linux/arch/arm/lib/clear_user.S
Catalin Marinas e814d826dc ARM: 6110/1: Fix Thumb-2 kernel builds when UACCESS_WITH_MEMCPY is enabled
The patch adds the ENDPROC declarations for the __copy_to_user_std and
__clear_user_std functions. Without these, the compiler generates BXL to
ARM when compiling the kernel in Thumb-2 mode.

Reported-by: Kyungmin Park <kmpark@infradead.org>
Tested-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-05-08 10:45:26 +01:00

55 lines
1.3 KiB
ArmAsm

/*
* linux/arch/arm/lib/clear_user.S
*
* Copyright (C) 1995, 1996,1997,1998 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.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
.text
/* Prototype: int __clear_user(void *addr, size_t sz)
* Purpose : clear some user memory
* Params : addr - user memory address to clear
* : sz - number of bytes to clear
* Returns : number of bytes NOT cleared
*/
ENTRY(__clear_user_std)
WEAK(__clear_user)
stmfd sp!, {r1, lr}
mov r2, #0
cmp r1, #4
blt 2f
ands ip, r0, #3
beq 1f
cmp ip, #2
strusr r2, r0, 1
strusr r2, r0, 1, le
strusr r2, r0, 1, lt
rsb ip, ip, #4
sub r1, r1, ip @ 7 6 5 4 3 2 1
1: subs r1, r1, #8 @ -1 -2 -3 -4 -5 -6 -7
strusr r2, r0, 4, pl, rept=2
bpl 1b
adds r1, r1, #4 @ 3 2 1 0 -1 -2 -3
strusr r2, r0, 4, pl
2: tst r1, #2 @ 1x 1x 0x 0x 1x 1x 0x
strusr r2, r0, 1, ne, rept=2
tst r1, #1 @ x1 x0 x1 x0 x1 x0 x1
it ne @ explicit IT needed for the label
USER( strnebt r2, [r0])
mov r0, #0
ldmfd sp!, {r1, pc}
ENDPROC(__clear_user)
ENDPROC(__clear_user_std)
.pushsection .fixup,"ax"
.align 0
9001: ldmfd sp!, {r0, pc}
.popsection