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  * Some data types as stored in coredump.
  42  */
  43 #define user_long_t             compat_long_t
  44 #define user_siginfo_t          compat_siginfo_t
  45 #define copy_siginfo_to_user    copy_siginfo_to_user32
  46
  47 /*
  48  * The machine-dependent core note format types are defined in elfcore-compat.h,
  49  * which requires asm/elf.h to define compat_elf_gregset_t et al.
  50  */
  51 #define elf_prstatus    compat_elf_prstatus
  52 #define elf_prpsinfo    compat_elf_prpsinfo
  53
  54 /*
  55  * Compat version of cputime_to_compat_timeval, perhaps this
  56  * should be an inline in <linux/compat.h>.
  57  */
  58 static void cputime_to_compat_timeval(const cputime_t cputime,
  59                                       struct compat_timeval *value)
  60 {
  61         struct timeval tv;
  62         cputime_to_timeval(cputime, &tv);
  63         value->tv_sec = tv.tv_sec;
  64         value->tv_usec = tv.tv_usec;
  65 }
  66
  67 #undef cputime_to_timeval
  68 #define cputime_to_timeval cputime_to_compat_timeval
  69
  70
  71 /*
  72  * To use this file, asm/elf.h must define compat_elf_check_arch.
  73  * The other following macros can be defined if the compat versions
  74  * differ from the native ones, or omitted when they match.
  75  */
  76
  77 #undef  ELF_ARCH
  78 #undef  elf_check_arch
  79 #define elf_check_arch  compat_elf_check_arch
  80
  81 #ifdef  COMPAT_ELF_PLATFORM
  82 #undef  ELF_PLATFORM
  83 #define ELF_PLATFORM            COMPAT_ELF_PLATFORM
  84 #endif
  85
  86 #ifdef  COMPAT_ELF_HWCAP
  87 #undef  ELF_HWCAP
  88 #define ELF_HWCAP               COMPAT_ELF_HWCAP
  89 #endif
  90
  91 #ifdef  COMPAT_ELF_HWCAP2
  92 #undef  ELF_HWCAP2
  93 #define ELF_HWCAP2              COMPAT_ELF_HWCAP2
  94 #endif
  95
  96 #ifdef  COMPAT_ARCH_DLINFO
  97 #undef  ARCH_DLINFO
  98 #define ARCH_DLINFO             COMPAT_ARCH_DLINFO
  99 #endif
 100
 101 #ifdef  COMPAT_ELF_ET_DYN_BASE
 102 #undef  ELF_ET_DYN_BASE
 103 #define ELF_ET_DYN_BASE         COMPAT_ELF_ET_DYN_BASE
 104 #endif
 105
 106 #ifdef COMPAT_ELF_EXEC_PAGESIZE
 107 #undef  ELF_EXEC_PAGESIZE
 108 #define ELF_EXEC_PAGESIZE       COMPAT_ELF_EXEC_PAGESIZE
 109 #endif
 110
 111 #ifdef  COMPAT_ELF_PLAT_INIT
 112 #undef  ELF_PLAT_INIT
 113 #define ELF_PLAT_INIT           COMPAT_ELF_PLAT_INIT
 114 #endif
 115
 116 #ifdef  COMPAT_SET_PERSONALITY
 117 #undef  SET_PERSONALITY
 118 #define SET_PERSONALITY         COMPAT_SET_PERSONALITY
 119 #endif
 120
 121 #ifdef  compat_start_thread
 122 #undef  start_thread
 123 #define start_thread            compat_start_thread
 124 #endif
 125
 126 #ifdef  compat_arch_setup_additional_pages
 127 #undef  ARCH_HAS_SETUP_ADDITIONAL_PAGES
 128 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
 129 #undef  arch_setup_additional_pages
 130 #define arch_setup_additional_pages compat_arch_setup_additional_pages
 131 #endif
 132
 133 /*
 134  * Rename a few of the symbols that binfmt_elf.c will define.
 135  * These are all local so the names don't really matter, but it
 136  * might make some debugging less confusing not to duplicate them.
 137  */
 138 #define elf_format              compat_elf_format
 139 #define init_elf_binfmt         init_compat_elf_binfmt
 140 #define exit_elf_binfmt         exit_compat_elf_binfmt
 141
 142 /*
 143  * We share all the actual code with the native (64-bit) version.
 144  */
 145 #include "binfmt_elf.c"