75 lines
2.0 KiB
C
75 lines
2.0 KiB
C
|
// SPDX-License-Identifier: GPL-2.0
|
||
|
|
/*
|
||
|
|
* arch/um/kernel/elf_aux.c
|
||
|
|
*
|
||
|
|
* Scan the Elf auxiliary vector provided by the host to extract
|
||
|
|
* information about vsyscall-page, etc.
|
||
|
|
*
|
||
|
|
* Copyright (C) 2004 Fujitsu Siemens Computers GmbH
|
||
|
|
* Author: Bodo Stroesser (bodo.stroesser@fujitsu-siemens.com)
|
||
|
|
*/
|
||
|
|
#include <elf.h>
|
||
|
|
#include <stddef.h>
|
||
|
|
#include <init.h>
|
||
|
|
#include <elf_user.h>
|
||
|
|
#include <mem_user.h>
|
||
|
|
|
||
|
|
typedef Elf32_auxv_t elf_auxv_t;
|
||
|
|
|
||
|
|
/* These are initialized very early in boot and never changed */
|
||
|
|
char * elf_aux_platform;
|
||
|
|
extern long elf_aux_hwcap;
|
||
|
|
unsigned long vsyscall_ehdr;
|
||
|
|
unsigned long vsyscall_end;
|
||
|
|
unsigned long __kernel_vsyscall;
|
||
|
|
|
||
|
|
__init void scan_elf_aux( char **envp)
|
||
|
|
{
|
||
|
|
long page_size = 0;
|
||
|
|
elf_auxv_t * auxv;
|
||
|
|
|
||
|
|
while ( *envp++ != NULL) ;
|
||
|
|
|
||
|
|
for ( auxv = (elf_auxv_t *)envp; auxv->a_type != AT_NULL; auxv++) {
|
||
|
|
switch ( auxv->a_type ) {
|
||
|
|
case AT_SYSINFO:
|
||
|
|
__kernel_vsyscall = auxv->a_un.a_val;
|
||
|
|
/* See if the page is under TASK_SIZE */
|
||
|
|
if (__kernel_vsyscall < (unsigned long) envp)
|
||
|
|
__kernel_vsyscall = 0;
|
||
|
|
break;
|
||
|
|
case AT_SYSINFO_EHDR:
|
||
|
|
vsyscall_ehdr = auxv->a_un.a_val;
|
||
|
|
/* See if the page is under TASK_SIZE */
|
||
|
|
if (vsyscall_ehdr < (unsigned long) envp)
|
||
|
|
vsyscall_ehdr = 0;
|
||
|
|
break;
|
||
|
|
case AT_HWCAP:
|
||
|
|
elf_aux_hwcap = auxv->a_un.a_val;
|
||
|
|
break;
|
||
|
|
case AT_PLATFORM:
|
||
|
|
/* elf.h removed the pointer elements from
|
||
|
|
* a_un, so we have to use a_val, which is
|
||
|
|
* all that's left.
|
||
|
|
*/
|
||
|
|
elf_aux_platform =
|
||
|
|
(char *) (long) auxv->a_un.a_val;
|
||
|
|
break;
|
||
|
|
case AT_PAGESZ:
|
||
|
|
page_size = auxv->a_un.a_val;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
if ( ! __kernel_vsyscall || ! vsyscall_ehdr ||
|
||
|
|
! elf_aux_hwcap || ! elf_aux_platform ||
|
||
|
|
! page_size || (vsyscall_ehdr % page_size) ) {
|
||
|
|
__kernel_vsyscall = 0;
|
||
|
|
vsyscall_ehdr = 0;
|
||
|
|
elf_aux_hwcap = 0;
|
||
|
|
elf_aux_platform = "i586";
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
vsyscall_end = vsyscall_ehdr + page_size;
|
||
|
|
}
|
||
|
|
}
|