aboutsummaryrefslogtreecommitdiff
path: root/elf/sprof.c
blob: 9ba28bc58186795f293c4c1bdaf71e38afdc2336 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
/* Read and display shared object profiling data.
   Copyright (C) 1997-2002, 2003, 2004 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <argp.h>
#include <dlfcn.h>
#include <elf.h>
#include <error.h>
#include <fcntl.h>
#include <inttypes.h>
#include <libintl.h>
#include <locale.h>
#include <obstack.h>
#include <search.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <ldsodefs.h>
#include <sys/gmon.h>
#include <sys/gmon_out.h>
#include <sys/mman.h>
#include <sys/param.h>
#include <sys/stat.h>

/* Get libc version number.  */
#include "../version.h"

#define PACKAGE _libc_intl_domainname


#include <endian.h>
#if BYTE_ORDER == BIG_ENDIAN
#define byteorder ELFDATA2MSB
#define byteorder_name "big-endian"
#elif BYTE_ORDER == LITTLE_ENDIAN
#define byteorder ELFDATA2LSB
#define byteorder_name "little-endian"
#else
#error "Unknown BYTE_ORDER " BYTE_ORDER
#define byteorder ELFDATANONE
#endif


extern int __profile_frequency (void);

/* Name and version of program.  */
static void print_version (FILE *stream, struct argp_state *state);
void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;

#define OPT_TEST	1

/* Definitions of arguments for argp functions.  */
static const struct argp_option options[] =
{
  { NULL, 0, NULL, 0, N_("Output selection:") },
  { "call-pairs", 'c', NULL, 0,
    N_("print list of count paths and their number of use") },
  { "flat-profile", 'p', NULL, 0,
    N_("generate flat profile with counts and ticks") },
  { "graph", 'q', NULL, 0, N_("generate call graph") },

  { "test", OPT_TEST, NULL, OPTION_HIDDEN, NULL },
  { NULL, 0, NULL, 0, NULL }
};

/* Short description of program.  */
static const char doc[] = N_("Read and display shared object profiling data");

/* Strings for arguments in help texts.  */
static const char args_doc[] = N_("SHOBJ [PROFDATA]");

/* Prototype for option handler.  */
static error_t parse_opt (int key, char *arg, struct argp_state *state);

/* Data structure to communicate with argp functions.  */
static struct argp argp =
{
  options, parse_opt, args_doc, doc, NULL, NULL
};


/* Operation modes.  */
static enum
{
  NONE = 0,
  FLAT_MODE = 1 << 0,
  CALL_GRAPH_MODE = 1 << 1,
  CALL_PAIRS = 1 << 2,

  DEFAULT_MODE = FLAT_MODE | CALL_GRAPH_MODE
} mode;

/* If nonzero the total number of invocations of a function is emitted.  */
int count_total;

/* Nozero for testing.  */
int do_test;

/* Strcuture describing calls.  */
struct here_fromstruct
{
  struct here_cg_arc_record volatile *here;
  uint16_t link;
};

/* We define a special type to address the elements of the arc table.
   This is basically the `gmon_cg_arc_record' format but it includes
   the room for the tag and it uses real types.  */
struct here_cg_arc_record
{
  uintptr_t from_pc;
  uintptr_t self_pc;
  uint32_t count;
} __attribute__ ((packed));


struct known_symbol;
struct arc_list
{
  size_t idx;
  uintmax_t count;

  struct arc_list *next;
};

static struct obstack ob_list;


struct known_symbol
{
  const char *name;
  uintptr_t addr;
  size_t size;

  uintmax_t ticks;
  uintmax_t calls;

  struct arc_list *froms;
  struct arc_list *tos;
};


struct shobj
{
  const char *name;		/* User-provided name.  */

  struct link_map *map;
  const char *dynstrtab;	/* Dynamic string table of shared object.  */
  const char *soname;		/* Soname of shared object.  */

  uintptr_t lowpc;
  uintptr_t highpc;
  unsigned long int kcountsize;
  size_t expected_size;		/* Expected size of profiling file.  */
  size_t tossize;
  size_t fromssize;
  size_t fromlimit;
  unsigned int hashfraction;
  int s_scale;

  void *symbol_map;
  size_t symbol_mapsize;
  const ElfW(Sym) *symtab;
  size_t symtab_size;
  const char *strtab;

  struct obstack ob_str;
  struct obstack ob_sym;
};


struct profdata
{
  void *addr;
  off_t size;

  char *hist;
  struct gmon_hist_hdr *hist_hdr;
  uint16_t *kcount;
  uint32_t narcs;		/* Number of arcs in toset.  */
  struct here_cg_arc_record *data;
  uint16_t *tos;
  struct here_fromstruct *froms;
};

/* Search tree for symbols.  */
void *symroot;
static struct known_symbol **sortsym;
static size_t symidx;
static uintmax_t total_ticks;

/* Prototypes for local functions.  */
static struct shobj *load_shobj (const char *name);
static void unload_shobj (struct shobj *shobj);
static struct profdata *load_profdata (const char *name, struct shobj *shobj);
static void unload_profdata (struct profdata *profdata);
static void count_total_ticks (struct shobj *shobj, struct profdata *profdata);
static void count_calls (struct shobj *shobj, struct profdata *profdata);
static void read_symbols (struct shobj *shobj);
static void add_arcs (struct profdata *profdata);
static void generate_flat_profile (struct profdata *profdata);
static void generate_call_graph (struct profdata *profdata);
static void generate_call_pair_list (struct profdata *profdata);


int
main (int argc, char *argv[])
{
  const char *shobj;
  const char *profdata;
  struct shobj *shobj_handle;
  struct profdata *profdata_handle;
  int remaining;

  setlocale (LC_ALL, "");

  /* Initialize the message catalog.  */
  textdomain (_libc_intl_domainname);

  /* Parse and process arguments.  */
  argp_parse (&argp, argc, argv, 0, &remaining, NULL);

  if (argc - remaining == 0 || argc - remaining > 2)
    {
      /* We need exactly two non-option parameter.  */
      argp_help (&argp, stdout, ARGP_HELP_SEE | ARGP_HELP_EXIT_ERR,
                 program_invocation_short_name);
      exit (1);
    }

  /* Get parameters.  */
  shobj = argv[remaining];
  if (argc - remaining == 2)
    profdata = argv[remaining + 1];
  else
    /* No filename for the profiling data given.  We will determine it
       from the soname of the shobj, later.  */
    profdata = NULL;

  /* First see whether we can load the shared object.  */
  shobj_handle = load_shobj (shobj);
  if (shobj_handle == NULL)
    exit (1);

  /* We can now determine the filename for the profiling data, if
     nececessary.  */
  if (profdata == NULL)
    {
      char *newp;
      const char *soname;
      size_t soname_len;

      soname = shobj_handle->soname ?: basename (shobj);
      soname_len = strlen (soname);
      newp = (char *) alloca (soname_len + sizeof ".profile");
      stpcpy (mempcpy (newp, soname, soname_len), ".profile");
      profdata = newp;
    }

  /* Now see whether the profiling data file matches the given object.   */
  profdata_handle = load_profdata (profdata, shobj_handle);
  if (profdata_handle == NULL)
    {
      unload_shobj (shobj_handle);

      exit (1);
    }

  read_symbols (shobj_handle);

  /* Count the ticks.  */
  count_total_ticks (shobj_handle, profdata_handle);

  /* Count the calls.  */
  count_calls (shobj_handle, profdata_handle);

  /* Add the arc information.  */
  add_arcs (profdata_handle);

  /* If no mode is specified fall back to the default mode.  */
  if (mode == NONE)
    mode = DEFAULT_MODE;

  /* Do some work.  */
  if (mode & FLAT_MODE)
    generate_flat_profile (profdata_handle);

  if (mode & CALL_GRAPH_MODE)
    generate_call_graph (profdata_handle);

  if (mode & CALL_PAIRS)
    generate_call_pair_list (profdata_handle);

  /* Free the resources.  */
  unload_shobj (shobj_handle);
  unload_profdata (profdata_handle);

  return 0;
}


/* Handle program arguments.  */
static error_t
parse_opt (int key, char *arg, struct argp_state *state)
{
  switch (key)
    {
    case 'c':
      mode |= CALL_PAIRS;
      break;
    case 'p':
      mode |= FLAT_MODE;
      break;
    case 'q':
      mode |= CALL_GRAPH_MODE;
      break;
    case OPT_TEST:
      do_test = 1;
      break;
    default:
      return ARGP_ERR_UNKNOWN;
    }
  return 0;
}


/* Print the version information.  */
static void
print_version (FILE *stream, struct argp_state *state)
{
  fprintf (stream, "sprof (GNU %s) %s\n", PACKAGE, VERSION);
  fprintf (stream, gettext ("\
Copyright (C) %s Free Software Foundation, Inc.\n\
This is free software; see the source for copying conditions.  There is NO\n\
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
"),
	   "2004");
  fprintf (stream, gettext ("Written by %s.\n"), "Ulrich Drepper");
}


/* Note that we must not use `dlopen' etc.  The shobj object must not
   be loaded for use.  */
static struct shobj *
load_shobj (const char *name)
{
  struct link_map *map = NULL;
  struct shobj *result;
  ElfW(Addr) mapstart = ~((ElfW(Addr)) 0);
  ElfW(Addr) mapend = 0;
  const ElfW(Phdr) *ph;
  size_t textsize;
  unsigned int log_hashfraction;
  ElfW(Ehdr) *ehdr;
  int fd;
  ElfW(Shdr) *shdr;
  void *ptr;
  size_t pagesize = getpagesize ();
  const char *shstrtab;
  int idx;
  ElfW(Shdr) *symtab_entry;

  /* Since we use dlopen() we must be prepared to work around the sometimes
     strange lookup rules for the shared objects.  If we have a file foo.so
     in the current directory and the user specfies foo.so on the command
     line (without specifying a directory) we should load the file in the
     current directory even if a normal dlopen() call would read the other
     file.  We do this by adding a directory portion to the name.  */
  if (strchr (name, '/') == NULL)
    {
      char *load_name = (char *) alloca (strlen (name) + 3);
      stpcpy (stpcpy (load_name, "./"), name);

      map = (struct link_map *) dlopen (load_name, RTLD_LAZY | __RTLD_SPROF);
    }
  if (map == NULL)
    {
      map = (struct link_map *) dlopen (name, RTLD_LAZY | __RTLD_SPROF);
      if (map == NULL)
	{
	  error (0, errno, _("failed to load shared object `%s'"), name);
	  return NULL;
	}
    }

  /* Prepare the result.  */
  result = (struct shobj *) calloc (1, sizeof (struct shobj));
  if (result == NULL)
    {
      error (0, errno, _("cannot create internal descriptors"));
      dlclose (map);
      return NULL;
    }
  result->name = name;
  result->map = map;

  /* Compute the size of the sections which contain program code.
     This must match the code in dl-profile.c (_dl_start_profile).  */
  for (ph = map->l_phdr; ph < &map->l_phdr[map->l_phnum]; ++ph)
    if (ph->p_type == PT_LOAD && (ph->p_flags & PF_X))
      {
	ElfW(Addr) start = (ph->p_vaddr & ~(pagesize - 1));
	ElfW(Addr) end = ((ph->p_vaddr + ph->p_memsz + pagesize - 1)
			  & ~(pagesize - 1));

	if (start < mapstart)
	  mapstart = start;
	if (end > mapend)
	  mapend = end;
      }

  result->lowpc = ROUNDDOWN ((uintptr_t) (mapstart + map->l_addr),
			     HISTFRACTION * sizeof (HISTCOUNTER));
  result->highpc = ROUNDUP ((uintptr_t) (mapend + map->l_addr),
			    HISTFRACTION * sizeof (HISTCOUNTER));
  if (do_test)
    printf ("load addr: %0#*" PRIxPTR "\n"
	    "lower bound PC: %0#*" PRIxPTR "\n"
	    "upper bound PC: %0#*" PRIxPTR "\n",
	    __ELF_NATIVE_CLASS == 32 ? 10 : 18, map->l_addr,
	    __ELF_NATIVE_CLASS == 32 ? 10 : 18, result->lowpc,
	    __ELF_NATIVE_CLASS == 32 ? 10 : 18, result->highpc);

  textsize = result->highpc - result->lowpc;
  result->kcountsize = textsize / HISTFRACTION;
  result->hashfraction = HASHFRACTION;
  if ((HASHFRACTION & (HASHFRACTION - 1)) == 0)
    /* If HASHFRACTION is a power of two, mcount can use shifting
       instead of integer division.  Precompute shift amount.  */
    log_hashfraction = __builtin_ffs (result->hashfraction
				      * sizeof (struct here_fromstruct)) - 1;
  else
    log_hashfraction = -1;
  if (do_test)
    printf ("hashfraction = %d\ndivider = %Zu\n",
	    result->hashfraction,
	    result->hashfraction * sizeof (struct here_fromstruct));
  result->tossize = textsize / HASHFRACTION;
  result->fromlimit = textsize * ARCDENSITY / 100;
  if (result->fromlimit < MINARCS)
    result->fromlimit = MINARCS;
  if (result->fromlimit > MAXARCS)
    result->fromlimit = MAXARCS;
  result->fromssize = result->fromlimit * sizeof (struct here_fromstruct);

  result->expected_size = (sizeof (struct gmon_hdr)
			   + 4 + sizeof (struct gmon_hist_hdr)
			   + result->kcountsize
			   + 4 + 4
			   + (result->fromssize
			      * sizeof (struct here_cg_arc_record)));

  if (do_test)
    printf ("expected size: %Zd\n", result->expected_size);

#define SCALE_1_TO_1	0x10000L

  if (result->kcountsize < result->highpc - result->lowpc)
    {
      size_t range = result->highpc - result->lowpc;
      size_t quot = range / result->kcountsize;

      if (quot >= SCALE_1_TO_1)
	result->s_scale = 1;
      else if (quot >= SCALE_1_TO_1 / 256)
	result->s_scale = SCALE_1_TO_1 / quot;
      else if (range > ULONG_MAX / 256)
	result->s_scale = ((SCALE_1_TO_1 * 256)
			   / (range / (result->kcountsize / 256)));
      else
	result->s_scale = ((SCALE_1_TO_1 * 256)
			   / ((range * 256) / result->kcountsize));
    }
  else
    result->s_scale = SCALE_1_TO_1;

  if (do_test)
    printf ("s_scale: %d\n", result->s_scale);

  /* Determine the dynamic string table.  */
  if (map->l_info[DT_STRTAB] == NULL)
    result->dynstrtab = NULL;
  else
    result->dynstrtab = (const char *) D_PTR (map, l_info[DT_STRTAB]);
  if (do_test)
    printf ("string table: %p\n", result->dynstrtab);

  /* Determine the soname.  */
  if (map->l_info[DT_SONAME] == NULL)
    result->soname = NULL;
  else
    result->soname = result->dynstrtab + map->l_info[DT_SONAME]->d_un.d_val;
  if (do_test && result->soname != NULL)
    printf ("soname: %s\n", result->soname);

  /* Now we have to load the symbol table.

     First load the section header table.  */
  ehdr = (ElfW(Ehdr) *) map->l_map_start;

  /* Make sure we are on the right party.  */
  if (ehdr->e_shentsize != sizeof (ElfW(Shdr)))
    abort ();

  /* And we need the shared object file descriptor again.  */
  fd = open (map->l_name, O_RDONLY);
  if (fd == -1)
    /* Dooh, this really shouldn't happen.  We know the file is available.  */
    error (EXIT_FAILURE, errno, _("Reopening shared object `%s' failed"),
	   map->l_name);

  /* Now map the section header.  */
  ptr = mmap (NULL, (ehdr->e_shnum * sizeof (ElfW(Shdr))
		     + (ehdr->e_shoff & (pagesize - 1))), PROT_READ,
	      MAP_SHARED|MAP_FILE, fd, ehdr->e_shoff & ~(pagesize - 1));
  if (ptr == MAP_FAILED)
    error (EXIT_FAILURE, errno, _("mapping of section headers failed"));
  shdr = (ElfW(Shdr) *) ((char *) ptr + (ehdr->e_shoff & (pagesize - 1)));

  /* Get the section header string table.  */
  ptr = mmap (NULL, (shdr[ehdr->e_shstrndx].sh_size
		     + (shdr[ehdr->e_shstrndx].sh_offset & (pagesize - 1))),
	      PROT_READ, MAP_SHARED|MAP_FILE, fd,
	      shdr[ehdr->e_shstrndx].sh_offset & ~(pagesize - 1));
  if (ptr == MAP_FAILED)
    error (EXIT_FAILURE, errno,
	   _("mapping of section header string table failed"));
  shstrtab = ((const char *) ptr
	      + (shdr[ehdr->e_shstrndx].sh_offset & (pagesize - 1)));

  /* Search for the ".symtab" section.  */
  symtab_entry = NULL;
  for (idx = 0; idx < ehdr->e_shnum; ++idx)
    if (shdr[idx].sh_type == SHT_SYMTAB
	&& strcmp (shstrtab + shdr[idx].sh_name, ".symtab") == 0)
      {
	symtab_entry = &shdr[idx];
	break;
      }

  /* We don't need the section header string table anymore.  */
  munmap (ptr, (shdr[ehdr->e_shstrndx].sh_size
		+ (shdr[ehdr->e_shstrndx].sh_offset & (pagesize - 1))));

  if (symtab_entry == NULL)
    {
      fprintf (stderr, _("\
*** The file `%s' is stripped: no detailed analysis possible\n"),
	      name);
      result->symtab = NULL;
      result->strtab = NULL;
    }
  else
    {
      ElfW(Off) min_offset, max_offset;
      ElfW(Shdr) *strtab_entry;

      strtab_entry = &shdr[symtab_entry->sh_link];

      /* Find the minimum and maximum offsets that include both the symbol
	 table and the string table.  */
      if (symtab_entry->sh_offset < strtab_entry->sh_offset)
	{
	  min_offset = symtab_entry->sh_offset & ~(pagesize - 1);
	  max_offset = strtab_entry->sh_offset + strtab_entry->sh_size;
	}
      else
	{
	  min_offset = strtab_entry->sh_offset & ~(pagesize - 1);
	  max_offset = symtab_entry->sh_offset + symtab_entry->sh_size;
	}

      result->symbol_map = mmap (NULL, max_offset - min_offset,
				 PROT_READ, MAP_SHARED|MAP_FILE, fd,
				 min_offset);
      if (result->symbol_map == NULL)
	error (EXIT_FAILURE, errno, _("failed to load symbol data"));

      result->symtab
	= (const ElfW(Sym) *) ((const char *) result->symbol_map
			       + (symtab_entry->sh_offset - min_offset));
      result->symtab_size = symtab_entry->sh_size;
      result->strtab = ((const char *) result->symbol_map
			+ (strtab_entry->sh_offset - min_offset));
      result->symbol_mapsize = max_offset - min_offset;
    }

  /* Now we also don't need the section header table anymore.  */
  munmap ((char *) shdr - (ehdr->e_shoff & (pagesize - 1)),
	  (ehdr->e_phnum * sizeof (ElfW(Shdr))
	   + (ehdr->e_shoff & (pagesize - 1))));

  /* Free the descriptor for the shared object.  */
  close (fd);

  return result;
}


static void
unload_shobj (struct shobj *shobj)
{
  munmap (shobj->symbol_map, shobj->symbol_mapsize);
  dlclose (shobj->map);
}


static struct profdata *
load_profdata (const char *name, struct shobj *shobj)
{
  struct profdata *result;
  int fd;
  struct stat st;
  void *addr;
  struct gmon_hdr gmon_hdr;
  struct gmon_hist_hdr hist_hdr;
  uint32_t *narcsp;
  size_t fromlimit;
  struct here_cg_arc_record *data;
  struct here_fromstruct *froms;
  uint16_t *tos;
  size_t fromidx;
  size_t idx;

  fd = open (name, O_RDONLY);
  if (fd == -1)
    {
      char *ext_name;

      if (errno != ENOENT || strchr (name, '/') != NULL)
	/* The file exists but we are not allowed to read it or the
	   file does not exist and the name includes a path
	   specification..  */
	return NULL;

      /* A file with the given name does not exist in the current
	 directory, try it in the default location where the profiling
	 files are created.  */
      ext_name = (char *) alloca (strlen (name) + sizeof "/var/tmp/");
      stpcpy (stpcpy (ext_name, "/var/tmp/"), name);
      name = ext_name;

      fd = open (ext_name, O_RDONLY);
      if (fd == -1)
	{
	  /* Even this file does not exist.  */
	  error (0, errno, _("cannot load profiling data"));
	  return NULL;
	}
    }

  /* We have found the file, now make sure it is the right one for the
     data file.  */
  if (fstat (fd, &st) < 0)
    {
      error (0, errno, _("while stat'ing profiling data file"));
      close (fd);
      return NULL;
    }

  if ((size_t) st.st_size != shobj->expected_size)
    {
      error (0, 0,
	     _("profiling data file `%s' does not match shared object `%s'"),
	     name, shobj->name);
      close (fd);
      return NULL;
    }

  /* The data file is most probably the right one for our shared
     object.  Map it now.  */
  addr = mmap (NULL, st.st_size, PROT_READ, MAP_SHARED|MAP_FILE, fd, 0);
  if (addr == MAP_FAILED)
    {
      error (0, errno, _("failed to mmap the profiling data file"));
      close (fd);
      return NULL;
    }

  /* We don't need the file desriptor anymore.  */
  if (close (fd) < 0)
    {
      error (0, errno, _("error while closing the profiling data file"));
      munmap (addr, st.st_size);
      return NULL;
    }

  /* Prepare the result.  */
  result = (struct profdata *) calloc (1, sizeof (struct profdata));
  if (result == NULL)
    {
      error (0, errno, _("cannot create internal descriptor"));
      munmap (addr, st.st_size);
      return NULL;
    }

  /* Store the address and size so that we can later free the resources.  */
  result->addr = addr;
  result->size = st.st_size;

  /* Pointer to data after the header.  */
  result->hist = (char *) ((struct gmon_hdr *) addr + 1);
  result->hist_hdr = (struct gmon_hist_hdr *) ((char *) result->hist
					       + sizeof (uint32_t));
  result->kcount = (uint16_t *) ((char *) result->hist + sizeof (uint32_t)
				 + sizeof (struct gmon_hist_hdr));

  /* Compute pointer to array of the arc information.  */
  narcsp = (uint32_t *) ((char *) result->kcount + shobj->kcountsize
			 + sizeof (uint32_t));
  result->narcs = *narcsp;
  result->data = (struct here_cg_arc_record *) ((char *) narcsp
						+ sizeof (uint32_t));

  /* Create the gmon_hdr we expect or write.  */
  memset (&gmon_hdr, '\0', sizeof (struct gmon_hdr));
  memcpy (&gmon_hdr.cookie[0], GMON_MAGIC, sizeof (gmon_hdr.cookie));
  *(int32_t *) gmon_hdr.version = GMON_SHOBJ_VERSION;

  /* Create the hist_hdr we expect or write.  */
  *(char **) hist_hdr.low_pc = (char *) shobj->lowpc - shobj->map->l_addr;
  *(char **) hist_hdr.high_pc = (char *) shobj->highpc - shobj->map->l_addr;
  if (do_test)
    printf ("low_pc = %p\nhigh_pc = %p\n",
	    *(char **) hist_hdr.low_pc, *(char **) hist_hdr.high_pc);
  *(int32_t *) hist_hdr.hist_size = shobj->kcountsize / sizeof (HISTCOUNTER);
  *(int32_t *) hist_hdr.prof_rate = __profile_frequency ();
  strncpy (hist_hdr.dimen, "seconds", sizeof (hist_hdr.dimen));
  hist_hdr.dimen_abbrev = 's';

  /* Test whether the header of the profiling data is ok.  */
  if (memcmp (addr, &gmon_hdr, sizeof (struct gmon_hdr)) != 0
      || *(uint32_t *) result->hist != GMON_TAG_TIME_HIST
      || memcmp (result->hist_hdr, &hist_hdr,
		 sizeof (struct gmon_hist_hdr)) != 0
      || narcsp[-1] != GMON_TAG_CG_ARC)
    {
      error (0, 0, _("`%s' is no correct profile data file for `%s'"),
	     name, shobj->name);
      if (do_test)
	{
	  if (memcmp (addr, &gmon_hdr, sizeof (struct gmon_hdr)) != 0)
	    puts ("gmon_hdr differs");
	  if (*(uint32_t *) result->hist != GMON_TAG_TIME_HIST)
	    puts ("result->hist differs");
	  if (memcmp (result->hist_hdr, &hist_hdr,
		      sizeof (struct gmon_hist_hdr)) != 0)
	    puts ("hist_hdr differs");
	  if (narcsp[-1] != GMON_TAG_CG_ARC)
	    puts ("narcsp[-1] differs");
	}
      free (result);
      munmap (addr, st.st_size);
      return NULL;
    }

  /* We are pretty sure now that this is a correct input file.  Set up
     the remaining information in the result structure and return.  */
  result->tos = (uint16_t *) calloc (shobj->tossize + shobj->fromssize, 1);
  if (result->tos == NULL)
    {
      error (0, errno, _("cannot create internal descriptor"));
      munmap (addr, st.st_size);
      free (result);
      return NULL;
    }

  result->froms = (struct here_fromstruct *) ((char *) result->tos
					      + shobj->tossize);
  fromidx = 0;

  /* Now we have to process all the arc count entries.  */
  fromlimit = shobj->fromlimit;
  data = result->data;
  froms = result->froms;
  tos = result->tos;
  for (idx = 0; idx < MIN (*narcsp, fromlimit); ++idx)
    {
      size_t to_index;
      size_t newfromidx;
      to_index = (data[idx].self_pc / (shobj->hashfraction * sizeof (*tos)));
      newfromidx = fromidx++;
      froms[newfromidx].here = &data[idx];
      froms[newfromidx].link = tos[to_index];
      tos[to_index] = newfromidx;
    }

  return result;
}


static void
unload_profdata (struct profdata *profdata)
{
  free (profdata->tos);
  munmap (profdata->addr, profdata->size);
  free (profdata);
}


static void
count_total_ticks (struct shobj *shobj, struct profdata *profdata)
{
  volatile uint16_t *kcount = profdata->kcount;
  size_t maxkidx = shobj->kcountsize;
  size_t factor = 2 * (65536 / shobj->s_scale);
  size_t kidx = 0;
  size_t sidx = 0;

  while (sidx < symidx)
    {
      uintptr_t start = sortsym[sidx]->addr;
      uintptr_t end = start + sortsym[sidx]->size;

      while (kidx < maxkidx && factor * kidx < start)
	++kidx;
      if (kidx == maxkidx)
	break;

      while (kidx < maxkidx && factor * kidx < end)
	sortsym[sidx]->ticks += kcount[kidx++];
      if (kidx == maxkidx)
	break;

      total_ticks += sortsym[sidx++]->ticks;
    }
}


static size_t
find_symbol (uintptr_t addr)
{
  size_t sidx = 0;

  while (sidx < symidx)
    {
      uintptr_t start = sortsym[sidx]->addr;
      uintptr_t end = start + sortsym[sidx]->size;

      if (addr >= start && addr < end)
	return sidx;

      if (addr < start)
	break;

      ++sidx;
    }

  return (size_t) -1l;
}


static void
count_calls (struct shobj *shobj, struct profdata *profdata)
{
  struct here_cg_arc_record *data = profdata->data;
  uint32_t narcs = profdata->narcs;
  uint32_t cnt;

  for (cnt = 0; cnt < narcs; ++cnt)
    {
      uintptr_t here = data[cnt].self_pc;
      size_t symbol_idx;

      /* Find the symbol for this address.  */
      symbol_idx = find_symbol (here);
      if (symbol_idx != (size_t) -1l)
	sortsym[symbol_idx]->calls += data[cnt].count;
    }
}


static int
symorder (const void *o1, const void *o2)
{
  const struct known_symbol *p1 = (const struct known_symbol *) o1;
  const struct known_symbol *p2 = (const struct known_symbol *) o2;

  return p1->addr - p2->addr;
}


static void
printsym (const void *node, VISIT value, int level)
{
  if (value == leaf || value == postorder)
    sortsym[symidx++] = *(struct known_symbol **) node;
}


static void
read_symbols (struct shobj *shobj)
{
  int n = 0;

  /* Initialize the obstacks.  */
#define obstack_chunk_alloc malloc
#define obstack_chunk_free free
  obstack_init (&shobj->ob_str);
  obstack_init (&shobj->ob_sym);
  obstack_init (&ob_list);

  /* Process the symbols.  */
  if (shobj->symtab != NULL)
    {
      const ElfW(Sym) *sym = shobj->symtab;
      const ElfW(Sym) *sym_end
	= (const ElfW(Sym) *) ((const char *) sym + shobj->symtab_size);
      for (; sym < sym_end; sym++)
	if ((ELFW(ST_TYPE) (sym->st_info) == STT_FUNC
	     || ELFW(ST_TYPE) (sym->st_info) == STT_NOTYPE)
	    && sym->st_size != 0)
	  {
	    struct known_symbol **existp;
	    struct known_symbol *newsym
	      = (struct known_symbol *) obstack_alloc (&shobj->ob_sym,
						       sizeof (*newsym));
	    if (newsym == NULL)
	      error (EXIT_FAILURE, errno, _("cannot allocate symbol data"));

	    newsym->name = &shobj->strtab[sym->st_name];
	    newsym->addr = sym->st_value;
	    newsym->size = sym->st_size;
	    newsym->ticks = 0;
	    newsym->calls = 0;

	    existp = tfind (newsym, &symroot, symorder);
	    if (existp == NULL)
	      {
		/* New function.  */
		tsearch (newsym, &symroot, symorder);
		++n;
	      }
	    else
	      {
		/* The function is already defined.  See whether we have
		   a better name here.  */
		if ((*existp)->name[0] == '_' && newsym->name[0] != '_')
		  *existp = newsym;
		else
		  /* We don't need the allocated memory.  */
		  obstack_free (&shobj->ob_sym, newsym);
	      }
	  }
    }
  else
    {
      /* Blarg, the binary is stripped.  We have to rely on the
	 information contained in the dynamic section of the object.  */
      const ElfW(Sym) *symtab = (ElfW(Sym) *) D_PTR (shobj->map,
						     l_info[DT_SYMTAB]);
      const char *strtab = (const char *) D_PTR (shobj->map,
						 l_info[DT_STRTAB]);

      /* We assume that the string table follows the symbol table,
	 because there is no way in ELF to know the size of the
	 dynamic symbol table without looking at the section headers.  */
      while ((void *) symtab < (void *) strtab)
	{
	  if ((ELFW(ST_TYPE)(symtab->st_info) == STT_FUNC
	       || ELFW(ST_TYPE)(symtab->st_info) == STT_NOTYPE)
	      && symtab->st_size != 0)
	    {
	      struct known_symbol *newsym;
	      struct known_symbol **existp;

	      newsym =
		(struct known_symbol *) obstack_alloc (&shobj->ob_sym,
						       sizeof (*newsym));
	      if (newsym == NULL)
		error (EXIT_FAILURE, errno, _("cannot allocate symbol data"));

	      newsym->name = &strtab[symtab->st_name];
	      newsym->addr = symtab->st_value;
	      newsym->size = symtab->st_size;
	      newsym->ticks = 0;
	      newsym->froms = NULL;
	      newsym->tos = NULL;

	      existp = tfind (newsym, &symroot, symorder);
	      if (existp == NULL)
		{
		  /* New function.  */
		  tsearch (newsym, &symroot, symorder);
		  ++n;
		}
	      else
		{
		  /* The function is already defined.  See whether we have
		     a better name here.  */
		  if ((*existp)->name[0] == '_' && newsym->name[0] != '_')
		    *existp = newsym;
		  else
		    /* We don't need the allocated memory.  */
		    obstack_free (&shobj->ob_sym, newsym);
		}
	    }

	  ++symtab;
	}
    }

  sortsym = malloc (n * sizeof (struct known_symbol *));
  if (sortsym == NULL)
    abort ();

  twalk (symroot, printsym);
}


static void
add_arcs (struct profdata *profdata)
{
  uint32_t narcs = profdata->narcs;
  struct here_cg_arc_record *data = profdata->data;
  uint32_t cnt;

  for (cnt = 0; cnt < narcs; ++cnt)
    {
      /* First add the incoming arc.  */
      size_t sym_idx = find_symbol (data[cnt].self_pc);

      if (sym_idx != (size_t) -1l)
	{
	  struct known_symbol *sym = sortsym[sym_idx];
	  struct arc_list *runp = sym->froms;

	  while (runp != NULL
		 && ((data[cnt].from_pc == 0 && runp->idx != (size_t) -1l)
		     || (data[cnt].from_pc != 0
			 && (runp->idx == (size_t) -1l
			     || data[cnt].from_pc < sortsym[runp->idx]->addr
			     || (data[cnt].from_pc
				 >= (sortsym[runp->idx]->addr
				     + sortsym[runp->idx]->size))))))
	    runp = runp->next;

	  if (runp == NULL)
	    {
	      /* We need a new entry.  */
	      struct arc_list *newp = (struct arc_list *)
		obstack_alloc (&ob_list, sizeof (struct arc_list));

	      if (data[cnt].from_pc == 0)
		newp->idx = (size_t) -1l;
	      else
		newp->idx = find_symbol (data[cnt].from_pc);
	      newp->count = data[cnt].count;
	      newp->next = sym->froms;
	      sym->froms = newp;
	    }
	  else
	    /* Increment the counter for the found entry.  */
	    runp->count += data[cnt].count;
	}

      /* Now add it to the appropriate outgoing list.  */
      sym_idx = find_symbol (data[cnt].from_pc);
      if (sym_idx != (size_t) -1l)
	{
	  struct known_symbol *sym = sortsym[sym_idx];
	  struct arc_list *runp = sym->tos;

	  while (runp != NULL
		 && (runp->idx == (size_t) -1l
		     || data[cnt].self_pc < sortsym[runp->idx]->addr
		     || data[cnt].self_pc >= (sortsym[runp->idx]->addr
					      + sortsym[runp->idx]->size)))
	    runp = runp->next;

	  if (runp == NULL)
	    {
	      /* We need a new entry.  */
	      struct arc_list *newp = (struct arc_list *)
		obstack_alloc (&ob_list, sizeof (struct arc_list));

	      newp->idx = find_symbol (data[cnt].self_pc);
	      newp->count = data[cnt].count;
	      newp->next = sym->tos;
	      sym->tos = newp;
	    }
	  else
	    /* Increment the counter for the found entry.  */
	    runp->count += data[cnt].count;
	}
    }
}


static int
countorder (const void *p1, const void *p2)
{
  struct known_symbol *s1 = (struct known_symbol *) p1;
  struct known_symbol *s2 = (struct known_symbol *) p2;

  if (s1->ticks != s2->ticks)
    return (int) (s2->ticks - s1->ticks);

  if (s1->calls != s2->calls)
    return (int) (s2->calls - s1->calls);

  return strcmp (s1->name, s2->name);
}


static double tick_unit;
static uintmax_t cumu_ticks;

static void
printflat (const void *node, VISIT value, int level)
{
  if (value == leaf || value == postorder)
    {
      struct known_symbol *s = *(struct known_symbol **) node;

      cumu_ticks += s->ticks;

      printf ("%6.2f%10.2f%9.2f%9" PRIdMAX "%9.2f           %s\n",
	      total_ticks ? (100.0 * s->ticks) / total_ticks : 0.0,
	      tick_unit * cumu_ticks,
	      tick_unit * s->ticks,
	      s->calls,
	      s->calls ? (s->ticks * 1000000) * tick_unit / s->calls : 0,
	      /* FIXME: don't know about called functions.  */
	      s->name);
    }
}


/* ARGUSED */
static void
freenoop (void *p)
{
}


static void
generate_flat_profile (struct profdata *profdata)
{
  size_t n;
  void *data = NULL;

  tick_unit = 1.0 / *(uint32_t *) profdata->hist_hdr->prof_rate;

  printf ("Flat profile:\n\n"
	  "Each sample counts as %g %s.\n",
	  tick_unit, profdata->hist_hdr->dimen);
  fputs ("  %   cumulative   self              self     total\n"
	 " time   seconds   seconds    calls  us/call  us/call  name\n",
	 stdout);

  for (n = 0; n < symidx; ++n)
    if (sortsym[n]->calls != 0 || sortsym[n]->ticks != 0)
      tsearch (sortsym[n], &data, countorder);

  twalk (data, printflat);

  tdestroy (data, freenoop);
}


static void
generate_call_graph (struct profdata *profdata)
{
  size_t cnt;

  puts ("\nindex % time    self  children    called     name\n");

  for (cnt = 0; cnt < symidx; ++cnt)
    if (sortsym[cnt]->froms != NULL || sortsym[cnt]->tos != NULL)
      {
	struct arc_list *runp;
	size_t n;

	/* First print the from-information.  */
	runp = sortsym[cnt]->froms;
	while (runp != NULL)
	  {
	    printf ("            %8.2f%8.2f%9" PRIdMAX "/%-9" PRIdMAX "   %s",
		    (runp->idx != (size_t) -1l
		     ? sortsym[runp->idx]->ticks * tick_unit : 0.0),
		    0.0, /* FIXME: what's time for the children, recursive */
		    runp->count, sortsym[cnt]->calls,
		    (runp->idx != (size_t) -1l ?
		     sortsym[runp->idx]->name : "<UNKNOWN>"));

	    if (runp->idx != (size_t) -1l)
	      printf (" [%Zd]", runp->idx);
	    putchar_unlocked ('\n');

	    runp = runp->next;
	  }

	/* Info abount the function itself.  */
	n = printf ("[%Zu]", cnt);
	printf ("%*s%5.1f%8.2f%8.2f%9" PRIdMAX "         %s [%Zd]\n",
		(int) (7 - n), " ",
		total_ticks ? (100.0 * sortsym[cnt]->ticks) / total_ticks : 0,
		sortsym[cnt]->ticks * tick_unit,
		0.0, /* FIXME: what's time for the children, recursive */
		sortsym[cnt]->calls,
		sortsym[cnt]->name, cnt);

	/* Info about the functions this function calls.  */
	runp = sortsym[cnt]->tos;
	while (runp != NULL)
	  {
	    printf ("            %8.2f%8.2f%9" PRIdMAX "/",
		    (runp->idx != (size_t) -1l
		     ? sortsym[runp->idx]->ticks * tick_unit : 0.0),
		    0.0, /* FIXME: what's time for the children, recursive */
		    runp->count);

	    if (runp->idx != (size_t) -1l)
	      printf ("%-9" PRIdMAX "   %s [%Zd]\n",
		      sortsym[runp->idx]->calls,
		      sortsym[runp->idx]->name,
		      runp->idx);
	    else
	      fputs ("???         <UNKNOWN>\n\n", stdout);

	    runp = runp->next;
	  }

	fputs ("-----------------------------------------------\n", stdout);
      }
}


static void
generate_call_pair_list (struct profdata *profdata)
{
  size_t cnt;

  for (cnt = 0; cnt < symidx; ++cnt)
    if (sortsym[cnt]->froms != NULL || sortsym[cnt]->tos != NULL)
      {
	struct arc_list *runp;

	/* First print the incoming arcs.  */
	runp = sortsym[cnt]->froms;
	while (runp != NULL)
	  {
	    if (runp->idx == (size_t) -1l)
	      printf ("\
<UNKNOWN>                          %-34s %9" PRIdMAX "\n",
		      sortsym[cnt]->name, runp->count);
	    runp = runp->next;
	  }

	/* Next the outgoing arcs.  */
	runp = sortsym[cnt]->tos;
	while (runp != NULL)
	  {
	    printf ("%-34s %-34s %9" PRIdMAX "\n",
		    sortsym[cnt]->name,
		    (runp->idx != (size_t) -1l
		     ? sortsym[runp->idx]->name : "<UNKNOWN>"),
		    runp->count);
	    runp = runp->next;
	  }
      }
}