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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * arch/um/kernel/elf_aux.c | |
3 | * | |
4 | * Scan the Elf auxiliary vector provided by the host to extract | |
5 | * information about vsyscall-page, etc. | |
6 | * | |
7 | * Copyright (C) 2004 Fujitsu Siemens Computers GmbH | |
8 | * Author: Bodo Stroesser (bodo.stroesser@fujitsu-siemens.com) | |
9 | */ | |
10 | #include <elf.h> | |
11 | #include <stddef.h> | |
12 | #include "init.h" | |
13 | #include "elf_user.h" | |
44456d37 | 14 | #include <asm/elf.h> |
1da177e4 LT |
15 | |
16 | #if ELF_CLASS == ELFCLASS32 | |
17 | typedef Elf32_auxv_t elf_auxv_t; | |
18 | #else | |
19 | typedef Elf64_auxv_t elf_auxv_t; | |
20 | #endif | |
21 | ||
22 | char * elf_aux_platform; | |
23 | long elf_aux_hwcap; | |
24 | ||
25 | unsigned long vsyscall_ehdr; | |
26 | unsigned long vsyscall_end; | |
27 | ||
28 | unsigned long __kernel_vsyscall; | |
29 | ||
30 | __init void scan_elf_aux( char **envp) | |
31 | { | |
32 | long page_size = 0; | |
33 | elf_auxv_t * auxv; | |
34 | ||
35 | while ( *envp++ != NULL) ; | |
36 | ||
37 | for ( auxv = (elf_auxv_t *)envp; auxv->a_type != AT_NULL; auxv++) { | |
38 | switch ( auxv->a_type ) { | |
39 | case AT_SYSINFO: | |
40 | __kernel_vsyscall = auxv->a_un.a_val; | |
41 | break; | |
42 | case AT_SYSINFO_EHDR: | |
43 | vsyscall_ehdr = auxv->a_un.a_val; | |
44 | break; | |
45 | case AT_HWCAP: | |
46 | elf_aux_hwcap = auxv->a_un.a_val; | |
47 | break; | |
48 | case AT_PLATFORM: | |
da00d9a5 JD |
49 | /* elf.h removed the pointer elements from |
50 | * a_un, so we have to use a_val, which is | |
51 | * all that's left. | |
52 | */ | |
53 | elf_aux_platform = (char *) auxv->a_un.a_val; | |
1da177e4 LT |
54 | break; |
55 | case AT_PAGESZ: | |
56 | page_size = auxv->a_un.a_val; | |
57 | break; | |
58 | } | |
59 | } | |
60 | if ( ! __kernel_vsyscall || ! vsyscall_ehdr || | |
61 | ! elf_aux_hwcap || ! elf_aux_platform || | |
62 | ! page_size || (vsyscall_ehdr % page_size) ) { | |
63 | __kernel_vsyscall = 0; | |
64 | vsyscall_ehdr = 0; | |
65 | elf_aux_hwcap = 0; | |
66 | elf_aux_platform = "i586"; | |
67 | } | |
68 | else { | |
69 | vsyscall_end = vsyscall_ehdr + page_size; | |
70 | } | |
71 | } |