Root/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 */
51static 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"
134

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