The Tor Browser: mozglue/linker/Elfxx.h@b8a032363ba2 (annotated)

mozglue/linker/Elfxx.h@b8a032363ba2 (annotated)

mozglue/linker/Elfxx.h

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

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

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mozglue/linker/Elfxx.h@b8a032363ba2 (annotated)

mozglue/linker/Elfxx.h