xref: /openbmc/linux/fs/compat_binfmt_elf.c (revision b737eecd)
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_prstatus_common	compat_elf_prstatus_common
54 #define elf_prpsinfo	compat_elf_prpsinfo
55 
56 #undef ns_to_kernel_old_timeval
57 #define ns_to_kernel_old_timeval ns_to_old_timeval32
58 
59 /*
60  * To use this file, asm/elf.h must define compat_elf_check_arch.
61  * The other following macros can be defined if the compat versions
62  * differ from the native ones, or omitted when they match.
63  */
64 
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_PLAT_INIT
94 #undef	ELF_PLAT_INIT
95 #define	ELF_PLAT_INIT		COMPAT_ELF_PLAT_INIT
96 #endif
97 
98 #ifdef	COMPAT_SET_PERSONALITY
99 #undef	SET_PERSONALITY
100 #define	SET_PERSONALITY		COMPAT_SET_PERSONALITY
101 #endif
102 
103 #ifdef	compat_start_thread
104 #define COMPAT_START_THREAD(ex, regs, new_ip, new_sp)	\
105 	compat_start_thread(regs, new_ip, new_sp)
106 #endif
107 
108 #ifdef	COMPAT_START_THREAD
109 #undef	START_THREAD
110 #define START_THREAD		COMPAT_START_THREAD
111 #endif
112 
113 #ifdef compat_arch_setup_additional_pages
114 #define COMPAT_ARCH_SETUP_ADDITIONAL_PAGES(bprm, ex, interpreter) \
115 	compat_arch_setup_additional_pages(bprm, interpreter)
116 #endif
117 
118 #ifdef	COMPAT_ARCH_SETUP_ADDITIONAL_PAGES
119 #undef	ARCH_HAS_SETUP_ADDITIONAL_PAGES
120 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
121 #undef	ARCH_SETUP_ADDITIONAL_PAGES
122 #define	ARCH_SETUP_ADDITIONAL_PAGES COMPAT_ARCH_SETUP_ADDITIONAL_PAGES
123 #endif
124 
125 #ifdef	compat_elf_read_implies_exec
126 #undef	elf_read_implies_exec
127 #define	elf_read_implies_exec compat_elf_read_implies_exec
128 #endif
129 
130 /*
131  * Rename a few of the symbols that binfmt_elf.c will define.
132  * These are all local so the names don't really matter, but it
133  * might make some debugging less confusing not to duplicate them.
134  */
135 #define elf_format		compat_elf_format
136 #define init_elf_binfmt		init_compat_elf_binfmt
137 #define exit_elf_binfmt		exit_compat_elf_binfmt
138 
139 /*
140  * We share all the actual code with the native (64-bit) version.
141  */
142 #include "binfmt_elf.c"
143