1
/* ELF support for BFD.
2
Copyright 1991, 1992, 1993, 1994, 1995, 1997, 1998, 2000, 2001, 2002,
3
2003, 2006, 2007, 2008, 2010, 2011 Free Software Foundation, Inc.
5
Written by Fred Fish @ Cygnus Support, from information published
6
in "UNIX System V Release 4, Programmers Guide: ANSI C and
7
Programming Support Tools".
9
This file is part of BFD, the Binary File Descriptor library.
11
This program is free software; you can redistribute it and/or modify
12
it under the terms of the GNU General Public License as published by
13
the Free Software Foundation; either version 3 of the License, or
14
(at your option) any later version.
16
This program is distributed in the hope that it will be useful,
17
but WITHOUT ANY WARRANTY; without even the implied warranty of
18
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19
GNU General Public License for more details.
21
You should have received a copy of the GNU General Public License
22
along with this program; if not, write to the Free Software
23
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
24
MA 02110-1301, USA. */
26
/* This file is part of ELF support for BFD, and contains the portions
27
that describe how ELF is represented internally in the BFD library.
28
I.E. it describes the in-memory representation of ELF. It requires
29
the elf-common.h file which contains the portions that are common to
30
both the internal and external representations. */
32
/* NOTE that these structures are not kept in the same order as they appear
33
in the object file. In some cases they've been reordered for more optimal
34
packing under various circumstances. */
36
#ifndef _ELF_INTERNAL_H
37
#define _ELF_INTERNAL_H
39
/* Special section indices, which may show up in st_shndx fields, among
52
#define SHN_UNDEF 0 /* Undefined section reference */
53
#define SHN_LORESERVE (-0x100u) /* Begin range of reserved indices */
54
#define SHN_LOPROC (-0x100u) /* Begin range of appl-specific */
55
#define SHN_HIPROC (-0xE1u) /* End range of appl-specific */
56
#define SHN_LOOS (-0xE0u) /* OS specific semantics, lo */
57
#define SHN_HIOS (-0xC1u) /* OS specific semantics, hi */
58
#define SHN_ABS (-0xFu) /* Associated symbol is absolute */
59
#define SHN_COMMON (-0xEu) /* Associated symbol is in common */
60
#define SHN_XINDEX (-0x1u) /* Section index is held elsewhere */
61
#define SHN_HIRESERVE (-0x1u) /* End range of reserved indices */
62
#define SHN_BAD (-0x101u) /* Used internally by bfd */
66
#define EI_NIDENT 16 /* Size of e_ident[] */
68
typedef struct elf_internal_ehdr {
69
unsigned char e_ident[EI_NIDENT]; /* ELF "magic number" */
70
bfd_vma e_entry; /* Entry point virtual address */
71
bfd_size_type e_phoff; /* Program header table file offset */
72
bfd_size_type e_shoff; /* Section header table file offset */
73
unsigned long e_version; /* Identifies object file version */
74
unsigned long e_flags; /* Processor-specific flags */
75
unsigned short e_type; /* Identifies object file type */
76
unsigned short e_machine; /* Specifies required architecture */
77
unsigned int e_ehsize; /* ELF header size in bytes */
78
unsigned int e_phentsize; /* Program header table entry size */
79
unsigned int e_phnum; /* Program header table entry count */
80
unsigned int e_shentsize; /* Section header table entry size */
81
unsigned int e_shnum; /* Section header table entry count */
82
unsigned int e_shstrndx; /* Section header string table index */
87
struct elf_internal_phdr {
88
unsigned long p_type; /* Identifies program segment type */
89
unsigned long p_flags; /* Segment flags */
90
bfd_vma p_offset; /* Segment file offset */
91
bfd_vma p_vaddr; /* Segment virtual address */
92
bfd_vma p_paddr; /* Segment physical address */
93
bfd_vma p_filesz; /* Segment size in file */
94
bfd_vma p_memsz; /* Segment size in memory */
95
bfd_vma p_align; /* Segment alignment, file & memory */
98
typedef struct elf_internal_phdr Elf_Internal_Phdr;
102
typedef struct elf_internal_shdr {
103
unsigned int sh_name; /* Section name, index in string tbl */
104
unsigned int sh_type; /* Type of section */
105
bfd_vma sh_flags; /* Miscellaneous section attributes */
106
bfd_vma sh_addr; /* Section virtual addr at execution */
107
file_ptr sh_offset; /* Section file offset */
108
bfd_size_type sh_size; /* Size of section in bytes */
109
unsigned int sh_link; /* Index of another section */
110
unsigned int sh_info; /* Additional section information */
111
bfd_vma sh_addralign; /* Section alignment */
112
bfd_size_type sh_entsize; /* Entry size if section holds table */
114
/* The internal rep also has some cached info associated with it. */
115
asection * bfd_section; /* Associated BFD section. */
116
unsigned char *contents; /* Section contents. */
119
/* Symbol table entry */
121
struct elf_internal_sym {
122
bfd_vma st_value; /* Value of the symbol */
123
bfd_vma st_size; /* Associated symbol size */
124
unsigned long st_name; /* Symbol name, index in string tbl */
125
unsigned char st_info; /* Type and binding attributes */
126
unsigned char st_other; /* Visibilty, and target specific */
127
unsigned char st_target_internal; /* Internal-only information */
128
unsigned int st_shndx; /* Associated section index */
131
typedef struct elf_internal_sym Elf_Internal_Sym;
135
typedef struct elf_internal_note {
136
unsigned long namesz; /* Size of entry's owner string */
137
unsigned long descsz; /* Size of the note descriptor */
138
unsigned long type; /* Interpretation of the descriptor */
139
char * namedata; /* Start of the name+desc data */
140
char * descdata; /* Start of the desc data */
141
bfd_vma descpos; /* File offset of the descdata */
144
/* Relocation Entries */
146
typedef struct elf_internal_rela {
147
bfd_vma r_offset; /* Location at which to apply the action */
148
bfd_vma r_info; /* Index and Type of relocation */
149
bfd_vma r_addend; /* Constant addend used to compute value */
152
/* dynamic section structure */
154
typedef struct elf_internal_dyn {
155
/* This needs to support 64-bit values in elf64. */
156
bfd_vma d_tag; /* entry tag value */
158
/* This needs to support 64-bit values in elf64. */
164
/* This structure appears in a SHT_GNU_verdef section. */
166
typedef struct elf_internal_verdef {
167
unsigned short vd_version; /* Version number of structure. */
168
unsigned short vd_flags; /* Flags (VER_FLG_*). */
169
unsigned short vd_ndx; /* Version index. */
170
unsigned short vd_cnt; /* Number of verdaux entries. */
171
unsigned long vd_hash; /* Hash of name. */
172
unsigned long vd_aux; /* Offset to verdaux entries. */
173
unsigned long vd_next; /* Offset to next verdef. */
175
/* These fields are set up when BFD reads in the structure. FIXME:
176
It would be cleaner to store these in a different structure. */
177
bfd *vd_bfd; /* BFD. */
178
const char *vd_nodename; /* Version name. */
179
struct elf_internal_verdef *vd_nextdef; /* vd_next as pointer. */
180
struct elf_internal_verdaux *vd_auxptr; /* vd_aux as pointer. */
181
unsigned int vd_exp_refno; /* Used by the linker. */
182
} Elf_Internal_Verdef;
184
/* This structure appears in a SHT_GNU_verdef section. */
186
typedef struct elf_internal_verdaux {
187
unsigned long vda_name; /* String table offset of name. */
188
unsigned long vda_next; /* Offset to next verdaux. */
190
/* These fields are set up when BFD reads in the structure. FIXME:
191
It would be cleaner to store these in a different structure. */
192
const char *vda_nodename; /* vda_name as pointer. */
193
struct elf_internal_verdaux *vda_nextptr; /* vda_next as pointer. */
194
} Elf_Internal_Verdaux;
196
/* This structure appears in a SHT_GNU_verneed section. */
198
typedef struct elf_internal_verneed {
199
unsigned short vn_version; /* Version number of structure. */
200
unsigned short vn_cnt; /* Number of vernaux entries. */
201
unsigned long vn_file; /* String table offset of library name. */
202
unsigned long vn_aux; /* Offset to vernaux entries. */
203
unsigned long vn_next; /* Offset to next verneed. */
205
/* These fields are set up when BFD reads in the structure. FIXME:
206
It would be cleaner to store these in a different structure. */
207
bfd *vn_bfd; /* BFD. */
208
const char *vn_filename; /* vn_file as pointer. */
209
struct elf_internal_vernaux *vn_auxptr; /* vn_aux as pointer. */
210
struct elf_internal_verneed *vn_nextref; /* vn_nextref as pointer. */
211
} Elf_Internal_Verneed;
213
/* This structure appears in a SHT_GNU_verneed section. */
215
typedef struct elf_internal_vernaux {
216
unsigned long vna_hash; /* Hash of dependency name. */
217
unsigned short vna_flags; /* Flags (VER_FLG_*). */
218
unsigned short vna_other; /* Unused. */
219
unsigned long vna_name; /* String table offset to version name. */
220
unsigned long vna_next; /* Offset to next vernaux. */
222
/* These fields are set up when BFD reads in the structure. FIXME:
223
It would be cleaner to store these in a different structure. */
224
const char *vna_nodename; /* vna_name as pointer. */
225
struct elf_internal_vernaux *vna_nextptr; /* vna_next as pointer. */
226
} Elf_Internal_Vernaux;
228
/* This structure appears in a SHT_GNU_versym section. This is not a
229
standard ELF structure; ELF just uses Elf32_Half. */
231
typedef struct elf_internal_versym {
232
unsigned short vs_vers;
233
} Elf_Internal_Versym;
235
/* Structure for syminfo section. */
238
unsigned short int si_boundto;
239
unsigned short int si_flags;
240
} Elf_Internal_Syminfo;
242
/* This structure appears on the stack and in NT_AUXV core file notes. */
250
/* This structure is used to describe how sections should be assigned
251
to program segments. */
253
struct elf_segment_map
255
/* Next program segment. */
256
struct elf_segment_map *next;
257
/* Program segment type. */
258
unsigned long p_type;
259
/* Program segment flags. */
260
unsigned long p_flags;
261
/* Program segment physical address. */
263
/* Program segment virtual address offset from section vma. */
264
bfd_vma p_vaddr_offset;
265
/* Program segment alignment. */
267
/* Segment size in file and memory */
269
/* Required size of filehdr + phdrs, if non-zero */
271
/* Whether the p_flags field is valid; if not, the flags are based
272
on the section flags. */
273
unsigned int p_flags_valid : 1;
274
/* Whether the p_paddr field is valid; if not, the physical address
275
is based on the section lma values. */
276
unsigned int p_paddr_valid : 1;
277
/* Whether the p_align field is valid; if not, PT_LOAD segment
278
alignment is based on the default maximum page size. */
279
unsigned int p_align_valid : 1;
280
/* Whether the p_size field is valid; if not, the size are based
281
on the section sizes. */
282
unsigned int p_size_valid : 1;
283
/* Whether this segment includes the file header. */
284
unsigned int includes_filehdr : 1;
285
/* Whether this segment includes the program headers. */
286
unsigned int includes_phdrs : 1;
287
/* Number of sections (may be 0). */
289
/* Sections. Actual number of elements is in count field. */
290
asection *sections[1];
293
/* .tbss is special. It doesn't contribute memory space to normal
294
segments and it doesn't take file space in normal segments. */
295
#define ELF_TBSS_SPECIAL(sec_hdr, segment) \
296
(((sec_hdr)->sh_flags & SHF_TLS) != 0 \
297
&& (sec_hdr)->sh_type == SHT_NOBITS \
298
&& (segment)->p_type != PT_TLS)
300
#define ELF_SECTION_SIZE(sec_hdr, segment) \
301
(ELF_TBSS_SPECIAL(sec_hdr, segment) ? 0 : (sec_hdr)->sh_size)
303
/* Decide if the section SEC_HDR is in SEGMENT. If CHECK_VMA, then
304
VMAs are checked for alloc sections. If STRICT, then a zero size
305
section won't match at the end of a segment, unless the segment
306
is also zero size. Regardless of STRICT and CHECK_VMA, zero size
307
sections won't match at the start or end of PT_DYNAMIC, unless
308
PT_DYNAMIC is itself zero sized. */
309
#define ELF_SECTION_IN_SEGMENT_1(sec_hdr, segment, check_vma, strict) \
310
((/* Only PT_LOAD, PT_GNU_RELRO and PT_TLS segments can contain \
311
SHF_TLS sections. */ \
312
((((sec_hdr)->sh_flags & SHF_TLS) != 0) \
313
&& ((segment)->p_type == PT_TLS \
314
|| (segment)->p_type == PT_GNU_RELRO \
315
|| (segment)->p_type == PT_LOAD)) \
316
/* PT_TLS segment contains only SHF_TLS sections, PT_PHDR no \
317
sections at all. */ \
318
|| (((sec_hdr)->sh_flags & SHF_TLS) == 0 \
319
&& (segment)->p_type != PT_TLS \
320
&& (segment)->p_type != PT_PHDR)) \
321
/* Any section besides one of type SHT_NOBITS must have file \
322
offsets within the segment. */ \
323
&& ((sec_hdr)->sh_type == SHT_NOBITS \
324
|| ((bfd_vma) (sec_hdr)->sh_offset >= (segment)->p_offset \
326
|| ((sec_hdr)->sh_offset - (segment)->p_offset \
327
<= (segment)->p_filesz - 1)) \
328
&& (((sec_hdr)->sh_offset - (segment)->p_offset \
329
+ ELF_SECTION_SIZE(sec_hdr, segment)) \
330
<= (segment)->p_filesz))) \
331
/* SHF_ALLOC sections must have VMAs within the segment. */ \
333
|| ((sec_hdr)->sh_flags & SHF_ALLOC) == 0 \
334
|| ((sec_hdr)->sh_addr >= (segment)->p_vaddr \
336
|| ((sec_hdr)->sh_addr - (segment)->p_vaddr \
337
<= (segment)->p_memsz - 1)) \
338
&& (((sec_hdr)->sh_addr - (segment)->p_vaddr \
339
+ ELF_SECTION_SIZE(sec_hdr, segment)) \
340
<= (segment)->p_memsz))) \
341
/* No zero size sections at start or end of PT_DYNAMIC. */ \
342
&& ((segment)->p_type != PT_DYNAMIC \
343
|| (sec_hdr)->sh_size != 0 \
344
|| (segment)->p_memsz == 0 \
345
|| (((sec_hdr)->sh_type == SHT_NOBITS \
346
|| ((bfd_vma) (sec_hdr)->sh_offset > (segment)->p_offset \
347
&& ((sec_hdr)->sh_offset - (segment)->p_offset \
348
< (segment)->p_filesz))) \
349
&& (((sec_hdr)->sh_flags & SHF_ALLOC) == 0 \
350
|| ((sec_hdr)->sh_addr > (segment)->p_vaddr \
351
&& ((sec_hdr)->sh_addr - (segment)->p_vaddr \
352
< (segment)->p_memsz))))))
354
#define ELF_SECTION_IN_SEGMENT(sec_hdr, segment) \
355
(ELF_SECTION_IN_SEGMENT_1 (sec_hdr, segment, 1, 0))
357
#define ELF_SECTION_IN_SEGMENT_STRICT(sec_hdr, segment) \
358
(ELF_SECTION_IN_SEGMENT_1 (sec_hdr, segment, 1, 1))
360
#endif /* _ELF_INTERNAL_H */