]>
Commit | Line | Data |
---|---|---|
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> | |
37185b33 AV |
12 | #include <init.h> |
13 | #include <elf_user.h> | |
14 | #include <mem_user.h> | |
1da177e4 | 15 | |
1da177e4 | 16 | typedef Elf32_auxv_t elf_auxv_t; |
1da177e4 | 17 | |
c538b391 | 18 | /* These are initialized very early in boot and never changed */ |
1da177e4 | 19 | char * elf_aux_platform; |
b743ac54 | 20 | extern long elf_aux_hwcap; |
1da177e4 LT |
21 | unsigned long vsyscall_ehdr; |
22 | unsigned long vsyscall_end; | |
1da177e4 LT |
23 | unsigned long __kernel_vsyscall; |
24 | ||
25 | __init void scan_elf_aux( char **envp) | |
26 | { | |
27 | long page_size = 0; | |
28 | elf_auxv_t * auxv; | |
29 | ||
30 | while ( *envp++ != NULL) ; | |
31 | ||
32 | for ( auxv = (elf_auxv_t *)envp; auxv->a_type != AT_NULL; auxv++) { | |
33 | switch ( auxv->a_type ) { | |
34 | case AT_SYSINFO: | |
35 | __kernel_vsyscall = auxv->a_un.a_val; | |
14251809 JD |
36 | /* See if the page is under TASK_SIZE */ |
37 | if (__kernel_vsyscall < (unsigned long) envp) | |
38 | __kernel_vsyscall = 0; | |
1da177e4 LT |
39 | break; |
40 | case AT_SYSINFO_EHDR: | |
41 | vsyscall_ehdr = auxv->a_un.a_val; | |
a502a359 JD |
42 | /* See if the page is under TASK_SIZE */ |
43 | if (vsyscall_ehdr < (unsigned long) envp) | |
44 | vsyscall_ehdr = 0; | |
1da177e4 LT |
45 | break; |
46 | case AT_HWCAP: | |
47 | elf_aux_hwcap = auxv->a_un.a_val; | |
48 | break; | |
49 | case AT_PLATFORM: | |
da00d9a5 JD |
50 | /* elf.h removed the pointer elements from |
51 | * a_un, so we have to use a_val, which is | |
52 | * all that's left. | |
53 | */ | |
64b7673f JD |
54 | elf_aux_platform = |
55 | (char *) (long) auxv->a_un.a_val; | |
1da177e4 LT |
56 | break; |
57 | case AT_PAGESZ: | |
58 | page_size = auxv->a_un.a_val; | |
59 | break; | |
60 | } | |
61 | } | |
62 | if ( ! __kernel_vsyscall || ! vsyscall_ehdr || | |
63 | ! elf_aux_hwcap || ! elf_aux_platform || | |
64 | ! page_size || (vsyscall_ehdr % page_size) ) { | |
65 | __kernel_vsyscall = 0; | |
66 | vsyscall_ehdr = 0; | |
67 | elf_aux_hwcap = 0; | |
68 | elf_aux_platform = "i586"; | |
69 | } | |
70 | else { | |
71 | vsyscall_end = vsyscall_ehdr + page_size; | |
72 | } | |
73 | } |