acrn-kernel/arch/ia64/lib/strncpy_from_user.S

45 lines
1.1 KiB
ArmAsm

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