root/fs/compat_binfmt_elf.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * 32-bit compatibility support for ELF format executables and core dumps.
   4  *
   5  * Copyright (C) 2007 Red Hat, Inc.  All rights reserved.
   6  *
   7  * Red Hat Author: Roland McGrath.
   8  *
   9  * This file is used in a 64-bit kernel that wants to support 32-bit ELF.
  10  * asm/elf.h is responsible for defining the compat_* and COMPAT_* macros
  11  * used below, with definitions appropriate for 32-bit ABI compatibility.
  12  *
  13  * We use macros to rename the ABI types and machine-dependent
  14  * functions used in binfmt_elf.c to compat versions.
  15  */
  16 
  17 #include <linux/elfcore-compat.h>
  18 #include <linux/time.h>
  19 
  20 /*
  21  * Rename the basic ELF layout types to refer to the 32-bit class of files.
  22  */
  23 #undef  ELF_CLASS
  24 #define ELF_CLASS       ELFCLASS32
  25 
  26 #undef  elfhdr
  27 #undef  elf_phdr
  28 #undef  elf_shdr
  29 #undef  elf_note
  30 #undef  elf_addr_t
  31 #define elfhdr          elf32_hdr
  32 #define elf_phdr        elf32_phdr
  33 #define elf_shdr        elf32_shdr
  34 #define elf_note        elf32_note
  35 #define elf_addr_t      Elf32_Addr
  36 
  37 /*
  38  * Some data types as stored in coredump.
  39  */
  40 #define user_long_t             compat_long_t
  41 #define user_siginfo_t          compat_siginfo_t
  42 #define copy_siginfo_to_user    copy_siginfo_to_user32
  43 
  44 /*
  45  * The machine-dependent core note format types are defined in elfcore-compat.h,
  46  * which requires asm/elf.h to define compat_elf_gregset_t et al.
  47  */
  48 #define elf_prstatus    compat_elf_prstatus
  49 #define elf_prpsinfo    compat_elf_prpsinfo
  50 
  51 #undef ns_to_timeval
  52 #define ns_to_timeval ns_to_old_timeval32
  53 
  54 /*
  55  * To use this file, asm/elf.h must define compat_elf_check_arch.
  56  * The other following macros can be defined if the compat versions
  57  * differ from the native ones, or omitted when they match.
  58  */
  59 
  60 #undef  ELF_ARCH
  61 #undef  elf_check_arch
  62 #define elf_check_arch  compat_elf_check_arch
  63 
  64 #ifdef  COMPAT_ELF_PLATFORM
  65 #undef  ELF_PLATFORM
  66 #define ELF_PLATFORM            COMPAT_ELF_PLATFORM
  67 #endif
  68 
  69 #ifdef  COMPAT_ELF_HWCAP
  70 #undef  ELF_HWCAP
  71 #define ELF_HWCAP               COMPAT_ELF_HWCAP
  72 #endif
  73 
  74 #ifdef  COMPAT_ELF_HWCAP2
  75 #undef  ELF_HWCAP2
  76 #define ELF_HWCAP2              COMPAT_ELF_HWCAP2
  77 #endif
  78 
  79 #ifdef  COMPAT_ARCH_DLINFO
  80 #undef  ARCH_DLINFO
  81 #define ARCH_DLINFO             COMPAT_ARCH_DLINFO
  82 #endif
  83 
  84 #ifdef  COMPAT_ELF_ET_DYN_BASE
  85 #undef  ELF_ET_DYN_BASE
  86 #define ELF_ET_DYN_BASE         COMPAT_ELF_ET_DYN_BASE
  87 #endif
  88 
  89 #ifdef COMPAT_ELF_EXEC_PAGESIZE
  90 #undef  ELF_EXEC_PAGESIZE
  91 #define ELF_EXEC_PAGESIZE       COMPAT_ELF_EXEC_PAGESIZE
  92 #endif
  93 
  94 #ifdef  COMPAT_ELF_PLAT_INIT
  95 #undef  ELF_PLAT_INIT
  96 #define ELF_PLAT_INIT           COMPAT_ELF_PLAT_INIT
  97 #endif
  98 
  99 #ifdef  COMPAT_SET_PERSONALITY
 100 #undef  SET_PERSONALITY
 101 #define SET_PERSONALITY         COMPAT_SET_PERSONALITY
 102 #endif
 103 
 104 #ifdef  compat_start_thread
 105 #undef  start_thread
 106 #define start_thread            compat_start_thread
 107 #endif
 108 
 109 #ifdef  compat_arch_setup_additional_pages
 110 #undef  ARCH_HAS_SETUP_ADDITIONAL_PAGES
 111 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
 112 #undef  arch_setup_additional_pages
 113 #define arch_setup_additional_pages compat_arch_setup_additional_pages
 114 #endif
 115 
 116 /*
 117  * Rename a few of the symbols that binfmt_elf.c will define.
 118  * These are all local so the names don't really matter, but it
 119  * might make some debugging less confusing not to duplicate them.
 120  */
 121 #define elf_format              compat_elf_format
 122 #define init_elf_binfmt         init_compat_elf_binfmt
 123 #define exit_elf_binfmt         exit_compat_elf_binfmt
 124 
 125 /*
 126  * We share all the actual code with the native (64-bit) version.
 127  */
 128 #include "binfmt_elf.c"