summary refs log tree commit diff
path: root/elf/dynamic-link.h
blob: 9d7ae3d3fadf1d3448c4ca9c956229da01651b16 (plain) (blame)
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
/* Inline functions for dynamic linking.
   Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 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
   Library General Public License for more details.

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

#include <elf.h>
#include <dl-machine.h>
#include <assert.h>


/* Global read-only variable defined in rtld.c which is nonzero if we
   shall give more warning messages.  */
extern int _dl_verbose __attribute__ ((unused));


/* Read the dynamic section at DYN and fill in INFO with indices DT_*.  */

static inline void __attribute__ ((unused))
elf_get_dynamic_info (ElfW(Dyn) *dyn,
		      ElfW(Dyn) *info[DT_NUM + DT_PROCNUM + DT_VERSIONTAGNUM
				     + DT_EXTRANUM])
{
  unsigned int i;

  for (i = 0; i < DT_NUM + DT_PROCNUM + DT_VERSIONTAGNUM + DT_EXTRANUM; ++i)
    info[i] = NULL;

  if (! dyn)
    return;

  while (dyn->d_tag != DT_NULL)
    {
      if (dyn->d_tag < DT_NUM)
	info[dyn->d_tag] = dyn;
      else if (dyn->d_tag >= DT_LOPROC &&
	       dyn->d_tag < DT_LOPROC + DT_PROCNUM)
	info[dyn->d_tag - DT_LOPROC + DT_NUM] = dyn;
      else if ((Elf32_Word) DT_VERSIONTAGIDX (dyn->d_tag) < DT_VERSIONTAGNUM)
	info[DT_VERSIONTAGIDX (dyn->d_tag) + DT_NUM + DT_PROCNUM] = dyn;
      else if ((Elf32_Word) DT_EXTRATAGIDX (dyn->d_tag) < DT_EXTRANUM)
	info[DT_EXTRATAGIDX (dyn->d_tag) + DT_NUM + DT_PROCNUM
	     + DT_VERSIONTAGNUM] = dyn;
      else
	assert (! "bad dynamic tag");
      ++dyn;
    }

  if (info[DT_RELA])
    assert (info[DT_RELAENT]->d_un.d_val == sizeof (ElfW(Rela)));
  if (info[DT_REL])
    assert (info[DT_RELENT]->d_un.d_val == sizeof (ElfW(Rel)));
  if (info[DT_PLTREL])
    assert (info[DT_PLTREL]->d_un.d_val == DT_REL ||
	    info[DT_PLTREL]->d_un.d_val == DT_RELA);
}

#ifdef RESOLVE

/* Get the definitions of `elf_dynamic_do_rel' and `elf_dynamic_do_rela'.
   These functions are almost identical, so we use cpp magic to avoid
   duplicating their code.  It cannot be done in a more general function
   because we must be able to completely inline.  */

/* On some machines, notably Sparc, DT_REL* includes DT_JMPREL in its
   range.  Note that according to the ELF spec, this is completely legal!
   But conditionally define things so that on machines we know this will
   not happen we do something more optimal.  */

#ifdef ELF_MACHINE_PLTREL_OVERLAP
#define _ELF_DYNAMIC_DO_RELOC(RELOC, reloc, map, lazy) \
  do {									      \
    ElfW(Addr) r_addr, r_size, p_addr, p_size;				      \
    if ((map)->l_info[DT_##RELOC])					      \
      {									      \
        r_addr = (map)->l_info[DT_##RELOC]->d_un.d_ptr;			      \
        r_size = (map)->l_info[DT_##RELOC##SZ]->d_un.d_val;		      \
        if ((map)->l_info[DT_PLTREL] &&					      \
            (map)->l_info[DT_PLTREL]->d_un.d_val == DT_##RELOC)		      \
	  {								      \
	    p_addr = (map)->l_info[DT_JMPREL]->d_un.d_ptr;		      \
	    p_size = (map)->l_info[DT_PLTRELSZ]->d_un.d_val;		      \
	    if (r_addr <= p_addr && r_addr+r_size > p_addr)		      \
	      {								      \
		ElfW(Addr) r2_addr, r2_size;				      \
		r2_addr = p_addr + p_size;				      \
		if (r2_addr < r_addr + r_size)				      \
		  {							      \
		    r2_size = r_addr + r_size - r2_addr;		      \
		    elf_dynamic_do_##reloc ((map), r2_addr, r2_size, 0);      \
		  }							      \
		r_size = p_addr - r_addr;				      \
	      }								      \
	  }								      \
									      \
	elf_dynamic_do_##reloc ((map), r_addr, r_size, 0);		      \
	if (p_addr)							      \
	  elf_dynamic_do_##reloc ((map), p_addr, p_size, (lazy));	      \
      }									      \
    else if ((map)->l_info[DT_PLTREL] &&				      \
	     (map)->l_info[DT_PLTREL]->d_un.d_val == DT_##RELOC)	      \
      {									      \
	p_addr = (map)->l_info[DT_JMPREL]->d_un.d_ptr;			      \
	p_size = (map)->l_info[DT_PLTRELSZ]->d_un.d_val;		      \
									      \
	elf_dynamic_do_##reloc ((map), p_addr, p_size, (lazy));		      \
      }									      \
  } while (0)
#else
#define _ELF_DYNAMIC_DO_RELOC(RELOC, reloc, map, lazy) \
  do {									      \
    if ((map)->l_info[DT_##RELOC])					      \
      {									      \
	ElfW(Addr) r_addr, r_size;					      \
        r_addr = (map)->l_info[DT_##RELOC]->d_un.d_ptr;			      \
        r_size = (map)->l_info[DT_##RELOC##SZ]->d_un.d_val;		      \
	elf_dynamic_do_##reloc ((map), r_addr, r_size, 0);		      \
      }									      \
    if ((map)->l_info[DT_PLTREL] &&					      \
	(map)->l_info[DT_PLTREL]->d_un.d_val == DT_##RELOC)		      \
      {									      \
	ElfW(Addr) p_addr, p_size;					      \
	p_addr = (map)->l_info[DT_JMPREL]->d_un.d_ptr;			      \
	p_size = (map)->l_info[DT_PLTRELSZ]->d_un.d_val;		      \
	elf_dynamic_do_##reloc ((map), p_addr, p_size, (lazy));		      \
      }									      \
  } while (0)
#endif

#if ! ELF_MACHINE_NO_REL
#include "do-rel.h"
#define ELF_DYNAMIC_DO_REL(map, lazy) \
  _ELF_DYNAMIC_DO_RELOC (REL, rel, map, lazy)
#else
#define ELF_DYNAMIC_DO_REL(map, lazy) /* Nothing to do.  */
#endif

#if ! ELF_MACHINE_NO_RELA
#define DO_RELA
#include "do-rel.h"
#define ELF_DYNAMIC_DO_RELA(map, lazy) \
  _ELF_DYNAMIC_DO_RELOC (RELA, rela, map, lazy)
#else
#define ELF_DYNAMIC_DO_RELA(map, lazy) /* Nothing to do.  */
#endif

/* This can't just be an inline function because GCC is too dumb
   to inline functions containing inlines themselves.  */
#define ELF_DYNAMIC_RELOCATE(map, lazy, consider_profile) \
  do {									      \
    int edr_lazy = elf_machine_runtime_setup ((map), (lazy),		      \
					      (consider_profile));	      \
    ELF_DYNAMIC_DO_REL ((map), edr_lazy);				      \
    ELF_DYNAMIC_DO_RELA ((map), edr_lazy);				      \
  } while (0)

#endif