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_note
  32 #undef  elf_addr_t
  33 #define elfhdr          elf32_hdr
  34 #define elf_phdr        elf32_phdr
  35 #define elf_note        elf32_note
  36 #define elf_addr_t      Elf32_Addr
  37
  38 /*
  39  * The machine-dependent core note format types are defined in elfcore-compat.h,
  40  * which requires asm/elf.h to define compat_elf_gregset_t et al.
  41  */
  42 #define elf_prstatus    compat_elf_prstatus
  43 #define elf_prpsinfo    compat_elf_prpsinfo
  44
  45 /*
  46  * Compat version of cputime_to_compat_timeval, perhaps this
  47  * should be an inline in <linux/compat.h>.
  48  */
  49 static void cputime_to_compat_timeval(const cputime_t cputime,
  50                                       struct compat_timeval *value)
  51 {
  52         struct timeval tv;
  53         cputime_to_timeval(cputime, &tv);
  54         value->tv_sec = tv.tv_sec;
  55         value->tv_usec = tv.tv_usec;
  56 }
  57
  58 #undef cputime_to_timeval
  59 #define cputime_to_timeval cputime_to_compat_timeval
  60
  61
  62 /*
  63  * To use this file, asm/elf.h must define compat_elf_check_arch.
  64  * The other following macros can be defined if the compat versions
  65  * differ from the native ones, or omitted when they match.
  66  */
  67
  68 #undef  ELF_ARCH
  69 #undef  elf_check_arch
  70 #define elf_check_arch  compat_elf_check_arch
  71
  72 #ifdef  COMPAT_ELF_PLATFORM
  73 #undef  ELF_PLATFORM
  74 #define ELF_PLATFORM            COMPAT_ELF_PLATFORM
  75 #endif
  76
  77 #ifdef  COMPAT_ELF_HWCAP
  78 #undef  ELF_HWCAP
  79 #define ELF_HWCAP               COMPAT_ELF_HWCAP
  80 #endif
  81
  82 #ifdef  COMPAT_ARCH_DLINFO
  83 #undef  ARCH_DLINFO
  84 #define ARCH_DLINFO             COMPAT_ARCH_DLINFO
  85 #endif
  86
  87 #ifdef  COMPAT_ELF_ET_DYN_BASE
  88 #undef  ELF_ET_DYN_BASE
  89 #define ELF_ET_DYN_BASE         COMPAT_ELF_ET_DYN_BASE
  90 #endif
  91
  92 #ifdef COMPAT_ELF_EXEC_PAGESIZE
  93 #undef  ELF_EXEC_PAGESIZE
  94 #define ELF_EXEC_PAGESIZE       COMPAT_ELF_EXEC_PAGESIZE
  95 #endif
  96
  97 #ifdef  COMPAT_ELF_PLAT_INIT
  98 #undef  ELF_PLAT_INIT
  99 #define ELF_PLAT_INIT           COMPAT_ELF_PLAT_INIT
 100 #endif
 101
 102 #ifdef  COMPAT_SET_PERSONALITY
 103 #undef  SET_PERSONALITY
 104 #define SET_PERSONALITY         COMPAT_SET_PERSONALITY
 105 #endif
 106
 107 #ifdef  compat_start_thread
 108 #undef  start_thread
 109 #define start_thread            compat_start_thread
 110 #endif
 111
 112 #ifdef  compat_arch_setup_additional_pages
 113 #undef  ARCH_HAS_SETUP_ADDITIONAL_PAGES
 114 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
 115 #undef  arch_setup_additional_pages
 116 #define arch_setup_additional_pages compat_arch_setup_additional_pages
 117 #endif
 118
 119 /*
 120  * Rename a few of the symbols that binfmt_elf.c will define.
 121  * These are all local so the names don't really matter, but it
 122  * might make some debugging less confusing not to duplicate them.
 123  */
 124 #define elf_format              compat_elf_format
 125 #define init_elf_binfmt         init_compat_elf_binfmt
 126 #define exit_elf_binfmt         exit_compat_elf_binfmt
 127
 128 /*
 129  * We share all the actual code with the native (64-bit) version.
 130  */
 131 #include "binfmt_elf.c"