aboutsummaryrefslogtreecommitdiff
path: root/gdb/solib-aix5.c
blob: 314408ec3687b86f1459fc6e29d1bb477d7f1669 (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
/* Handle AIX5 shared libraries for GDB, the GNU Debugger.
   Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000,
   2001
   Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program 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 General Public License for more details.

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

#include "defs.h"

#include <sys/types.h>
#include <signal.h>
#include "gdb_string.h"
#include <sys/param.h>
#include <fcntl.h>
#include <sys/procfs.h>

#include "elf/external.h"

#include "symtab.h"
#include "bfd.h"
#include "symfile.h"
#include "objfiles.h"
#include "gdbcore.h"
#include "command.h"
#include "target.h"
#include "frame.h"
#include "gdb_regex.h"
#include "inferior.h"
#include "environ.h"
#include "language.h"
#include "gdbcmd.h"

#include "solist.h"

/* Link map info to include in an allocated so_list entry */

struct lm_info
  {
    int nmappings;		/* number of mappings */
    struct lm_mapping
      {
	CORE_ADDR addr;		/* base address */
	CORE_ADDR size;		/* size of mapped object */
	CORE_ADDR offset;	/* offset into mapped object */
	long flags;		/* MA_ protection and attribute flags */
	CORE_ADDR gp;		/* global pointer value */
      } *mapping;
      char *mapname;		/* name in /proc/pid/object */
      char *pathname;		/* full pathname to object */
      char *membername;		/* member name in archive file */
  };

/* List of symbols in the dynamic linker where GDB can try to place
   a breakpoint to monitor shared library events. */

static char *solib_break_names[] =
{
  "_r_debug_state",
  NULL
};

static void aix5_relocate_main_executable (void);

/*

   LOCAL FUNCTION

   bfd_lookup_symbol -- lookup the value for a specific symbol

   SYNOPSIS

   CORE_ADDR bfd_lookup_symbol (bfd *abfd, char *symname)

   DESCRIPTION

   An expensive way to lookup the value of a single symbol for
   bfd's that are only temporary anyway.  This is used by the
   shared library support to find the address of the debugger
   interface structures in the shared library.

   Note that 0 is specifically allowed as an error return (no
   such symbol).
 */

static CORE_ADDR
bfd_lookup_symbol (bfd *abfd, char *symname)
{
  long storage_needed;
  asymbol *sym;
  asymbol **symbol_table;
  unsigned int number_of_symbols;
  unsigned int i;
  struct cleanup *back_to;
  CORE_ADDR symaddr = 0;

  storage_needed = bfd_get_symtab_upper_bound (abfd);

  if (storage_needed > 0)
    {
      symbol_table = (asymbol **) xmalloc (storage_needed);
      back_to = make_cleanup (xfree, symbol_table);
      number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);

      for (i = 0; i < number_of_symbols; i++)
	{
	  sym = *symbol_table++;
	  if (strcmp (sym->name, symname) == 0)
	    {
	      /* Bfd symbols are section relative. */
	      symaddr = sym->value + sym->section->vma;
	      break;
	    }
	}
      do_cleanups (back_to);
    }

  if (symaddr)
    return symaddr;

  /* Look for the symbol in the dynamic string table too.  */

  storage_needed = bfd_get_dynamic_symtab_upper_bound (abfd);

  if (storage_needed > 0)
    {
      symbol_table = (asymbol **) xmalloc (storage_needed);
      back_to = make_cleanup (xfree, symbol_table);
      number_of_symbols = bfd_canonicalize_dynamic_symtab (abfd, symbol_table);

      for (i = 0; i < number_of_symbols; i++)
	{
	  sym = *symbol_table++;
	  if (strcmp (sym->name, symname) == 0)
	    {
	      /* Bfd symbols are section relative. */
	      symaddr = sym->value + sym->section->vma;
	      break;
	    }
	}
      do_cleanups (back_to);
    }

  return symaddr;
}


/* Read /proc/PID/map and build a list of shared objects such that
   the pr_mflags value AND'd with MATCH_MASK is equal to MATCH_VAL.
   This gives us a convenient way to find all of the mappings that
   don't belong to the main executable or vice versa.  Here are
   some of the possibilities:

    - Fetch all mappings:
        MATCH_MASK: 0
        MATCH_VAL: 0
    - Fetch all mappings except for main executable:
        MATCH_MASK: MA_MAINEXEC
	MATCH_VAL: 0
    - Fetch only main executable:
        MATCH_MASK: MA_MAINEXEC
	MATCH_VAL: MA_MAINEXEC
	
   A cleanup chain for the list allocations done by this function should
   be established prior to calling build_so_list_from_mapfile().  */

static struct so_list *
build_so_list_from_mapfile (int pid, long match_mask, long match_val)
{
  char *mapbuf = NULL;
  struct prmap *prmap;
  int mapbuf_size;
  struct so_list *sos = NULL;

  {
    int mapbuf_allocation_size = 8192;
    char *map_pathname;
    int map_fd;

    /* Open the map file */

    xasprintf (&map_pathname, "/proc/%d/map", pid);
    map_fd = open (map_pathname, O_RDONLY);
    xfree (map_pathname);
    if (map_fd < 0)
      return 0;

    /* Read the entire map file in */
    do
      {
	if (mapbuf)
	  {
	    xfree (mapbuf);
	    mapbuf_allocation_size *= 2;
	    lseek (map_fd, 0, SEEK_SET);
	  }
	mapbuf = xmalloc (mapbuf_allocation_size);
	mapbuf_size = read (map_fd, mapbuf, mapbuf_allocation_size);
	if (mapbuf_size < 0)
	  {
	    xfree (mapbuf);
	    /* FIXME: This warrants an error or a warning of some sort */
	    return 0;
	  }
      } while (mapbuf_size == mapbuf_allocation_size);

    close (map_fd);
  }

  for (prmap = (struct prmap *) mapbuf;
       (char *) prmap < mapbuf + mapbuf_size;
       prmap++)
    {
      char *mapname, *pathname, *membername;
      struct so_list *sop;
      int mapidx;

      if (prmap->pr_size == 0)
	break;

      /* Skip to the next entry if there's no path associated with the
         map, unless we're looking for the kernel text region, in which
	 case it's okay if there's no path.  */
      if ((prmap->pr_pathoff == 0 || prmap->pr_pathoff >= mapbuf_size)
	  && ((match_mask & MA_KERNTEXT) == 0))
	continue;

      /* Skip to the next entry if our match conditions don't hold.  */
      if ((prmap->pr_mflags & match_mask) != match_val)
	continue;

      mapname = prmap->pr_mapname;
      if (prmap->pr_pathoff == 0)
        {
	  pathname = "";
	  membername = "";
	}
      else
        {
	  pathname = mapbuf + prmap->pr_pathoff;
	  membername = pathname + strlen (pathname) + 1;
        }

      for (sop = sos; sop != NULL; sop = sop->next)
	if (strcmp (pathname, sop->lm_info->pathname) == 0
	    && strcmp (membername, sop->lm_info->membername) == 0)
	  break;

      if (sop == NULL)
	{
	  sop = xcalloc (sizeof (struct so_list), 1);
	  make_cleanup (xfree, sop);
	  sop->lm_info = xcalloc (sizeof (struct lm_info), 1);
	  make_cleanup (xfree, sop->lm_info);
	  sop->lm_info->mapname = xstrdup (mapname);
	  make_cleanup (xfree, sop->lm_info->mapname);
	  /* FIXME: Eliminate the pathname field once length restriction
	     is lifted on so_name and so_original_name.  */
	  sop->lm_info->pathname = xstrdup (pathname);
	  make_cleanup (xfree, sop->lm_info->pathname);
	  sop->lm_info->membername = xstrdup (membername);
	  make_cleanup (xfree, sop->lm_info->membername);

	  strncpy (sop->so_name, pathname, SO_NAME_MAX_PATH_SIZE - 1);
	  sop->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
	  strcpy (sop->so_original_name, sop->so_name);

	  sop->next = sos;
	  sos = sop;
	}

      mapidx = sop->lm_info->nmappings;
      sop->lm_info->nmappings += 1;
      sop->lm_info->mapping 
	= xrealloc (sop->lm_info->mapping,
	            sop->lm_info->nmappings * sizeof (struct lm_mapping));
      sop->lm_info->mapping[mapidx].addr = (CORE_ADDR) prmap->pr_vaddr;
      sop->lm_info->mapping[mapidx].size = prmap->pr_size;
      sop->lm_info->mapping[mapidx].offset = prmap->pr_off;
      sop->lm_info->mapping[mapidx].flags = prmap->pr_mflags;
      sop->lm_info->mapping[mapidx].gp = (CORE_ADDR) prmap->pr_gp;
    }

  xfree (mapbuf);
  return sos;
}

/*

  LOCAL FUNCTION

  open_symbol_file_object

  SYNOPSIS

  void open_symbol_file_object (void *from_tty)

  DESCRIPTION

  If no open symbol file, attempt to locate and open the main symbol
  file.

  If FROM_TTYP dereferences to a non-zero integer, allow messages to
  be printed.  This parameter is a pointer rather than an int because
  open_symbol_file_object() is called via catch_errors() and
  catch_errors() requires a pointer argument. */

static int
open_symbol_file_object (void *from_ttyp)
{
  CORE_ADDR lm, l_name;
  char *filename;
  int errcode;
  int from_tty = *(int *)from_ttyp;
  struct cleanup *old_chain = make_cleanup (null_cleanup, 0);
  struct so_list *sos;

  sos = build_so_list_from_mapfile (PIDGET (inferior_pid),
                                    MA_MAINEXEC, MA_MAINEXEC);


  if (sos == NULL)
    {
      warning ("Could not find name of main executable in map file");
      return 0;
    }

  symbol_file_command (sos->lm_info->pathname, from_tty);

  do_cleanups (old_chain);

  aix5_relocate_main_executable ();

  return 1;
}

/* LOCAL FUNCTION

   aix5_current_sos -- build a list of currently loaded shared objects

   SYNOPSIS

   struct so_list *aix5_current_sos ()

   DESCRIPTION

   Build a list of `struct so_list' objects describing the shared
   objects currently loaded in the inferior.  This list does not
   include an entry for the main executable file.

   Note that we only gather information directly available from the
   inferior --- we don't examine any of the shared library files
   themselves.  The declaration of `struct so_list' says which fields
   we provide values for.  */

static struct so_list *
aix5_current_sos (void)
{
  struct cleanup *old_chain = make_cleanup (null_cleanup, 0);
  struct so_list *sos;

  /* Fetch the list of mappings, excluding the main executable. */
  sos = build_so_list_from_mapfile (PIDGET (inferior_pid), MA_MAINEXEC, 0);

  /* Reverse the list; it looks nicer when we print it if the mappings
     are in the same order as in the map file.  */
  if (sos)
    {
      struct so_list *next = sos->next;

      sos->next = 0;
      while (next)
	{
	  struct so_list *prev = sos;

	  sos = next;
	  next = next->next;
	  sos->next = prev;
	}
    }
  discard_cleanups (old_chain);
  return sos;
}


/* Return 1 if PC lies in the dynamic symbol resolution code of the
   run time loader.  */

static CORE_ADDR interp_text_sect_low;
static CORE_ADDR interp_text_sect_high;
static CORE_ADDR interp_plt_sect_low;
static CORE_ADDR interp_plt_sect_high;

static int
aix5_in_dynsym_resolve_code (CORE_ADDR pc)
{
  return ((pc >= interp_text_sect_low && pc < interp_text_sect_high)
	  || (pc >= interp_plt_sect_low && pc < interp_plt_sect_high)
	  || in_plt_section (pc, NULL));
}

/*

   LOCAL FUNCTION

   enable_break -- arrange for dynamic linker to hit breakpoint

   SYNOPSIS

   int enable_break (void)

   DESCRIPTION

   The dynamic linkers has, as part of its debugger interface, support
   for arranging for the inferior to hit a breakpoint after mapping in
   the shared libraries.  This function enables that breakpoint.

 */

static int
enable_break (void)
{
  int success = 0;

  struct minimal_symbol *msymbol;
  char **bkpt_namep;
  asection *interp_sect;

  /* First, remove all the solib event breakpoints.  Their addresses
     may have changed since the last time we ran the program.  */
  remove_solib_event_breakpoints ();

  interp_text_sect_low = interp_text_sect_high = 0;
  interp_plt_sect_low = interp_plt_sect_high = 0;

  /* Find the .interp section; if not found, warn the user and drop
     into the old breakpoint at symbol code.  */
  interp_sect = bfd_get_section_by_name (exec_bfd, ".interp");
  if (interp_sect)
    {
      unsigned int interp_sect_size;
      char *buf;
      CORE_ADDR load_addr;
      bfd *tmp_bfd;
      CORE_ADDR sym_addr = 0;

      /* Read the contents of the .interp section into a local buffer;
         the contents specify the dynamic linker this program uses.  */
      interp_sect_size = bfd_section_size (exec_bfd, interp_sect);
      buf = alloca (interp_sect_size);
      bfd_get_section_contents (exec_bfd, interp_sect,
				buf, 0, interp_sect_size);

      /* Now we need to figure out where the dynamic linker was
         loaded so that we can load its symbols and place a breakpoint
         in the dynamic linker itself.

         This address is stored on the stack.  However, I've been unable
         to find any magic formula to find it for Solaris (appears to
         be trivial on GNU/Linux).  Therefore, we have to try an alternate
         mechanism to find the dynamic linker's base address.  */
      tmp_bfd = bfd_openr (buf, gnutarget);
      if (tmp_bfd == NULL)
	goto bkpt_at_symbol;

      /* Make sure the dynamic linker's really a useful object.  */
      if (!bfd_check_format (tmp_bfd, bfd_object))
	{
	  warning ("Unable to grok dynamic linker %s as an object file", buf);
	  bfd_close (tmp_bfd);
	  goto bkpt_at_symbol;
	}

      /* We find the dynamic linker's base address by examining the
         current pc (which point at the entry point for the dynamic
         linker) and subtracting the offset of the entry point.  */
      load_addr = read_pc () - tmp_bfd->start_address;

      /* Record the relocated start and end address of the dynamic linker
         text and plt section for aix5_in_dynsym_resolve_code.  */
      interp_sect = bfd_get_section_by_name (tmp_bfd, ".text");
      if (interp_sect)
	{
	  interp_text_sect_low =
	    bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
	  interp_text_sect_high =
	    interp_text_sect_low + bfd_section_size (tmp_bfd, interp_sect);
	}
      interp_sect = bfd_get_section_by_name (tmp_bfd, ".plt");
      if (interp_sect)
	{
	  interp_plt_sect_low =
	    bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
	  interp_plt_sect_high =
	    interp_plt_sect_low + bfd_section_size (tmp_bfd, interp_sect);
	}

      /* Now try to set a breakpoint in the dynamic linker.  */
      for (bkpt_namep = solib_break_names; *bkpt_namep != NULL; bkpt_namep++)
	{
	  sym_addr = bfd_lookup_symbol (tmp_bfd, *bkpt_namep);
	  if (sym_addr != 0)
	    break;
	}

      /* We're done with the temporary bfd.  */
      bfd_close (tmp_bfd);

      if (sym_addr != 0)
	{
	  create_solib_event_breakpoint (load_addr + sym_addr);
	  return 1;
	}

      /* For whatever reason we couldn't set a breakpoint in the dynamic
         linker.  Warn and drop into the old code.  */
    bkpt_at_symbol:
      warning ("Unable to find dynamic linker breakpoint function.\nGDB will be unable to debug shared library initializers\nand track explicitly loaded dynamic code.");
    }

  /* Nothing good happened.  */
  success = 0;

  return (success);
}

/*

   LOCAL FUNCTION

   special_symbol_handling -- additional shared library symbol handling

   SYNOPSIS

   void special_symbol_handling ()

   DESCRIPTION

   Once the symbols from a shared object have been loaded in the usual
   way, we are called to do any system specific symbol handling that 
   is needed.

 */

static void
aix5_special_symbol_handling (void)
{
  /* Nothing needed (yet) for AIX5. */
}

#define SECTMAPMASK (~ (CORE_ADDR) 0x03ffffff)

static void
aix5_relocate_main_executable (void)
{
  struct so_list *so;
  struct section_offsets *new_offsets;
  int i;
  int changed = 0;
  struct cleanup *old_chain = make_cleanup (null_cleanup, 0);

  /* Fetch the mappings for the main executable from the map file.  */
  so = build_so_list_from_mapfile (PIDGET (inferior_pid),
                                   MA_MAINEXEC, MA_MAINEXEC);

  /* Make sure we actually have some mappings to work with.  */
  if (so == NULL)
    {
      warning ("Could not find main executable in map file");
      do_cleanups (old_chain);
      return;
    }

  /* Allocate the data structure which'll contain the new offsets to
     relocate by.  Initialize it so it contains the current offsets.  */
  new_offsets = xcalloc (sizeof (struct section_offsets),
                         symfile_objfile->num_sections);
  make_cleanup (xfree, new_offsets);
  for (i = 0; i < symfile_objfile->num_sections; i++)
    new_offsets->offsets[i] = ANOFFSET (symfile_objfile->section_offsets, i);

  /* Iterate over the mappings in the main executable and compute
     the new offset value as appropriate.  */
  for (i = 0; i < so->lm_info->nmappings; i++)
    {
      CORE_ADDR increment = 0;
      struct obj_section *sect;
      bfd *obfd = symfile_objfile->obfd;
      struct lm_mapping *mapping = &so->lm_info->mapping[i];

      ALL_OBJFILE_OSECTIONS (symfile_objfile, sect)
	{
	  int flags = bfd_get_section_flags (obfd, sect->the_bfd_section);
	  if (flags & SEC_ALLOC)
	    {
	      file_ptr filepos = sect->the_bfd_section->filepos;
	      if (mapping->offset <= filepos
	          && filepos <= mapping->offset + mapping->size)
		{
		  int idx = sect->the_bfd_section->index;

		  if (increment == 0)
		    increment = mapping->addr
		      - (bfd_section_vma (obfd, sect->the_bfd_section) 
		         & SECTMAPMASK);

		  if (increment != ANOFFSET (new_offsets, idx))
		    {
		      new_offsets->offsets[idx] = increment;
		      changed = 1;
		    }
		}
	    }
	}
    }

  /* If any of the offsets have changed, then relocate the objfile.  */
  if (changed)
    objfile_relocate (symfile_objfile, new_offsets);

  /* Free up all the space we've allocated.  */
  do_cleanups (old_chain);
}

/*

   GLOBAL FUNCTION

   aix5_solib_create_inferior_hook -- shared library startup support

   SYNOPSIS

   void aix5_solib_create_inferior_hook()

   DESCRIPTION

   When gdb starts up the inferior, it nurses it along (through the
   shell) until it is ready to execute it's first instruction.  At this
   point, this function gets called via expansion of the macro
   SOLIB_CREATE_INFERIOR_HOOK.

   For AIX5 executables, this first instruction is the first
   instruction in the dynamic linker (for dynamically linked
   executables) or the instruction at "start" for statically linked
   executables.  For dynamically linked executables, the system
   first exec's libc.so.N, which contains the dynamic linker,
   and starts it running.  The dynamic linker maps in any needed
   shared libraries, maps in the actual user executable, and then
   jumps to "start" in the user executable.

 */

static void
aix5_solib_create_inferior_hook (void)
{
  aix5_relocate_main_executable ();

  if (!enable_break ())
    {
      warning ("shared library handler failed to enable breakpoint");
      return;
    }
}

static void
aix5_clear_solib (void)
{
}

static void
aix5_free_so (struct so_list *so)
{
  xfree (so->lm_info->mapname);
  xfree (so->lm_info->pathname);
  xfree (so->lm_info->membername);
  xfree (so->lm_info);
}

static void
aix5_relocate_section_addresses (struct so_list *so,
                                 struct section_table *sec)
{
  int flags = bfd_get_section_flags (sec->bfd, sec->the_bfd_section);
  file_ptr filepos = sec->the_bfd_section->filepos;

  if (flags & SEC_ALLOC)
    {
      int idx;
      CORE_ADDR addr;

      for (idx = 0; idx < so->lm_info->nmappings; idx++)
	{
	  struct lm_mapping *mapping = &so->lm_info->mapping[idx];
	  if (mapping->offset <= filepos
	      && filepos <= mapping->offset + mapping->size)
	    break;
	}

      if (idx >= so->lm_info->nmappings)
	internal_error (__FILE__, __LINE__,
	  "aix_relocate_section_addresses: Can't find mapping for section %s",
	  bfd_get_section_name (sec->bfd, sec->the_bfd_section));
      
      addr = so->lm_info->mapping[idx].addr;

      sec->addr += addr;
      sec->endaddr += addr;
    }
}

/* Find the global pointer for the given function address ADDR.  */

static CORE_ADDR
aix5_find_global_pointer (CORE_ADDR addr)
{
  struct so_list *sos, *so;
  CORE_ADDR global_pointer = 0;
  struct cleanup *old_chain = make_cleanup (null_cleanup, 0);

  sos = build_so_list_from_mapfile (PIDGET (inferior_pid), 0, 0);

  for (so = sos; so != NULL; so = so->next)
    {
      int idx;
      for (idx = 0; idx < so->lm_info->nmappings; idx++)
	if (so->lm_info->mapping[idx].addr <= addr
	    && addr <= so->lm_info->mapping[idx].addr
			 + so->lm_info->mapping[idx].size)
	  {
	    break;
	  }

      if (idx < so->lm_info->nmappings)
	{
	  /* Look for a non-zero global pointer in the current set of
	     mappings.  */
	  for (idx = 0; idx < so->lm_info->nmappings; idx++)
	    if (so->lm_info->mapping[idx].gp != 0)
	      {
		global_pointer = so->lm_info->mapping[idx].gp;
		break;
	      }
	  /* Get out regardless of whether we found one or not.  Mappings
	     don't overlap, so it would be pointless to continue.  */
	  break;
	}
    }

  do_cleanups (old_chain);

  return global_pointer;
}

/* Find the execute-only kernel region known as the gate page.  This
   page is where the signal trampoline lives.  It may be found by
   querying the map file and looking for the MA_KERNTEXT flag.  */
static void
aix5_find_gate_addresses (CORE_ADDR *start, CORE_ADDR *end)
{
  struct so_list *so;
  struct cleanup *old_chain = make_cleanup (null_cleanup, 0);

  /* Fetch the mappings for the main executable from the map file.  */
  so = build_so_list_from_mapfile (PIDGET (inferior_pid),
                                   MA_KERNTEXT, MA_KERNTEXT);

  /* Make sure we actually have some mappings to work with.  */
  if (so == NULL)
    {
      warning ("Could not find gate page in map file");
      *start = 0;
      *end = 0;
      do_cleanups (old_chain);
      return;
    }

  /* There should only be on kernel mapping for the gate page and
     it'll be in the read-only (even though it's execute-only)
     mapping in the lm_info struct.  */

  *start = so->lm_info->mapping[0].addr;
  *end = *start + so->lm_info->mapping[0].size;

  /* Free up all the space we've allocated.  */
  do_cleanups (old_chain);
}

/* From ia64-tdep.c.  FIXME:  If we end up using this for rs6000 too,
   we'll need to make the names match.  */
extern CORE_ADDR (*native_find_global_pointer) (CORE_ADDR);

/* From ia64-aix-tdep.c.  Hook for finding the starting and
   ending gate page addresses.  The only reason that this hook
   is in this file is because this is where the map file reading
   code is located.  */
extern void (*aix5_find_gate_addresses_hook) (CORE_ADDR *, CORE_ADDR *);

static struct target_so_ops aix5_so_ops;

void
_initialize_aix5_solib (void)
{
  aix5_so_ops.relocate_section_addresses = aix5_relocate_section_addresses;
  aix5_so_ops.free_so = aix5_free_so;
  aix5_so_ops.clear_solib = aix5_clear_solib;
  aix5_so_ops.solib_create_inferior_hook = aix5_solib_create_inferior_hook;
  aix5_so_ops.special_symbol_handling = aix5_special_symbol_handling;
  aix5_so_ops.current_sos = aix5_current_sos;
  aix5_so_ops.open_symbol_file_object = open_symbol_file_object;
  aix5_so_ops.in_dynsym_resolve_code = aix5_in_dynsym_resolve_code;

  native_find_global_pointer = aix5_find_global_pointer;
  aix5_find_gate_addresses_hook = aix5_find_gate_addresses;

  /* FIXME: Don't do this here.  *_gdbarch_init() should set so_ops. */
  current_target_so_ops = &aix5_so_ops;
}