M7350/kernel/arch/avr32/lib/strnlen_user.S

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2024-09-09 08:52:07 +00:00
/*
* Copy to/from userspace with optional address space checking.
*
* Copyright 2004-2006 Atmel Corporation
*
* 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 <asm/page.h>
#include <asm/thread_info.h>
#include <asm/processor.h>
#include <asm/asm.h>
.text
.align 1
.global strnlen_user
.type strnlen_user, "function"
strnlen_user:
branch_if_kernel r8, __strnlen_user
sub r8, r11, 1
add r8, r12
retcs 0
brmi adjust_length /* do a closer inspection */
.global __strnlen_user
.type __strnlen_user, "function"
__strnlen_user:
mov r10, r12
10: ld.ub r8, r12++
cp.w r8, 0
breq 2f
sub r11, 1
brne 10b
sub r12, -1
2: sub r12, r10
retal r12
.type adjust_length, "function"
adjust_length:
cp.w r12, 0 /* addr must always be < TASK_SIZE */
retmi 0
pushm lr
lddpc lr, _task_size
sub r11, lr, r12
mov r9, r11
call __strnlen_user
cp.w r12, r9
brgt 1f
popm pc
1: popm pc, r12=0
.align 2
_task_size:
.long TASK_SIZE
.section .fixup, "ax"
.align 1
19: retal 0
.section __ex_table, "a"
.align 2
.long 10b, 19b