68 lines
1.2 KiB
ArmAsm
68 lines
1.2 KiB
ArmAsm
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/*
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* Copy to/from userspace with optional address space checking.
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*
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* Copyright 2004-2006 Atmel Corporation
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <asm/page.h>
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#include <asm/thread_info.h>
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#include <asm/processor.h>
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#include <asm/asm.h>
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.text
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.align 1
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.global strnlen_user
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.type strnlen_user, "function"
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strnlen_user:
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branch_if_kernel r8, __strnlen_user
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sub r8, r11, 1
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add r8, r12
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retcs 0
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brmi adjust_length /* do a closer inspection */
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.global __strnlen_user
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.type __strnlen_user, "function"
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__strnlen_user:
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mov r10, r12
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10: ld.ub r8, r12++
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cp.w r8, 0
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breq 2f
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sub r11, 1
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brne 10b
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sub r12, -1
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2: sub r12, r10
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retal r12
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.type adjust_length, "function"
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adjust_length:
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cp.w r12, 0 /* addr must always be < TASK_SIZE */
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retmi 0
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pushm lr
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lddpc lr, _task_size
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sub r11, lr, r12
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mov r9, r11
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rcall __strnlen_user
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cp.w r12, r9
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brgt 1f
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popm pc
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1: popm pc, r12=0
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.align 2
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_task_size:
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.long TASK_SIZE
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.section .fixup, "ax"
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.align 1
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19: retal 0
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.section __ex_table, "a"
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.align 2
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.long 10b, 19b
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