mirror of https://gitee.com/openkylin/linux.git
45 lines
1.1 KiB
ArmAsm
45 lines
1.1 KiB
ArmAsm
/*
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* Just like strncpy() except that if a fault occurs during copying,
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* -EFAULT is returned.
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*
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* Inputs:
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* in0: address of destination buffer
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* in1: address of string to be copied
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* in2: length of buffer in bytes
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* Outputs:
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* r8: -EFAULT in case of fault or number of bytes copied if no fault
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*
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* Copyright (C) 1998-2001 Hewlett-Packard Co
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* Copyright (C) 1998-2001 David Mosberger-Tang <davidm@hpl.hp.com>
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*
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* 00/03/06 D. Mosberger Fixed to return proper return value (bug found by
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* by Andreas Schwab <schwab@suse.de>).
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*/
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#include <asm/asmmacro.h>
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GLOBAL_ENTRY(__strncpy_from_user)
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alloc r2=ar.pfs,3,0,0,0
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mov r8=0
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mov r9=in1
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;;
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add r10=in1,in2
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cmp.eq p6,p0=r0,in2
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(p6) br.ret.spnt.many rp
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// XXX braindead copy loop---this needs to be optimized
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.Loop1:
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EX(.Lexit, ld1 r8=[in1],1)
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;;
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EX(.Lexit, st1 [in0]=r8,1)
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cmp.ne p6,p7=r8,r0
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;;
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(p6) cmp.ne.unc p8,p0=in1,r10
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(p8) br.cond.dpnt.few .Loop1
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;;
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(p6) mov r8=in2 // buffer filled up---return buffer length
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(p7) sub r8=in1,r9,1 // return string length (excluding NUL character)
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[.Lexit:]
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br.ret.sptk.many rp
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END(__strncpy_from_user)
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