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 #define ELF_COMPAT      1
  21
  22 /*
  23  * Rename the basic ELF layout types to refer to the 32-bit class of files.
  24  */
  25 #undef  ELF_CLASS
  26 #define ELF_CLASS       ELFCLASS32
  27
  28 #undef  elfhdr
  29 #undef  elf_phdr
  30 #undef  elf_shdr
  31 #undef  elf_note
  32 #undef  elf_addr_t
  33 #undef  ELF_GNU_PROPERTY_ALIGN
  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 #define ELF_GNU_PROPERTY_ALIGN  ELF32_GNU_PROPERTY_ALIGN
  40
  41 /*
  42  * Some data types as stored in coredump.
  43  */
  44 #define user_long_t             compat_long_t
  45 #define user_siginfo_t          compat_siginfo_t
  46 #define copy_siginfo_to_external        copy_siginfo_to_external32
  47
  48 /*
  49  * The machine-dependent core note format types are defined in elfcore-compat.h,
  50  * which requires asm/elf.h to define compat_elf_gregset_t et al.
  51  */
  52 #define elf_prstatus    compat_elf_prstatus
  53 #define elf_prpsinfo    compat_elf_prpsinfo
  54
  55 #undef ns_to_kernel_old_timeval
  56 #define ns_to_kernel_old_timeval ns_to_old_timeval32
  57
  58 /*
  59  * To use this file, asm/elf.h must define compat_elf_check_arch.
  60  * The other following macros can be defined if the compat versions
  61  * differ from the native ones, or omitted when they match.
  62  */
  63
  64 #undef  ELF_ARCH
  65 #undef  elf_check_arch
  66 #define elf_check_arch  compat_elf_check_arch
  67
  68 #ifdef  COMPAT_ELF_PLATFORM
  69 #undef  ELF_PLATFORM
  70 #define ELF_PLATFORM            COMPAT_ELF_PLATFORM
  71 #endif
  72
  73 #ifdef  COMPAT_ELF_HWCAP
  74 #undef  ELF_HWCAP
  75 #define ELF_HWCAP               COMPAT_ELF_HWCAP
  76 #endif
  77
  78 #ifdef  COMPAT_ELF_HWCAP2
  79 #undef  ELF_HWCAP2
  80 #define ELF_HWCAP2              COMPAT_ELF_HWCAP2
  81 #endif
  82
  83 #ifdef  COMPAT_ARCH_DLINFO
  84 #undef  ARCH_DLINFO
  85 #define ARCH_DLINFO             COMPAT_ARCH_DLINFO
  86 #endif
  87
  88 #ifdef  COMPAT_ELF_ET_DYN_BASE
  89 #undef  ELF_ET_DYN_BASE
  90 #define ELF_ET_DYN_BASE         COMPAT_ELF_ET_DYN_BASE
  91 #endif
  92
  93 #ifdef COMPAT_ELF_EXEC_PAGESIZE
  94 #undef  ELF_EXEC_PAGESIZE
  95 #define ELF_EXEC_PAGESIZE       COMPAT_ELF_EXEC_PAGESIZE
  96 #endif
  97
  98 #ifdef  COMPAT_ELF_PLAT_INIT
  99 #undef  ELF_PLAT_INIT
 100 #define ELF_PLAT_INIT           COMPAT_ELF_PLAT_INIT
 101 #endif
 102
 103 #ifdef  COMPAT_SET_PERSONALITY
 104 #undef  SET_PERSONALITY
 105 #define SET_PERSONALITY         COMPAT_SET_PERSONALITY
 106 #endif
 107
 108 #ifdef  compat_start_thread
 109 #define COMPAT_START_THREAD(ex, regs, new_ip, new_sp)   \
 110         compat_start_thread(regs, new_ip, new_sp)
 111 #endif
 112
 113 #ifdef  COMPAT_START_THREAD
 114 #undef  START_THREAD
 115 #define START_THREAD            COMPAT_START_THREAD
 116 #endif
 117
 118 #ifdef compat_arch_setup_additional_pages
 119 #define COMPAT_ARCH_SETUP_ADDITIONAL_PAGES(bprm, ex, interpreter) \
 120         compat_arch_setup_additional_pages(bprm, interpreter)
 121 #endif
 122
 123 #ifdef  COMPAT_ARCH_SETUP_ADDITIONAL_PAGES
 124 #undef  ARCH_HAS_SETUP_ADDITIONAL_PAGES
 125 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
 126 #undef  ARCH_SETUP_ADDITIONAL_PAGES
 127 #define ARCH_SETUP_ADDITIONAL_PAGES COMPAT_ARCH_SETUP_ADDITIONAL_PAGES
 128 #endif
 129
 130 #ifdef  compat_elf_read_implies_exec
 131 #undef  elf_read_implies_exec
 132 #define elf_read_implies_exec compat_elf_read_implies_exec
 133 #endif
 134
 135 /*
 136  * Rename a few of the symbols that binfmt_elf.c will define.
 137  * These are all local so the names don't really matter, but it
 138  * might make some debugging less confusing not to duplicate them.
 139  */
 140 #define elf_format              compat_elf_format
 141 #define init_elf_binfmt         init_compat_elf_binfmt
 142 #define exit_elf_binfmt         exit_compat_elf_binfmt
 143
 144 /*
 145  * We share all the actual code with the native (64-bit) version.
 146  */
 147 #include "binfmt_elf.c"