fs/compat_binfmt_elf.c

   1 /*
   2  * 32-bit compatibility support for ELF format executables and core dumps.
   3  *
   4  * Copyright (C) 2007 Red Hat, Inc.  All rights reserved.
   5  *
   6  * This copyrighted material is made available to anyone wishing to use,
   7  * modify, copy, or redistribute it subject to the terms and conditions
   8  * of the GNU General Public License v.2.
   9  *
  10  * Red Hat Author: Roland McGrath.
  11  *
  12  * This file is used in a 64-bit kernel that wants to support 32-bit ELF.
  13  * asm/elf.h is responsible for defining the compat_* and COMPAT_* macros
  14  * used below, with definitions appropriate for 32-bit ABI compatibility.
  15  *
  16  * We use macros to rename the ABI types and machine-dependent
  17  * functions used in binfmt_elf.c to compat versions.
  18  */
  19
  20 #include <linux/elfcore-compat.h>
  21 #include <linux/time.h>
  22
  23 /*
  24  * Rename the basic ELF layout types to refer to the 32-bit class of files.
  25  */
  26 #undef  ELF_CLASS
  27 #define ELF_CLASS       ELFCLASS32
  28
  29 #undef  elfhdr
  30 #undef  elf_phdr
  31 #undef  elf_shdr
  32 #undef  elf_note
  33 #undef  elf_addr_t
  34 #define elfhdr          elf32_hdr
  35 #define elf_phdr        elf32_phdr
  36 #define elf_shdr        elf32_shdr
  37 #define elf_note        elf32_note
  38 #define elf_addr_t      Elf32_Addr
  39
  40 /*
  41  * The machine-dependent core note format types are defined in elfcore-compat.h,
  42  * which requires asm/elf.h to define compat_elf_gregset_t et al.
  43  */
  44 #define elf_prstatus    compat_elf_prstatus
  45 #define elf_prpsinfo    compat_elf_prpsinfo
  46
  47 /*
  48  * Compat version of cputime_to_compat_timeval, perhaps this
  49  * should be an inline in <linux/compat.h>.
  50  */
  51 static void cputime_to_compat_timeval(const cputime_t cputime,
  52                                       struct compat_timeval *value)
  53 {
  54         struct timeval tv;
  55         cputime_to_timeval(cputime, &tv);
  56         value->tv_sec = tv.tv_sec;
  57         value->tv_usec = tv.tv_usec;
  58 }
  59
  60 #undef cputime_to_timeval
  61 #define cputime_to_timeval cputime_to_compat_timeval
  62
  63
  64 /*
  65  * To use this file, asm/elf.h must define compat_elf_check_arch.
  66  * The other following macros can be defined if the compat versions
  67  * differ from the native ones, or omitted when they match.
  68  */
  69
  70 #undef  ELF_ARCH
  71 #undef  elf_check_arch
  72 #define elf_check_arch  compat_elf_check_arch
  73
  74 #ifdef  COMPAT_ELF_PLATFORM
  75 #undef  ELF_PLATFORM
  76 #define ELF_PLATFORM            COMPAT_ELF_PLATFORM
  77 #endif
  78
  79 #ifdef  COMPAT_ELF_HWCAP
  80 #undef  ELF_HWCAP
  81 #define ELF_HWCAP               COMPAT_ELF_HWCAP
  82 #endif
  83
  84 #ifdef  COMPAT_ARCH_DLINFO
  85 #undef  ARCH_DLINFO
  86 #define ARCH_DLINFO             COMPAT_ARCH_DLINFO
  87 #endif
  88
  89 #ifdef  COMPAT_ELF_ET_DYN_BASE
  90 #undef  ELF_ET_DYN_BASE
  91 #define ELF_ET_DYN_BASE         COMPAT_ELF_ET_DYN_BASE
  92 #endif
  93
  94 #ifdef COMPAT_ELF_EXEC_PAGESIZE
  95 #undef  ELF_EXEC_PAGESIZE
  96 #define ELF_EXEC_PAGESIZE       COMPAT_ELF_EXEC_PAGESIZE
  97 #endif
  98
  99 #ifdef  COMPAT_ELF_PLAT_INIT
 100 #undef  ELF_PLAT_INIT
 101 #define ELF_PLAT_INIT           COMPAT_ELF_PLAT_INIT
 102 #endif
 103
 104 #ifdef  COMPAT_SET_PERSONALITY
 105 #undef  SET_PERSONALITY
 106 #define SET_PERSONALITY         COMPAT_SET_PERSONALITY
 107 #endif
 108
 109 #ifdef  compat_start_thread
 110 #undef  start_thread
 111 #define start_thread            compat_start_thread
 112 #endif
 113
 114 #ifdef  compat_arch_setup_additional_pages
 115 #undef  ARCH_HAS_SETUP_ADDITIONAL_PAGES
 116 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
 117 #undef  arch_setup_additional_pages
 118 #define arch_setup_additional_pages compat_arch_setup_additional_pages
 119 #endif
 120
 121 /*
 122  * Rename a few of the symbols that binfmt_elf.c will define.
 123  * These are all local so the names don't really matter, but it
 124  * might make some debugging less confusing not to duplicate them.
 125  */
 126 #define elf_format              compat_elf_format
 127 #define init_elf_binfmt         init_compat_elf_binfmt
 128 #define exit_elf_binfmt         exit_compat_elf_binfmt
 129
 130 /*
 131  * We share all the actual code with the native (64-bit) version.
 132  */
 133 #include "binfmt_elf.c"