about summary refs log tree commit diff
path: root/elf/do-rel.h
blob: afea61cfd25093a1a20e08f7389e1a9efed48b80 (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
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
/* Do relocations for ELF dynamic linking.
   Copyright (C) 1995-2024 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/>.  */

#include <ldsodefs.h>

/* This file may be included twice, to define both
   `elf_dynamic_do_rel' and `elf_dynamic_do_rela'.  */

#ifdef DO_RELA
# define elf_dynamic_do_Rel		elf_dynamic_do_Rela
# define Rel				Rela
# define elf_machine_rel		elf_machine_rela
# define elf_machine_rel_relative	elf_machine_rela_relative
#endif

#ifndef DO_ELF_MACHINE_REL_RELATIVE
# define DO_ELF_MACHINE_REL_RELATIVE(map, l_addr, relative) \
  elf_machine_rel_relative (l_addr, relative,				      \
			    (void *) (l_addr + relative->r_offset))
#endif

/* Perform the relocations in MAP on the running program image as specified
   by RELTAG, SZTAG.  If LAZY is nonzero, this is the first pass on PLT
   relocations; they should be set up to call _dl_runtime_resolve, rather
   than fully resolved now.  */

static inline void __attribute__ ((always_inline))
elf_dynamic_do_Rel (struct link_map *map, struct r_scope_elem *scope[],
		    ElfW(Addr) reladdr, ElfW(Addr) relsize,
		    __typeof (((ElfW(Dyn) *) 0)->d_un.d_val) nrelative,
		    int lazy, int skip_ifunc)
{
  const ElfW(Rel) *relative = (const void *) reladdr;
  const ElfW(Rel) *r = relative + nrelative;
  const ElfW(Rel) *end = (const void *) (reladdr + relsize);
  ElfW(Addr) l_addr = map->l_addr;
  const ElfW(Sym) *const symtab
      = (const void *) D_PTR (map, l_info[DT_SYMTAB]);

#ifdef RTLD_BOOTSTRAP
  for (; relative < r; ++relative)
    DO_ELF_MACHINE_REL_RELATIVE (map, l_addr, relative);

  const ElfW (Half) *const version
      = (const void *) D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]);
  for (; r < end; ++r)
    {
      ElfW (Half) ndx = version[ELFW (R_SYM) (r->r_info)] & 0x7fff;
      const ElfW (Sym) *sym = &symtab[ELFW (R_SYM) (r->r_info)];
      void *const r_addr_arg = (void *) (l_addr + r->r_offset);
      const struct r_found_version *rversion = &map->l_versions[ndx];

      elf_machine_rel (map, scope, r, sym, rversion, r_addr_arg, skip_ifunc);
    }
#else /* !RTLD_BOOTSTRAP */
# if defined ELF_MACHINE_IRELATIVE
  const ElfW(Rel) *r2 = NULL;
  const ElfW(Rel) *end2 = NULL;
# endif

#if !defined DO_RELA || !defined ELF_MACHINE_PLT_REL
  /* We never bind lazily during ld.so bootstrap.  Unfortunately gcc is
     not clever enough to see through all the function calls to realize
     that.  */
  if (lazy)
    {
      /* Doing lazy PLT relocations; they need very little info.  */
      for (; r < end; ++r)
# ifdef ELF_MACHINE_IRELATIVE
	if (ELFW(R_TYPE) (r->r_info) == ELF_MACHINE_IRELATIVE)
	  {
	    if (r2 == NULL)
	      r2 = r;
	    end2 = r;
	  }
	else
# endif
	  elf_machine_lazy_rel (map, scope, l_addr, r, skip_ifunc);

# ifdef ELF_MACHINE_IRELATIVE
      if (r2 != NULL)
	for (; r2 <= end2; ++r2)
	  if (ELFW(R_TYPE) (r2->r_info) == ELF_MACHINE_IRELATIVE)
	    elf_machine_lazy_rel (map, scope, l_addr, r2, skip_ifunc);
# endif
    }
  else
#endif
    {
      /* This is defined in rtld.c, but nowhere in the static libc.a; make
	 the reference weak so static programs can still link.  This
	 declaration cannot be done when compiling rtld.c (i.e. #ifdef
	 RTLD_BOOTSTRAP) because rtld.c contains the common defn for
	 _dl_rtld_map, which is incompatible with a weak decl in the same
	 file.  */
# ifndef SHARED
      weak_extern (GL(dl_rtld_map));
# endif
      if (map != &GL(dl_rtld_map)) /* Already done in rtld itself.  */
# if !defined DO_RELA || defined ELF_MACHINE_REL_RELATIVE
	/* Rela platforms get the offset from r_addend and this must
	   be copied in the relocation address.  Therefore we can skip
	   the relative relocations only if this is for rel
	   relocations or rela relocations if they are computed as
	   memory_loc += l_addr...  */
	if (l_addr != 0)
# endif
	  for (; relative < r; ++relative)
	    DO_ELF_MACHINE_REL_RELATIVE (map, l_addr, relative);

      if (map->l_info[VERSYMIDX (DT_VERSYM)])
	{
	  const ElfW(Half) *const version =
	    (const void *) D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]);

	  for (; r < end; ++r)
	    {
	      ElfW(Half) ndx = version[ELFW(R_SYM) (r->r_info)] & 0x7fff;
	      const ElfW(Sym) *sym = &symtab[ELFW(R_SYM) (r->r_info)];
	      void *const r_addr_arg = (void *) (l_addr + r->r_offset);
	      const struct r_found_version *rversion = &map->l_versions[ndx];
#if defined ELF_MACHINE_IRELATIVE
	      if (ELFW(R_TYPE) (r->r_info) == ELF_MACHINE_IRELATIVE)
		{
		  if (r2 == NULL)
		    r2 = r;
		  end2 = r;
		  continue;
		}
#endif

	      elf_machine_rel (map, scope, r, sym, rversion, r_addr_arg,
			       skip_ifunc);
#if defined SHARED
	      if (ELFW(R_TYPE) (r->r_info) == ELF_MACHINE_JMP_SLOT
		  && GLRO(dl_naudit) > 0)
		{
		  struct link_map *sym_map
		    = RESOLVE_MAP (map, scope, &sym, rversion,
				   ELF_MACHINE_JMP_SLOT);
		  if (sym != NULL)
		    _dl_audit_symbind (map, NULL, r, sym, r_addr_arg, sym_map,
				       false);
		}
#endif
	    }

#if defined ELF_MACHINE_IRELATIVE
	  if (r2 != NULL)
	    for (; r2 <= end2; ++r2)
	      if (ELFW(R_TYPE) (r2->r_info) == ELF_MACHINE_IRELATIVE)
		{
		  ElfW(Half) ndx
		    = version[ELFW(R_SYM) (r2->r_info)] & 0x7fff;
		  elf_machine_rel (map, scope, r2,
				   &symtab[ELFW(R_SYM) (r2->r_info)],
				   &map->l_versions[ndx],
				   (void *) (l_addr + r2->r_offset),
				   skip_ifunc);
		}
#endif
	}
      else
	{
	  for (; r < end; ++r)
	    {
	      const ElfW(Sym) *sym = &symtab[ELFW(R_SYM) (r->r_info)];
	      void *const r_addr_arg = (void *) (l_addr + r->r_offset);
# ifdef ELF_MACHINE_IRELATIVE
	      if (ELFW(R_TYPE) (r->r_info) == ELF_MACHINE_IRELATIVE)
		{
		  if (r2 == NULL)
		    r2 = r;
		  end2 = r;
		  continue;
		}
# endif
	      elf_machine_rel (map, scope, r, sym, NULL, r_addr_arg,
			       skip_ifunc);
# if defined SHARED
	      if (ELFW(R_TYPE) (r->r_info) == ELF_MACHINE_JMP_SLOT
		  && GLRO(dl_naudit) > 0)
		{
		  struct link_map *sym_map
		    = RESOLVE_MAP (map, scope, &sym,
				   (struct r_found_version *) NULL,
				   ELF_MACHINE_JMP_SLOT);
		  if (sym != NULL)
		    _dl_audit_symbind (map, NULL, r, sym,r_addr_arg, sym_map,
				       false);
		}
# endif
	    }

# ifdef ELF_MACHINE_IRELATIVE
	  if (r2 != NULL)
	    for (; r2 <= end2; ++r2)
	      if (ELFW(R_TYPE) (r2->r_info) == ELF_MACHINE_IRELATIVE)
		elf_machine_rel (map, scope, r2, &symtab[ELFW(R_SYM) (r2->r_info)],
				 NULL, (void *) (l_addr + r2->r_offset),
				 skip_ifunc);
# endif
	}
    }
#endif /* !RTLD_BOOTSTRAP */
}

#undef elf_dynamic_do_Rel
#undef Rel
#undef elf_machine_rel
#undef elf_machine_rel_relative
#undef DO_ELF_MACHINE_REL_RELATIVE
#undef DO_RELA