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)
15 #if ELF_CLASS == ELFCLASS32
16 typedef Elf32_auxv_t elf_auxv_t;
18 typedef Elf64_auxv_t elf_auxv_t;
21 char * elf_aux_platform;
24 unsigned long vsyscall_ehdr;
25 unsigned long vsyscall_end;
27 unsigned long __kernel_vsyscall;
29 __init void scan_elf_aux( char **envp)
34 while ( *envp++ != NULL) ;
36 for ( auxv = (elf_auxv_t *)envp; auxv->a_type != AT_NULL; auxv++) {
37 switch ( auxv->a_type ) {
39 __kernel_vsyscall = auxv->a_un.a_val;
42 vsyscall_ehdr = auxv->a_un.a_val;
45 elf_aux_hwcap = auxv->a_un.a_val;
48 /* elf.h removed the pointer elements from
49 * a_un, so we have to use a_val, which is
52 elf_aux_platform = (char *) auxv->a_un.a_val;
55 page_size = auxv->a_un.a_val;
59 if ( ! __kernel_vsyscall || ! vsyscall_ehdr ||
60 ! elf_aux_hwcap || ! elf_aux_platform ||
61 ! page_size || (vsyscall_ehdr % page_size) ) {
62 __kernel_vsyscall = 0;
65 elf_aux_platform = "i586";
68 vsyscall_end = vsyscall_ehdr + page_size;