summary refs log tree commit diff
path: root/elf/get-dynamic-info.h
blob: 4f6a86ef375ac6225cf067594b4851cbf8a1ded5 (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
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
/* Read the dynamic section at DYN and fill in INFO with indices DT_*.
   Copyright (C) 2012-2020 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 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, see
   <https://www.gnu.org/licenses/>.  */

/* This file is included multiple times and therefore lacks a header
   file inclusion guard.  */

#include <assert.h>
#include <libc-diag.h>

#ifndef RESOLVE_MAP
static
#else
auto
#endif
inline void __attribute__ ((unused, always_inline))
elf_get_dynamic_info (struct link_map *l, ElfW(Dyn) *temp)
{
  ElfW(Dyn) *dyn = l->l_ld;
  ElfW(Dyn) **info;
#if __ELF_NATIVE_CLASS == 32
  typedef Elf32_Word d_tag_utype;
#elif __ELF_NATIVE_CLASS == 64
  typedef Elf64_Xword d_tag_utype;
#endif

#if !defined RTLD_BOOTSTRAP && !defined STATIC_PIE_BOOTSTRAP
  if (dyn == NULL)
    return;
#endif

  info = l->l_info;

  while (dyn->d_tag != DT_NULL)
    {
      if ((d_tag_utype) dyn->d_tag < DT_NUM)
	info[dyn->d_tag] = dyn;
      else if (dyn->d_tag >= DT_LOPROC
	       && dyn->d_tag < DT_LOPROC + DT_THISPROCNUM)
	{
	  /* This does not violate the array bounds of l->l_info, but
	     gcc 4.6 on sparc somehow does not see this.  */
	  DIAG_PUSH_NEEDS_COMMENT;
	  DIAG_IGNORE_NEEDS_COMMENT (4.6,
				     "-Warray-bounds");
	  info[dyn->d_tag - DT_LOPROC + DT_NUM] = dyn;
	  DIAG_POP_NEEDS_COMMENT;
	}
      else if ((d_tag_utype) DT_VERSIONTAGIDX (dyn->d_tag) < DT_VERSIONTAGNUM)
	info[VERSYMIDX (dyn->d_tag)] = dyn;
      else if ((d_tag_utype) DT_EXTRATAGIDX (dyn->d_tag) < DT_EXTRANUM)
	info[DT_EXTRATAGIDX (dyn->d_tag) + DT_NUM + DT_THISPROCNUM
	     + DT_VERSIONTAGNUM] = dyn;
      else if ((d_tag_utype) DT_VALTAGIDX (dyn->d_tag) < DT_VALNUM)
	info[DT_VALTAGIDX (dyn->d_tag) + DT_NUM + DT_THISPROCNUM
	     + DT_VERSIONTAGNUM + DT_EXTRANUM] = dyn;
      else if ((d_tag_utype) DT_ADDRTAGIDX (dyn->d_tag) < DT_ADDRNUM)
	info[DT_ADDRTAGIDX (dyn->d_tag) + DT_NUM + DT_THISPROCNUM
	     + DT_VERSIONTAGNUM + DT_EXTRANUM + DT_VALNUM] = dyn;
      ++dyn;
    }

#define DL_RO_DYN_TEMP_CNT	8

#ifndef DL_RO_DYN_SECTION
  /* Don't adjust .dynamic unnecessarily.  */
  if (l->l_addr != 0)
    {
      ElfW(Addr) l_addr = l->l_addr;
      int cnt = 0;

# define ADJUST_DYN_INFO(tag) \
      do								      \
	if (info[tag] != NULL)						      \
	  {								      \
	    if (temp)							      \
	      {								      \
		temp[cnt].d_tag = info[tag]->d_tag;			      \
		temp[cnt].d_un.d_ptr = info[tag]->d_un.d_ptr + l_addr;	      \
		info[tag] = temp + cnt++;				      \
	      }								      \
	    else							      \
	      info[tag]->d_un.d_ptr += l_addr;				      \
	  }								      \
      while (0)

      ADJUST_DYN_INFO (DT_HASH);
      ADJUST_DYN_INFO (DT_PLTGOT);
      ADJUST_DYN_INFO (DT_STRTAB);
      ADJUST_DYN_INFO (DT_SYMTAB);
# if ! ELF_MACHINE_NO_RELA
      ADJUST_DYN_INFO (DT_RELA);
# endif
# if ! ELF_MACHINE_NO_REL
      ADJUST_DYN_INFO (DT_REL);
# endif
      ADJUST_DYN_INFO (DT_JMPREL);
      ADJUST_DYN_INFO (VERSYMIDX (DT_VERSYM));
      ADJUST_DYN_INFO (ADDRIDX (DT_GNU_HASH));
# undef ADJUST_DYN_INFO
      assert (cnt <= DL_RO_DYN_TEMP_CNT);
    }
#endif
  if (info[DT_PLTREL] != NULL)
    {
#if ELF_MACHINE_NO_RELA
      assert (info[DT_PLTREL]->d_un.d_val == DT_REL);
#elif ELF_MACHINE_NO_REL
      assert (info[DT_PLTREL]->d_un.d_val == DT_RELA);
#else
      assert (info[DT_PLTREL]->d_un.d_val == DT_REL
	      || info[DT_PLTREL]->d_un.d_val == DT_RELA);
#endif
    }
#if ! ELF_MACHINE_NO_RELA
  if (info[DT_RELA] != NULL)
    assert (info[DT_RELAENT]->d_un.d_val == sizeof (ElfW(Rela)));
# endif
# if ! ELF_MACHINE_NO_REL
  if (info[DT_REL] != NULL)
    assert (info[DT_RELENT]->d_un.d_val == sizeof (ElfW(Rel)));
#endif
#ifdef RTLD_BOOTSTRAP
  /* Only the bind now flags are allowed.  */
  assert (info[VERSYMIDX (DT_FLAGS_1)] == NULL
	  || (info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val & ~DF_1_NOW) == 0);
  /* Flags must not be set for ld.so.  */
  assert (info[DT_FLAGS] == NULL
	  || (info[DT_FLAGS]->d_un.d_val & ~DF_BIND_NOW) == 0);
#endif
#if defined RTLD_BOOTSTRAP || defined STATIC_PIE_BOOTSTRAP
  assert (info[DT_RUNPATH] == NULL);
  assert (info[DT_RPATH] == NULL);
#else
  if (info[DT_FLAGS] != NULL)
    {
      /* Flags are used.  Translate to the old form where available.
	 Since these l_info entries are only tested for NULL pointers it
	 is ok if they point to the DT_FLAGS entry.  */
      l->l_flags = info[DT_FLAGS]->d_un.d_val;

      if (l->l_flags & DF_SYMBOLIC)
	info[DT_SYMBOLIC] = info[DT_FLAGS];
      if (l->l_flags & DF_TEXTREL)
	info[DT_TEXTREL] = info[DT_FLAGS];
      if (l->l_flags & DF_BIND_NOW)
	info[DT_BIND_NOW] = info[DT_FLAGS];
    }
  if (info[VERSYMIDX (DT_FLAGS_1)] != NULL)
    {
      l->l_flags_1 = info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val;
      if (l->l_flags_1 & DF_1_NODELETE)
	l->l_nodelete_pending = true;

      /* Only DT_1_SUPPORTED_MASK bits are supported, and we would like
	 to assert this, but we can't. Users have been setting
	 unsupported DF_1_* flags for a long time and glibc has ignored
	 them. Therefore to avoid breaking existing applications the
	 best we can do is add a warning during debugging with the
	 intent of notifying the user of the problem.  */
      if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0)
	  && l->l_flags_1 & ~DT_1_SUPPORTED_MASK)
	_dl_debug_printf ("\nWARNING: Unsupported flag value(s) of 0x%x in DT_FLAGS_1.\n",
			  l->l_flags_1 & ~DT_1_SUPPORTED_MASK);

      if (l->l_flags_1 & DF_1_NOW)
	info[DT_BIND_NOW] = info[VERSYMIDX (DT_FLAGS_1)];
    }
  if (info[DT_RUNPATH] != NULL)
    /* If both RUNPATH and RPATH are given, the latter is ignored.  */
    info[DT_RPATH] = NULL;
#endif
}