xref: /openbmc/linux/tools/perf/util/header.c (revision c819e2cf)
1 #include "util.h"
2 #include <sys/types.h>
3 #include <byteswap.h>
4 #include <unistd.h>
5 #include <stdio.h>
6 #include <stdlib.h>
7 #include <linux/list.h>
8 #include <linux/kernel.h>
9 #include <linux/bitops.h>
10 #include <sys/utsname.h>
11 
12 #include "evlist.h"
13 #include "evsel.h"
14 #include "header.h"
15 #include "../perf.h"
16 #include "trace-event.h"
17 #include "session.h"
18 #include "symbol.h"
19 #include "debug.h"
20 #include "cpumap.h"
21 #include "pmu.h"
22 #include "vdso.h"
23 #include "strbuf.h"
24 #include "build-id.h"
25 #include "data.h"
26 
27 static u32 header_argc;
28 static const char **header_argv;
29 
30 /*
31  * magic2 = "PERFILE2"
32  * must be a numerical value to let the endianness
33  * determine the memory layout. That way we are able
34  * to detect endianness when reading the perf.data file
35  * back.
36  *
37  * we check for legacy (PERFFILE) format.
38  */
39 static const char *__perf_magic1 = "PERFFILE";
40 static const u64 __perf_magic2    = 0x32454c4946524550ULL;
41 static const u64 __perf_magic2_sw = 0x50455246494c4532ULL;
42 
43 #define PERF_MAGIC	__perf_magic2
44 
45 struct perf_file_attr {
46 	struct perf_event_attr	attr;
47 	struct perf_file_section	ids;
48 };
49 
50 void perf_header__set_feat(struct perf_header *header, int feat)
51 {
52 	set_bit(feat, header->adds_features);
53 }
54 
55 void perf_header__clear_feat(struct perf_header *header, int feat)
56 {
57 	clear_bit(feat, header->adds_features);
58 }
59 
60 bool perf_header__has_feat(const struct perf_header *header, int feat)
61 {
62 	return test_bit(feat, header->adds_features);
63 }
64 
65 static int do_write(int fd, const void *buf, size_t size)
66 {
67 	while (size) {
68 		int ret = write(fd, buf, size);
69 
70 		if (ret < 0)
71 			return -errno;
72 
73 		size -= ret;
74 		buf += ret;
75 	}
76 
77 	return 0;
78 }
79 
80 int write_padded(int fd, const void *bf, size_t count, size_t count_aligned)
81 {
82 	static const char zero_buf[NAME_ALIGN];
83 	int err = do_write(fd, bf, count);
84 
85 	if (!err)
86 		err = do_write(fd, zero_buf, count_aligned - count);
87 
88 	return err;
89 }
90 
91 static int do_write_string(int fd, const char *str)
92 {
93 	u32 len, olen;
94 	int ret;
95 
96 	olen = strlen(str) + 1;
97 	len = PERF_ALIGN(olen, NAME_ALIGN);
98 
99 	/* write len, incl. \0 */
100 	ret = do_write(fd, &len, sizeof(len));
101 	if (ret < 0)
102 		return ret;
103 
104 	return write_padded(fd, str, olen, len);
105 }
106 
107 static char *do_read_string(int fd, struct perf_header *ph)
108 {
109 	ssize_t sz, ret;
110 	u32 len;
111 	char *buf;
112 
113 	sz = readn(fd, &len, sizeof(len));
114 	if (sz < (ssize_t)sizeof(len))
115 		return NULL;
116 
117 	if (ph->needs_swap)
118 		len = bswap_32(len);
119 
120 	buf = malloc(len);
121 	if (!buf)
122 		return NULL;
123 
124 	ret = readn(fd, buf, len);
125 	if (ret == (ssize_t)len) {
126 		/*
127 		 * strings are padded by zeroes
128 		 * thus the actual strlen of buf
129 		 * may be less than len
130 		 */
131 		return buf;
132 	}
133 
134 	free(buf);
135 	return NULL;
136 }
137 
138 int
139 perf_header__set_cmdline(int argc, const char **argv)
140 {
141 	int i;
142 
143 	/*
144 	 * If header_argv has already been set, do not override it.
145 	 * This allows a command to set the cmdline, parse args and
146 	 * then call another builtin function that implements a
147 	 * command -- e.g, cmd_kvm calling cmd_record.
148 	 */
149 	if (header_argv)
150 		return 0;
151 
152 	header_argc = (u32)argc;
153 
154 	/* do not include NULL termination */
155 	header_argv = calloc(argc, sizeof(char *));
156 	if (!header_argv)
157 		return -ENOMEM;
158 
159 	/*
160 	 * must copy argv contents because it gets moved
161 	 * around during option parsing
162 	 */
163 	for (i = 0; i < argc ; i++)
164 		header_argv[i] = argv[i];
165 
166 	return 0;
167 }
168 
169 static int write_tracing_data(int fd, struct perf_header *h __maybe_unused,
170 			    struct perf_evlist *evlist)
171 {
172 	return read_tracing_data(fd, &evlist->entries);
173 }
174 
175 
176 static int write_build_id(int fd, struct perf_header *h,
177 			  struct perf_evlist *evlist __maybe_unused)
178 {
179 	struct perf_session *session;
180 	int err;
181 
182 	session = container_of(h, struct perf_session, header);
183 
184 	if (!perf_session__read_build_ids(session, true))
185 		return -1;
186 
187 	err = perf_session__write_buildid_table(session, fd);
188 	if (err < 0) {
189 		pr_debug("failed to write buildid table\n");
190 		return err;
191 	}
192 	perf_session__cache_build_ids(session);
193 
194 	return 0;
195 }
196 
197 static int write_hostname(int fd, struct perf_header *h __maybe_unused,
198 			  struct perf_evlist *evlist __maybe_unused)
199 {
200 	struct utsname uts;
201 	int ret;
202 
203 	ret = uname(&uts);
204 	if (ret < 0)
205 		return -1;
206 
207 	return do_write_string(fd, uts.nodename);
208 }
209 
210 static int write_osrelease(int fd, struct perf_header *h __maybe_unused,
211 			   struct perf_evlist *evlist __maybe_unused)
212 {
213 	struct utsname uts;
214 	int ret;
215 
216 	ret = uname(&uts);
217 	if (ret < 0)
218 		return -1;
219 
220 	return do_write_string(fd, uts.release);
221 }
222 
223 static int write_arch(int fd, struct perf_header *h __maybe_unused,
224 		      struct perf_evlist *evlist __maybe_unused)
225 {
226 	struct utsname uts;
227 	int ret;
228 
229 	ret = uname(&uts);
230 	if (ret < 0)
231 		return -1;
232 
233 	return do_write_string(fd, uts.machine);
234 }
235 
236 static int write_version(int fd, struct perf_header *h __maybe_unused,
237 			 struct perf_evlist *evlist __maybe_unused)
238 {
239 	return do_write_string(fd, perf_version_string);
240 }
241 
242 static int __write_cpudesc(int fd, const char *cpuinfo_proc)
243 {
244 	FILE *file;
245 	char *buf = NULL;
246 	char *s, *p;
247 	const char *search = cpuinfo_proc;
248 	size_t len = 0;
249 	int ret = -1;
250 
251 	if (!search)
252 		return -1;
253 
254 	file = fopen("/proc/cpuinfo", "r");
255 	if (!file)
256 		return -1;
257 
258 	while (getline(&buf, &len, file) > 0) {
259 		ret = strncmp(buf, search, strlen(search));
260 		if (!ret)
261 			break;
262 	}
263 
264 	if (ret) {
265 		ret = -1;
266 		goto done;
267 	}
268 
269 	s = buf;
270 
271 	p = strchr(buf, ':');
272 	if (p && *(p+1) == ' ' && *(p+2))
273 		s = p + 2;
274 	p = strchr(s, '\n');
275 	if (p)
276 		*p = '\0';
277 
278 	/* squash extra space characters (branding string) */
279 	p = s;
280 	while (*p) {
281 		if (isspace(*p)) {
282 			char *r = p + 1;
283 			char *q = r;
284 			*p = ' ';
285 			while (*q && isspace(*q))
286 				q++;
287 			if (q != (p+1))
288 				while ((*r++ = *q++));
289 		}
290 		p++;
291 	}
292 	ret = do_write_string(fd, s);
293 done:
294 	free(buf);
295 	fclose(file);
296 	return ret;
297 }
298 
299 static int write_cpudesc(int fd, struct perf_header *h __maybe_unused,
300 		       struct perf_evlist *evlist __maybe_unused)
301 {
302 #ifndef CPUINFO_PROC
303 #define CPUINFO_PROC {"model name", }
304 #endif
305 	const char *cpuinfo_procs[] = CPUINFO_PROC;
306 	unsigned int i;
307 
308 	for (i = 0; i < ARRAY_SIZE(cpuinfo_procs); i++) {
309 		int ret;
310 		ret = __write_cpudesc(fd, cpuinfo_procs[i]);
311 		if (ret >= 0)
312 			return ret;
313 	}
314 	return -1;
315 }
316 
317 
318 static int write_nrcpus(int fd, struct perf_header *h __maybe_unused,
319 			struct perf_evlist *evlist __maybe_unused)
320 {
321 	long nr;
322 	u32 nrc, nra;
323 	int ret;
324 
325 	nr = sysconf(_SC_NPROCESSORS_CONF);
326 	if (nr < 0)
327 		return -1;
328 
329 	nrc = (u32)(nr & UINT_MAX);
330 
331 	nr = sysconf(_SC_NPROCESSORS_ONLN);
332 	if (nr < 0)
333 		return -1;
334 
335 	nra = (u32)(nr & UINT_MAX);
336 
337 	ret = do_write(fd, &nrc, sizeof(nrc));
338 	if (ret < 0)
339 		return ret;
340 
341 	return do_write(fd, &nra, sizeof(nra));
342 }
343 
344 static int write_event_desc(int fd, struct perf_header *h __maybe_unused,
345 			    struct perf_evlist *evlist)
346 {
347 	struct perf_evsel *evsel;
348 	u32 nre, nri, sz;
349 	int ret;
350 
351 	nre = evlist->nr_entries;
352 
353 	/*
354 	 * write number of events
355 	 */
356 	ret = do_write(fd, &nre, sizeof(nre));
357 	if (ret < 0)
358 		return ret;
359 
360 	/*
361 	 * size of perf_event_attr struct
362 	 */
363 	sz = (u32)sizeof(evsel->attr);
364 	ret = do_write(fd, &sz, sizeof(sz));
365 	if (ret < 0)
366 		return ret;
367 
368 	evlist__for_each(evlist, evsel) {
369 		ret = do_write(fd, &evsel->attr, sz);
370 		if (ret < 0)
371 			return ret;
372 		/*
373 		 * write number of unique id per event
374 		 * there is one id per instance of an event
375 		 *
376 		 * copy into an nri to be independent of the
377 		 * type of ids,
378 		 */
379 		nri = evsel->ids;
380 		ret = do_write(fd, &nri, sizeof(nri));
381 		if (ret < 0)
382 			return ret;
383 
384 		/*
385 		 * write event string as passed on cmdline
386 		 */
387 		ret = do_write_string(fd, perf_evsel__name(evsel));
388 		if (ret < 0)
389 			return ret;
390 		/*
391 		 * write unique ids for this event
392 		 */
393 		ret = do_write(fd, evsel->id, evsel->ids * sizeof(u64));
394 		if (ret < 0)
395 			return ret;
396 	}
397 	return 0;
398 }
399 
400 static int write_cmdline(int fd, struct perf_header *h __maybe_unused,
401 			 struct perf_evlist *evlist __maybe_unused)
402 {
403 	char buf[MAXPATHLEN];
404 	char proc[32];
405 	u32 i, n;
406 	int ret;
407 
408 	/*
409 	 * actual atual path to perf binary
410 	 */
411 	sprintf(proc, "/proc/%d/exe", getpid());
412 	ret = readlink(proc, buf, sizeof(buf));
413 	if (ret <= 0)
414 		return -1;
415 
416 	/* readlink() does not add null termination */
417 	buf[ret] = '\0';
418 
419 	/* account for binary path */
420 	n = header_argc + 1;
421 
422 	ret = do_write(fd, &n, sizeof(n));
423 	if (ret < 0)
424 		return ret;
425 
426 	ret = do_write_string(fd, buf);
427 	if (ret < 0)
428 		return ret;
429 
430 	for (i = 0 ; i < header_argc; i++) {
431 		ret = do_write_string(fd, header_argv[i]);
432 		if (ret < 0)
433 			return ret;
434 	}
435 	return 0;
436 }
437 
438 #define CORE_SIB_FMT \
439 	"/sys/devices/system/cpu/cpu%d/topology/core_siblings_list"
440 #define THRD_SIB_FMT \
441 	"/sys/devices/system/cpu/cpu%d/topology/thread_siblings_list"
442 
443 struct cpu_topo {
444 	u32 core_sib;
445 	u32 thread_sib;
446 	char **core_siblings;
447 	char **thread_siblings;
448 };
449 
450 static int build_cpu_topo(struct cpu_topo *tp, int cpu)
451 {
452 	FILE *fp;
453 	char filename[MAXPATHLEN];
454 	char *buf = NULL, *p;
455 	size_t len = 0;
456 	ssize_t sret;
457 	u32 i = 0;
458 	int ret = -1;
459 
460 	sprintf(filename, CORE_SIB_FMT, cpu);
461 	fp = fopen(filename, "r");
462 	if (!fp)
463 		goto try_threads;
464 
465 	sret = getline(&buf, &len, fp);
466 	fclose(fp);
467 	if (sret <= 0)
468 		goto try_threads;
469 
470 	p = strchr(buf, '\n');
471 	if (p)
472 		*p = '\0';
473 
474 	for (i = 0; i < tp->core_sib; i++) {
475 		if (!strcmp(buf, tp->core_siblings[i]))
476 			break;
477 	}
478 	if (i == tp->core_sib) {
479 		tp->core_siblings[i] = buf;
480 		tp->core_sib++;
481 		buf = NULL;
482 		len = 0;
483 	}
484 	ret = 0;
485 
486 try_threads:
487 	sprintf(filename, THRD_SIB_FMT, cpu);
488 	fp = fopen(filename, "r");
489 	if (!fp)
490 		goto done;
491 
492 	if (getline(&buf, &len, fp) <= 0)
493 		goto done;
494 
495 	p = strchr(buf, '\n');
496 	if (p)
497 		*p = '\0';
498 
499 	for (i = 0; i < tp->thread_sib; i++) {
500 		if (!strcmp(buf, tp->thread_siblings[i]))
501 			break;
502 	}
503 	if (i == tp->thread_sib) {
504 		tp->thread_siblings[i] = buf;
505 		tp->thread_sib++;
506 		buf = NULL;
507 	}
508 	ret = 0;
509 done:
510 	if(fp)
511 		fclose(fp);
512 	free(buf);
513 	return ret;
514 }
515 
516 static void free_cpu_topo(struct cpu_topo *tp)
517 {
518 	u32 i;
519 
520 	if (!tp)
521 		return;
522 
523 	for (i = 0 ; i < tp->core_sib; i++)
524 		zfree(&tp->core_siblings[i]);
525 
526 	for (i = 0 ; i < tp->thread_sib; i++)
527 		zfree(&tp->thread_siblings[i]);
528 
529 	free(tp);
530 }
531 
532 static struct cpu_topo *build_cpu_topology(void)
533 {
534 	struct cpu_topo *tp;
535 	void *addr;
536 	u32 nr, i;
537 	size_t sz;
538 	long ncpus;
539 	int ret = -1;
540 
541 	ncpus = sysconf(_SC_NPROCESSORS_CONF);
542 	if (ncpus < 0)
543 		return NULL;
544 
545 	nr = (u32)(ncpus & UINT_MAX);
546 
547 	sz = nr * sizeof(char *);
548 
549 	addr = calloc(1, sizeof(*tp) + 2 * sz);
550 	if (!addr)
551 		return NULL;
552 
553 	tp = addr;
554 
555 	addr += sizeof(*tp);
556 	tp->core_siblings = addr;
557 	addr += sz;
558 	tp->thread_siblings = addr;
559 
560 	for (i = 0; i < nr; i++) {
561 		ret = build_cpu_topo(tp, i);
562 		if (ret < 0)
563 			break;
564 	}
565 	if (ret) {
566 		free_cpu_topo(tp);
567 		tp = NULL;
568 	}
569 	return tp;
570 }
571 
572 static int write_cpu_topology(int fd, struct perf_header *h __maybe_unused,
573 			  struct perf_evlist *evlist __maybe_unused)
574 {
575 	struct cpu_topo *tp;
576 	u32 i;
577 	int ret;
578 
579 	tp = build_cpu_topology();
580 	if (!tp)
581 		return -1;
582 
583 	ret = do_write(fd, &tp->core_sib, sizeof(tp->core_sib));
584 	if (ret < 0)
585 		goto done;
586 
587 	for (i = 0; i < tp->core_sib; i++) {
588 		ret = do_write_string(fd, tp->core_siblings[i]);
589 		if (ret < 0)
590 			goto done;
591 	}
592 	ret = do_write(fd, &tp->thread_sib, sizeof(tp->thread_sib));
593 	if (ret < 0)
594 		goto done;
595 
596 	for (i = 0; i < tp->thread_sib; i++) {
597 		ret = do_write_string(fd, tp->thread_siblings[i]);
598 		if (ret < 0)
599 			break;
600 	}
601 done:
602 	free_cpu_topo(tp);
603 	return ret;
604 }
605 
606 
607 
608 static int write_total_mem(int fd, struct perf_header *h __maybe_unused,
609 			  struct perf_evlist *evlist __maybe_unused)
610 {
611 	char *buf = NULL;
612 	FILE *fp;
613 	size_t len = 0;
614 	int ret = -1, n;
615 	uint64_t mem;
616 
617 	fp = fopen("/proc/meminfo", "r");
618 	if (!fp)
619 		return -1;
620 
621 	while (getline(&buf, &len, fp) > 0) {
622 		ret = strncmp(buf, "MemTotal:", 9);
623 		if (!ret)
624 			break;
625 	}
626 	if (!ret) {
627 		n = sscanf(buf, "%*s %"PRIu64, &mem);
628 		if (n == 1)
629 			ret = do_write(fd, &mem, sizeof(mem));
630 	} else
631 		ret = -1;
632 	free(buf);
633 	fclose(fp);
634 	return ret;
635 }
636 
637 static int write_topo_node(int fd, int node)
638 {
639 	char str[MAXPATHLEN];
640 	char field[32];
641 	char *buf = NULL, *p;
642 	size_t len = 0;
643 	FILE *fp;
644 	u64 mem_total, mem_free, mem;
645 	int ret = -1;
646 
647 	sprintf(str, "/sys/devices/system/node/node%d/meminfo", node);
648 	fp = fopen(str, "r");
649 	if (!fp)
650 		return -1;
651 
652 	while (getline(&buf, &len, fp) > 0) {
653 		/* skip over invalid lines */
654 		if (!strchr(buf, ':'))
655 			continue;
656 		if (sscanf(buf, "%*s %*d %31s %"PRIu64, field, &mem) != 2)
657 			goto done;
658 		if (!strcmp(field, "MemTotal:"))
659 			mem_total = mem;
660 		if (!strcmp(field, "MemFree:"))
661 			mem_free = mem;
662 	}
663 
664 	fclose(fp);
665 	fp = NULL;
666 
667 	ret = do_write(fd, &mem_total, sizeof(u64));
668 	if (ret)
669 		goto done;
670 
671 	ret = do_write(fd, &mem_free, sizeof(u64));
672 	if (ret)
673 		goto done;
674 
675 	ret = -1;
676 	sprintf(str, "/sys/devices/system/node/node%d/cpulist", node);
677 
678 	fp = fopen(str, "r");
679 	if (!fp)
680 		goto done;
681 
682 	if (getline(&buf, &len, fp) <= 0)
683 		goto done;
684 
685 	p = strchr(buf, '\n');
686 	if (p)
687 		*p = '\0';
688 
689 	ret = do_write_string(fd, buf);
690 done:
691 	free(buf);
692 	if (fp)
693 		fclose(fp);
694 	return ret;
695 }
696 
697 static int write_numa_topology(int fd, struct perf_header *h __maybe_unused,
698 			  struct perf_evlist *evlist __maybe_unused)
699 {
700 	char *buf = NULL;
701 	size_t len = 0;
702 	FILE *fp;
703 	struct cpu_map *node_map = NULL;
704 	char *c;
705 	u32 nr, i, j;
706 	int ret = -1;
707 
708 	fp = fopen("/sys/devices/system/node/online", "r");
709 	if (!fp)
710 		return -1;
711 
712 	if (getline(&buf, &len, fp) <= 0)
713 		goto done;
714 
715 	c = strchr(buf, '\n');
716 	if (c)
717 		*c = '\0';
718 
719 	node_map = cpu_map__new(buf);
720 	if (!node_map)
721 		goto done;
722 
723 	nr = (u32)node_map->nr;
724 
725 	ret = do_write(fd, &nr, sizeof(nr));
726 	if (ret < 0)
727 		goto done;
728 
729 	for (i = 0; i < nr; i++) {
730 		j = (u32)node_map->map[i];
731 		ret = do_write(fd, &j, sizeof(j));
732 		if (ret < 0)
733 			break;
734 
735 		ret = write_topo_node(fd, i);
736 		if (ret < 0)
737 			break;
738 	}
739 done:
740 	free(buf);
741 	fclose(fp);
742 	free(node_map);
743 	return ret;
744 }
745 
746 /*
747  * File format:
748  *
749  * struct pmu_mappings {
750  *	u32	pmu_num;
751  *	struct pmu_map {
752  *		u32	type;
753  *		char	name[];
754  *	}[pmu_num];
755  * };
756  */
757 
758 static int write_pmu_mappings(int fd, struct perf_header *h __maybe_unused,
759 			      struct perf_evlist *evlist __maybe_unused)
760 {
761 	struct perf_pmu *pmu = NULL;
762 	off_t offset = lseek(fd, 0, SEEK_CUR);
763 	__u32 pmu_num = 0;
764 	int ret;
765 
766 	/* write real pmu_num later */
767 	ret = do_write(fd, &pmu_num, sizeof(pmu_num));
768 	if (ret < 0)
769 		return ret;
770 
771 	while ((pmu = perf_pmu__scan(pmu))) {
772 		if (!pmu->name)
773 			continue;
774 		pmu_num++;
775 
776 		ret = do_write(fd, &pmu->type, sizeof(pmu->type));
777 		if (ret < 0)
778 			return ret;
779 
780 		ret = do_write_string(fd, pmu->name);
781 		if (ret < 0)
782 			return ret;
783 	}
784 
785 	if (pwrite(fd, &pmu_num, sizeof(pmu_num), offset) != sizeof(pmu_num)) {
786 		/* discard all */
787 		lseek(fd, offset, SEEK_SET);
788 		return -1;
789 	}
790 
791 	return 0;
792 }
793 
794 /*
795  * File format:
796  *
797  * struct group_descs {
798  *	u32	nr_groups;
799  *	struct group_desc {
800  *		char	name[];
801  *		u32	leader_idx;
802  *		u32	nr_members;
803  *	}[nr_groups];
804  * };
805  */
806 static int write_group_desc(int fd, struct perf_header *h __maybe_unused,
807 			    struct perf_evlist *evlist)
808 {
809 	u32 nr_groups = evlist->nr_groups;
810 	struct perf_evsel *evsel;
811 	int ret;
812 
813 	ret = do_write(fd, &nr_groups, sizeof(nr_groups));
814 	if (ret < 0)
815 		return ret;
816 
817 	evlist__for_each(evlist, evsel) {
818 		if (perf_evsel__is_group_leader(evsel) &&
819 		    evsel->nr_members > 1) {
820 			const char *name = evsel->group_name ?: "{anon_group}";
821 			u32 leader_idx = evsel->idx;
822 			u32 nr_members = evsel->nr_members;
823 
824 			ret = do_write_string(fd, name);
825 			if (ret < 0)
826 				return ret;
827 
828 			ret = do_write(fd, &leader_idx, sizeof(leader_idx));
829 			if (ret < 0)
830 				return ret;
831 
832 			ret = do_write(fd, &nr_members, sizeof(nr_members));
833 			if (ret < 0)
834 				return ret;
835 		}
836 	}
837 	return 0;
838 }
839 
840 /*
841  * default get_cpuid(): nothing gets recorded
842  * actual implementation must be in arch/$(ARCH)/util/header.c
843  */
844 int __attribute__ ((weak)) get_cpuid(char *buffer __maybe_unused,
845 				     size_t sz __maybe_unused)
846 {
847 	return -1;
848 }
849 
850 static int write_cpuid(int fd, struct perf_header *h __maybe_unused,
851 		       struct perf_evlist *evlist __maybe_unused)
852 {
853 	char buffer[64];
854 	int ret;
855 
856 	ret = get_cpuid(buffer, sizeof(buffer));
857 	if (!ret)
858 		goto write_it;
859 
860 	return -1;
861 write_it:
862 	return do_write_string(fd, buffer);
863 }
864 
865 static int write_branch_stack(int fd __maybe_unused,
866 			      struct perf_header *h __maybe_unused,
867 		       struct perf_evlist *evlist __maybe_unused)
868 {
869 	return 0;
870 }
871 
872 static void print_hostname(struct perf_header *ph, int fd __maybe_unused,
873 			   FILE *fp)
874 {
875 	fprintf(fp, "# hostname : %s\n", ph->env.hostname);
876 }
877 
878 static void print_osrelease(struct perf_header *ph, int fd __maybe_unused,
879 			    FILE *fp)
880 {
881 	fprintf(fp, "# os release : %s\n", ph->env.os_release);
882 }
883 
884 static void print_arch(struct perf_header *ph, int fd __maybe_unused, FILE *fp)
885 {
886 	fprintf(fp, "# arch : %s\n", ph->env.arch);
887 }
888 
889 static void print_cpudesc(struct perf_header *ph, int fd __maybe_unused,
890 			  FILE *fp)
891 {
892 	fprintf(fp, "# cpudesc : %s\n", ph->env.cpu_desc);
893 }
894 
895 static void print_nrcpus(struct perf_header *ph, int fd __maybe_unused,
896 			 FILE *fp)
897 {
898 	fprintf(fp, "# nrcpus online : %u\n", ph->env.nr_cpus_online);
899 	fprintf(fp, "# nrcpus avail : %u\n", ph->env.nr_cpus_avail);
900 }
901 
902 static void print_version(struct perf_header *ph, int fd __maybe_unused,
903 			  FILE *fp)
904 {
905 	fprintf(fp, "# perf version : %s\n", ph->env.version);
906 }
907 
908 static void print_cmdline(struct perf_header *ph, int fd __maybe_unused,
909 			  FILE *fp)
910 {
911 	int nr, i;
912 	char *str;
913 
914 	nr = ph->env.nr_cmdline;
915 	str = ph->env.cmdline;
916 
917 	fprintf(fp, "# cmdline : ");
918 
919 	for (i = 0; i < nr; i++) {
920 		fprintf(fp, "%s ", str);
921 		str += strlen(str) + 1;
922 	}
923 	fputc('\n', fp);
924 }
925 
926 static void print_cpu_topology(struct perf_header *ph, int fd __maybe_unused,
927 			       FILE *fp)
928 {
929 	int nr, i;
930 	char *str;
931 
932 	nr = ph->env.nr_sibling_cores;
933 	str = ph->env.sibling_cores;
934 
935 	for (i = 0; i < nr; i++) {
936 		fprintf(fp, "# sibling cores   : %s\n", str);
937 		str += strlen(str) + 1;
938 	}
939 
940 	nr = ph->env.nr_sibling_threads;
941 	str = ph->env.sibling_threads;
942 
943 	for (i = 0; i < nr; i++) {
944 		fprintf(fp, "# sibling threads : %s\n", str);
945 		str += strlen(str) + 1;
946 	}
947 }
948 
949 static void free_event_desc(struct perf_evsel *events)
950 {
951 	struct perf_evsel *evsel;
952 
953 	if (!events)
954 		return;
955 
956 	for (evsel = events; evsel->attr.size; evsel++) {
957 		zfree(&evsel->name);
958 		zfree(&evsel->id);
959 	}
960 
961 	free(events);
962 }
963 
964 static struct perf_evsel *
965 read_event_desc(struct perf_header *ph, int fd)
966 {
967 	struct perf_evsel *evsel, *events = NULL;
968 	u64 *id;
969 	void *buf = NULL;
970 	u32 nre, sz, nr, i, j;
971 	ssize_t ret;
972 	size_t msz;
973 
974 	/* number of events */
975 	ret = readn(fd, &nre, sizeof(nre));
976 	if (ret != (ssize_t)sizeof(nre))
977 		goto error;
978 
979 	if (ph->needs_swap)
980 		nre = bswap_32(nre);
981 
982 	ret = readn(fd, &sz, sizeof(sz));
983 	if (ret != (ssize_t)sizeof(sz))
984 		goto error;
985 
986 	if (ph->needs_swap)
987 		sz = bswap_32(sz);
988 
989 	/* buffer to hold on file attr struct */
990 	buf = malloc(sz);
991 	if (!buf)
992 		goto error;
993 
994 	/* the last event terminates with evsel->attr.size == 0: */
995 	events = calloc(nre + 1, sizeof(*events));
996 	if (!events)
997 		goto error;
998 
999 	msz = sizeof(evsel->attr);
1000 	if (sz < msz)
1001 		msz = sz;
1002 
1003 	for (i = 0, evsel = events; i < nre; evsel++, i++) {
1004 		evsel->idx = i;
1005 
1006 		/*
1007 		 * must read entire on-file attr struct to
1008 		 * sync up with layout.
1009 		 */
1010 		ret = readn(fd, buf, sz);
1011 		if (ret != (ssize_t)sz)
1012 			goto error;
1013 
1014 		if (ph->needs_swap)
1015 			perf_event__attr_swap(buf);
1016 
1017 		memcpy(&evsel->attr, buf, msz);
1018 
1019 		ret = readn(fd, &nr, sizeof(nr));
1020 		if (ret != (ssize_t)sizeof(nr))
1021 			goto error;
1022 
1023 		if (ph->needs_swap) {
1024 			nr = bswap_32(nr);
1025 			evsel->needs_swap = true;
1026 		}
1027 
1028 		evsel->name = do_read_string(fd, ph);
1029 
1030 		if (!nr)
1031 			continue;
1032 
1033 		id = calloc(nr, sizeof(*id));
1034 		if (!id)
1035 			goto error;
1036 		evsel->ids = nr;
1037 		evsel->id = id;
1038 
1039 		for (j = 0 ; j < nr; j++) {
1040 			ret = readn(fd, id, sizeof(*id));
1041 			if (ret != (ssize_t)sizeof(*id))
1042 				goto error;
1043 			if (ph->needs_swap)
1044 				*id = bswap_64(*id);
1045 			id++;
1046 		}
1047 	}
1048 out:
1049 	free(buf);
1050 	return events;
1051 error:
1052 	if (events)
1053 		free_event_desc(events);
1054 	events = NULL;
1055 	goto out;
1056 }
1057 
1058 static void print_event_desc(struct perf_header *ph, int fd, FILE *fp)
1059 {
1060 	struct perf_evsel *evsel, *events = read_event_desc(ph, fd);
1061 	u32 j;
1062 	u64 *id;
1063 
1064 	if (!events) {
1065 		fprintf(fp, "# event desc: not available or unable to read\n");
1066 		return;
1067 	}
1068 
1069 	for (evsel = events; evsel->attr.size; evsel++) {
1070 		fprintf(fp, "# event : name = %s, ", evsel->name);
1071 
1072 		fprintf(fp, "type = %d, config = 0x%"PRIx64
1073 			    ", config1 = 0x%"PRIx64", config2 = 0x%"PRIx64,
1074 				evsel->attr.type,
1075 				(u64)evsel->attr.config,
1076 				(u64)evsel->attr.config1,
1077 				(u64)evsel->attr.config2);
1078 
1079 		fprintf(fp, ", excl_usr = %d, excl_kern = %d",
1080 				evsel->attr.exclude_user,
1081 				evsel->attr.exclude_kernel);
1082 
1083 		fprintf(fp, ", excl_host = %d, excl_guest = %d",
1084 				evsel->attr.exclude_host,
1085 				evsel->attr.exclude_guest);
1086 
1087 		fprintf(fp, ", precise_ip = %d", evsel->attr.precise_ip);
1088 
1089 		fprintf(fp, ", attr_mmap2 = %d", evsel->attr.mmap2);
1090 		fprintf(fp, ", attr_mmap  = %d", evsel->attr.mmap);
1091 		fprintf(fp, ", attr_mmap_data = %d", evsel->attr.mmap_data);
1092 		if (evsel->ids) {
1093 			fprintf(fp, ", id = {");
1094 			for (j = 0, id = evsel->id; j < evsel->ids; j++, id++) {
1095 				if (j)
1096 					fputc(',', fp);
1097 				fprintf(fp, " %"PRIu64, *id);
1098 			}
1099 			fprintf(fp, " }");
1100 		}
1101 
1102 		fputc('\n', fp);
1103 	}
1104 
1105 	free_event_desc(events);
1106 }
1107 
1108 static void print_total_mem(struct perf_header *ph, int fd __maybe_unused,
1109 			    FILE *fp)
1110 {
1111 	fprintf(fp, "# total memory : %Lu kB\n", ph->env.total_mem);
1112 }
1113 
1114 static void print_numa_topology(struct perf_header *ph, int fd __maybe_unused,
1115 				FILE *fp)
1116 {
1117 	u32 nr, c, i;
1118 	char *str, *tmp;
1119 	uint64_t mem_total, mem_free;
1120 
1121 	/* nr nodes */
1122 	nr = ph->env.nr_numa_nodes;
1123 	str = ph->env.numa_nodes;
1124 
1125 	for (i = 0; i < nr; i++) {
1126 		/* node number */
1127 		c = strtoul(str, &tmp, 0);
1128 		if (*tmp != ':')
1129 			goto error;
1130 
1131 		str = tmp + 1;
1132 		mem_total = strtoull(str, &tmp, 0);
1133 		if (*tmp != ':')
1134 			goto error;
1135 
1136 		str = tmp + 1;
1137 		mem_free = strtoull(str, &tmp, 0);
1138 		if (*tmp != ':')
1139 			goto error;
1140 
1141 		fprintf(fp, "# node%u meminfo  : total = %"PRIu64" kB,"
1142 			    " free = %"PRIu64" kB\n",
1143 			c, mem_total, mem_free);
1144 
1145 		str = tmp + 1;
1146 		fprintf(fp, "# node%u cpu list : %s\n", c, str);
1147 
1148 		str += strlen(str) + 1;
1149 	}
1150 	return;
1151 error:
1152 	fprintf(fp, "# numa topology : not available\n");
1153 }
1154 
1155 static void print_cpuid(struct perf_header *ph, int fd __maybe_unused, FILE *fp)
1156 {
1157 	fprintf(fp, "# cpuid : %s\n", ph->env.cpuid);
1158 }
1159 
1160 static void print_branch_stack(struct perf_header *ph __maybe_unused,
1161 			       int fd __maybe_unused, FILE *fp)
1162 {
1163 	fprintf(fp, "# contains samples with branch stack\n");
1164 }
1165 
1166 static void print_pmu_mappings(struct perf_header *ph, int fd __maybe_unused,
1167 			       FILE *fp)
1168 {
1169 	const char *delimiter = "# pmu mappings: ";
1170 	char *str, *tmp;
1171 	u32 pmu_num;
1172 	u32 type;
1173 
1174 	pmu_num = ph->env.nr_pmu_mappings;
1175 	if (!pmu_num) {
1176 		fprintf(fp, "# pmu mappings: not available\n");
1177 		return;
1178 	}
1179 
1180 	str = ph->env.pmu_mappings;
1181 
1182 	while (pmu_num) {
1183 		type = strtoul(str, &tmp, 0);
1184 		if (*tmp != ':')
1185 			goto error;
1186 
1187 		str = tmp + 1;
1188 		fprintf(fp, "%s%s = %" PRIu32, delimiter, str, type);
1189 
1190 		delimiter = ", ";
1191 		str += strlen(str) + 1;
1192 		pmu_num--;
1193 	}
1194 
1195 	fprintf(fp, "\n");
1196 
1197 	if (!pmu_num)
1198 		return;
1199 error:
1200 	fprintf(fp, "# pmu mappings: unable to read\n");
1201 }
1202 
1203 static void print_group_desc(struct perf_header *ph, int fd __maybe_unused,
1204 			     FILE *fp)
1205 {
1206 	struct perf_session *session;
1207 	struct perf_evsel *evsel;
1208 	u32 nr = 0;
1209 
1210 	session = container_of(ph, struct perf_session, header);
1211 
1212 	evlist__for_each(session->evlist, evsel) {
1213 		if (perf_evsel__is_group_leader(evsel) &&
1214 		    evsel->nr_members > 1) {
1215 			fprintf(fp, "# group: %s{%s", evsel->group_name ?: "",
1216 				perf_evsel__name(evsel));
1217 
1218 			nr = evsel->nr_members - 1;
1219 		} else if (nr) {
1220 			fprintf(fp, ",%s", perf_evsel__name(evsel));
1221 
1222 			if (--nr == 0)
1223 				fprintf(fp, "}\n");
1224 		}
1225 	}
1226 }
1227 
1228 static int __event_process_build_id(struct build_id_event *bev,
1229 				    char *filename,
1230 				    struct perf_session *session)
1231 {
1232 	int err = -1;
1233 	struct dsos *dsos;
1234 	struct machine *machine;
1235 	u16 misc;
1236 	struct dso *dso;
1237 	enum dso_kernel_type dso_type;
1238 
1239 	machine = perf_session__findnew_machine(session, bev->pid);
1240 	if (!machine)
1241 		goto out;
1242 
1243 	misc = bev->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
1244 
1245 	switch (misc) {
1246 	case PERF_RECORD_MISC_KERNEL:
1247 		dso_type = DSO_TYPE_KERNEL;
1248 		dsos = &machine->kernel_dsos;
1249 		break;
1250 	case PERF_RECORD_MISC_GUEST_KERNEL:
1251 		dso_type = DSO_TYPE_GUEST_KERNEL;
1252 		dsos = &machine->kernel_dsos;
1253 		break;
1254 	case PERF_RECORD_MISC_USER:
1255 	case PERF_RECORD_MISC_GUEST_USER:
1256 		dso_type = DSO_TYPE_USER;
1257 		dsos = &machine->user_dsos;
1258 		break;
1259 	default:
1260 		goto out;
1261 	}
1262 
1263 	dso = __dsos__findnew(dsos, filename);
1264 	if (dso != NULL) {
1265 		char sbuild_id[BUILD_ID_SIZE * 2 + 1];
1266 
1267 		dso__set_build_id(dso, &bev->build_id);
1268 
1269 		if (!is_kernel_module(filename, NULL))
1270 			dso->kernel = dso_type;
1271 
1272 		build_id__sprintf(dso->build_id, sizeof(dso->build_id),
1273 				  sbuild_id);
1274 		pr_debug("build id event received for %s: %s\n",
1275 			 dso->long_name, sbuild_id);
1276 	}
1277 
1278 	err = 0;
1279 out:
1280 	return err;
1281 }
1282 
1283 static int perf_header__read_build_ids_abi_quirk(struct perf_header *header,
1284 						 int input, u64 offset, u64 size)
1285 {
1286 	struct perf_session *session = container_of(header, struct perf_session, header);
1287 	struct {
1288 		struct perf_event_header   header;
1289 		u8			   build_id[PERF_ALIGN(BUILD_ID_SIZE, sizeof(u64))];
1290 		char			   filename[0];
1291 	} old_bev;
1292 	struct build_id_event bev;
1293 	char filename[PATH_MAX];
1294 	u64 limit = offset + size;
1295 
1296 	while (offset < limit) {
1297 		ssize_t len;
1298 
1299 		if (readn(input, &old_bev, sizeof(old_bev)) != sizeof(old_bev))
1300 			return -1;
1301 
1302 		if (header->needs_swap)
1303 			perf_event_header__bswap(&old_bev.header);
1304 
1305 		len = old_bev.header.size - sizeof(old_bev);
1306 		if (readn(input, filename, len) != len)
1307 			return -1;
1308 
1309 		bev.header = old_bev.header;
1310 
1311 		/*
1312 		 * As the pid is the missing value, we need to fill
1313 		 * it properly. The header.misc value give us nice hint.
1314 		 */
1315 		bev.pid	= HOST_KERNEL_ID;
1316 		if (bev.header.misc == PERF_RECORD_MISC_GUEST_USER ||
1317 		    bev.header.misc == PERF_RECORD_MISC_GUEST_KERNEL)
1318 			bev.pid	= DEFAULT_GUEST_KERNEL_ID;
1319 
1320 		memcpy(bev.build_id, old_bev.build_id, sizeof(bev.build_id));
1321 		__event_process_build_id(&bev, filename, session);
1322 
1323 		offset += bev.header.size;
1324 	}
1325 
1326 	return 0;
1327 }
1328 
1329 static int perf_header__read_build_ids(struct perf_header *header,
1330 				       int input, u64 offset, u64 size)
1331 {
1332 	struct perf_session *session = container_of(header, struct perf_session, header);
1333 	struct build_id_event bev;
1334 	char filename[PATH_MAX];
1335 	u64 limit = offset + size, orig_offset = offset;
1336 	int err = -1;
1337 
1338 	while (offset < limit) {
1339 		ssize_t len;
1340 
1341 		if (readn(input, &bev, sizeof(bev)) != sizeof(bev))
1342 			goto out;
1343 
1344 		if (header->needs_swap)
1345 			perf_event_header__bswap(&bev.header);
1346 
1347 		len = bev.header.size - sizeof(bev);
1348 		if (readn(input, filename, len) != len)
1349 			goto out;
1350 		/*
1351 		 * The a1645ce1 changeset:
1352 		 *
1353 		 * "perf: 'perf kvm' tool for monitoring guest performance from host"
1354 		 *
1355 		 * Added a field to struct build_id_event that broke the file
1356 		 * format.
1357 		 *
1358 		 * Since the kernel build-id is the first entry, process the
1359 		 * table using the old format if the well known
1360 		 * '[kernel.kallsyms]' string for the kernel build-id has the
1361 		 * first 4 characters chopped off (where the pid_t sits).
1362 		 */
1363 		if (memcmp(filename, "nel.kallsyms]", 13) == 0) {
1364 			if (lseek(input, orig_offset, SEEK_SET) == (off_t)-1)
1365 				return -1;
1366 			return perf_header__read_build_ids_abi_quirk(header, input, offset, size);
1367 		}
1368 
1369 		__event_process_build_id(&bev, filename, session);
1370 
1371 		offset += bev.header.size;
1372 	}
1373 	err = 0;
1374 out:
1375 	return err;
1376 }
1377 
1378 static int process_tracing_data(struct perf_file_section *section __maybe_unused,
1379 				struct perf_header *ph __maybe_unused,
1380 				int fd, void *data)
1381 {
1382 	ssize_t ret = trace_report(fd, data, false);
1383 	return ret < 0 ? -1 : 0;
1384 }
1385 
1386 static int process_build_id(struct perf_file_section *section,
1387 			    struct perf_header *ph, int fd,
1388 			    void *data __maybe_unused)
1389 {
1390 	if (perf_header__read_build_ids(ph, fd, section->offset, section->size))
1391 		pr_debug("Failed to read buildids, continuing...\n");
1392 	return 0;
1393 }
1394 
1395 static int process_hostname(struct perf_file_section *section __maybe_unused,
1396 			    struct perf_header *ph, int fd,
1397 			    void *data __maybe_unused)
1398 {
1399 	ph->env.hostname = do_read_string(fd, ph);
1400 	return ph->env.hostname ? 0 : -ENOMEM;
1401 }
1402 
1403 static int process_osrelease(struct perf_file_section *section __maybe_unused,
1404 			     struct perf_header *ph, int fd,
1405 			     void *data __maybe_unused)
1406 {
1407 	ph->env.os_release = do_read_string(fd, ph);
1408 	return ph->env.os_release ? 0 : -ENOMEM;
1409 }
1410 
1411 static int process_version(struct perf_file_section *section __maybe_unused,
1412 			   struct perf_header *ph, int fd,
1413 			   void *data __maybe_unused)
1414 {
1415 	ph->env.version = do_read_string(fd, ph);
1416 	return ph->env.version ? 0 : -ENOMEM;
1417 }
1418 
1419 static int process_arch(struct perf_file_section *section __maybe_unused,
1420 			struct perf_header *ph,	int fd,
1421 			void *data __maybe_unused)
1422 {
1423 	ph->env.arch = do_read_string(fd, ph);
1424 	return ph->env.arch ? 0 : -ENOMEM;
1425 }
1426 
1427 static int process_nrcpus(struct perf_file_section *section __maybe_unused,
1428 			  struct perf_header *ph, int fd,
1429 			  void *data __maybe_unused)
1430 {
1431 	ssize_t ret;
1432 	u32 nr;
1433 
1434 	ret = readn(fd, &nr, sizeof(nr));
1435 	if (ret != sizeof(nr))
1436 		return -1;
1437 
1438 	if (ph->needs_swap)
1439 		nr = bswap_32(nr);
1440 
1441 	ph->env.nr_cpus_online = nr;
1442 
1443 	ret = readn(fd, &nr, sizeof(nr));
1444 	if (ret != sizeof(nr))
1445 		return -1;
1446 
1447 	if (ph->needs_swap)
1448 		nr = bswap_32(nr);
1449 
1450 	ph->env.nr_cpus_avail = nr;
1451 	return 0;
1452 }
1453 
1454 static int process_cpudesc(struct perf_file_section *section __maybe_unused,
1455 			   struct perf_header *ph, int fd,
1456 			   void *data __maybe_unused)
1457 {
1458 	ph->env.cpu_desc = do_read_string(fd, ph);
1459 	return ph->env.cpu_desc ? 0 : -ENOMEM;
1460 }
1461 
1462 static int process_cpuid(struct perf_file_section *section __maybe_unused,
1463 			 struct perf_header *ph,  int fd,
1464 			 void *data __maybe_unused)
1465 {
1466 	ph->env.cpuid = do_read_string(fd, ph);
1467 	return ph->env.cpuid ? 0 : -ENOMEM;
1468 }
1469 
1470 static int process_total_mem(struct perf_file_section *section __maybe_unused,
1471 			     struct perf_header *ph, int fd,
1472 			     void *data __maybe_unused)
1473 {
1474 	uint64_t mem;
1475 	ssize_t ret;
1476 
1477 	ret = readn(fd, &mem, sizeof(mem));
1478 	if (ret != sizeof(mem))
1479 		return -1;
1480 
1481 	if (ph->needs_swap)
1482 		mem = bswap_64(mem);
1483 
1484 	ph->env.total_mem = mem;
1485 	return 0;
1486 }
1487 
1488 static struct perf_evsel *
1489 perf_evlist__find_by_index(struct perf_evlist *evlist, int idx)
1490 {
1491 	struct perf_evsel *evsel;
1492 
1493 	evlist__for_each(evlist, evsel) {
1494 		if (evsel->idx == idx)
1495 			return evsel;
1496 	}
1497 
1498 	return NULL;
1499 }
1500 
1501 static void
1502 perf_evlist__set_event_name(struct perf_evlist *evlist,
1503 			    struct perf_evsel *event)
1504 {
1505 	struct perf_evsel *evsel;
1506 
1507 	if (!event->name)
1508 		return;
1509 
1510 	evsel = perf_evlist__find_by_index(evlist, event->idx);
1511 	if (!evsel)
1512 		return;
1513 
1514 	if (evsel->name)
1515 		return;
1516 
1517 	evsel->name = strdup(event->name);
1518 }
1519 
1520 static int
1521 process_event_desc(struct perf_file_section *section __maybe_unused,
1522 		   struct perf_header *header, int fd,
1523 		   void *data __maybe_unused)
1524 {
1525 	struct perf_session *session;
1526 	struct perf_evsel *evsel, *events = read_event_desc(header, fd);
1527 
1528 	if (!events)
1529 		return 0;
1530 
1531 	session = container_of(header, struct perf_session, header);
1532 	for (evsel = events; evsel->attr.size; evsel++)
1533 		perf_evlist__set_event_name(session->evlist, evsel);
1534 
1535 	free_event_desc(events);
1536 
1537 	return 0;
1538 }
1539 
1540 static int process_cmdline(struct perf_file_section *section __maybe_unused,
1541 			   struct perf_header *ph, int fd,
1542 			   void *data __maybe_unused)
1543 {
1544 	ssize_t ret;
1545 	char *str;
1546 	u32 nr, i;
1547 	struct strbuf sb;
1548 
1549 	ret = readn(fd, &nr, sizeof(nr));
1550 	if (ret != sizeof(nr))
1551 		return -1;
1552 
1553 	if (ph->needs_swap)
1554 		nr = bswap_32(nr);
1555 
1556 	ph->env.nr_cmdline = nr;
1557 	strbuf_init(&sb, 128);
1558 
1559 	for (i = 0; i < nr; i++) {
1560 		str = do_read_string(fd, ph);
1561 		if (!str)
1562 			goto error;
1563 
1564 		/* include a NULL character at the end */
1565 		strbuf_add(&sb, str, strlen(str) + 1);
1566 		free(str);
1567 	}
1568 	ph->env.cmdline = strbuf_detach(&sb, NULL);
1569 	return 0;
1570 
1571 error:
1572 	strbuf_release(&sb);
1573 	return -1;
1574 }
1575 
1576 static int process_cpu_topology(struct perf_file_section *section __maybe_unused,
1577 				struct perf_header *ph, int fd,
1578 				void *data __maybe_unused)
1579 {
1580 	ssize_t ret;
1581 	u32 nr, i;
1582 	char *str;
1583 	struct strbuf sb;
1584 
1585 	ret = readn(fd, &nr, sizeof(nr));
1586 	if (ret != sizeof(nr))
1587 		return -1;
1588 
1589 	if (ph->needs_swap)
1590 		nr = bswap_32(nr);
1591 
1592 	ph->env.nr_sibling_cores = nr;
1593 	strbuf_init(&sb, 128);
1594 
1595 	for (i = 0; i < nr; i++) {
1596 		str = do_read_string(fd, ph);
1597 		if (!str)
1598 			goto error;
1599 
1600 		/* include a NULL character at the end */
1601 		strbuf_add(&sb, str, strlen(str) + 1);
1602 		free(str);
1603 	}
1604 	ph->env.sibling_cores = strbuf_detach(&sb, NULL);
1605 
1606 	ret = readn(fd, &nr, sizeof(nr));
1607 	if (ret != sizeof(nr))
1608 		return -1;
1609 
1610 	if (ph->needs_swap)
1611 		nr = bswap_32(nr);
1612 
1613 	ph->env.nr_sibling_threads = nr;
1614 
1615 	for (i = 0; i < nr; i++) {
1616 		str = do_read_string(fd, ph);
1617 		if (!str)
1618 			goto error;
1619 
1620 		/* include a NULL character at the end */
1621 		strbuf_add(&sb, str, strlen(str) + 1);
1622 		free(str);
1623 	}
1624 	ph->env.sibling_threads = strbuf_detach(&sb, NULL);
1625 	return 0;
1626 
1627 error:
1628 	strbuf_release(&sb);
1629 	return -1;
1630 }
1631 
1632 static int process_numa_topology(struct perf_file_section *section __maybe_unused,
1633 				 struct perf_header *ph, int fd,
1634 				 void *data __maybe_unused)
1635 {
1636 	ssize_t ret;
1637 	u32 nr, node, i;
1638 	char *str;
1639 	uint64_t mem_total, mem_free;
1640 	struct strbuf sb;
1641 
1642 	/* nr nodes */
1643 	ret = readn(fd, &nr, sizeof(nr));
1644 	if (ret != sizeof(nr))
1645 		goto error;
1646 
1647 	if (ph->needs_swap)
1648 		nr = bswap_32(nr);
1649 
1650 	ph->env.nr_numa_nodes = nr;
1651 	strbuf_init(&sb, 256);
1652 
1653 	for (i = 0; i < nr; i++) {
1654 		/* node number */
1655 		ret = readn(fd, &node, sizeof(node));
1656 		if (ret != sizeof(node))
1657 			goto error;
1658 
1659 		ret = readn(fd, &mem_total, sizeof(u64));
1660 		if (ret != sizeof(u64))
1661 			goto error;
1662 
1663 		ret = readn(fd, &mem_free, sizeof(u64));
1664 		if (ret != sizeof(u64))
1665 			goto error;
1666 
1667 		if (ph->needs_swap) {
1668 			node = bswap_32(node);
1669 			mem_total = bswap_64(mem_total);
1670 			mem_free = bswap_64(mem_free);
1671 		}
1672 
1673 		strbuf_addf(&sb, "%u:%"PRIu64":%"PRIu64":",
1674 			    node, mem_total, mem_free);
1675 
1676 		str = do_read_string(fd, ph);
1677 		if (!str)
1678 			goto error;
1679 
1680 		/* include a NULL character at the end */
1681 		strbuf_add(&sb, str, strlen(str) + 1);
1682 		free(str);
1683 	}
1684 	ph->env.numa_nodes = strbuf_detach(&sb, NULL);
1685 	return 0;
1686 
1687 error:
1688 	strbuf_release(&sb);
1689 	return -1;
1690 }
1691 
1692 static int process_pmu_mappings(struct perf_file_section *section __maybe_unused,
1693 				struct perf_header *ph, int fd,
1694 				void *data __maybe_unused)
1695 {
1696 	ssize_t ret;
1697 	char *name;
1698 	u32 pmu_num;
1699 	u32 type;
1700 	struct strbuf sb;
1701 
1702 	ret = readn(fd, &pmu_num, sizeof(pmu_num));
1703 	if (ret != sizeof(pmu_num))
1704 		return -1;
1705 
1706 	if (ph->needs_swap)
1707 		pmu_num = bswap_32(pmu_num);
1708 
1709 	if (!pmu_num) {
1710 		pr_debug("pmu mappings not available\n");
1711 		return 0;
1712 	}
1713 
1714 	ph->env.nr_pmu_mappings = pmu_num;
1715 	strbuf_init(&sb, 128);
1716 
1717 	while (pmu_num) {
1718 		if (readn(fd, &type, sizeof(type)) != sizeof(type))
1719 			goto error;
1720 		if (ph->needs_swap)
1721 			type = bswap_32(type);
1722 
1723 		name = do_read_string(fd, ph);
1724 		if (!name)
1725 			goto error;
1726 
1727 		strbuf_addf(&sb, "%u:%s", type, name);
1728 		/* include a NULL character at the end */
1729 		strbuf_add(&sb, "", 1);
1730 
1731 		free(name);
1732 		pmu_num--;
1733 	}
1734 	ph->env.pmu_mappings = strbuf_detach(&sb, NULL);
1735 	return 0;
1736 
1737 error:
1738 	strbuf_release(&sb);
1739 	return -1;
1740 }
1741 
1742 static int process_group_desc(struct perf_file_section *section __maybe_unused,
1743 			      struct perf_header *ph, int fd,
1744 			      void *data __maybe_unused)
1745 {
1746 	size_t ret = -1;
1747 	u32 i, nr, nr_groups;
1748 	struct perf_session *session;
1749 	struct perf_evsel *evsel, *leader = NULL;
1750 	struct group_desc {
1751 		char *name;
1752 		u32 leader_idx;
1753 		u32 nr_members;
1754 	} *desc;
1755 
1756 	if (readn(fd, &nr_groups, sizeof(nr_groups)) != sizeof(nr_groups))
1757 		return -1;
1758 
1759 	if (ph->needs_swap)
1760 		nr_groups = bswap_32(nr_groups);
1761 
1762 	ph->env.nr_groups = nr_groups;
1763 	if (!nr_groups) {
1764 		pr_debug("group desc not available\n");
1765 		return 0;
1766 	}
1767 
1768 	desc = calloc(nr_groups, sizeof(*desc));
1769 	if (!desc)
1770 		return -1;
1771 
1772 	for (i = 0; i < nr_groups; i++) {
1773 		desc[i].name = do_read_string(fd, ph);
1774 		if (!desc[i].name)
1775 			goto out_free;
1776 
1777 		if (readn(fd, &desc[i].leader_idx, sizeof(u32)) != sizeof(u32))
1778 			goto out_free;
1779 
1780 		if (readn(fd, &desc[i].nr_members, sizeof(u32)) != sizeof(u32))
1781 			goto out_free;
1782 
1783 		if (ph->needs_swap) {
1784 			desc[i].leader_idx = bswap_32(desc[i].leader_idx);
1785 			desc[i].nr_members = bswap_32(desc[i].nr_members);
1786 		}
1787 	}
1788 
1789 	/*
1790 	 * Rebuild group relationship based on the group_desc
1791 	 */
1792 	session = container_of(ph, struct perf_session, header);
1793 	session->evlist->nr_groups = nr_groups;
1794 
1795 	i = nr = 0;
1796 	evlist__for_each(session->evlist, evsel) {
1797 		if (evsel->idx == (int) desc[i].leader_idx) {
1798 			evsel->leader = evsel;
1799 			/* {anon_group} is a dummy name */
1800 			if (strcmp(desc[i].name, "{anon_group}")) {
1801 				evsel->group_name = desc[i].name;
1802 				desc[i].name = NULL;
1803 			}
1804 			evsel->nr_members = desc[i].nr_members;
1805 
1806 			if (i >= nr_groups || nr > 0) {
1807 				pr_debug("invalid group desc\n");
1808 				goto out_free;
1809 			}
1810 
1811 			leader = evsel;
1812 			nr = evsel->nr_members - 1;
1813 			i++;
1814 		} else if (nr) {
1815 			/* This is a group member */
1816 			evsel->leader = leader;
1817 
1818 			nr--;
1819 		}
1820 	}
1821 
1822 	if (i != nr_groups || nr != 0) {
1823 		pr_debug("invalid group desc\n");
1824 		goto out_free;
1825 	}
1826 
1827 	ret = 0;
1828 out_free:
1829 	for (i = 0; i < nr_groups; i++)
1830 		zfree(&desc[i].name);
1831 	free(desc);
1832 
1833 	return ret;
1834 }
1835 
1836 struct feature_ops {
1837 	int (*write)(int fd, struct perf_header *h, struct perf_evlist *evlist);
1838 	void (*print)(struct perf_header *h, int fd, FILE *fp);
1839 	int (*process)(struct perf_file_section *section,
1840 		       struct perf_header *h, int fd, void *data);
1841 	const char *name;
1842 	bool full_only;
1843 };
1844 
1845 #define FEAT_OPA(n, func) \
1846 	[n] = { .name = #n, .write = write_##func, .print = print_##func }
1847 #define FEAT_OPP(n, func) \
1848 	[n] = { .name = #n, .write = write_##func, .print = print_##func, \
1849 		.process = process_##func }
1850 #define FEAT_OPF(n, func) \
1851 	[n] = { .name = #n, .write = write_##func, .print = print_##func, \
1852 		.process = process_##func, .full_only = true }
1853 
1854 /* feature_ops not implemented: */
1855 #define print_tracing_data	NULL
1856 #define print_build_id		NULL
1857 
1858 static const struct feature_ops feat_ops[HEADER_LAST_FEATURE] = {
1859 	FEAT_OPP(HEADER_TRACING_DATA,	tracing_data),
1860 	FEAT_OPP(HEADER_BUILD_ID,	build_id),
1861 	FEAT_OPP(HEADER_HOSTNAME,	hostname),
1862 	FEAT_OPP(HEADER_OSRELEASE,	osrelease),
1863 	FEAT_OPP(HEADER_VERSION,	version),
1864 	FEAT_OPP(HEADER_ARCH,		arch),
1865 	FEAT_OPP(HEADER_NRCPUS,		nrcpus),
1866 	FEAT_OPP(HEADER_CPUDESC,	cpudesc),
1867 	FEAT_OPP(HEADER_CPUID,		cpuid),
1868 	FEAT_OPP(HEADER_TOTAL_MEM,	total_mem),
1869 	FEAT_OPP(HEADER_EVENT_DESC,	event_desc),
1870 	FEAT_OPP(HEADER_CMDLINE,	cmdline),
1871 	FEAT_OPF(HEADER_CPU_TOPOLOGY,	cpu_topology),
1872 	FEAT_OPF(HEADER_NUMA_TOPOLOGY,	numa_topology),
1873 	FEAT_OPA(HEADER_BRANCH_STACK,	branch_stack),
1874 	FEAT_OPP(HEADER_PMU_MAPPINGS,	pmu_mappings),
1875 	FEAT_OPP(HEADER_GROUP_DESC,	group_desc),
1876 };
1877 
1878 struct header_print_data {
1879 	FILE *fp;
1880 	bool full; /* extended list of headers */
1881 };
1882 
1883 static int perf_file_section__fprintf_info(struct perf_file_section *section,
1884 					   struct perf_header *ph,
1885 					   int feat, int fd, void *data)
1886 {
1887 	struct header_print_data *hd = data;
1888 
1889 	if (lseek(fd, section->offset, SEEK_SET) == (off_t)-1) {
1890 		pr_debug("Failed to lseek to %" PRIu64 " offset for feature "
1891 				"%d, continuing...\n", section->offset, feat);
1892 		return 0;
1893 	}
1894 	if (feat >= HEADER_LAST_FEATURE) {
1895 		pr_warning("unknown feature %d\n", feat);
1896 		return 0;
1897 	}
1898 	if (!feat_ops[feat].print)
1899 		return 0;
1900 
1901 	if (!feat_ops[feat].full_only || hd->full)
1902 		feat_ops[feat].print(ph, fd, hd->fp);
1903 	else
1904 		fprintf(hd->fp, "# %s info available, use -I to display\n",
1905 			feat_ops[feat].name);
1906 
1907 	return 0;
1908 }
1909 
1910 int perf_header__fprintf_info(struct perf_session *session, FILE *fp, bool full)
1911 {
1912 	struct header_print_data hd;
1913 	struct perf_header *header = &session->header;
1914 	int fd = perf_data_file__fd(session->file);
1915 	hd.fp = fp;
1916 	hd.full = full;
1917 
1918 	perf_header__process_sections(header, fd, &hd,
1919 				      perf_file_section__fprintf_info);
1920 	return 0;
1921 }
1922 
1923 static int do_write_feat(int fd, struct perf_header *h, int type,
1924 			 struct perf_file_section **p,
1925 			 struct perf_evlist *evlist)
1926 {
1927 	int err;
1928 	int ret = 0;
1929 
1930 	if (perf_header__has_feat(h, type)) {
1931 		if (!feat_ops[type].write)
1932 			return -1;
1933 
1934 		(*p)->offset = lseek(fd, 0, SEEK_CUR);
1935 
1936 		err = feat_ops[type].write(fd, h, evlist);
1937 		if (err < 0) {
1938 			pr_debug("failed to write feature %d\n", type);
1939 
1940 			/* undo anything written */
1941 			lseek(fd, (*p)->offset, SEEK_SET);
1942 
1943 			return -1;
1944 		}
1945 		(*p)->size = lseek(fd, 0, SEEK_CUR) - (*p)->offset;
1946 		(*p)++;
1947 	}
1948 	return ret;
1949 }
1950 
1951 static int perf_header__adds_write(struct perf_header *header,
1952 				   struct perf_evlist *evlist, int fd)
1953 {
1954 	int nr_sections;
1955 	struct perf_file_section *feat_sec, *p;
1956 	int sec_size;
1957 	u64 sec_start;
1958 	int feat;
1959 	int err;
1960 
1961 	nr_sections = bitmap_weight(header->adds_features, HEADER_FEAT_BITS);
1962 	if (!nr_sections)
1963 		return 0;
1964 
1965 	feat_sec = p = calloc(nr_sections, sizeof(*feat_sec));
1966 	if (feat_sec == NULL)
1967 		return -ENOMEM;
1968 
1969 	sec_size = sizeof(*feat_sec) * nr_sections;
1970 
1971 	sec_start = header->feat_offset;
1972 	lseek(fd, sec_start + sec_size, SEEK_SET);
1973 
1974 	for_each_set_bit(feat, header->adds_features, HEADER_FEAT_BITS) {
1975 		if (do_write_feat(fd, header, feat, &p, evlist))
1976 			perf_header__clear_feat(header, feat);
1977 	}
1978 
1979 	lseek(fd, sec_start, SEEK_SET);
1980 	/*
1981 	 * may write more than needed due to dropped feature, but
1982 	 * this is okay, reader will skip the mising entries
1983 	 */
1984 	err = do_write(fd, feat_sec, sec_size);
1985 	if (err < 0)
1986 		pr_debug("failed to write feature section\n");
1987 	free(feat_sec);
1988 	return err;
1989 }
1990 
1991 int perf_header__write_pipe(int fd)
1992 {
1993 	struct perf_pipe_file_header f_header;
1994 	int err;
1995 
1996 	f_header = (struct perf_pipe_file_header){
1997 		.magic	   = PERF_MAGIC,
1998 		.size	   = sizeof(f_header),
1999 	};
2000 
2001 	err = do_write(fd, &f_header, sizeof(f_header));
2002 	if (err < 0) {
2003 		pr_debug("failed to write perf pipe header\n");
2004 		return err;
2005 	}
2006 
2007 	return 0;
2008 }
2009 
2010 int perf_session__write_header(struct perf_session *session,
2011 			       struct perf_evlist *evlist,
2012 			       int fd, bool at_exit)
2013 {
2014 	struct perf_file_header f_header;
2015 	struct perf_file_attr   f_attr;
2016 	struct perf_header *header = &session->header;
2017 	struct perf_evsel *evsel;
2018 	u64 attr_offset;
2019 	int err;
2020 
2021 	lseek(fd, sizeof(f_header), SEEK_SET);
2022 
2023 	evlist__for_each(session->evlist, evsel) {
2024 		evsel->id_offset = lseek(fd, 0, SEEK_CUR);
2025 		err = do_write(fd, evsel->id, evsel->ids * sizeof(u64));
2026 		if (err < 0) {
2027 			pr_debug("failed to write perf header\n");
2028 			return err;
2029 		}
2030 	}
2031 
2032 	attr_offset = lseek(fd, 0, SEEK_CUR);
2033 
2034 	evlist__for_each(evlist, evsel) {
2035 		f_attr = (struct perf_file_attr){
2036 			.attr = evsel->attr,
2037 			.ids  = {
2038 				.offset = evsel->id_offset,
2039 				.size   = evsel->ids * sizeof(u64),
2040 			}
2041 		};
2042 		err = do_write(fd, &f_attr, sizeof(f_attr));
2043 		if (err < 0) {
2044 			pr_debug("failed to write perf header attribute\n");
2045 			return err;
2046 		}
2047 	}
2048 
2049 	if (!header->data_offset)
2050 		header->data_offset = lseek(fd, 0, SEEK_CUR);
2051 	header->feat_offset = header->data_offset + header->data_size;
2052 
2053 	if (at_exit) {
2054 		err = perf_header__adds_write(header, evlist, fd);
2055 		if (err < 0)
2056 			return err;
2057 	}
2058 
2059 	f_header = (struct perf_file_header){
2060 		.magic	   = PERF_MAGIC,
2061 		.size	   = sizeof(f_header),
2062 		.attr_size = sizeof(f_attr),
2063 		.attrs = {
2064 			.offset = attr_offset,
2065 			.size   = evlist->nr_entries * sizeof(f_attr),
2066 		},
2067 		.data = {
2068 			.offset = header->data_offset,
2069 			.size	= header->data_size,
2070 		},
2071 		/* event_types is ignored, store zeros */
2072 	};
2073 
2074 	memcpy(&f_header.adds_features, &header->adds_features, sizeof(header->adds_features));
2075 
2076 	lseek(fd, 0, SEEK_SET);
2077 	err = do_write(fd, &f_header, sizeof(f_header));
2078 	if (err < 0) {
2079 		pr_debug("failed to write perf header\n");
2080 		return err;
2081 	}
2082 	lseek(fd, header->data_offset + header->data_size, SEEK_SET);
2083 
2084 	return 0;
2085 }
2086 
2087 static int perf_header__getbuffer64(struct perf_header *header,
2088 				    int fd, void *buf, size_t size)
2089 {
2090 	if (readn(fd, buf, size) <= 0)
2091 		return -1;
2092 
2093 	if (header->needs_swap)
2094 		mem_bswap_64(buf, size);
2095 
2096 	return 0;
2097 }
2098 
2099 int perf_header__process_sections(struct perf_header *header, int fd,
2100 				  void *data,
2101 				  int (*process)(struct perf_file_section *section,
2102 						 struct perf_header *ph,
2103 						 int feat, int fd, void *data))
2104 {
2105 	struct perf_file_section *feat_sec, *sec;
2106 	int nr_sections;
2107 	int sec_size;
2108 	int feat;
2109 	int err;
2110 
2111 	nr_sections = bitmap_weight(header->adds_features, HEADER_FEAT_BITS);
2112 	if (!nr_sections)
2113 		return 0;
2114 
2115 	feat_sec = sec = calloc(nr_sections, sizeof(*feat_sec));
2116 	if (!feat_sec)
2117 		return -1;
2118 
2119 	sec_size = sizeof(*feat_sec) * nr_sections;
2120 
2121 	lseek(fd, header->feat_offset, SEEK_SET);
2122 
2123 	err = perf_header__getbuffer64(header, fd, feat_sec, sec_size);
2124 	if (err < 0)
2125 		goto out_free;
2126 
2127 	for_each_set_bit(feat, header->adds_features, HEADER_LAST_FEATURE) {
2128 		err = process(sec++, header, feat, fd, data);
2129 		if (err < 0)
2130 			goto out_free;
2131 	}
2132 	err = 0;
2133 out_free:
2134 	free(feat_sec);
2135 	return err;
2136 }
2137 
2138 static const int attr_file_abi_sizes[] = {
2139 	[0] = PERF_ATTR_SIZE_VER0,
2140 	[1] = PERF_ATTR_SIZE_VER1,
2141 	[2] = PERF_ATTR_SIZE_VER2,
2142 	[3] = PERF_ATTR_SIZE_VER3,
2143 	[4] = PERF_ATTR_SIZE_VER4,
2144 	0,
2145 };
2146 
2147 /*
2148  * In the legacy file format, the magic number is not used to encode endianness.
2149  * hdr_sz was used to encode endianness. But given that hdr_sz can vary based
2150  * on ABI revisions, we need to try all combinations for all endianness to
2151  * detect the endianness.
2152  */
2153 static int try_all_file_abis(uint64_t hdr_sz, struct perf_header *ph)
2154 {
2155 	uint64_t ref_size, attr_size;
2156 	int i;
2157 
2158 	for (i = 0 ; attr_file_abi_sizes[i]; i++) {
2159 		ref_size = attr_file_abi_sizes[i]
2160 			 + sizeof(struct perf_file_section);
2161 		if (hdr_sz != ref_size) {
2162 			attr_size = bswap_64(hdr_sz);
2163 			if (attr_size != ref_size)
2164 				continue;
2165 
2166 			ph->needs_swap = true;
2167 		}
2168 		pr_debug("ABI%d perf.data file detected, need_swap=%d\n",
2169 			 i,
2170 			 ph->needs_swap);
2171 		return 0;
2172 	}
2173 	/* could not determine endianness */
2174 	return -1;
2175 }
2176 
2177 #define PERF_PIPE_HDR_VER0	16
2178 
2179 static const size_t attr_pipe_abi_sizes[] = {
2180 	[0] = PERF_PIPE_HDR_VER0,
2181 	0,
2182 };
2183 
2184 /*
2185  * In the legacy pipe format, there is an implicit assumption that endiannesss
2186  * between host recording the samples, and host parsing the samples is the
2187  * same. This is not always the case given that the pipe output may always be
2188  * redirected into a file and analyzed on a different machine with possibly a
2189  * different endianness and perf_event ABI revsions in the perf tool itself.
2190  */
2191 static int try_all_pipe_abis(uint64_t hdr_sz, struct perf_header *ph)
2192 {
2193 	u64 attr_size;
2194 	int i;
2195 
2196 	for (i = 0 ; attr_pipe_abi_sizes[i]; i++) {
2197 		if (hdr_sz != attr_pipe_abi_sizes[i]) {
2198 			attr_size = bswap_64(hdr_sz);
2199 			if (attr_size != hdr_sz)
2200 				continue;
2201 
2202 			ph->needs_swap = true;
2203 		}
2204 		pr_debug("Pipe ABI%d perf.data file detected\n", i);
2205 		return 0;
2206 	}
2207 	return -1;
2208 }
2209 
2210 bool is_perf_magic(u64 magic)
2211 {
2212 	if (!memcmp(&magic, __perf_magic1, sizeof(magic))
2213 		|| magic == __perf_magic2
2214 		|| magic == __perf_magic2_sw)
2215 		return true;
2216 
2217 	return false;
2218 }
2219 
2220 static int check_magic_endian(u64 magic, uint64_t hdr_sz,
2221 			      bool is_pipe, struct perf_header *ph)
2222 {
2223 	int ret;
2224 
2225 	/* check for legacy format */
2226 	ret = memcmp(&magic, __perf_magic1, sizeof(magic));
2227 	if (ret == 0) {
2228 		ph->version = PERF_HEADER_VERSION_1;
2229 		pr_debug("legacy perf.data format\n");
2230 		if (is_pipe)
2231 			return try_all_pipe_abis(hdr_sz, ph);
2232 
2233 		return try_all_file_abis(hdr_sz, ph);
2234 	}
2235 	/*
2236 	 * the new magic number serves two purposes:
2237 	 * - unique number to identify actual perf.data files
2238 	 * - encode endianness of file
2239 	 */
2240 	ph->version = PERF_HEADER_VERSION_2;
2241 
2242 	/* check magic number with one endianness */
2243 	if (magic == __perf_magic2)
2244 		return 0;
2245 
2246 	/* check magic number with opposite endianness */
2247 	if (magic != __perf_magic2_sw)
2248 		return -1;
2249 
2250 	ph->needs_swap = true;
2251 
2252 	return 0;
2253 }
2254 
2255 int perf_file_header__read(struct perf_file_header *header,
2256 			   struct perf_header *ph, int fd)
2257 {
2258 	ssize_t ret;
2259 
2260 	lseek(fd, 0, SEEK_SET);
2261 
2262 	ret = readn(fd, header, sizeof(*header));
2263 	if (ret <= 0)
2264 		return -1;
2265 
2266 	if (check_magic_endian(header->magic,
2267 			       header->attr_size, false, ph) < 0) {
2268 		pr_debug("magic/endian check failed\n");
2269 		return -1;
2270 	}
2271 
2272 	if (ph->needs_swap) {
2273 		mem_bswap_64(header, offsetof(struct perf_file_header,
2274 			     adds_features));
2275 	}
2276 
2277 	if (header->size != sizeof(*header)) {
2278 		/* Support the previous format */
2279 		if (header->size == offsetof(typeof(*header), adds_features))
2280 			bitmap_zero(header->adds_features, HEADER_FEAT_BITS);
2281 		else
2282 			return -1;
2283 	} else if (ph->needs_swap) {
2284 		/*
2285 		 * feature bitmap is declared as an array of unsigned longs --
2286 		 * not good since its size can differ between the host that
2287 		 * generated the data file and the host analyzing the file.
2288 		 *
2289 		 * We need to handle endianness, but we don't know the size of
2290 		 * the unsigned long where the file was generated. Take a best
2291 		 * guess at determining it: try 64-bit swap first (ie., file
2292 		 * created on a 64-bit host), and check if the hostname feature
2293 		 * bit is set (this feature bit is forced on as of fbe96f2).
2294 		 * If the bit is not, undo the 64-bit swap and try a 32-bit
2295 		 * swap. If the hostname bit is still not set (e.g., older data
2296 		 * file), punt and fallback to the original behavior --
2297 		 * clearing all feature bits and setting buildid.
2298 		 */
2299 		mem_bswap_64(&header->adds_features,
2300 			    BITS_TO_U64(HEADER_FEAT_BITS));
2301 
2302 		if (!test_bit(HEADER_HOSTNAME, header->adds_features)) {
2303 			/* unswap as u64 */
2304 			mem_bswap_64(&header->adds_features,
2305 				    BITS_TO_U64(HEADER_FEAT_BITS));
2306 
2307 			/* unswap as u32 */
2308 			mem_bswap_32(&header->adds_features,
2309 				    BITS_TO_U32(HEADER_FEAT_BITS));
2310 		}
2311 
2312 		if (!test_bit(HEADER_HOSTNAME, header->adds_features)) {
2313 			bitmap_zero(header->adds_features, HEADER_FEAT_BITS);
2314 			set_bit(HEADER_BUILD_ID, header->adds_features);
2315 		}
2316 	}
2317 
2318 	memcpy(&ph->adds_features, &header->adds_features,
2319 	       sizeof(ph->adds_features));
2320 
2321 	ph->data_offset  = header->data.offset;
2322 	ph->data_size	 = header->data.size;
2323 	ph->feat_offset  = header->data.offset + header->data.size;
2324 	return 0;
2325 }
2326 
2327 static int perf_file_section__process(struct perf_file_section *section,
2328 				      struct perf_header *ph,
2329 				      int feat, int fd, void *data)
2330 {
2331 	if (lseek(fd, section->offset, SEEK_SET) == (off_t)-1) {
2332 		pr_debug("Failed to lseek to %" PRIu64 " offset for feature "
2333 			  "%d, continuing...\n", section->offset, feat);
2334 		return 0;
2335 	}
2336 
2337 	if (feat >= HEADER_LAST_FEATURE) {
2338 		pr_debug("unknown feature %d, continuing...\n", feat);
2339 		return 0;
2340 	}
2341 
2342 	if (!feat_ops[feat].process)
2343 		return 0;
2344 
2345 	return feat_ops[feat].process(section, ph, fd, data);
2346 }
2347 
2348 static int perf_file_header__read_pipe(struct perf_pipe_file_header *header,
2349 				       struct perf_header *ph, int fd,
2350 				       bool repipe)
2351 {
2352 	ssize_t ret;
2353 
2354 	ret = readn(fd, header, sizeof(*header));
2355 	if (ret <= 0)
2356 		return -1;
2357 
2358 	if (check_magic_endian(header->magic, header->size, true, ph) < 0) {
2359 		pr_debug("endian/magic failed\n");
2360 		return -1;
2361 	}
2362 
2363 	if (ph->needs_swap)
2364 		header->size = bswap_64(header->size);
2365 
2366 	if (repipe && do_write(STDOUT_FILENO, header, sizeof(*header)) < 0)
2367 		return -1;
2368 
2369 	return 0;
2370 }
2371 
2372 static int perf_header__read_pipe(struct perf_session *session)
2373 {
2374 	struct perf_header *header = &session->header;
2375 	struct perf_pipe_file_header f_header;
2376 
2377 	if (perf_file_header__read_pipe(&f_header, header,
2378 					perf_data_file__fd(session->file),
2379 					session->repipe) < 0) {
2380 		pr_debug("incompatible file format\n");
2381 		return -EINVAL;
2382 	}
2383 
2384 	return 0;
2385 }
2386 
2387 static int read_attr(int fd, struct perf_header *ph,
2388 		     struct perf_file_attr *f_attr)
2389 {
2390 	struct perf_event_attr *attr = &f_attr->attr;
2391 	size_t sz, left;
2392 	size_t our_sz = sizeof(f_attr->attr);
2393 	ssize_t ret;
2394 
2395 	memset(f_attr, 0, sizeof(*f_attr));
2396 
2397 	/* read minimal guaranteed structure */
2398 	ret = readn(fd, attr, PERF_ATTR_SIZE_VER0);
2399 	if (ret <= 0) {
2400 		pr_debug("cannot read %d bytes of header attr\n",
2401 			 PERF_ATTR_SIZE_VER0);
2402 		return -1;
2403 	}
2404 
2405 	/* on file perf_event_attr size */
2406 	sz = attr->size;
2407 
2408 	if (ph->needs_swap)
2409 		sz = bswap_32(sz);
2410 
2411 	if (sz == 0) {
2412 		/* assume ABI0 */
2413 		sz =  PERF_ATTR_SIZE_VER0;
2414 	} else if (sz > our_sz) {
2415 		pr_debug("file uses a more recent and unsupported ABI"
2416 			 " (%zu bytes extra)\n", sz - our_sz);
2417 		return -1;
2418 	}
2419 	/* what we have not yet read and that we know about */
2420 	left = sz - PERF_ATTR_SIZE_VER0;
2421 	if (left) {
2422 		void *ptr = attr;
2423 		ptr += PERF_ATTR_SIZE_VER0;
2424 
2425 		ret = readn(fd, ptr, left);
2426 	}
2427 	/* read perf_file_section, ids are read in caller */
2428 	ret = readn(fd, &f_attr->ids, sizeof(f_attr->ids));
2429 
2430 	return ret <= 0 ? -1 : 0;
2431 }
2432 
2433 static int perf_evsel__prepare_tracepoint_event(struct perf_evsel *evsel,
2434 						struct pevent *pevent)
2435 {
2436 	struct event_format *event;
2437 	char bf[128];
2438 
2439 	/* already prepared */
2440 	if (evsel->tp_format)
2441 		return 0;
2442 
2443 	if (pevent == NULL) {
2444 		pr_debug("broken or missing trace data\n");
2445 		return -1;
2446 	}
2447 
2448 	event = pevent_find_event(pevent, evsel->attr.config);
2449 	if (event == NULL)
2450 		return -1;
2451 
2452 	if (!evsel->name) {
2453 		snprintf(bf, sizeof(bf), "%s:%s", event->system, event->name);
2454 		evsel->name = strdup(bf);
2455 		if (evsel->name == NULL)
2456 			return -1;
2457 	}
2458 
2459 	evsel->tp_format = event;
2460 	return 0;
2461 }
2462 
2463 static int perf_evlist__prepare_tracepoint_events(struct perf_evlist *evlist,
2464 						  struct pevent *pevent)
2465 {
2466 	struct perf_evsel *pos;
2467 
2468 	evlist__for_each(evlist, pos) {
2469 		if (pos->attr.type == PERF_TYPE_TRACEPOINT &&
2470 		    perf_evsel__prepare_tracepoint_event(pos, pevent))
2471 			return -1;
2472 	}
2473 
2474 	return 0;
2475 }
2476 
2477 int perf_session__read_header(struct perf_session *session)
2478 {
2479 	struct perf_data_file *file = session->file;
2480 	struct perf_header *header = &session->header;
2481 	struct perf_file_header	f_header;
2482 	struct perf_file_attr	f_attr;
2483 	u64			f_id;
2484 	int nr_attrs, nr_ids, i, j;
2485 	int fd = perf_data_file__fd(file);
2486 
2487 	session->evlist = perf_evlist__new();
2488 	if (session->evlist == NULL)
2489 		return -ENOMEM;
2490 
2491 	if (perf_data_file__is_pipe(file))
2492 		return perf_header__read_pipe(session);
2493 
2494 	if (perf_file_header__read(&f_header, header, fd) < 0)
2495 		return -EINVAL;
2496 
2497 	/*
2498 	 * Sanity check that perf.data was written cleanly; data size is
2499 	 * initialized to 0 and updated only if the on_exit function is run.
2500 	 * If data size is still 0 then the file contains only partial
2501 	 * information.  Just warn user and process it as much as it can.
2502 	 */
2503 	if (f_header.data.size == 0) {
2504 		pr_warning("WARNING: The %s file's data size field is 0 which is unexpected.\n"
2505 			   "Was the 'perf record' command properly terminated?\n",
2506 			   file->path);
2507 	}
2508 
2509 	nr_attrs = f_header.attrs.size / f_header.attr_size;
2510 	lseek(fd, f_header.attrs.offset, SEEK_SET);
2511 
2512 	for (i = 0; i < nr_attrs; i++) {
2513 		struct perf_evsel *evsel;
2514 		off_t tmp;
2515 
2516 		if (read_attr(fd, header, &f_attr) < 0)
2517 			goto out_errno;
2518 
2519 		if (header->needs_swap)
2520 			perf_event__attr_swap(&f_attr.attr);
2521 
2522 		tmp = lseek(fd, 0, SEEK_CUR);
2523 		evsel = perf_evsel__new(&f_attr.attr);
2524 
2525 		if (evsel == NULL)
2526 			goto out_delete_evlist;
2527 
2528 		evsel->needs_swap = header->needs_swap;
2529 		/*
2530 		 * Do it before so that if perf_evsel__alloc_id fails, this
2531 		 * entry gets purged too at perf_evlist__delete().
2532 		 */
2533 		perf_evlist__add(session->evlist, evsel);
2534 
2535 		nr_ids = f_attr.ids.size / sizeof(u64);
2536 		/*
2537 		 * We don't have the cpu and thread maps on the header, so
2538 		 * for allocating the perf_sample_id table we fake 1 cpu and
2539 		 * hattr->ids threads.
2540 		 */
2541 		if (perf_evsel__alloc_id(evsel, 1, nr_ids))
2542 			goto out_delete_evlist;
2543 
2544 		lseek(fd, f_attr.ids.offset, SEEK_SET);
2545 
2546 		for (j = 0; j < nr_ids; j++) {
2547 			if (perf_header__getbuffer64(header, fd, &f_id, sizeof(f_id)))
2548 				goto out_errno;
2549 
2550 			perf_evlist__id_add(session->evlist, evsel, 0, j, f_id);
2551 		}
2552 
2553 		lseek(fd, tmp, SEEK_SET);
2554 	}
2555 
2556 	symbol_conf.nr_events = nr_attrs;
2557 
2558 	perf_header__process_sections(header, fd, &session->tevent,
2559 				      perf_file_section__process);
2560 
2561 	if (perf_evlist__prepare_tracepoint_events(session->evlist,
2562 						   session->tevent.pevent))
2563 		goto out_delete_evlist;
2564 
2565 	return 0;
2566 out_errno:
2567 	return -errno;
2568 
2569 out_delete_evlist:
2570 	perf_evlist__delete(session->evlist);
2571 	session->evlist = NULL;
2572 	return -ENOMEM;
2573 }
2574 
2575 int perf_event__synthesize_attr(struct perf_tool *tool,
2576 				struct perf_event_attr *attr, u32 ids, u64 *id,
2577 				perf_event__handler_t process)
2578 {
2579 	union perf_event *ev;
2580 	size_t size;
2581 	int err;
2582 
2583 	size = sizeof(struct perf_event_attr);
2584 	size = PERF_ALIGN(size, sizeof(u64));
2585 	size += sizeof(struct perf_event_header);
2586 	size += ids * sizeof(u64);
2587 
2588 	ev = malloc(size);
2589 
2590 	if (ev == NULL)
2591 		return -ENOMEM;
2592 
2593 	ev->attr.attr = *attr;
2594 	memcpy(ev->attr.id, id, ids * sizeof(u64));
2595 
2596 	ev->attr.header.type = PERF_RECORD_HEADER_ATTR;
2597 	ev->attr.header.size = (u16)size;
2598 
2599 	if (ev->attr.header.size == size)
2600 		err = process(tool, ev, NULL, NULL);
2601 	else
2602 		err = -E2BIG;
2603 
2604 	free(ev);
2605 
2606 	return err;
2607 }
2608 
2609 int perf_event__synthesize_attrs(struct perf_tool *tool,
2610 				   struct perf_session *session,
2611 				   perf_event__handler_t process)
2612 {
2613 	struct perf_evsel *evsel;
2614 	int err = 0;
2615 
2616 	evlist__for_each(session->evlist, evsel) {
2617 		err = perf_event__synthesize_attr(tool, &evsel->attr, evsel->ids,
2618 						  evsel->id, process);
2619 		if (err) {
2620 			pr_debug("failed to create perf header attribute\n");
2621 			return err;
2622 		}
2623 	}
2624 
2625 	return err;
2626 }
2627 
2628 int perf_event__process_attr(struct perf_tool *tool __maybe_unused,
2629 			     union perf_event *event,
2630 			     struct perf_evlist **pevlist)
2631 {
2632 	u32 i, ids, n_ids;
2633 	struct perf_evsel *evsel;
2634 	struct perf_evlist *evlist = *pevlist;
2635 
2636 	if (evlist == NULL) {
2637 		*pevlist = evlist = perf_evlist__new();
2638 		if (evlist == NULL)
2639 			return -ENOMEM;
2640 	}
2641 
2642 	evsel = perf_evsel__new(&event->attr.attr);
2643 	if (evsel == NULL)
2644 		return -ENOMEM;
2645 
2646 	perf_evlist__add(evlist, evsel);
2647 
2648 	ids = event->header.size;
2649 	ids -= (void *)&event->attr.id - (void *)event;
2650 	n_ids = ids / sizeof(u64);
2651 	/*
2652 	 * We don't have the cpu and thread maps on the header, so
2653 	 * for allocating the perf_sample_id table we fake 1 cpu and
2654 	 * hattr->ids threads.
2655 	 */
2656 	if (perf_evsel__alloc_id(evsel, 1, n_ids))
2657 		return -ENOMEM;
2658 
2659 	for (i = 0; i < n_ids; i++) {
2660 		perf_evlist__id_add(evlist, evsel, 0, i, event->attr.id[i]);
2661 	}
2662 
2663 	symbol_conf.nr_events = evlist->nr_entries;
2664 
2665 	return 0;
2666 }
2667 
2668 int perf_event__synthesize_tracing_data(struct perf_tool *tool, int fd,
2669 					struct perf_evlist *evlist,
2670 					perf_event__handler_t process)
2671 {
2672 	union perf_event ev;
2673 	struct tracing_data *tdata;
2674 	ssize_t size = 0, aligned_size = 0, padding;
2675 	int err __maybe_unused = 0;
2676 
2677 	/*
2678 	 * We are going to store the size of the data followed
2679 	 * by the data contents. Since the fd descriptor is a pipe,
2680 	 * we cannot seek back to store the size of the data once
2681 	 * we know it. Instead we:
2682 	 *
2683 	 * - write the tracing data to the temp file
2684 	 * - get/write the data size to pipe
2685 	 * - write the tracing data from the temp file
2686 	 *   to the pipe
2687 	 */
2688 	tdata = tracing_data_get(&evlist->entries, fd, true);
2689 	if (!tdata)
2690 		return -1;
2691 
2692 	memset(&ev, 0, sizeof(ev));
2693 
2694 	ev.tracing_data.header.type = PERF_RECORD_HEADER_TRACING_DATA;
2695 	size = tdata->size;
2696 	aligned_size = PERF_ALIGN(size, sizeof(u64));
2697 	padding = aligned_size - size;
2698 	ev.tracing_data.header.size = sizeof(ev.tracing_data);
2699 	ev.tracing_data.size = aligned_size;
2700 
2701 	process(tool, &ev, NULL, NULL);
2702 
2703 	/*
2704 	 * The put function will copy all the tracing data
2705 	 * stored in temp file to the pipe.
2706 	 */
2707 	tracing_data_put(tdata);
2708 
2709 	write_padded(fd, NULL, 0, padding);
2710 
2711 	return aligned_size;
2712 }
2713 
2714 int perf_event__process_tracing_data(struct perf_tool *tool __maybe_unused,
2715 				     union perf_event *event,
2716 				     struct perf_session *session)
2717 {
2718 	ssize_t size_read, padding, size = event->tracing_data.size;
2719 	int fd = perf_data_file__fd(session->file);
2720 	off_t offset = lseek(fd, 0, SEEK_CUR);
2721 	char buf[BUFSIZ];
2722 
2723 	/* setup for reading amidst mmap */
2724 	lseek(fd, offset + sizeof(struct tracing_data_event),
2725 	      SEEK_SET);
2726 
2727 	size_read = trace_report(fd, &session->tevent,
2728 				 session->repipe);
2729 	padding = PERF_ALIGN(size_read, sizeof(u64)) - size_read;
2730 
2731 	if (readn(fd, buf, padding) < 0) {
2732 		pr_err("%s: reading input file", __func__);
2733 		return -1;
2734 	}
2735 	if (session->repipe) {
2736 		int retw = write(STDOUT_FILENO, buf, padding);
2737 		if (retw <= 0 || retw != padding) {
2738 			pr_err("%s: repiping tracing data padding", __func__);
2739 			return -1;
2740 		}
2741 	}
2742 
2743 	if (size_read + padding != size) {
2744 		pr_err("%s: tracing data size mismatch", __func__);
2745 		return -1;
2746 	}
2747 
2748 	perf_evlist__prepare_tracepoint_events(session->evlist,
2749 					       session->tevent.pevent);
2750 
2751 	return size_read + padding;
2752 }
2753 
2754 int perf_event__synthesize_build_id(struct perf_tool *tool,
2755 				    struct dso *pos, u16 misc,
2756 				    perf_event__handler_t process,
2757 				    struct machine *machine)
2758 {
2759 	union perf_event ev;
2760 	size_t len;
2761 	int err = 0;
2762 
2763 	if (!pos->hit)
2764 		return err;
2765 
2766 	memset(&ev, 0, sizeof(ev));
2767 
2768 	len = pos->long_name_len + 1;
2769 	len = PERF_ALIGN(len, NAME_ALIGN);
2770 	memcpy(&ev.build_id.build_id, pos->build_id, sizeof(pos->build_id));
2771 	ev.build_id.header.type = PERF_RECORD_HEADER_BUILD_ID;
2772 	ev.build_id.header.misc = misc;
2773 	ev.build_id.pid = machine->pid;
2774 	ev.build_id.header.size = sizeof(ev.build_id) + len;
2775 	memcpy(&ev.build_id.filename, pos->long_name, pos->long_name_len);
2776 
2777 	err = process(tool, &ev, NULL, machine);
2778 
2779 	return err;
2780 }
2781 
2782 int perf_event__process_build_id(struct perf_tool *tool __maybe_unused,
2783 				 union perf_event *event,
2784 				 struct perf_session *session)
2785 {
2786 	__event_process_build_id(&event->build_id,
2787 				 event->build_id.filename,
2788 				 session);
2789 	return 0;
2790 }
2791