source: trunk/libs/newlib/src/include/elf/internal.h @ 496

Last change on this file since 496 was 444, checked in by satin@…, 7 years ago

add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc
File size: 14.4 KB
Line 
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.
4
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".
8
9   This file is part of BFD, the Binary File Descriptor library.
10
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.
15
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.
20
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.  */
25
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.  */
31
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.  */
35
36#ifndef _ELF_INTERNAL_H
37#define _ELF_INTERNAL_H
38
39/* Special section indices, which may show up in st_shndx fields, among
40   other places.  */
41
42#undef SHN_UNDEF
43#undef SHN_LORESERVE
44#undef SHN_LOPROC
45#undef SHN_HIPROC
46#undef SHN_LOOS
47#undef SHN_HIOS
48#undef SHN_ABS
49#undef SHN_COMMON
50#undef SHN_XINDEX
51#undef SHN_HIRESERVE
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 */
63
64/* ELF Header */
65
66#define EI_NIDENT       16              /* Size of e_ident[] */
67
68typedef 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 */
83} Elf_Internal_Ehdr;
84
85/* Program header */
86
87struct 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 */
96};
97
98typedef struct elf_internal_phdr Elf_Internal_Phdr;
99
100/* Section header */
101
102typedef 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 */
113
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.  */
117} Elf_Internal_Shdr;
118
119/* Symbol table entry */
120
121struct 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 */
129};
130
131typedef struct elf_internal_sym Elf_Internal_Sym;
132
133/* Note segments */
134
135typedef 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 */
142} Elf_Internal_Note;
143
144/* Relocation Entries */
145
146typedef 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 */
150} Elf_Internal_Rela;
151
152/* dynamic section structure */
153
154typedef struct elf_internal_dyn {
155  /* This needs to support 64-bit values in elf64.  */
156  bfd_vma d_tag;                /* entry tag value */
157  union {
158    /* This needs to support 64-bit values in elf64.  */
159    bfd_vma     d_val;
160    bfd_vma     d_ptr;
161  } d_un;
162} Elf_Internal_Dyn;
163
164/* This structure appears in a SHT_GNU_verdef section.  */
165
166typedef 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.  */
174
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;
183
184/* This structure appears in a SHT_GNU_verdef section.  */
185
186typedef struct elf_internal_verdaux {
187  unsigned long vda_name;       /* String table offset of name.  */
188  unsigned long vda_next;       /* Offset to next verdaux.  */
189
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;
195
196/* This structure appears in a SHT_GNU_verneed section.  */
197
198typedef 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.  */
204
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;
212
213/* This structure appears in a SHT_GNU_verneed section.  */
214
215typedef 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.  */
221
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;
227
228/* This structure appears in a SHT_GNU_versym section.  This is not a
229   standard ELF structure; ELF just uses Elf32_Half.  */
230
231typedef struct elf_internal_versym {
232  unsigned short vs_vers;
233} Elf_Internal_Versym;
234
235/* Structure for syminfo section.  */
236typedef struct
237{
238  unsigned short int    si_boundto;
239  unsigned short int    si_flags;
240} Elf_Internal_Syminfo;
241
242/* This structure appears on the stack and in NT_AUXV core file notes.  */
243typedef struct
244{
245  bfd_vma a_type;
246  bfd_vma a_val;
247} Elf_Internal_Auxv;
248
249
250/* This structure is used to describe how sections should be assigned
251   to program segments.  */
252
253struct elf_segment_map
254{
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.  */
262  bfd_vma p_paddr;
263  /* Program segment virtual address offset from section vma.  */
264  bfd_vma p_vaddr_offset;
265  /* Program segment alignment.  */
266  bfd_vma p_align;
267  /* Segment size in file and memory */
268  bfd_vma p_size;
269  /* Required size of filehdr + phdrs, if non-zero */
270  bfd_vma header_size;
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).  */
288  unsigned int count;
289  /* Sections.  Actual number of elements is in count field.  */
290  asection *sections[1];
291};
292
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)
299
300#define ELF_SECTION_SIZE(sec_hdr, segment)                      \
301  (ELF_TBSS_SPECIAL(sec_hdr, segment) ? 0 : (sec_hdr)->sh_size)
302
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        \
325           && (!(strict)                                                \
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.  */         \
332   && (!(check_vma)                                                     \
333       || ((sec_hdr)->sh_flags & SHF_ALLOC) == 0                        \
334       || ((sec_hdr)->sh_addr >= (segment)->p_vaddr                     \
335           && (!(strict)                                                \
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))))))
353
354#define ELF_SECTION_IN_SEGMENT(sec_hdr, segment)                        \
355  (ELF_SECTION_IN_SEGMENT_1 (sec_hdr, segment, 1, 0))
356
357#define ELF_SECTION_IN_SEGMENT_STRICT(sec_hdr, segment)                 \
358  (ELF_SECTION_IN_SEGMENT_1 (sec_hdr, segment, 1, 1))
359
360#endif /* _ELF_INTERNAL_H */
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