso->build_id),
1376 				  sbuild_id);
1377 		pr_debug("build id event received for %s: %s\n",
1378 			 dso->long_name, sbuild_id);
1379 	}
1380 
1381 	err = 0;
1382 out:
1383 	return err;
1384 }
1385 
1386 static int perf_header__read_build_ids_abi_quirk(struct perf_header *header,
1387 						 int input, u64 offset, u64 size)
1388 {
1389 	struct perf_session *session = container_of(header, struct perf_session, header);
1390 	struct {
1391 		struct perf_event_header   header;
1392 		u8			   build_id[ALIGN(BUILD_ID_SIZE, sizeof(u64))];
1393 		char			   filename[0];
1394 	} old_bev;
1395 	struct build_id_event bev;
1396 	char filename[PATH_MAX];
1397 	u64 limit = offset + size;
1398 
1399 	while (offset < limit) {
1400 		ssize_t len;
1401 
1402 		if (read(input, &old_bev, sizeof(old_bev)) != sizeof(old_bev))
1403 			return -1;
1404 
1405 		if (header->needs_swap)
1406 			perf_event_header__bswap(&old_bev.header);
1407 
1408 		len = old_bev.header.size - sizeof(old_bev);
1409 		if (read(input, filename, len) != len)
1410 			return -1;
1411 
1412 		bev.header = old_bev.header;
1413 
1414 		/*
1415 		 * As the pid is the missing value, we need to fill
1416 		 * it properly. The header.misc value give us nice hint.
1417 		 */
1418 		bev.pid	= HOST_KERNEL_ID;
1419 		if (bev.header.misc == PERF_RECORD_MISC_GUEST_USER ||
1420 		    bev.header.misc == PERF_RECORD_MISC_GUEST_KERNEL)
1421 			bev.pid	= DEFAULT_GUEST_KERNEL_ID;
1422 
1423 		memcpy(bev.build_id, old_bev.build_id, sizeof(bev.build_id));
1424 		__event_process_build_id(&bev, filename, session);
1425 
1426 		offset += bev.header.size;
1427 	}
1428 
1429 	return 0;
1430 }
1431 
1432 static int perf_header__read_build_ids(struct perf_header *header,
1433 				       int input, u64 offset, u64 size)
1434 {
1435 	struct perf_session *session = container_of(header, struct perf_session, header);
1436 	struct build_id_event bev;
1437 	char filename[PATH_MAX];
1438 	u64 limit = offset + size, orig_offset = offset;
1439 	int err = -1;
1440 
1441 	while (offset < limit) {
1442 		ssize_t len;
1443 
1444 		if (read(input, &bev, sizeof(bev)) != sizeof(bev))
1445 			goto out;
1446 
1447 		if (header->needs_swap)
1448 			perf_event_header__bswap(&bev.header);
1449 
1450 		len = bev.header.size - sizeof(bev);
1451 		if (read(input, filename, len) != len)
1452 			goto out;
1453 		/*
1454 		 * The a1645ce1 changeset:
1455 		 *
1456 		 * "perf: 'perf kvm' tool for monitoring guest performance from host"
1457 		 *
1458 		 * Added a field to struct build_id_event that broke the file
1459 		 * format.
1460 		 *
1461 		 * Since the kernel build-id is the first entry, process the
1462 		 * table using the old format if the well known
1463 		 * '[kernel.kallsyms]' string for the kernel build-id has the
1464 		 * first 4 characters chopped off (where the pid_t sits).
1465 		 */
1466 		if (memcmp(filename, "nel.kallsyms]", 13) == 0) {
1467 			if (lseek(input, orig_offset, SEEK_SET) == (off_t)-1)
1468 				return -1;
1469 			return perf_header__read_build_ids_abi_quirk(header, input, offset, size);
1470 		}
1471 
1472 		__event_process_build_id(&bev, filename, session);
1473 
1474 		offset += bev.header.size;
1475 	}
1476 	err = 0;
1477 out:
1478 	return err;
1479 }
1480 
1481 static int process_tracing_data(struct perf_file_section *section __unused,
1482 			      struct perf_header *ph __unused,
1483 			      int feat __unused, int fd, void *data)
1484 {
1485 	trace_report(fd, data, false);
1486 	return 0;
1487 }
1488 
1489 static int process_build_id(struct perf_file_section *section,
1490 			    struct perf_header *ph,
1491 			    int feat __unused, int fd, void *data __used)
1492 {
1493 	if (perf_header__read_build_ids(ph, fd, section->offset, section->size))
1494 		pr_debug("Failed to read buildids, continuing...\n");
1495 	return 0;
1496 }
1497 
1498 struct feature_ops {
1499 	int (*write)(int fd, struct perf_header *h, struct perf_evlist *evlist);
1500 	void (*print)(struct perf_header *h, int fd, FILE *fp);
1501 	int (*process)(struct perf_file_section *section,
1502 		       struct perf_header *h, int feat, int fd, void *data);
1503 	const char *name;
1504 	bool full_only;
1505 };
1506 
1507 #define FEAT_OPA(n, func) \
1508 	[n] = { .name = #n, .write = write_##func, .print = print_##func }
1509 #define FEAT_OPP(n, func) \
1510 	[n] = { .name = #n, .write = write_##func, .print = print_##func, \
1511 		.process = process_##func }
1512 #define FEAT_OPF(n, func) \
1513 	[n] = { .name = #n, .write = write_##func, .print = print_##func, \
1514 		.full_only = true }
1515 
1516 /* feature_ops not implemented: */
1517 #define print_tracing_data	NULL
1518 #define print_build_id		NULL
1519 
1520 static const struct feature_ops feat_ops[HEADER_LAST_FEATURE] = {
1521 	FEAT_OPP(HEADER_TRACING_DATA,	tracing_data),
1522 	FEAT_OPP(HEADER_BUILD_ID,	build_id),
1523 	FEAT_OPA(HEADER_HOSTNAME,	hostname),
1524 	FEAT_OPA(HEADER_OSRELEASE,	osrelease),
1525 	FEAT_OPA(HEADER_VERSION,	version),
1526 	FEAT_OPA(HEADER_ARCH,		arch),
1527 	FEAT_OPA(HEADER_NRCPUS,		nrcpus),
1528 	FEAT_OPA(HEADER_CPUDESC,	cpudesc),
1529 	FEAT_OPA(HEADER_CPUID,		cpuid),
1530 	FEAT_OPA(HEADER_TOTAL_MEM,	total_mem),
1531 	FEAT_OPA(HEADER_EVENT_DESC,	event_desc),
1532 	FEAT_OPA(HEADER_CMDLINE,	cmdline),
1533 	FEAT_OPF(HEADER_CPU_TOPOLOGY,	cpu_topology),
1534 	FEAT_OPF(HEADER_NUMA_TOPOLOGY,	numa_topology),
1535 	FEAT_OPA(HEADER_BRANCH_STACK,	branch_stack),
1536 };
1537 
1538 struct header_print_data {
1539 	FILE *fp;
1540 	bool full; /* extended list of headers */
1541 };
1542 
1543 static int perf_file_section__fprintf_info(struct perf_file_section *section,
1544 					   struct perf_header *ph,
1545 					   int feat, int fd, void *data)
1546 {
1547 	struct header_print_data *hd = data;
1548 
1549 	if (lseek(fd, section->offset, SEEK_SET) == (off_t)-1) {
1550 		pr_debug("Failed to lseek to %" PRIu64 " offset for feature "
1551 				"%d, continuing...\n", section->offset, feat);
1552 		return 0;
1553 	}
1554 	if (feat >= HEADER_LAST_FEATURE) {
1555 		pr_warning("unknown feature %d\n", feat);
1556 		return 0;
1557 	}
1558 	if (!feat_ops[feat].print)
1559 		return 0;
1560 
1561 	if (!feat_ops[feat].full_only || hd->full)
1562 		feat_ops[feat].print(ph, fd, hd->fp);
1563 	else
1564 		fprintf(hd->fp, "# %s info available, use -I to display\n",
1565 			feat_ops[feat].name);
1566 
1567 	return 0;
1568 }
1569 
1570 int perf_header__fprintf_info(struct perf_session *session, FILE *fp, bool full)
1571 {
1572 	struct header_print_data hd;
1573 	struct perf_header *header = &session->header;
1574 	int fd = session->fd;
1575 	hd.fp = fp;
1576 	hd.full = full;
1577 
1578 	perf_header__process_sections(header, fd, &hd,
1579 				      perf_file_section__fprintf_info);
1580 	return 0;
1581 }
1582 
1583 static int do_write_feat(int fd, struct perf_header *h, int type,
1584 			 struct perf_file_section **p,
1585 			 struct perf_evlist *evlist)
1586 {
1587 	int err;
1588 	int ret = 0;
1589 
1590 	if (perf_header__has_feat(h, type)) {
1591 		if (!feat_ops[type].write)
1592 			return -1;
1593 
1594 		(*p)->offset = lseek(fd, 0, SEEK_CUR);
1595 
1596 		err = feat_ops[type].write(fd, h, evlist);
1597 		if (err < 0) {
1598 			pr_debug("failed to write feature %d\n", type);
1599 
1600 			/* undo anything written */
1601 			lseek(fd, (*p)->offset, SEEK_SET);
1602 
1603 			return -1;
1604 		}
1605 		(*p)->size = lseek(fd, 0, SEEK_CUR) - (*p)->offset;
1606 		(*p)++;
1607 	}
1608 	return ret;
1609 }
1610 
1611 static int perf_header__adds_write(struct perf_header *header,
1612 				   struct perf_evlist *evlist, int fd)
1613 {
1614 	int nr_sections;
1615 	struct perf_file_section *feat_sec, *p;
1616 	int sec_size;
1617 	u64 sec_start;
1618 	int feat;
1619 	int err;
1620 
1621 	nr_sections = bitmap_weight(header->adds_features, HEADER_FEAT_BITS);
1622 	if (!nr_sections)
1623 		return 0;
1624 
1625 	feat_sec = p = calloc(sizeof(*feat_sec), nr_sections);
1626 	if (feat_sec == NULL)
1627 		return -ENOMEM;
1628 
1629 	sec_size = sizeof(*feat_sec) * nr_sections;
1630 
1631 	sec_start = header->data_offset + header->data_size;
1632 	lseek(fd, sec_start + sec_size, SEEK_SET);
1633 
1634 	for_each_set_bit(feat, header->adds_features, HEADER_FEAT_BITS) {
1635 		if (do_write_feat(fd, header, feat, &p, evlist))
1636 			perf_header__clear_feat(header, feat);
1637 	}
1638 
1639 	lseek(fd, sec_start, SEEK_SET);
1640 	/*
1641 	 * may write more than needed due to dropped feature, but
1642 	 * this is okay, reader will skip the mising entries
1643 	 */
1644 	err = do_write(fd, feat_sec, sec_size);
1645 	if (err < 0)
1646 		pr_debug("failed to write feature section\n");
1647 	free(feat_sec);
1648 	return err;
1649 }
1650 
1651 int perf_header__write_pipe(int fd)
1652 {
1653 	struct perf_pipe_file_header f_header;
1654 	int err;
1655 
1656 	f_header = (struct perf_pipe_file_header){
1657 		.magic	   = PERF_MAGIC,
1658 		.size	   = sizeof(f_header),
1659 	};
1660 
1661 	err = do_write(fd, &f_header, sizeof(f_header));
1662 	if (err < 0) {
1663 		pr_debug("failed to write perf pipe header\n");
1664 		return err;
1665 	}
1666 
1667 	return 0;
1668 }
1669 
1670 int perf_session__write_header(struct perf_session *session,
1671 			       struct perf_evlist *evlist,
1672 			       int fd, bool at_exit)
1673 {
1674 	struct perf_file_header f_header;
1675 	struct perf_file_attr   f_attr;
1676 	struct perf_header *header = &session->header;
1677 	struct perf_evsel *attr, *pair = NULL;
1678 	int err;
1679 
1680 	lseek(fd, sizeof(f_header), SEEK_SET);
1681 
1682 	if (session->evlist != evlist)
1683 		pair = list_entry(session->evlist->entries.next, struct perf_evsel, node);
1684 
1685 	list_for_each_entry(attr, &evlist->entries, node) {
1686 		attr->id_offset = lseek(fd, 0, SEEK_CUR);
1687 		err = do_write(fd, attr->id, attr->ids * sizeof(u64));
1688 		if (err < 0) {
1689 out_err_write:
1690 			pr_debug("failed to write perf header\n");
1691 			return err;
1692 		}
1693 		if (session->evlist != evlist) {
1694 			err = do_write(fd, pair->id, pair->ids * sizeof(u64));
1695 			if (err < 0)
1696 				goto out_err_write;
1697 			attr->ids += pair->ids;
1698 			pair = list_entry(pair->node.next, struct perf_evsel, node);
1699 		}
1700 	}
1701 
1702 	header->attr_offset = lseek(fd, 0, SEEK_CUR);
1703 
1704 	list_for_each_entry(attr, &evlist->entries, node) {
1705 		f_attr = (struct perf_file_attr){
1706 			.attr = attr->attr,
1707 			.ids  = {
1708 				.offset = attr->id_offset,
1709 				.size   = attr->ids * sizeof(u64),
1710 			}
1711 		};
1712 		err = do_write(fd, &f_attr, sizeof(f_attr));
1713 		if (err < 0) {
1714 			pr_debug("failed to write perf header attribute\n");
1715 			return err;
1716 		}
1717 	}
1718 
1719 	header->event_offset = lseek(fd, 0, SEEK_CUR);
1720 	header->event_size = event_count * sizeof(struct perf_trace_event_type);
1721 	if (events) {
1722 		err = do_write(fd, events, header->event_size);
1723 		if (err < 0) {
1724 			pr_debug("failed to write perf header events\n");
1725 			return err;
1726 		}
1727 	}
1728 
1729 	header->data_offset = lseek(fd, 0, SEEK_CUR);
1730 
1731 	if (at_exit) {
1732 		err = perf_header__adds_write(header, evlist, fd);
1733 		if (err < 0)
1734 			return err;
1735 	}
1736 
1737 	f_header = (struct perf_file_header){
1738 		.magic	   = PERF_MAGIC,
1739 		.size	   = sizeof(f_header),
1740 		.attr_size = sizeof(f_attr),
1741 		.attrs = {
1742 			.offset = header->attr_offset,
1743 			.size   = evlist->nr_entries * sizeof(f_attr),
1744 		},
1745 		.data = {
1746 			.offset = header->data_offset,
1747 			.size	= header->data_size,
1748 		},
1749 		.event_types = {
1750 			.offset = header->event_offset,
1751 			.size	= header->event_size,
1752 		},
1753 	};
1754 
1755 	memcpy(&f_header.adds_features, &header->adds_features, sizeof(header->adds_features));
1756 
1757 	lseek(fd, 0, SEEK_SET);
1758 	err = do_write(fd, &f_header, sizeof(f_header));
1759 	if (err < 0) {
1760 		pr_debug("failed to write perf header\n");
1761 		return err;
1762 	}
1763 	lseek(fd, header->data_offset + header->data_size, SEEK_SET);
1764 
1765 	header->frozen = 1;
1766 	return 0;
1767 }
1768 
1769 static int perf_header__getbuffer64(struct perf_header *header,
1770 				    int fd, void *buf, size_t size)
1771 {
1772 	if (readn(fd, buf, size) <= 0)
1773 		return -1;
1774 
1775 	if (header->needs_swap)
1776 		mem_bswap_64(buf, size);
1777 
1778 	return 0;
1779 }
1780 
1781 int perf_header__process_sections(struct perf_header *header, int fd,
1782 				  void *data,
1783 				  int (*process)(struct perf_file_section *section,
1784 						 struct perf_header *ph,
1785 						 int feat, int fd, void *data))
1786 {
1787 	struct perf_file_section *feat_sec, *sec;
1788 	int nr_sections;
1789 	int sec_size;
1790 	int feat;
1791 	int err;
1792 
1793 	nr_sections = bitmap_weight(header->adds_features, HEADER_FEAT_BITS);
1794 	if (!nr_sections)
1795 		return 0;
1796 
1797 	feat_sec = sec = calloc(sizeof(*feat_sec), nr_sections);
1798 	if (!feat_sec)
1799 		return -1;
1800 
1801 	sec_size = sizeof(*feat_sec) * nr_sections;
1802 
1803 	lseek(fd, header->data_offset + header->data_size, SEEK_SET);
1804 
1805 	err = perf_header__getbuffer64(header, fd, feat_sec, sec_size);
1806 	if (err < 0)
1807 		goto out_free;
1808 
1809 	for_each_set_bit(feat, header->adds_features, HEADER_LAST_FEATURE) {
1810 		err = process(sec++, header, feat, fd, data);
1811 		if (err < 0)
1812 			goto out_free;
1813 	}
1814 	err = 0;
1815 out_free:
1816 	free(feat_sec);
1817 	return err;
1818 }
1819 
1820 static const int attr_file_abi_sizes[] = {
1821 	[0] = PERF_ATTR_SIZE_VER0,
1822 	[1] = PERF_ATTR_SIZE_VER1,
1823 	0,
1824 };
1825 
1826 /*
1827  * In the legacy file format, the magic number is not used to encode endianness.
1828  * hdr_sz was used to encode endianness. But given that hdr_sz can vary based
1829  * on ABI revisions, we need to try all combinations for all endianness to
1830  * detect the endianness.
1831  */
1832 static int try_all_file_abis(uint64_t hdr_sz, struct perf_header *ph)
1833 {
1834 	uint64_t ref_size, attr_size;
1835 	int i;
1836 
1837 	for (i = 0 ; attr_file_abi_sizes[i]; i++) {
1838 		ref_size = attr_file_abi_sizes[i]
1839 			 + sizeof(struct perf_file_section);
1840 		if (hdr_sz != ref_size) {
1841 			attr_size = bswap_64(hdr_sz);
1842 			if (attr_size != ref_size)
1843 				continue;
1844 
1845 			ph->needs_swap = true;
1846 		}
1847 		pr_debug("ABI%d perf.data file detected, need_swap=%d\n",
1848 			 i,
1849 			 ph->needs_swap);
1850 		return 0;
1851 	}
1852 	/* could not determine endianness */
1853 	return -1;
1854 }
1855 
1856 #define PERF_PIPE_HDR_VER0	16
1857 
1858 static const size_t attr_pipe_abi_sizes[] = {
1859 	[0] = PERF_PIPE_HDR_VER0,
1860 	0,
1861 };
1862 
1863 /*
1864  * In the legacy pipe format, there is an implicit assumption that endiannesss
1865  * between host recording the samples, and host parsing the samples is the
1866  * same. This is not always the case given that the pipe output may always be
1867  * redirected into a file and analyzed on a different machine with possibly a
1868  * different endianness and perf_event ABI revsions in the perf tool itself.
1869  */
1870 static int try_all_pipe_abis(uint64_t hdr_sz, struct perf_header *ph)
1871 {
1872 	u64 attr_size;
1873 	int i;
1874 
1875 	for (i = 0 ; attr_pipe_abi_sizes[i]; i++) {
1876 		if (hdr_sz != attr_pipe_abi_sizes[i]) {
1877 			attr_size = bswap_64(hdr_sz);
1878 			if (attr_size != hdr_sz)
1879 				continue;
1880 
1881 			ph->needs_swap = true;
1882 		}
1883 		pr_debug("Pipe ABI%d perf.data file detected\n", i);
1884 		return 0;
1885 	}
1886 	return -1;
1887 }
1888 
1889 static int check_magic_endian(u64 magic, uint64_t hdr_sz,
1890 			      bool is_pipe, struct perf_header *ph)
1891 {
1892 	int ret;
1893 
1894 	/* check for legacy format */
1895 	ret = memcmp(&magic, __perf_magic1, sizeof(magic));
1896 	if (ret == 0) {
1897 		pr_debug("legacy perf.data format\n");
1898 		if (is_pipe)
1899 			return try_all_pipe_abis(hdr_sz, ph);
1900 
1901 		return try_all_file_abis(hdr_sz, ph);
1902 	}
1903 	/*
1904 	 * the new magic number serves two purposes:
1905 	 * - unique number to identify actual perf.data files
1906 	 * - encode endianness of file
1907 	 */
1908 
1909 	/* check magic number with one endianness */
1910 	if (magic == __perf_magic2)
1911 		return 0;
1912 
1913 	/* check magic number with opposite endianness */
1914 	if (magic != __perf_magic2_sw)
1915 		return -1;
1916 
1917 	ph->needs_swap = true;
1918 
1919 	return 0;
1920 }
1921 
1922 int perf_file_header__read(struct perf_file_header *header,
1923 			   struct perf_header *ph, int fd)
1924 {
1925 	int ret;
1926 
1927 	lseek(fd, 0, SEEK_SET);
1928 
1929 	ret = readn(fd, header, sizeof(*header));
1930 	if (ret <= 0)
1931 		return -1;
1932 
1933 	if (check_magic_endian(header->magic,
1934 			       header->attr_size, false, ph) < 0) {
1935 		pr_debug("magic/endian check failed\n");
1936 		return -1;
1937 	}
1938 
1939 	if (ph->needs_swap) {
1940 		mem_bswap_64(header, offsetof(struct perf_file_header,
1941 			     adds_features));
1942 	}
1943 
1944 	if (header->size != sizeof(*header)) {
1945 		/* Support the previous format */
1946 		if (header->size == offsetof(typeof(*header), adds_features))
1947 			bitmap_zero(header->adds_features, HEADER_FEAT_BITS);
1948 		else
1949 			return -1;
1950 	} else if (ph->needs_swap) {
1951 		/*
1952 		 * feature bitmap is declared as an array of unsigned longs --
1953 		 * not good since its size can differ between the host that
1954 		 * generated the data file and the host analyzing the file.
1955 		 *
1956 		 * We need to handle endianness, but we don't know the size of
1957 		 * the unsigned long where the file was generated. Take a best
1958 		 * guess at determining it: try 64-bit swap first (ie., file
1959 		 * created on a 64-bit host), and check if the hostname feature
1960 		 * bit is set (this feature bit is forced on as of fbe96f2).
1961 		 * If the bit is not, undo the 64-bit swap and try a 32-bit
1962 		 * swap. If the hostname bit is still not set (e.g., older data
1963 		 * file), punt and fallback to the original behavior --
1964 		 * clearing all feature bits and setting buildid.
1965 		 */
1966 		mem_bswap_64(&header->adds_features,
1967 			    BITS_TO_U64(HEADER_FEAT_BITS));
1968 
1969 		if (!test_bit(HEADER_HOSTNAME, header->adds_features)) {
1970 			/* unswap as u64 */
1971 			mem_bswap_64(&header->adds_features,
1972 				    BITS_TO_U64(HEADER_FEAT_BITS));
1973 
1974 			/* unswap as u32 */
1975 			mem_bswap_32(&header->adds_features,
1976 				    BITS_TO_U32(HEADER_FEAT_BITS));
1977 		}
1978 
1979 		if (!test_bit(HEADER_HOSTNAME, header->adds_features)) {
1980 			bitmap_zero(header->adds_features, HEADER_FEAT_BITS);
1981 			set_bit(HEADER_BUILD_ID, header->adds_features);
1982 		}
1983 	}
1984 
1985 	memcpy(&ph->adds_features, &header->adds_features,
1986 	       sizeof(ph->adds_features));
1987 
1988 	ph->event_offset = header->event_types.offset;
1989 	ph->event_size   = header->event_types.size;
1990 	ph->data_offset  = header->data.offset;
1991 	ph->data_size	 = header->data.size;
1992 	return 0;
1993 }
1994 
1995 static int perf_file_section__process(struct perf_file_section *section,
1996 				      struct perf_header *ph,
1997 				      int feat, int fd, void *data)
1998 {
1999 	if (lseek(fd, section->offset, SEEK_SET) == (off_t)-1) {
2000 		pr_debug("Failed to lseek to %" PRIu64 " offset for feature "
2001 			  "%d, continuing...\n", section->offset, feat);
2002 		return 0;
2003 	}
2004 
2005 	if (feat >= HEADER_LAST_FEATURE) {
2006 		pr_debug("unknown feature %d, continuing...\n", feat);
2007 		return 0;
2008 	}
2009 
2010 	if (!feat_ops[feat].process)
2011 		return 0;
2012 
2013 	return feat_ops[feat].process(section, ph, feat, fd, data);
2014 }
2015 
2016 static int perf_file_header__read_pipe(struct perf_pipe_file_header *header,
2017 				       struct perf_header *ph, int fd,
2018 				       bool repipe)
2019 {
2020 	int ret;
2021 
2022 	ret = readn(fd, header, sizeof(*header));
2023 	if (ret <= 0)
2024 		return -1;
2025 
2026 	if (check_magic_endian(header->magic, header->size, true, ph) < 0) {
2027 		pr_debug("endian/magic failed\n");
2028 		return -1;
2029 	}
2030 
2031 	if (ph->needs_swap)
2032 		header->size = bswap_64(header->size);
2033 
2034 	if (repipe && do_write(STDOUT_FILENO, header, sizeof(*header)) < 0)
2035 		return -1;
2036 
2037 	return 0;
2038 }
2039 
2040 static int perf_header__read_pipe(struct perf_session *session, int fd)
2041 {
2042 	struct perf_header *header = &session->header;
2043 	struct perf_pipe_file_header f_header;
2044 
2045 	if (perf_file_header__read_pipe(&f_header, header, fd,
2046 					session->repipe) < 0) {
2047 		pr_debug("incompatible file format\n");
2048 		return -EINVAL;
2049 	}
2050 
2051 	session->fd = fd;
2052 
2053 	return 0;
2054 }
2055 
2056 static int read_attr(int fd, struct perf_header *ph,
2057 		     struct perf_file_attr *f_attr)
2058 {
2059 	struct perf_event_attr *attr = &f_attr->attr;
2060 	size_t sz, left;
2061 	size_t our_sz = sizeof(f_attr->attr);
2062 	int ret;
2063 
2064 	memset(f_attr, 0, sizeof(*f_attr));
2065 
2066 	/* read minimal guaranteed structure */
2067 	ret = readn(fd, attr, PERF_ATTR_SIZE_VER0);
2068 	if (ret <= 0) {
2069 		pr_debug("cannot read %d bytes of header attr\n",
2070 			 PERF_ATTR_SIZE_VER0);
2071 		return -1;
2072 	}
2073 
2074 	/* on file perf_event_attr size */
2075 	sz = attr->size;
2076 
2077 	if (ph->needs_swap)
2078 		sz = bswap_32(sz);
2079 
2080 	if (sz == 0) {
2081 		/* assume ABI0 */
2082 		sz =  PERF_ATTR_SIZE_VER0;
2083 	} else if (sz > our_sz) {
2084 		pr_debug("file uses a more recent and unsupported ABI"
2085 			 " (%zu bytes extra)\n", sz - our_sz);
2086 		return -1;
2087 	}
2088 	/* what we have not yet read and that we know about */
2089 	left = sz - PERF_ATTR_SIZE_VER0;
2090 	if (left) {
2091 		void *ptr = attr;
2092 		ptr += PERF_ATTR_SIZE_VER0;
2093 
2094 		ret = readn(fd, ptr, left);
2095 	}
2096 	/* read perf_file_section, ids are read in caller */
2097 	ret = readn(fd, &f_attr->ids, sizeof(f_attr->ids));
2098 
2099 	return ret <= 0 ? -1 : 0;
2100 }
2101 
2102 static int perf_evsel__set_tracepoint_name(struct perf_evsel *evsel,
2103 					   struct pevent *pevent)
2104 {
2105 	struct event_format *event = pevent_find_event(pevent,
2106 						       evsel->attr.config);
2107 	char bf[128];
2108 
2109 	if (event == NULL)
2110 		return -1;
2111 
2112 	snprintf(bf, sizeof(bf), "%s:%s", event->system, event->name);
2113 	evsel->name = strdup(bf);
2114 	if (event->name == NULL)
2115 		return -1;
2116 
2117 	return 0;
2118 }
2119 
2120 static int perf_evlist__set_tracepoint_names(struct perf_evlist *evlist,
2121 					     struct pevent *pevent)
2122 {
2123 	struct perf_evsel *pos;
2124 
2125 	list_for_each_entry(pos, &evlist->entries, node) {
2126 		if (pos->attr.type == PERF_TYPE_TRACEPOINT &&
2127 		    perf_evsel__set_tracepoint_name(pos, pevent))
2128 			return -1;
2129 	}
2130 
2131 	return 0;
2132 }
2133 
2134 int perf_session__read_header(struct perf_session *session, int fd)
2135 {
2136 	struct perf_header *header = &session->header;
2137 	struct perf_file_header	f_header;
2138 	struct perf_file_attr	f_attr;
2139 	u64			f_id;
2140 	int nr_attrs, nr_ids, i, j;
2141 
2142 	session->evlist = perf_evlist__new(NULL, NULL);
2143 	if (session->evlist == NULL)
2144 		return -ENOMEM;
2145 
2146 	if (session->fd_pipe)
2147 		return perf_header__read_pipe(session, fd);
2148 
2149 	if (perf_file_header__read(&f_header, header, fd) < 0)
2150 		return -EINVAL;
2151 
2152 	nr_attrs = f_header.attrs.size / f_header.attr_size;
2153 	lseek(fd, f_header.attrs.offset, SEEK_SET);
2154 
2155 	for (i = 0; i < nr_attrs; i++) {
2156 		struct perf_evsel *evsel;
2157 		off_t tmp;
2158 
2159 		if (read_attr(fd, header, &f_attr) < 0)
2160 			goto out_errno;
2161 
2162 		if (header->needs_swap)
2163 			perf_event__attr_swap(&f_attr.attr);
2164 
2165 		tmp = lseek(fd, 0, SEEK_CUR);
2166 		evsel = perf_evsel__new(&f_attr.attr, i);
2167 
2168 		if (evsel == NULL)
2169 			goto out_delete_evlist;
2170 		/*
2171 		 * Do it before so that if perf_evsel__alloc_id fails, this
2172 		 * entry gets purged too at perf_evlist__delete().
2173 		 */
2174 		perf_evlist__add(session->evlist, evsel);
2175 
2176 		nr_ids = f_attr.ids.size / sizeof(u64);
2177 		/*
2178 		 * We don't have the cpu and thread maps on the header, so
2179 		 * for allocating the perf_sample_id table we fake 1 cpu and
2180 		 * hattr->ids threads.
2181 		 */
2182 		if (perf_evsel__alloc_id(evsel, 1, nr_ids))
2183 			goto out_delete_evlist;
2184 
2185 		lseek(fd, f_attr.ids.offset, SEEK_SET);
2186 
2187 		for (j = 0; j < nr_ids; j++) {
2188 			if (perf_header__getbuffer64(header, fd, &f_id, sizeof(f_id)))
2189 				goto out_errno;
2190 
2191 			perf_evlist__id_add(session->evlist, evsel, 0, j, f_id);
2192 		}
2193 
2194 		lseek(fd, tmp, SEEK_SET);
2195 	}
2196 
2197 	symbol_conf.nr_events = nr_attrs;
2198 
2199 	if (f_header.event_types.size) {
2200 		lseek(fd, f_header.event_types.offset, SEEK_SET);
2201 		events = malloc(f_header.event_types.size);
2202 		if (events == NULL)
2203 			return -ENOMEM;
2204 		if (perf_header__getbuffer64(header, fd, events,
2205 					     f_header.event_types.size))
2206 			goto out_errno;
2207 		event_count =  f_header.event_types.size / sizeof(struct perf_trace_event_type);
2208 	}
2209 
2210 	perf_header__process_sections(header, fd, &session->pevent,
2211 				      perf_file_section__process);
2212 
2213 	lseek(fd, header->data_offset, SEEK_SET);
2214 
2215 	if (perf_evlist__set_tracepoint_names(session->evlist, session->pevent))
2216 		goto out_delete_evlist;
2217 
2218 	header->frozen = 1;
2219 	return 0;
2220 out_errno:
2221 	return -errno;
2222 
2223 out_delete_evlist:
2224 	perf_evlist__delete(session->evlist);
2225 	session->evlist = NULL;
2226 	return -ENOMEM;
2227 }
2228 
2229 int perf_event__synthesize_attr(struct perf_tool *tool,
2230 				struct perf_event_attr *attr, u16 ids, u64 *id,
2231 				perf_event__handler_t process)
2232 {
2233 	union perf_event *ev;
2234 	size_t size;
2235 	int err;
2236 
2237 	size = sizeof(struct perf_event_attr);
2238 	size = ALIGN(size, sizeof(u64));
2239 	size += sizeof(struct perf_event_header);
2240 	size += ids * sizeof(u64);
2241 
2242 	ev = malloc(size);
2243 
2244 	if (ev == NULL)
2245 		return -ENOMEM;
2246 
2247 	ev->attr.attr = *attr;
2248 	memcpy(ev->attr.id, id, ids * sizeof(u64));
2249 
2250 	ev->attr.header.type = PERF_RECORD_HEADER_ATTR;
2251 	ev->attr.header.size = size;
2252 
2253 	err = process(tool, ev, NULL, NULL);
2254 
2255 	free(ev);
2256 
2257 	return err;
2258 }
2259 
2260 int perf_event__synthesize_attrs(struct perf_tool *tool,
2261 				   struct perf_session *session,
2262 				   perf_event__handler_t process)
2263 {
2264 	struct perf_evsel *attr;
2265 	int err = 0;
2266 
2267 	list_for_each_entry(attr, &session->evlist->entries, node) {
2268 		err = perf_event__synthesize_attr(tool, &attr->attr, attr->ids,
2269 						  attr->id, process);
2270 		if (err) {
2271 			pr_debug("failed to create perf header attribute\n");
2272 			return err;
2273 		}
2274 	}
2275 
2276 	return err;
2277 }
2278 
2279 int perf_event__process_attr(union perf_event *event,
2280 			     struct perf_evlist **pevlist)
2281 {
2282 	unsigned int i, ids, n_ids;
2283 	struct perf_evsel *evsel;
2284 	struct perf_evlist *evlist = *pevlist;
2285 
2286 	if (evlist == NULL) {
2287 		*pevlist = evlist = perf_evlist__new(NULL, NULL);
2288 		if (evlist == NULL)
2289 			return -ENOMEM;
2290 	}
2291 
2292 	evsel = perf_evsel__new(&event->attr.attr, evlist->nr_entries);
2293 	if (evsel == NULL)
2294 		return -ENOMEM;
2295 
2296 	perf_evlist__add(evlist, evsel);
2297 
2298 	ids = event->header.size;
2299 	ids -= (void *)&event->attr.id - (void *)event;
2300 	n_ids = ids / sizeof(u64);
2301 	/*
2302 	 * We don't have the cpu and thread maps on the header, so
2303 	 * for allocating the perf_sample_id table we fake 1 cpu and
2304 	 * hattr->ids threads.
2305 	 */
2306 	if (perf_evsel__alloc_id(evsel, 1, n_ids))
2307 		return -ENOMEM;
2308 
2309 	for (i = 0; i < n_ids; i++) {
2310 		perf_evlist__id_add(evlist, evsel, 0, i, event->attr.id[i]);
2311 	}
2312 
2313 	return 0;
2314 }
2315 
2316 int perf_event__synthesize_event_type(struct perf_tool *tool,
2317 				      u64 event_id, char *name,
2318 				      perf_event__handler_t process,
2319 				      struct machine *machine)
2320 {
2321 	union perf_event ev;
2322 	size_t size = 0;
2323 	int err = 0;
2324 
2325 	memset(&ev, 0, sizeof(ev));
2326 
2327 	ev.event_type.event_type.event_id = event_id;
2328 	memset(ev.event_type.event_type.name, 0, MAX_EVENT_NAME);
2329 	strncpy(ev.event_type.event_type.name, name, MAX_EVENT_NAME - 1);
2330 
2331 	ev.event_type.header.type = PERF_RECORD_HEADER_EVENT_TYPE;
2332 	size = strlen(ev.event_type.event_type.name);
2333 	size = ALIGN(size, sizeof(u64));
2334 	ev.event_type.header.size = sizeof(ev.event_type) -
2335 		(sizeof(ev.event_type.event_type.name) - size);
2336 
2337 	err = process(tool, &ev, NULL, machine);
2338 
2339 	return err;
2340 }
2341 
2342 int perf_event__synthesize_event_types(struct perf_tool *tool,
2343 				       perf_event__handler_t process,
2344 				       struct machine *machine)
2345 {
2346 	struct perf_trace_event_type *type;
2347 	int i, err = 0;
2348 
2349 	for (i = 0; i < event_count; i++) {
2350 		type = &events[i];
2351 
2352 		err = perf_event__synthesize_event_type(tool, type->event_id,
2353 							type->name, process,
2354 							machine);
2355 		if (err) {
2356 			pr_debug("failed to create perf header event type\n");
2357 			return err;
2358 		}
2359 	}
2360 
2361 	return err;
2362 }
2363 
2364 int perf_event__process_event_type(struct perf_tool *tool __unused,
2365 				   union perf_event *event)
2366 {
2367 	if (perf_header__push_event(event->event_type.event_type.event_id,
2368 				    event->event_type.event_type.name) < 0)
2369 		return -ENOMEM;
2370 
2371 	return 0;
2372 }
2373 
2374 int perf_event__synthesize_tracing_data(struct perf_tool *tool, int fd,
2375 					struct perf_evlist *evlist,
2376 					perf_event__handler_t process)
2377 {
2378 	union perf_event ev;
2379 	struct tracing_data *tdata;
2380 	ssize_t size = 0, aligned_size = 0, padding;
2381 	int err __used = 0;
2382 
2383 	/*
2384 	 * We are going to store the size of the data followed
2385 	 * by the data contents. Since the fd descriptor is a pipe,
2386 	 * we cannot seek back to store the size of the data once
2387 	 * we know it. Instead we:
2388 	 *
2389 	 * - write the tracing data to the temp file
2390 	 * - get/write the data size to pipe
2391 	 * - write the tracing data from the temp file
2392 	 *   to the pipe
2393 	 */
2394 	tdata = tracing_data_get(&evlist->entries, fd, true);
2395 	if (!tdata)
2396 		return -1;
2397 
2398 	memset(&ev, 0, sizeof(ev));
2399 
2400 	ev.tracing_data.header.type = PERF_RECORD_HEADER_TRACING_DATA;
2401 	size = tdata->size;
2402 	aligned_size = ALIGN(size, sizeof(u64));
2403 	padding = aligned_size - size;
2404 	ev.tracing_data.header.size = sizeof(ev.tracing_data);
2405 	ev.tracing_data.size = aligned_size;
2406 
2407 	process(tool, &ev, NULL, NULL);
2408 
2409 	/*
2410 	 * The put function will copy all the tracing data
2411 	 * stored in temp file to the pipe.
2412 	 */
2413 	tracing_data_put(tdata);
2414 
2415 	write_padded(fd, NULL, 0, padding);
2416 
2417 	return aligned_size;
2418 }
2419 
2420 int perf_event__process_tracing_data(union perf_event *event,
2421 				     struct perf_session *session)
2422 {
2423 	ssize_t size_read, padding, size = event->tracing_data.size;
2424 	off_t offset = lseek(session->fd, 0, SEEK_CUR);
2425 	char buf[BUFSIZ];
2426 
2427 	/* setup for reading amidst mmap */
2428 	lseek(session->fd, offset + sizeof(struct tracing_data_event),
2429 	      SEEK_SET);
2430 
2431 	size_read = trace_report(session->fd, &session->pevent,
2432 				 session->repipe);
2433 	padding = ALIGN(size_read, sizeof(u64)) - size_read;
2434 
2435 	if (read(session->fd, buf, padding) < 0)
2436 		die("reading input file");
2437 	if (session->repipe) {
2438 		int retw = write(STDOUT_FILENO, buf, padding);
2439 		if (retw <= 0 || retw != padding)
2440 			die("repiping tracing data padding");
2441 	}
2442 
2443 	if (size_read + padding != size)
2444 		die("tracing data size mismatch");
2445 
2446 	return size_read + padding;
2447 }
2448 
2449 int perf_event__synthesize_build_id(struct perf_tool *tool,
2450 				    struct dso *pos, u16 misc,
2451 				    perf_event__handler_t process,
2452 				    struct machine *machine)
2453 {
2454 	union perf_event ev;
2455 	size_t len;
2456 	int err = 0;
2457 
2458 	if (!pos->hit)
2459 		return err;
2460 
2461 	memset(&ev, 0, sizeof(ev));
2462 
2463 	len = pos->long_name_len + 1;
2464 	len = ALIGN(len, NAME_ALIGN);
2465 	memcpy(&ev.build_id.build_id, pos->build_id, sizeof(pos->build_id));
2466 	ev.build_id.header.type = PERF_RECORD_HEADER_BUILD_ID;
2467 	ev.build_id.header.misc = misc;
2468 	ev.build_id.pid = machine->pid;
2469 	ev.build_id.header.size = sizeof(ev.build_id) + len;
2470 	memcpy(&ev.build_id.filename, pos->long_name, pos->long_name_len);
2471 
2472 	err = process(tool, &ev, NULL, machine);
2473 
2474 	return err;
2475 }
2476 
2477 int perf_event__process_build_id(struct perf_tool *tool __used,
2478 				 union perf_event *event,
2479 				 struct perf_session *session)
2480 {
2481 	__event_process_build_id(&event->build_id,
2482 				 event->build_id.filename,
2483 				 session);
2484 	return 0;
2485 }
2486 
2487 void disable_buildid_cache(void)
2488 {
2489 	no_buildid_cache = true;
2490 }
2491