Linux-2.6.12-rc2
[linux-2.6/kvm.git] / arch / um / os-Linux / elf_aux.c
blob9aee0b62ebca19c1551242c49c3e11ed17ad0baf
1 /*
2 * arch/um/kernel/elf_aux.c
4 * Scan the Elf auxiliary vector provided by the host to extract
5 * information about vsyscall-page, etc.
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"
15 #if ELF_CLASS == ELFCLASS32
16 typedef Elf32_auxv_t elf_auxv_t;
17 #else
18 typedef Elf64_auxv_t elf_auxv_t;
19 #endif
21 char * elf_aux_platform;
22 long elf_aux_hwcap;
24 unsigned long vsyscall_ehdr;
25 unsigned long vsyscall_end;
27 unsigned long __kernel_vsyscall;
29 __init void scan_elf_aux( char **envp)
31 long page_size = 0;
32 elf_auxv_t * auxv;
34 while ( *envp++ != NULL) ;
36 for ( auxv = (elf_auxv_t *)envp; auxv->a_type != AT_NULL; auxv++) {
37 switch ( auxv->a_type ) {
38 case AT_SYSINFO:
39 __kernel_vsyscall = auxv->a_un.a_val;
40 break;
41 case AT_SYSINFO_EHDR:
42 vsyscall_ehdr = auxv->a_un.a_val;
43 break;
44 case AT_HWCAP:
45 elf_aux_hwcap = auxv->a_un.a_val;
46 break;
47 case AT_PLATFORM:
48 elf_aux_platform = auxv->a_un.a_ptr;
49 break;
50 case AT_PAGESZ:
51 page_size = auxv->a_un.a_val;
52 break;
55 if ( ! __kernel_vsyscall || ! vsyscall_ehdr ||
56 ! elf_aux_hwcap || ! elf_aux_platform ||
57 ! page_size || (vsyscall_ehdr % page_size) ) {
58 __kernel_vsyscall = 0;
59 vsyscall_ehdr = 0;
60 elf_aux_hwcap = 0;
61 elf_aux_platform = "i586";
63 else {
64 vsyscall_end = vsyscall_ehdr + page_size;