385 lines
16 KiB
C
385 lines
16 KiB
C
/* ELF support for BFD.
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Copyright (C) 1991-2022 Free Software Foundation, Inc.
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Written by Fred Fish @ Cygnus Support, from information published
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in "UNIX System V Release 4, Programmers Guide: ANSI C and
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Programming Support Tools".
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This file is part of BFD, the Binary File Descriptor library.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
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MA 02110-1301, USA. */
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/* This file is part of ELF support for BFD, and contains the portions
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that describe how ELF is represented internally in the BFD library.
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I.E. it describes the in-memory representation of ELF. It requires
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the elf-common.h file which contains the portions that are common to
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both the internal and external representations. */
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/* NOTE that these structures are not kept in the same order as they appear
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in the object file. In some cases they've been reordered for more optimal
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packing under various circumstances. */
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#ifndef _ELF_INTERNAL_H
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#define _ELF_INTERNAL_H
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/* Special section indices, which may show up in st_shndx fields, among
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other places. */
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#undef SHN_UNDEF
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#undef SHN_LORESERVE
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#undef SHN_LOPROC
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#undef SHN_HIPROC
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#undef SHN_LOOS
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#undef SHN_HIOS
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#undef SHN_ABS
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#undef SHN_COMMON
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#undef SHN_XINDEX
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#undef SHN_HIRESERVE
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#define SHN_UNDEF 0 /* Undefined section reference */
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#define SHN_LORESERVE (-0x100u) /* Begin range of reserved indices */
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#define SHN_LOPROC (-0x100u) /* Begin range of appl-specific */
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#define SHN_HIPROC (-0xE1u) /* End range of appl-specific */
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#define SHN_LOOS (-0xE0u) /* OS specific semantics, lo */
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#define SHN_HIOS (-0xC1u) /* OS specific semantics, hi */
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#define SHN_ABS (-0xFu) /* Associated symbol is absolute */
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#define SHN_COMMON (-0xEu) /* Associated symbol is in common */
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#define SHN_XINDEX (-0x1u) /* Section index is held elsewhere */
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#define SHN_HIRESERVE (-0x1u) /* End range of reserved indices */
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#define SHN_BAD (-0x101u) /* Used internally by bfd */
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/* ELF Header */
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#define EI_NIDENT 16 /* Size of e_ident[] */
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typedef struct elf_internal_ehdr {
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unsigned char e_ident[EI_NIDENT]; /* ELF "magic number" */
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bfd_vma e_entry; /* Entry point virtual address */
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bfd_size_type e_phoff; /* Program header table file offset */
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bfd_size_type e_shoff; /* Section header table file offset */
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unsigned long e_version; /* Identifies object file version */
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unsigned long e_flags; /* Processor-specific flags */
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unsigned short e_type; /* Identifies object file type */
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unsigned short e_machine; /* Specifies required architecture */
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unsigned int e_ehsize; /* ELF header size in bytes */
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unsigned int e_phentsize; /* Program header table entry size */
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unsigned int e_phnum; /* Program header table entry count */
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unsigned int e_shentsize; /* Section header table entry size */
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unsigned int e_shnum; /* Section header table entry count */
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unsigned int e_shstrndx; /* Section header string table index */
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} Elf_Internal_Ehdr;
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/* Program header */
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struct elf_internal_phdr {
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unsigned long p_type; /* Identifies program segment type. */
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unsigned long p_flags; /* Segment flags. */
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bfd_vma p_offset; /* Segment file offset in octets. */
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bfd_vma p_vaddr; /* Segment virtual address in octets. */
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bfd_vma p_paddr; /* Segment physical address in octets. */
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bfd_vma p_filesz; /* Segment size in file in octets. */
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bfd_vma p_memsz; /* Segment size in memory in octets. */
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bfd_vma p_align; /* Segment alignment in bytes, file
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& memory */
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};
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typedef struct elf_internal_phdr Elf_Internal_Phdr;
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/* Section header */
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typedef struct elf_internal_shdr {
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unsigned int sh_name; /* Section name, index in string tbl */
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unsigned int sh_type; /* Type of section */
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bfd_vma sh_flags; /* Miscellaneous section attributes */
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bfd_vma sh_addr; /* Section virtual addr at execution in
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octets. */
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file_ptr sh_offset; /* Section file offset in octets. */
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bfd_size_type sh_size; /* Size of section in octets. */
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unsigned int sh_link; /* Index of another section */
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unsigned int sh_info; /* Additional section information */
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bfd_vma sh_addralign; /* Section alignment */
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bfd_size_type sh_entsize; /* Entry size if section holds table */
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/* The internal rep also has some cached info associated with it. */
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asection * bfd_section; /* Associated BFD section. */
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unsigned char *contents; /* Section contents. */
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} Elf_Internal_Shdr;
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/* Compression header */
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typedef struct elf_internal_chdr {
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unsigned int ch_type; /* Type of compression */
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bfd_size_type ch_size; /* Size of uncompressed data in bytes */
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bfd_vma ch_addralign; /* Alignment of uncompressed data */
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} Elf_Internal_Chdr;
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/* Symbol table entry */
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struct elf_internal_sym {
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bfd_vma st_value; /* Value of the symbol */
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bfd_vma st_size; /* Associated symbol size */
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unsigned long st_name; /* Symbol name, index in string tbl */
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unsigned char st_info; /* Type and binding attributes */
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unsigned char st_other; /* Visibilty, and target specific */
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unsigned char st_target_internal; /* Internal-only information */
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unsigned int st_shndx; /* Associated section index */
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};
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typedef struct elf_internal_sym Elf_Internal_Sym;
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/* Note segments */
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typedef struct elf_internal_note {
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unsigned long namesz; /* Size of entry's owner string */
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unsigned long descsz; /* Size of the note descriptor */
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unsigned long type; /* Interpretation of the descriptor */
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char * namedata; /* Start of the name+desc data */
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char * descdata; /* Start of the desc data */
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bfd_vma descpos; /* File offset of the descdata */
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} Elf_Internal_Note;
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/* Relocation Entries */
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typedef struct elf_internal_rela {
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bfd_vma r_offset; /* Location at which to apply the action */
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bfd_vma r_info; /* Index and Type of relocation */
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bfd_vma r_addend; /* Constant addend used to compute value */
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} Elf_Internal_Rela;
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/* dynamic section structure */
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typedef struct elf_internal_dyn {
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/* This needs to support 64-bit values in elf64. */
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bfd_vma d_tag; /* entry tag value */
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union {
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/* This needs to support 64-bit values in elf64. */
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bfd_vma d_val;
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bfd_vma d_ptr;
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} d_un;
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} Elf_Internal_Dyn;
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/* This structure appears in a SHT_GNU_verdef section. */
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typedef struct elf_internal_verdef {
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unsigned short vd_version; /* Version number of structure. */
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unsigned short vd_flags; /* Flags (VER_FLG_*). */
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unsigned short vd_ndx; /* Version index. */
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unsigned short vd_cnt; /* Number of verdaux entries. */
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unsigned long vd_hash; /* Hash of name. */
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unsigned long vd_aux; /* Offset to verdaux entries. */
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unsigned long vd_next; /* Offset to next verdef. */
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/* These fields are set up when BFD reads in the structure. FIXME:
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It would be cleaner to store these in a different structure. */
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bfd *vd_bfd; /* BFD. */
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const char *vd_nodename; /* Version name. */
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struct elf_internal_verdef *vd_nextdef; /* vd_next as pointer. */
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struct elf_internal_verdaux *vd_auxptr; /* vd_aux as pointer. */
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unsigned int vd_exp_refno; /* Used by the linker. */
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} Elf_Internal_Verdef;
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/* This structure appears in a SHT_GNU_verdef section. */
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typedef struct elf_internal_verdaux {
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unsigned long vda_name; /* String table offset of name. */
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unsigned long vda_next; /* Offset to next verdaux. */
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/* These fields are set up when BFD reads in the structure. FIXME:
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It would be cleaner to store these in a different structure. */
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const char *vda_nodename; /* vda_name as pointer. */
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struct elf_internal_verdaux *vda_nextptr; /* vda_next as pointer. */
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} Elf_Internal_Verdaux;
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/* This structure appears in a SHT_GNU_verneed section. */
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typedef struct elf_internal_verneed {
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unsigned short vn_version; /* Version number of structure. */
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unsigned short vn_cnt; /* Number of vernaux entries. */
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unsigned long vn_file; /* String table offset of library name. */
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unsigned long vn_aux; /* Offset to vernaux entries. */
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unsigned long vn_next; /* Offset to next verneed. */
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/* These fields are set up when BFD reads in the structure. FIXME:
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It would be cleaner to store these in a different structure. */
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bfd *vn_bfd; /* BFD. */
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const char *vn_filename; /* vn_file as pointer. */
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struct elf_internal_vernaux *vn_auxptr; /* vn_aux as pointer. */
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struct elf_internal_verneed *vn_nextref; /* vn_nextref as pointer. */
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} Elf_Internal_Verneed;
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/* This structure appears in a SHT_GNU_verneed section. */
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typedef struct elf_internal_vernaux {
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unsigned long vna_hash; /* Hash of dependency name. */
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unsigned short vna_flags; /* Flags (VER_FLG_*). */
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unsigned short vna_other; /* Unused. */
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unsigned long vna_name; /* String table offset to version name. */
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unsigned long vna_next; /* Offset to next vernaux. */
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/* These fields are set up when BFD reads in the structure. FIXME:
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It would be cleaner to store these in a different structure. */
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const char *vna_nodename; /* vna_name as pointer. */
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struct elf_internal_vernaux *vna_nextptr; /* vna_next as pointer. */
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} Elf_Internal_Vernaux;
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/* This structure appears in a SHT_GNU_versym section. This is not a
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standard ELF structure; ELF just uses Elf32_Half. */
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typedef struct elf_internal_versym {
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unsigned short vs_vers;
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} Elf_Internal_Versym;
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/* Structure for syminfo section. */
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typedef struct
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{
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unsigned short int si_boundto;
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unsigned short int si_flags;
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} Elf_Internal_Syminfo;
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/* This structure appears on the stack and in NT_AUXV core file notes. */
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typedef struct
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{
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bfd_vma a_type;
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bfd_vma a_val;
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} Elf_Internal_Auxv;
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/* This structure is used to describe how sections should be assigned
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to program segments. */
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struct elf_segment_map
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{
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/* Next program segment. */
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struct elf_segment_map *next;
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/* Program segment type. */
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unsigned long p_type;
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/* Program segment flags. */
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unsigned long p_flags;
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/* Program segment physical address in octets. */
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bfd_vma p_paddr;
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/* Program segment virtual address offset from section vma in bytes. */
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bfd_vma p_vaddr_offset;
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/* Program segment alignment. */
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bfd_vma p_align;
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/* Segment size in file and memory in octets. */
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bfd_vma p_size;
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/* Whether the p_flags field is valid; if not, the flags are based
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on the section flags. */
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unsigned int p_flags_valid : 1;
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/* Whether the p_paddr field is valid; if not, the physical address
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is based on the section lma values. */
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unsigned int p_paddr_valid : 1;
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/* Whether the p_align field is valid; if not, PT_LOAD segment
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alignment is based on the default maximum page size. */
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unsigned int p_align_valid : 1;
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/* Whether the p_size field is valid; if not, the size are based
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on the section sizes. */
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unsigned int p_size_valid : 1;
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/* Whether this segment includes the file header. */
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unsigned int includes_filehdr : 1;
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/* Whether this segment includes the program headers. */
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unsigned int includes_phdrs : 1;
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/* Assume this PT_LOAD header has an lma of zero when sorting
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headers before assigning file offsets. PT_LOAD headers with this
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flag set are placed after one with includes_filehdr set, and
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before PT_LOAD headers without this flag set. */
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unsigned int no_sort_lma : 1;
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/* Index holding original order before sorting segments. */
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unsigned int idx;
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/* Number of sections (may be 0). */
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unsigned int count;
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/* Sections. Actual number of elements is in count field. */
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asection *sections[1];
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};
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/* .tbss is special. It doesn't contribute memory space to normal
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segments and it doesn't take file space in normal segments. */
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#define ELF_TBSS_SPECIAL(sec_hdr, segment) \
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(((sec_hdr)->sh_flags & SHF_TLS) != 0 \
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&& (sec_hdr)->sh_type == SHT_NOBITS \
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&& (segment)->p_type != PT_TLS)
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#define ELF_SECTION_SIZE(sec_hdr, segment) \
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(ELF_TBSS_SPECIAL(sec_hdr, segment) ? 0 : (sec_hdr)->sh_size)
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/* Decide if the section SEC_HDR is in SEGMENT. If CHECK_VMA, then
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VMAs are checked for alloc sections. If STRICT, then a zero size
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section won't match at the end of a segment, unless the segment
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is also zero size. Regardless of STRICT and CHECK_VMA, zero size
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sections won't match at the start or end of PT_DYNAMIC nor PT_NOTE,
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unless PT_DYNAMIC and PT_NOTE are themselves zero sized. */
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#define ELF_SECTION_IN_SEGMENT_1(sec_hdr, segment, check_vma, strict) \
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((/* Only PT_LOAD, PT_GNU_RELRO and PT_TLS segments can contain \
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SHF_TLS sections. */ \
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((((sec_hdr)->sh_flags & SHF_TLS) != 0) \
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&& ((segment)->p_type == PT_TLS \
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|| (segment)->p_type == PT_GNU_RELRO \
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|| (segment)->p_type == PT_LOAD)) \
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/* PT_TLS segment contains only SHF_TLS sections, PT_PHDR no \
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sections at all. */ \
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|| (((sec_hdr)->sh_flags & SHF_TLS) == 0 \
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&& (segment)->p_type != PT_TLS \
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&& (segment)->p_type != PT_PHDR)) \
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/* PT_LOAD and similar segments only have SHF_ALLOC sections. */ \
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&& !(((sec_hdr)->sh_flags & SHF_ALLOC) == 0 \
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&& ((segment)->p_type == PT_LOAD \
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|| (segment)->p_type == PT_DYNAMIC \
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|| (segment)->p_type == PT_GNU_EH_FRAME \
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|| (segment)->p_type == PT_GNU_STACK \
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|| (segment)->p_type == PT_GNU_RELRO \
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|| ((segment)->p_type >= PT_GNU_MBIND_LO \
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&& (segment)->p_type <= PT_GNU_MBIND_HI))) \
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/* Any section besides one of type SHT_NOBITS must have file \
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offsets within the segment. */ \
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&& ((sec_hdr)->sh_type == SHT_NOBITS \
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|| ((bfd_vma) (sec_hdr)->sh_offset >= (segment)->p_offset \
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&& (!(strict) \
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|| ((sec_hdr)->sh_offset - (segment)->p_offset \
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<= (segment)->p_filesz - 1)) \
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&& (((sec_hdr)->sh_offset - (segment)->p_offset \
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+ ELF_SECTION_SIZE(sec_hdr, segment)) \
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<= (segment)->p_filesz))) \
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/* SHF_ALLOC sections must have VMAs within the segment. */ \
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&& (!(check_vma) \
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|| ((sec_hdr)->sh_flags & SHF_ALLOC) == 0 \
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|| ((sec_hdr)->sh_addr >= (segment)->p_vaddr \
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&& (!(strict) \
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|| ((sec_hdr)->sh_addr - (segment)->p_vaddr \
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<= (segment)->p_memsz - 1)) \
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&& (((sec_hdr)->sh_addr - (segment)->p_vaddr \
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+ ELF_SECTION_SIZE(sec_hdr, segment)) \
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<= (segment)->p_memsz))) \
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/* No zero size sections at start or end of PT_DYNAMIC nor \
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PT_NOTE. */ \
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&& (((segment)->p_type != PT_DYNAMIC \
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&& (segment)->p_type != PT_NOTE) \
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|| (sec_hdr)->sh_size != 0 \
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|| (segment)->p_memsz == 0 \
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|| (((sec_hdr)->sh_type == SHT_NOBITS \
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|| ((bfd_vma) (sec_hdr)->sh_offset > (segment)->p_offset \
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&& ((sec_hdr)->sh_offset - (segment)->p_offset \
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< (segment)->p_filesz))) \
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&& (((sec_hdr)->sh_flags & SHF_ALLOC) == 0 \
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|| ((sec_hdr)->sh_addr > (segment)->p_vaddr \
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&& ((sec_hdr)->sh_addr - (segment)->p_vaddr \
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< (segment)->p_memsz))))))
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#define ELF_SECTION_IN_SEGMENT(sec_hdr, segment) \
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(ELF_SECTION_IN_SEGMENT_1 (sec_hdr, segment, 1, 0))
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#define ELF_SECTION_IN_SEGMENT_STRICT(sec_hdr, segment) \
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(ELF_SECTION_IN_SEGMENT_1 (sec_hdr, segment, 1, 1))
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#endif /* _ELF_INTERNAL_H */
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