mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-25 03:55:09 +08:00
8404663f81
The {get,put}_user macros don't perform range checking on the provided
__user address when !CPU_HAS_DOMAINS.
This patch reworks the out-of-line assembly accessors to check the user
address against a specified limit, returning -EFAULT if is is out of
range.
[will: changed get_user register allocation to match put_user]
[rmk: fixed building on older ARM architectures]
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
81 lines
1.8 KiB
ArmAsm
81 lines
1.8 KiB
ArmAsm
/*
|
|
* linux/arch/arm/lib/getuser.S
|
|
*
|
|
* Copyright (C) 2001 Russell King
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* Idea from x86 version, (C) Copyright 1998 Linus Torvalds
|
|
*
|
|
* These functions have a non-standard call interface to make them more
|
|
* efficient, especially as they return an error value in addition to
|
|
* the "real" return value.
|
|
*
|
|
* __get_user_X
|
|
*
|
|
* Inputs: r0 contains the address
|
|
* r1 contains the address limit, which must be preserved
|
|
* Outputs: r0 is the error code
|
|
* r2 contains the zero-extended value
|
|
* lr corrupted
|
|
*
|
|
* No other registers must be altered. (see <asm/uaccess.h>
|
|
* for specific ASM register usage).
|
|
*
|
|
* Note that ADDR_LIMIT is either 0 or 0xc0000000.
|
|
* Note also that it is intended that __get_user_bad is not global.
|
|
*/
|
|
#include <linux/linkage.h>
|
|
#include <asm/assembler.h>
|
|
#include <asm/errno.h>
|
|
#include <asm/domain.h>
|
|
|
|
ENTRY(__get_user_1)
|
|
check_uaccess r0, 1, r1, r2, __get_user_bad
|
|
1: TUSER(ldrb) r2, [r0]
|
|
mov r0, #0
|
|
mov pc, lr
|
|
ENDPROC(__get_user_1)
|
|
|
|
ENTRY(__get_user_2)
|
|
check_uaccess r0, 2, r1, r2, __get_user_bad
|
|
#ifdef CONFIG_CPU_USE_DOMAINS
|
|
rb .req ip
|
|
2: ldrbt r2, [r0], #1
|
|
3: ldrbt rb, [r0], #0
|
|
#else
|
|
rb .req r0
|
|
2: ldrb r2, [r0]
|
|
3: ldrb rb, [r0, #1]
|
|
#endif
|
|
#ifndef __ARMEB__
|
|
orr r2, r2, rb, lsl #8
|
|
#else
|
|
orr r2, rb, r2, lsl #8
|
|
#endif
|
|
mov r0, #0
|
|
mov pc, lr
|
|
ENDPROC(__get_user_2)
|
|
|
|
ENTRY(__get_user_4)
|
|
check_uaccess r0, 4, r1, r2, __get_user_bad
|
|
4: TUSER(ldr) r2, [r0]
|
|
mov r0, #0
|
|
mov pc, lr
|
|
ENDPROC(__get_user_4)
|
|
|
|
__get_user_bad:
|
|
mov r2, #0
|
|
mov r0, #-EFAULT
|
|
mov pc, lr
|
|
ENDPROC(__get_user_bad)
|
|
|
|
.pushsection __ex_table, "a"
|
|
.long 1b, __get_user_bad
|
|
.long 2b, __get_user_bad
|
|
.long 3b, __get_user_bad
|
|
.long 4b, __get_user_bad
|
|
.popsection
|