053529f526
Also remove workarounds for older NDKs. Differential Revision: https://phabricator.services.mozilla.com/D211299
186 lines
4.3 KiB
C++
186 lines
4.3 KiB
C++
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this file,
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* You can obtain one at http://mozilla.org/MPL/2.0/. */
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#ifndef Elfxx_h
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#define Elfxx_h
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#include "Utils.h"
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#include <elf.h>
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#include <endian.h>
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/**
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* Generic ELF macros for the target system
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*/
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#ifdef __LP64__
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# define Elf_(type) Elf64_##type
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# define ELFCLASS ELFCLASS64
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# define ELF_R_TYPE ELF64_R_TYPE
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# define ELF_R_SYM ELF64_R_SYM
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# ifndef ELF_ST_BIND
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# define ELF_ST_BIND ELF64_ST_BIND
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# endif
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#else
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# define Elf_(type) Elf32_##type
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# define ELFCLASS ELFCLASS32
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# define ELF_R_TYPE ELF32_R_TYPE
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# define ELF_R_SYM ELF32_R_SYM
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# ifndef ELF_ST_BIND
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# define ELF_ST_BIND ELF32_ST_BIND
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# endif
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#endif
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#ifndef __BYTE_ORDER
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# error Cannot find endianness
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#endif
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#if __BYTE_ORDER == __LITTLE_ENDIAN
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# define ELFDATA ELFDATA2LSB
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#elif __BYTE_ORDER == __BIG_ENDIAN
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# define ELFDATA ELFDATA2MSB
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#endif
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#ifdef __linux__
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# define ELFOSABI ELFOSABI_LINUX
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# ifdef EI_ABIVERSION
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# define ELFABIVERSION 0
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# endif
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#else
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# error Unknown ELF OSABI
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#endif
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#if defined(__i386__)
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# define ELFMACHINE EM_386
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// Doing this way probably doesn't scale to other architectures
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# define R_ABS R_386_32
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# define R_GLOB_DAT R_386_GLOB_DAT
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# define R_JMP_SLOT R_386_JMP_SLOT
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# define R_RELATIVE R_386_RELATIVE
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# define RELOC(n) DT_REL##n
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# define UNSUPPORTED_RELOC(n) DT_RELA##n
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# define STR_RELOC(n) "DT_REL" #n
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# define Reloc Rel
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#elif defined(__x86_64__)
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# define ELFMACHINE EM_X86_64
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# define R_ABS R_X86_64_64
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# define R_GLOB_DAT R_X86_64_GLOB_DAT
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# define R_JMP_SLOT R_X86_64_JUMP_SLOT
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# define R_RELATIVE R_X86_64_RELATIVE
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# define RELOC(n) DT_RELA##n
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# define UNSUPPORTED_RELOC(n) DT_REL##n
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# define STR_RELOC(n) "DT_RELA" #n
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# define Reloc Rela
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#elif defined(__arm__)
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# define ELFMACHINE EM_ARM
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# ifndef R_ARM_ABS32
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# define R_ARM_ABS32 2
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# endif
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# ifndef R_ARM_GLOB_DAT
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# define R_ARM_GLOB_DAT 21
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# endif
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# ifndef R_ARM_JUMP_SLOT
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# define R_ARM_JUMP_SLOT 22
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# endif
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# ifndef R_ARM_RELATIVE
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# define R_ARM_RELATIVE 23
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# endif
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# define R_ABS R_ARM_ABS32
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# define R_GLOB_DAT R_ARM_GLOB_DAT
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# define R_JMP_SLOT R_ARM_JUMP_SLOT
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# define R_RELATIVE R_ARM_RELATIVE
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# define RELOC(n) DT_REL##n
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# define UNSUPPORTED_RELOC(n) DT_RELA##n
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# define STR_RELOC(n) "DT_REL" #n
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# define Reloc Rel
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#elif defined(__aarch64__)
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# define ELFMACHINE EM_AARCH64
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# define R_ABS R_AARCH64_ABS64
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# define R_GLOB_DAT R_AARCH64_GLOB_DAT
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# define R_JMP_SLOT R_AARCH64_JUMP_SLOT
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# define R_RELATIVE R_AARCH64_RELATIVE
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# define RELOC(n) DT_RELA##n
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# define UNSUPPORTED_RELOC(n) DT_REL##n
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# define STR_RELOC(n) "DT_RELA" #n
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# define Reloc Rela
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#else
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# error Unknown ELF machine type
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#endif
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namespace Elf {
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/**
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* Define a few basic Elf Types
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*/
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typedef Elf_(Phdr) Phdr;
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typedef Elf_(Dyn) Dyn;
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typedef Elf_(Sym) Sym;
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typedef Elf_(Addr) Addr;
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typedef Elf_(Word) Word;
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typedef Elf_(Half) Half;
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/**
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* Helper class around the standard Elf header struct
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*/
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struct Ehdr : public Elf_(Ehdr) {
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/**
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* Equivalent to reinterpret_cast<const Ehdr *>(buf), but additionally
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* checking that this is indeed an Elf header and that the Elf type
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* corresponds to that of the system
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*/
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static const Ehdr* validate(const void* buf);
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};
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/**
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* Elf String table
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*/
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class Strtab : public UnsizedArray<const char> {
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public:
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/**
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* Returns the string at the given index in the table
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*/
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const char* GetStringAt(off_t index) const {
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return &UnsizedArray<const char>::operator[](index);
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}
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};
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/**
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* Helper class around Elf relocation.
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*/
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struct Rel
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: public Elf_(Rel){/**
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* Returns the addend for the relocation, which is the
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* value stored at r_offset.
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*/
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Addr GetAddend(void* base)
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const {return *(reinterpret_cast<const Addr*>(
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reinterpret_cast<const char*>(base) + r_offset));
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} // namespace Elf
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}
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;
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/**
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* Helper class around Elf relocation with addend.
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*/
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struct Rela
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: public Elf_(Rela){/**
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* Returns the addend for the relocation.
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*/
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Addr GetAddend(void* base) const {return r_addend;
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}
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}
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;
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} /* namespace Elf */
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#endif /* Elfxx_h */
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