blob: 0a0f91cf4d6d5457b44bd4b3f6d0a84e2bfa7ee9 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
|
// 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>
#include "internal.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;
}
}
|
