michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef Elfxx_h
michael@0: #define Elfxx_h
michael@0: 
michael@0: /**
michael@0:  * Android system headers have two different elf.h file. The one under linux/
michael@0:  * is the most complete.
michael@0:  */
michael@0: #ifdef ANDROID
michael@0: #include <linux/elf.h>
michael@0: #else
michael@0: #include <elf.h>
michael@0: #endif
michael@0: #include <endian.h>
michael@0: 
michael@0: #if defined(__ARM_EABI__) && !defined(PT_ARM_EXIDX)
michael@0: #define PT_ARM_EXIDX 0x70000001
michael@0: #endif
michael@0: 
michael@0: /**
michael@0:  * Generic ELF macros for the target system
michael@0:  */
michael@0: #ifdef __LP64__
michael@0: #define Elf_(type) Elf64_ ## type
michael@0: #define ELFCLASS ELFCLASS64
michael@0: #define ELF_R_TYPE ELF64_R_TYPE
michael@0: #define ELF_R_SYM ELF64_R_SYM
michael@0: #ifndef ELF_ST_BIND
michael@0: #define ELF_ST_BIND ELF64_ST_BIND
michael@0: #endif
michael@0: #else
michael@0: #define Elf_(type) Elf32_ ## type
michael@0: #define ELFCLASS ELFCLASS32
michael@0: #define ELF_R_TYPE ELF32_R_TYPE
michael@0: #define ELF_R_SYM ELF32_R_SYM
michael@0: #ifndef ELF_ST_BIND
michael@0: #define ELF_ST_BIND ELF32_ST_BIND
michael@0: #endif
michael@0: #endif
michael@0: 
michael@0: #ifndef __BYTE_ORDER
michael@0: #error Cannot find endianness
michael@0: #endif
michael@0: 
michael@0: #if __BYTE_ORDER == __LITTLE_ENDIAN
michael@0: #define ELFDATA ELFDATA2LSB
michael@0: #elif __BYTE_ORDER == __BIG_ENDIAN
michael@0: #define ELFDATA ELFDATA2MSB
michael@0: #endif
michael@0: 
michael@0: #ifdef __linux__
michael@0: #define ELFOSABI ELFOSABI_LINUX
michael@0: #ifdef EI_ABIVERSION
michael@0: #define ELFABIVERSION 0
michael@0: #endif
michael@0: #else
michael@0: #error Unknown ELF OSABI
michael@0: #endif
michael@0: 
michael@0: #if defined(__i386__)
michael@0: #define ELFMACHINE EM_386
michael@0: 
michael@0: // Doing this way probably doesn't scale to other architectures
michael@0: #define R_ABS R_386_32
michael@0: #define R_GLOB_DAT R_386_GLOB_DAT
michael@0: #define R_JMP_SLOT R_386_JMP_SLOT
michael@0: #define R_RELATIVE R_386_RELATIVE
michael@0: #define RELOC(n) DT_REL ## n
michael@0: #define UNSUPPORTED_RELOC(n) DT_RELA ## n
michael@0: #define STR_RELOC(n) "DT_REL" # n
michael@0: #define Reloc Rel
michael@0: 
michael@0: #elif defined(__x86_64__)
michael@0: #define ELFMACHINE EM_X86_64
michael@0: 
michael@0: #define R_ABS R_X86_64_64
michael@0: #define R_GLOB_DAT R_X86_64_GLOB_DAT
michael@0: #define R_JMP_SLOT R_X86_64_JUMP_SLOT
michael@0: #define R_RELATIVE R_X86_64_RELATIVE
michael@0: #define RELOC(n) DT_RELA ## n
michael@0: #define UNSUPPORTED_RELOC(n) DT_REL ## n
michael@0: #define STR_RELOC(n) "DT_RELA" # n
michael@0: #define Reloc Rela
michael@0: 
michael@0: #elif defined(__arm__)
michael@0: #define ELFMACHINE EM_ARM
michael@0: 
michael@0: #ifndef R_ARM_ABS32
michael@0: #define R_ARM_ABS32 2
michael@0: #endif
michael@0: #ifndef R_ARM_GLOB_DAT
michael@0: #define R_ARM_GLOB_DAT 21
michael@0: #endif
michael@0: #ifndef R_ARM_JUMP_SLOT
michael@0: #define R_ARM_JUMP_SLOT 22
michael@0: #endif
michael@0: #ifndef R_ARM_RELATIVE
michael@0: #define R_ARM_RELATIVE 23
michael@0: #endif
michael@0: 
michael@0: #define R_ABS R_ARM_ABS32
michael@0: #define R_GLOB_DAT R_ARM_GLOB_DAT
michael@0: #define R_JMP_SLOT R_ARM_JUMP_SLOT
michael@0: #define R_RELATIVE R_ARM_RELATIVE
michael@0: #define RELOC(n) DT_REL ## n
michael@0: #define UNSUPPORTED_RELOC(n) DT_RELA ## n
michael@0: #define STR_RELOC(n) "DT_REL" # n
michael@0: #define Reloc Rel
michael@0: 
michael@0: #else
michael@0: #error Unknown ELF machine type
michael@0: #endif
michael@0: 
michael@0: /**
michael@0:  * Android system headers don't have all definitions
michael@0:  */
michael@0: #ifndef STN_UNDEF
michael@0: #define STN_UNDEF 0
michael@0: #endif
michael@0: #ifndef DT_INIT_ARRAY
michael@0: #define DT_INIT_ARRAY 25
michael@0: #endif
michael@0: #ifndef DT_FINI_ARRAY
michael@0: #define DT_FINI_ARRAY 26
michael@0: #endif
michael@0: #ifndef DT_INIT_ARRAYSZ
michael@0: #define DT_INIT_ARRAYSZ 27
michael@0: #endif
michael@0: #ifndef DT_FINI_ARRAYSZ
michael@0: #define DT_FINI_ARRAYSZ 28
michael@0: #endif
michael@0: #ifndef DT_RELACOUNT
michael@0: #define DT_RELACOUNT 0x6ffffff9
michael@0: #endif
michael@0: #ifndef DT_RELCOUNT
michael@0: #define DT_RELCOUNT 0x6ffffffa
michael@0: #endif
michael@0: #ifndef DT_VERSYM
michael@0: #define DT_VERSYM 0x6ffffff0
michael@0: #endif
michael@0: #ifndef DT_VERDEF
michael@0: #define DT_VERDEF 0x6ffffffc
michael@0: #endif
michael@0: #ifndef DT_VERDEFNUM
michael@0: #define DT_VERDEFNUM 0x6ffffffd
michael@0: #endif
michael@0: #ifndef DT_VERNEED
michael@0: #define DT_VERNEED 0x6ffffffe
michael@0: #endif
michael@0: #ifndef DT_VERNEEDNUM
michael@0: #define DT_VERNEEDNUM 0x6fffffff
michael@0: #endif
michael@0: #ifndef DT_FLAGS_1
michael@0: #define DT_FLAGS_1 0x6ffffffb
michael@0: #endif
michael@0: #ifndef DT_FLAGS
michael@0: #define DT_FLAGS 30
michael@0: #endif
michael@0: #ifndef DF_SYMBOLIC
michael@0: #define DF_SYMBOLIC 0x00000002
michael@0: #endif
michael@0: #ifndef DF_TEXTREL
michael@0: #define DF_TEXTREL 0x00000004
michael@0: #endif
michael@0: 
michael@0: namespace Elf {
michael@0: 
michael@0: /**
michael@0:  * Define a few basic Elf Types
michael@0:  */
michael@0: typedef Elf_(Phdr) Phdr;
michael@0: typedef Elf_(Dyn) Dyn;
michael@0: typedef Elf_(Sym) Sym;
michael@0: typedef Elf_(Addr) Addr;
michael@0: typedef Elf_(Word) Word;
michael@0: typedef Elf_(Half) Half;
michael@0: 
michael@0: /**
michael@0:  * Helper class around the standard Elf header struct
michael@0:  */
michael@0: struct Ehdr: public Elf_(Ehdr)
michael@0: {
michael@0:   /**
michael@0:    * Equivalent to reinterpret_cast<const Ehdr *>(buf), but additionally
michael@0:    * checking that this is indeed an Elf header and that the Elf type
michael@0:    * corresponds to that of the system
michael@0:    */
michael@0:   static const Ehdr *validate(const void *buf);
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Elf String table
michael@0:  */
michael@0: class Strtab: public UnsizedArray<const char>
michael@0: {
michael@0: public:
michael@0:   /**
michael@0:    * Returns the string at the given index in the table
michael@0:    */
michael@0:   const char *GetStringAt(off_t index) const
michael@0:   {
michael@0:     return &UnsizedArray<const char>::operator[](index);
michael@0:   }
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Helper class around Elf relocation.
michael@0:  */
michael@0: struct Rel: public Elf_(Rel)
michael@0: {
michael@0:   /**
michael@0:    * Returns the addend for the relocation, which is the value stored
michael@0:    * at r_offset.
michael@0:    */
michael@0:   Addr GetAddend(void *base) const
michael@0:   {
michael@0:     return *(reinterpret_cast<const Addr *>(
michael@0:                    reinterpret_cast<const char *>(base) + r_offset));
michael@0:   }
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Helper class around Elf relocation with addend.
michael@0:  */
michael@0: struct Rela: public Elf_(Rela)
michael@0: {
michael@0:   /**
michael@0:    * Returns the addend for the relocation.
michael@0:    */
michael@0:   Addr GetAddend(void *base) const
michael@0:   {
michael@0:     return r_addend;
michael@0:   }
michael@0: };
michael@0: 
michael@0: } /* namespace Elf */
michael@0: 
michael@0: #endif /* Elfxx_h */