xref: /openbmc/linux/fs/compat_binfmt_elf.c (revision 63dc02bd)
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  */
51 static 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