1 /* ELF support for BFD.
2 Copyright 1991, 1992, 1993, 1994, 1995, 1997, 1998, 2000, 2001, 2002,
3 2003, 2006, 2007, 2008, 2010 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 int st_shndx
; /* Associated section index */
130 typedef struct elf_internal_sym Elf_Internal_Sym
;
134 typedef struct elf_internal_note
{
135 unsigned long namesz
; /* Size of entry's owner string */
136 unsigned long descsz
; /* Size of the note descriptor */
137 unsigned long type
; /* Interpretation of the descriptor */
138 char * namedata
; /* Start of the name+desc data */
139 char * descdata
; /* Start of the desc data */
140 bfd_vma descpos
; /* File offset of the descdata */
143 /* Relocation Entries */
145 typedef struct elf_internal_rela
{
146 bfd_vma r_offset
; /* Location at which to apply the action */
147 bfd_vma r_info
; /* Index and Type of relocation */
148 bfd_vma r_addend
; /* Constant addend used to compute value */
151 /* dynamic section structure */
153 typedef struct elf_internal_dyn
{
154 /* This needs to support 64-bit values in elf64. */
155 bfd_vma d_tag
; /* entry tag value */
157 /* This needs to support 64-bit values in elf64. */
163 /* This structure appears in a SHT_GNU_verdef section. */
165 typedef struct elf_internal_verdef
{
166 unsigned short vd_version
; /* Version number of structure. */
167 unsigned short vd_flags
; /* Flags (VER_FLG_*). */
168 unsigned short vd_ndx
; /* Version index. */
169 unsigned short vd_cnt
; /* Number of verdaux entries. */
170 unsigned long vd_hash
; /* Hash of name. */
171 unsigned long vd_aux
; /* Offset to verdaux entries. */
172 unsigned long vd_next
; /* Offset to next verdef. */
174 /* These fields are set up when BFD reads in the structure. FIXME:
175 It would be cleaner to store these in a different structure. */
176 bfd
*vd_bfd
; /* BFD. */
177 const char *vd_nodename
; /* Version name. */
178 struct elf_internal_verdef
*vd_nextdef
; /* vd_next as pointer. */
179 struct elf_internal_verdaux
*vd_auxptr
; /* vd_aux as pointer. */
180 unsigned int vd_exp_refno
; /* Used by the linker. */
181 } Elf_Internal_Verdef
;
183 /* This structure appears in a SHT_GNU_verdef section. */
185 typedef struct elf_internal_verdaux
{
186 unsigned long vda_name
; /* String table offset of name. */
187 unsigned long vda_next
; /* Offset to next verdaux. */
189 /* These fields are set up when BFD reads in the structure. FIXME:
190 It would be cleaner to store these in a different structure. */
191 const char *vda_nodename
; /* vda_name as pointer. */
192 struct elf_internal_verdaux
*vda_nextptr
; /* vda_next as pointer. */
193 } Elf_Internal_Verdaux
;
195 /* This structure appears in a SHT_GNU_verneed section. */
197 typedef struct elf_internal_verneed
{
198 unsigned short vn_version
; /* Version number of structure. */
199 unsigned short vn_cnt
; /* Number of vernaux entries. */
200 unsigned long vn_file
; /* String table offset of library name. */
201 unsigned long vn_aux
; /* Offset to vernaux entries. */
202 unsigned long vn_next
; /* Offset to next verneed. */
204 /* These fields are set up when BFD reads in the structure. FIXME:
205 It would be cleaner to store these in a different structure. */
206 bfd
*vn_bfd
; /* BFD. */
207 const char *vn_filename
; /* vn_file as pointer. */
208 struct elf_internal_vernaux
*vn_auxptr
; /* vn_aux as pointer. */
209 struct elf_internal_verneed
*vn_nextref
; /* vn_nextref as pointer. */
210 } Elf_Internal_Verneed
;
212 /* This structure appears in a SHT_GNU_verneed section. */
214 typedef struct elf_internal_vernaux
{
215 unsigned long vna_hash
; /* Hash of dependency name. */
216 unsigned short vna_flags
; /* Flags (VER_FLG_*). */
217 unsigned short vna_other
; /* Unused. */
218 unsigned long vna_name
; /* String table offset to version name. */
219 unsigned long vna_next
; /* Offset to next vernaux. */
221 /* These fields are set up when BFD reads in the structure. FIXME:
222 It would be cleaner to store these in a different structure. */
223 const char *vna_nodename
; /* vna_name as pointer. */
224 struct elf_internal_vernaux
*vna_nextptr
; /* vna_next as pointer. */
225 } Elf_Internal_Vernaux
;
227 /* This structure appears in a SHT_GNU_versym section. This is not a
228 standard ELF structure; ELF just uses Elf32_Half. */
230 typedef struct elf_internal_versym
{
231 unsigned short vs_vers
;
232 } Elf_Internal_Versym
;
234 /* Structure for syminfo section. */
237 unsigned short int si_boundto
;
238 unsigned short int si_flags
;
239 } Elf_Internal_Syminfo
;
241 /* This structure appears on the stack and in NT_AUXV core file notes. */
249 /* This structure is used to describe how sections should be assigned
250 to program segments. */
252 struct elf_segment_map
254 /* Next program segment. */
255 struct elf_segment_map
*next
;
256 /* Program segment type. */
257 unsigned long p_type
;
258 /* Program segment flags. */
259 unsigned long p_flags
;
260 /* Program segment physical address. */
262 /* Program segment virtual address offset from section vma. */
263 bfd_vma p_vaddr_offset
;
264 /* Program segment alignment. */
266 /* Segment size in file and memory */
268 /* Required size of filehdr + phdrs, if non-zero */
270 /* Whether the p_flags field is valid; if not, the flags are based
271 on the section flags. */
272 unsigned int p_flags_valid
: 1;
273 /* Whether the p_paddr field is valid; if not, the physical address
274 is based on the section lma values. */
275 unsigned int p_paddr_valid
: 1;
276 /* Whether the p_align field is valid; if not, PT_LOAD segment
277 alignment is based on the default maximum page size. */
278 unsigned int p_align_valid
: 1;
279 /* Whether the p_size field is valid; if not, the size are based
280 on the section sizes. */
281 unsigned int p_size_valid
: 1;
282 /* Whether this segment includes the file header. */
283 unsigned int includes_filehdr
: 1;
284 /* Whether this segment includes the program headers. */
285 unsigned int includes_phdrs
: 1;
286 /* Number of sections (may be 0). */
288 /* Sections. Actual number of elements is in count field. */
289 asection
*sections
[1];
292 /* .tbss is special. It doesn't contribute memory space to normal
293 segments and it doesn't take file space in normal segments. */
294 #define ELF_SECTION_SIZE(sec_hdr, segment) \
295 ((!(((sec_hdr)->sh_flags & SHF_TLS) != 0 \
296 && (sec_hdr)->sh_type == SHT_NOBITS) \
297 || (segment)->p_type == PT_TLS) ? (sec_hdr)->sh_size : 0)
299 /* Decide if the given sec_hdr is in the given segment. PT_TLS segment
300 contains only SHF_TLS sections. Only PT_LOAD, PT_GNU_RELRO and
301 and PT_TLS segments can contain SHF_TLS sections. */
302 #define ELF_SECTION_IN_SEGMENT_1(sec_hdr, segment, check_vma) \
303 ((((((sec_hdr)->sh_flags & SHF_TLS) != 0) \
304 && ((segment)->p_type == PT_TLS \
305 || (segment)->p_type == PT_GNU_RELRO \
306 || (segment)->p_type == PT_LOAD)) \
307 || (((sec_hdr)->sh_flags & SHF_TLS) == 0 \
308 && (segment)->p_type != PT_TLS \
309 && (segment)->p_type != PT_PHDR)) \
310 /* Any section besides one of type SHT_NOBITS must have a file \
311 offset within the segment. */ \
312 && ((sec_hdr)->sh_type == SHT_NOBITS \
313 || ((bfd_vma) (sec_hdr)->sh_offset >= (segment)->p_offset \
314 && ((sec_hdr)->sh_offset + ELF_SECTION_SIZE(sec_hdr, segment) \
315 <= (segment)->p_offset + (segment)->p_filesz))) \
316 /* SHF_ALLOC sections must have VMAs within the segment. Be \
317 careful about segments right at the end of memory. */ \
319 || ((sec_hdr)->sh_flags & SHF_ALLOC) == 0 \
320 || ((sec_hdr)->sh_addr >= (segment)->p_vaddr \
321 && ((sec_hdr)->sh_addr - (segment)->p_vaddr \
322 + ELF_SECTION_SIZE(sec_hdr, segment) <= (segment)->p_memsz))))
324 #define ELF_SECTION_IN_SEGMENT(sec_hdr, segment) \
325 (ELF_SECTION_IN_SEGMENT_1 (sec_hdr, segment, 1))
327 #endif /* _ELF_INTERNAL_H */