xref: /linux/fs/compat_binfmt_elf.c (revision 8a79db5e83a5d52c74e6f3c40d6f312cf899213e)
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_kernel_old_timeval
52 #define ns_to_kernel_old_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"
129