perf: Convert perf header attrs into attr events
[safe/jmp/linux-2.6] / tools / perf / util / header.c
1 #define _FILE_OFFSET_BITS 64
2
3 #include <sys/types.h>
4 #include <byteswap.h>
5 #include <unistd.h>
6 #include <stdio.h>
7 #include <stdlib.h>
8 #include <linux/list.h>
9 #include <linux/kernel.h>
10
11 #include "util.h"
12 #include "header.h"
13 #include "../perf.h"
14 #include "trace-event.h"
15 #include "session.h"
16 #include "symbol.h"
17 #include "debug.h"
18
19 /*
20  * Create new perf.data header attribute:
21  */
22 struct perf_header_attr *perf_header_attr__new(struct perf_event_attr *attr)
23 {
24         struct perf_header_attr *self = malloc(sizeof(*self));
25
26         if (self != NULL) {
27                 self->attr = *attr;
28                 self->ids  = 0;
29                 self->size = 1;
30                 self->id   = malloc(sizeof(u64));
31                 if (self->id == NULL) {
32                         free(self);
33                         self = NULL;
34                 }
35         }
36
37         return self;
38 }
39
40 void perf_header_attr__delete(struct perf_header_attr *self)
41 {
42         free(self->id);
43         free(self);
44 }
45
46 int perf_header_attr__add_id(struct perf_header_attr *self, u64 id)
47 {
48         int pos = self->ids;
49
50         self->ids++;
51         if (self->ids > self->size) {
52                 int nsize = self->size * 2;
53                 u64 *nid = realloc(self->id, nsize * sizeof(u64));
54
55                 if (nid == NULL)
56                         return -1;
57
58                 self->size = nsize;
59                 self->id = nid;
60         }
61         self->id[pos] = id;
62         return 0;
63 }
64
65 int perf_header__init(struct perf_header *self)
66 {
67         self->size = 1;
68         self->attr = malloc(sizeof(void *));
69         return self->attr == NULL ? -ENOMEM : 0;
70 }
71
72 void perf_header__exit(struct perf_header *self)
73 {
74         int i;
75         for (i = 0; i < self->attrs; ++i)
76                 perf_header_attr__delete(self->attr[i]);
77         free(self->attr);
78 }
79
80 int perf_header__add_attr(struct perf_header *self,
81                           struct perf_header_attr *attr)
82 {
83         if (self->frozen)
84                 return -1;
85
86         if (self->attrs == self->size) {
87                 int nsize = self->size * 2;
88                 struct perf_header_attr **nattr;
89
90                 nattr = realloc(self->attr, nsize * sizeof(void *));
91                 if (nattr == NULL)
92                         return -1;
93
94                 self->size = nsize;
95                 self->attr = nattr;
96         }
97
98         self->attr[self->attrs++] = attr;
99         return 0;
100 }
101
102 #define MAX_EVENT_NAME 64
103
104 struct perf_trace_event_type {
105         u64     event_id;
106         char    name[MAX_EVENT_NAME];
107 };
108
109 static int event_count;
110 static struct perf_trace_event_type *events;
111
112 int perf_header__push_event(u64 id, const char *name)
113 {
114         if (strlen(name) > MAX_EVENT_NAME)
115                 pr_warning("Event %s will be truncated\n", name);
116
117         if (!events) {
118                 events = malloc(sizeof(struct perf_trace_event_type));
119                 if (events == NULL)
120                         return -ENOMEM;
121         } else {
122                 struct perf_trace_event_type *nevents;
123
124                 nevents = realloc(events, (event_count + 1) * sizeof(*events));
125                 if (nevents == NULL)
126                         return -ENOMEM;
127                 events = nevents;
128         }
129         memset(&events[event_count], 0, sizeof(struct perf_trace_event_type));
130         events[event_count].event_id = id;
131         strncpy(events[event_count].name, name, MAX_EVENT_NAME - 1);
132         event_count++;
133         return 0;
134 }
135
136 char *perf_header__find_event(u64 id)
137 {
138         int i;
139         for (i = 0 ; i < event_count; i++) {
140                 if (events[i].event_id == id)
141                         return events[i].name;
142         }
143         return NULL;
144 }
145
146 static const char *__perf_magic = "PERFFILE";
147
148 #define PERF_MAGIC      (*(u64 *)__perf_magic)
149
150 struct perf_file_attr {
151         struct perf_event_attr  attr;
152         struct perf_file_section        ids;
153 };
154
155 void perf_header__set_feat(struct perf_header *self, int feat)
156 {
157         set_bit(feat, self->adds_features);
158 }
159
160 bool perf_header__has_feat(const struct perf_header *self, int feat)
161 {
162         return test_bit(feat, self->adds_features);
163 }
164
165 static int do_write(int fd, const void *buf, size_t size)
166 {
167         while (size) {
168                 int ret = write(fd, buf, size);
169
170                 if (ret < 0)
171                         return -errno;
172
173                 size -= ret;
174                 buf += ret;
175         }
176
177         return 0;
178 }
179
180 #define NAME_ALIGN 64
181
182 static int write_padded(int fd, const void *bf, size_t count,
183                         size_t count_aligned)
184 {
185         static const char zero_buf[NAME_ALIGN];
186         int err = do_write(fd, bf, count);
187
188         if (!err)
189                 err = do_write(fd, zero_buf, count_aligned - count);
190
191         return err;
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, u16 misc, int fd)
201 {
202         struct dso *pos;
203
204         dsos__for_each_with_build_id(pos, head) {
205                 int err;
206                 struct build_id_event b;
207                 size_t len;
208
209                 if (!pos->hit)
210                         continue;
211                 len = pos->long_name_len + 1;
212                 len = ALIGN(len, NAME_ALIGN);
213                 memset(&b, 0, sizeof(b));
214                 memcpy(&b.build_id, pos->build_id, sizeof(pos->build_id));
215                 b.header.misc = misc;
216                 b.header.size = sizeof(b) + len;
217                 err = do_write(fd, &b, sizeof(b));
218                 if (err < 0)
219                         return err;
220                 err = write_padded(fd, pos->long_name,
221                                    pos->long_name_len + 1, len);
222                 if (err < 0)
223                         return err;
224         }
225
226         return 0;
227 }
228
229 static int dsos__write_buildid_table(int fd)
230 {
231         int err = __dsos__write_buildid_table(&dsos__kernel,
232                                               PERF_RECORD_MISC_KERNEL, fd);
233         if (err == 0)
234                 err = __dsos__write_buildid_table(&dsos__user,
235                                                   PERF_RECORD_MISC_USER, fd);
236         return err;
237 }
238
239 int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
240                           const char *name, bool is_kallsyms)
241 {
242         const size_t size = PATH_MAX;
243         char *filename = malloc(size),
244              *linkname = malloc(size), *targetname;
245         int len, err = -1;
246
247         if (filename == NULL || linkname == NULL)
248                 goto out_free;
249
250         len = snprintf(filename, size, "%s%s%s",
251                        debugdir, is_kallsyms ? "/" : "", name);
252         if (mkdir_p(filename, 0755))
253                 goto out_free;
254
255         snprintf(filename + len, sizeof(filename) - len, "/%s", sbuild_id);
256
257         if (access(filename, F_OK)) {
258                 if (is_kallsyms) {
259                          if (copyfile("/proc/kallsyms", filename))
260                                 goto out_free;
261                 } else if (link(name, filename) && copyfile(name, filename))
262                         goto out_free;
263         }
264
265         len = snprintf(linkname, size, "%s/.build-id/%.2s",
266                        debugdir, sbuild_id);
267
268         if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
269                 goto out_free;
270
271         snprintf(linkname + len, size - len, "/%s", sbuild_id + 2);
272         targetname = filename + strlen(debugdir) - 5;
273         memcpy(targetname, "../..", 5);
274
275         if (symlink(targetname, linkname) == 0)
276                 err = 0;
277 out_free:
278         free(filename);
279         free(linkname);
280         return err;
281 }
282
283 static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
284                                  const char *name, const char *debugdir,
285                                  bool is_kallsyms)
286 {
287         char sbuild_id[BUILD_ID_SIZE * 2 + 1];
288
289         build_id__sprintf(build_id, build_id_size, sbuild_id);
290
291         return build_id_cache__add_s(sbuild_id, debugdir, name, is_kallsyms);
292 }
293
294 int build_id_cache__remove_s(const char *sbuild_id, const char *debugdir)
295 {
296         const size_t size = PATH_MAX;
297         char *filename = malloc(size),
298              *linkname = malloc(size);
299         int err = -1;
300
301         if (filename == NULL || linkname == NULL)
302                 goto out_free;
303
304         snprintf(linkname, size, "%s/.build-id/%.2s/%s",
305                  debugdir, sbuild_id, sbuild_id + 2);
306
307         if (access(linkname, F_OK))
308                 goto out_free;
309
310         if (readlink(linkname, filename, size) < 0)
311                 goto out_free;
312
313         if (unlink(linkname))
314                 goto out_free;
315
316         /*
317          * Since the link is relative, we must make it absolute:
318          */
319         snprintf(linkname, size, "%s/.build-id/%.2s/%s",
320                  debugdir, sbuild_id, filename);
321
322         if (unlink(linkname))
323                 goto out_free;
324
325         err = 0;
326 out_free:
327         free(filename);
328         free(linkname);
329         return err;
330 }
331
332 static int dso__cache_build_id(struct dso *self, const char *debugdir)
333 {
334         bool is_kallsyms = self->kernel && self->long_name[0] != '/';
335
336         return build_id_cache__add_b(self->build_id, sizeof(self->build_id),
337                                      self->long_name, debugdir, is_kallsyms);
338 }
339
340 static int __dsos__cache_build_ids(struct list_head *head, const char *debugdir)
341 {
342         struct dso *pos;
343         int err = 0;
344
345         dsos__for_each_with_build_id(pos, head)
346                 if (dso__cache_build_id(pos, debugdir))
347                         err = -1;
348
349         return err;
350 }
351
352 static int dsos__cache_build_ids(void)
353 {
354         int err_kernel, err_user;
355         char debugdir[PATH_MAX];
356
357         snprintf(debugdir, sizeof(debugdir), "%s/%s", getenv("HOME"),
358                  DEBUG_CACHE_DIR);
359
360         if (mkdir(debugdir, 0755) != 0 && errno != EEXIST)
361                 return -1;
362
363         err_kernel = __dsos__cache_build_ids(&dsos__kernel, debugdir);
364         err_user   = __dsos__cache_build_ids(&dsos__user, debugdir);
365         return err_kernel || err_user ? -1 : 0;
366 }
367
368 static int perf_header__adds_write(struct perf_header *self, int fd)
369 {
370         int nr_sections;
371         struct perf_file_section *feat_sec;
372         int sec_size;
373         u64 sec_start;
374         int idx = 0, err;
375
376         if (dsos__read_build_ids(true))
377                 perf_header__set_feat(self, HEADER_BUILD_ID);
378
379         nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
380         if (!nr_sections)
381                 return 0;
382
383         feat_sec = calloc(sizeof(*feat_sec), nr_sections);
384         if (feat_sec == NULL)
385                 return -ENOMEM;
386
387         sec_size = sizeof(*feat_sec) * nr_sections;
388
389         sec_start = self->data_offset + self->data_size;
390         lseek(fd, sec_start + sec_size, SEEK_SET);
391
392         if (perf_header__has_feat(self, HEADER_TRACE_INFO)) {
393                 struct perf_file_section *trace_sec;
394
395                 trace_sec = &feat_sec[idx++];
396
397                 /* Write trace info */
398                 trace_sec->offset = lseek(fd, 0, SEEK_CUR);
399                 read_tracing_data(fd, attrs, nr_counters);
400                 trace_sec->size = lseek(fd, 0, SEEK_CUR) - trace_sec->offset;
401         }
402
403
404         if (perf_header__has_feat(self, HEADER_BUILD_ID)) {
405                 struct perf_file_section *buildid_sec;
406
407                 buildid_sec = &feat_sec[idx++];
408
409                 /* Write build-ids */
410                 buildid_sec->offset = lseek(fd, 0, SEEK_CUR);
411                 err = dsos__write_buildid_table(fd);
412                 if (err < 0) {
413                         pr_debug("failed to write buildid table\n");
414                         goto out_free;
415                 }
416                 buildid_sec->size = lseek(fd, 0, SEEK_CUR) -
417                                           buildid_sec->offset;
418                 dsos__cache_build_ids();
419         }
420
421         lseek(fd, sec_start, SEEK_SET);
422         err = do_write(fd, feat_sec, sec_size);
423         if (err < 0)
424                 pr_debug("failed to write feature section\n");
425 out_free:
426         free(feat_sec);
427         return err;
428 }
429
430 int perf_header__write_pipe(int fd)
431 {
432         struct perf_pipe_file_header f_header;
433         int err;
434
435         f_header = (struct perf_pipe_file_header){
436                 .magic     = PERF_MAGIC,
437                 .size      = sizeof(f_header),
438         };
439
440         err = do_write(fd, &f_header, sizeof(f_header));
441         if (err < 0) {
442                 pr_debug("failed to write perf pipe header\n");
443                 return err;
444         }
445
446         return 0;
447 }
448
449 int perf_header__write(struct perf_header *self, int fd, bool at_exit)
450 {
451         struct perf_file_header f_header;
452         struct perf_file_attr   f_attr;
453         struct perf_header_attr *attr;
454         int i, err;
455
456         lseek(fd, sizeof(f_header), SEEK_SET);
457
458
459         for (i = 0; i < self->attrs; i++) {
460                 attr = self->attr[i];
461
462                 attr->id_offset = lseek(fd, 0, SEEK_CUR);
463                 err = do_write(fd, attr->id, attr->ids * sizeof(u64));
464                 if (err < 0) {
465                         pr_debug("failed to write perf header\n");
466                         return err;
467                 }
468         }
469
470
471         self->attr_offset = lseek(fd, 0, SEEK_CUR);
472
473         for (i = 0; i < self->attrs; i++) {
474                 attr = self->attr[i];
475
476                 f_attr = (struct perf_file_attr){
477                         .attr = attr->attr,
478                         .ids  = {
479                                 .offset = attr->id_offset,
480                                 .size   = attr->ids * sizeof(u64),
481                         }
482                 };
483                 err = do_write(fd, &f_attr, sizeof(f_attr));
484                 if (err < 0) {
485                         pr_debug("failed to write perf header attribute\n");
486                         return err;
487                 }
488         }
489
490         self->event_offset = lseek(fd, 0, SEEK_CUR);
491         self->event_size = event_count * sizeof(struct perf_trace_event_type);
492         if (events) {
493                 err = do_write(fd, events, self->event_size);
494                 if (err < 0) {
495                         pr_debug("failed to write perf header events\n");
496                         return err;
497                 }
498         }
499
500         self->data_offset = lseek(fd, 0, SEEK_CUR);
501
502         if (at_exit) {
503                 err = perf_header__adds_write(self, fd);
504                 if (err < 0)
505                         return err;
506         }
507
508         f_header = (struct perf_file_header){
509                 .magic     = PERF_MAGIC,
510                 .size      = sizeof(f_header),
511                 .attr_size = sizeof(f_attr),
512                 .attrs = {
513                         .offset = self->attr_offset,
514                         .size   = self->attrs * sizeof(f_attr),
515                 },
516                 .data = {
517                         .offset = self->data_offset,
518                         .size   = self->data_size,
519                 },
520                 .event_types = {
521                         .offset = self->event_offset,
522                         .size   = self->event_size,
523                 },
524         };
525
526         memcpy(&f_header.adds_features, &self->adds_features, sizeof(self->adds_features));
527
528         lseek(fd, 0, SEEK_SET);
529         err = do_write(fd, &f_header, sizeof(f_header));
530         if (err < 0) {
531                 pr_debug("failed to write perf header\n");
532                 return err;
533         }
534         lseek(fd, self->data_offset + self->data_size, SEEK_SET);
535
536         self->frozen = 1;
537         return 0;
538 }
539
540 static int perf_header__getbuffer64(struct perf_header *self,
541                                     int fd, void *buf, size_t size)
542 {
543         if (do_read(fd, buf, size) <= 0)
544                 return -1;
545
546         if (self->needs_swap)
547                 mem_bswap_64(buf, size);
548
549         return 0;
550 }
551
552 int perf_header__process_sections(struct perf_header *self, int fd,
553                                   int (*process)(struct perf_file_section *self,
554                                                  struct perf_header *ph,
555                                                  int feat, int fd))
556 {
557         struct perf_file_section *feat_sec;
558         int nr_sections;
559         int sec_size;
560         int idx = 0;
561         int err = -1, feat = 1;
562
563         nr_sections = bitmap_weight(self->adds_features, HEADER_FEAT_BITS);
564         if (!nr_sections)
565                 return 0;
566
567         feat_sec = calloc(sizeof(*feat_sec), nr_sections);
568         if (!feat_sec)
569                 return -1;
570
571         sec_size = sizeof(*feat_sec) * nr_sections;
572
573         lseek(fd, self->data_offset + self->data_size, SEEK_SET);
574
575         if (perf_header__getbuffer64(self, fd, feat_sec, sec_size))
576                 goto out_free;
577
578         err = 0;
579         while (idx < nr_sections && feat < HEADER_LAST_FEATURE) {
580                 if (perf_header__has_feat(self, feat)) {
581                         struct perf_file_section *sec = &feat_sec[idx++];
582
583                         err = process(sec, self, feat, fd);
584                         if (err < 0)
585                                 break;
586                 }
587                 ++feat;
588         }
589 out_free:
590         free(feat_sec);
591         return err;
592 }
593
594 int perf_file_header__read(struct perf_file_header *self,
595                            struct perf_header *ph, int fd)
596 {
597         lseek(fd, 0, SEEK_SET);
598
599         if (do_read(fd, self, sizeof(*self)) <= 0 ||
600             memcmp(&self->magic, __perf_magic, sizeof(self->magic)))
601                 return -1;
602
603         if (self->attr_size != sizeof(struct perf_file_attr)) {
604                 u64 attr_size = bswap_64(self->attr_size);
605
606                 if (attr_size != sizeof(struct perf_file_attr))
607                         return -1;
608
609                 mem_bswap_64(self, offsetof(struct perf_file_header,
610                                             adds_features));
611                 ph->needs_swap = true;
612         }
613
614         if (self->size != sizeof(*self)) {
615                 /* Support the previous format */
616                 if (self->size == offsetof(typeof(*self), adds_features))
617                         bitmap_zero(self->adds_features, HEADER_FEAT_BITS);
618                 else
619                         return -1;
620         }
621
622         memcpy(&ph->adds_features, &self->adds_features,
623                sizeof(ph->adds_features));
624         /*
625          * FIXME: hack that assumes that if we need swap the perf.data file
626          * may be coming from an arch with a different word-size, ergo different
627          * DEFINE_BITMAP format, investigate more later, but for now its mostly
628          * safe to assume that we have a build-id section. Trace files probably
629          * have several other issues in this realm anyway...
630          */
631         if (ph->needs_swap) {
632                 memset(&ph->adds_features, 0, sizeof(ph->adds_features));
633                 perf_header__set_feat(ph, HEADER_BUILD_ID);
634         }
635
636         ph->event_offset = self->event_types.offset;
637         ph->event_size   = self->event_types.size;
638         ph->data_offset  = self->data.offset;
639         ph->data_size    = self->data.size;
640         return 0;
641 }
642
643 static int perf_file_section__process(struct perf_file_section *self,
644                                       struct perf_header *ph,
645                                       int feat, int fd)
646 {
647         if (lseek(fd, self->offset, SEEK_SET) == (off_t)-1) {
648                 pr_debug("Failed to lseek to %Ld offset for feature %d, "
649                          "continuing...\n", self->offset, feat);
650                 return 0;
651         }
652
653         switch (feat) {
654         case HEADER_TRACE_INFO:
655                 trace_report(fd);
656                 break;
657
658         case HEADER_BUILD_ID:
659                 if (perf_header__read_build_ids(ph, fd, self->offset, self->size))
660                         pr_debug("Failed to read buildids, continuing...\n");
661                 break;
662         default:
663                 pr_debug("unknown feature %d, continuing...\n", feat);
664         }
665
666         return 0;
667 }
668
669 static int perf_file_header__read_pipe(struct perf_pipe_file_header *self,
670                                        struct perf_header *ph, int fd)
671 {
672         if (do_read(fd, self, sizeof(*self)) <= 0 ||
673             memcmp(&self->magic, __perf_magic, sizeof(self->magic)))
674                 return -1;
675
676         if (self->size != sizeof(*self)) {
677                 u64 size = bswap_64(self->size);
678
679                 if (size != sizeof(*self))
680                         return -1;
681
682                 ph->needs_swap = true;
683         }
684
685         return 0;
686 }
687
688 static int perf_header__read_pipe(struct perf_session *session, int fd)
689 {
690         struct perf_header *self = &session->header;
691         struct perf_pipe_file_header f_header;
692
693         if (perf_file_header__read_pipe(&f_header, self, fd) < 0) {
694                 pr_debug("incompatible file format\n");
695                 return -EINVAL;
696         }
697
698         session->fd = fd;
699
700         return 0;
701 }
702
703 int perf_header__read(struct perf_session *session, int fd)
704 {
705         struct perf_header *self = &session->header;
706         struct perf_file_header f_header;
707         struct perf_file_attr   f_attr;
708         u64                     f_id;
709         int nr_attrs, nr_ids, i, j;
710
711         if (session->fd_pipe)
712                 return perf_header__read_pipe(session, fd);
713
714         if (perf_file_header__read(&f_header, self, fd) < 0) {
715                 pr_debug("incompatible file format\n");
716                 return -EINVAL;
717         }
718
719         nr_attrs = f_header.attrs.size / sizeof(f_attr);
720         lseek(fd, f_header.attrs.offset, SEEK_SET);
721
722         for (i = 0; i < nr_attrs; i++) {
723                 struct perf_header_attr *attr;
724                 off_t tmp;
725
726                 if (perf_header__getbuffer64(self, fd, &f_attr, sizeof(f_attr)))
727                         goto out_errno;
728
729                 tmp = lseek(fd, 0, SEEK_CUR);
730
731                 attr = perf_header_attr__new(&f_attr.attr);
732                 if (attr == NULL)
733                          return -ENOMEM;
734
735                 nr_ids = f_attr.ids.size / sizeof(u64);
736                 lseek(fd, f_attr.ids.offset, SEEK_SET);
737
738                 for (j = 0; j < nr_ids; j++) {
739                         if (perf_header__getbuffer64(self, fd, &f_id, sizeof(f_id)))
740                                 goto out_errno;
741
742                         if (perf_header_attr__add_id(attr, f_id) < 0) {
743                                 perf_header_attr__delete(attr);
744                                 return -ENOMEM;
745                         }
746                 }
747                 if (perf_header__add_attr(self, attr) < 0) {
748                         perf_header_attr__delete(attr);
749                         return -ENOMEM;
750                 }
751
752                 lseek(fd, tmp, SEEK_SET);
753         }
754
755         if (f_header.event_types.size) {
756                 lseek(fd, f_header.event_types.offset, SEEK_SET);
757                 events = malloc(f_header.event_types.size);
758                 if (events == NULL)
759                         return -ENOMEM;
760                 if (perf_header__getbuffer64(self, fd, events,
761                                              f_header.event_types.size))
762                         goto out_errno;
763                 event_count =  f_header.event_types.size / sizeof(struct perf_trace_event_type);
764         }
765
766         perf_header__process_sections(self, fd, perf_file_section__process);
767
768         lseek(fd, self->data_offset, SEEK_SET);
769
770         self->frozen = 1;
771         return 0;
772 out_errno:
773         return -errno;
774 }
775
776 u64 perf_header__sample_type(struct perf_header *header)
777 {
778         u64 type = 0;
779         int i;
780
781         for (i = 0; i < header->attrs; i++) {
782                 struct perf_header_attr *attr = header->attr[i];
783
784                 if (!type)
785                         type = attr->attr.sample_type;
786                 else if (type != attr->attr.sample_type)
787                         die("non matching sample_type");
788         }
789
790         return type;
791 }
792
793 struct perf_event_attr *
794 perf_header__find_attr(u64 id, struct perf_header *header)
795 {
796         int i;
797
798         for (i = 0; i < header->attrs; i++) {
799                 struct perf_header_attr *attr = header->attr[i];
800                 int j;
801
802                 for (j = 0; j < attr->ids; j++) {
803                         if (attr->id[j] == id)
804                                 return &attr->attr;
805                 }
806         }
807
808         return NULL;
809 }
810
811 int event__synthesize_attr(struct perf_event_attr *attr, u16 ids, u64 *id,
812                            event__handler_t process,
813                            struct perf_session *session)
814 {
815         event_t *ev;
816         size_t size;
817         int err;
818
819         size = sizeof(struct perf_event_attr);
820         size = ALIGN(size, sizeof(u64));
821         size += sizeof(struct perf_event_header);
822         size += ids * sizeof(u64);
823
824         ev = malloc(size);
825
826         ev->attr.attr = *attr;
827         memcpy(ev->attr.id, id, ids * sizeof(u64));
828
829         ev->attr.header.type = PERF_RECORD_HEADER_ATTR;
830         ev->attr.header.size = size;
831
832         err = process(ev, session);
833
834         free(ev);
835
836         return err;
837 }
838
839 int event__synthesize_attrs(struct perf_header *self,
840                             event__handler_t process,
841                             struct perf_session *session)
842 {
843         struct perf_header_attr *attr;
844         int i, err = 0;
845
846         for (i = 0; i < self->attrs; i++) {
847                 attr = self->attr[i];
848
849                 err = event__synthesize_attr(&attr->attr, attr->ids, attr->id,
850                                              process, session);
851                 if (err) {
852                         pr_debug("failed to create perf header attribute\n");
853                         return err;
854                 }
855         }
856
857         return err;
858 }
859
860 int event__process_attr(event_t *self, struct perf_session *session)
861 {
862         struct perf_header_attr *attr;
863         unsigned int i, ids, n_ids;
864
865         attr = perf_header_attr__new(&self->attr.attr);
866         if (attr == NULL)
867                 return -ENOMEM;
868
869         ids = self->header.size;
870         ids -= (void *)&self->attr.id - (void *)self;
871         n_ids = ids / sizeof(u64);
872
873         for (i = 0; i < n_ids; i++) {
874                 if (perf_header_attr__add_id(attr, self->attr.id[i]) < 0) {
875                         perf_header_attr__delete(attr);
876                         return -ENOMEM;
877                 }
878         }
879
880         if (perf_header__add_attr(&session->header, attr) < 0) {
881                 perf_header_attr__delete(attr);
882                 return -ENOMEM;
883         }
884
885         perf_session__update_sample_type(session);
886
887         return 0;
888 }