/arch/ia64/lib/strncpy_from_user.S

 1/*
 2 * Just like strncpy() except that if a fault occurs during copying,
 3 * -EFAULT is returned.
 4 *
 5 * Inputs:
 6 *	in0:	address of destination buffer
 7 *	in1:	address of string to be copied
 8 *	in2:	length of buffer in bytes
 9 * Outputs:
10 *	r8:	-EFAULT in case of fault or number of bytes copied if no fault
11 *
12 * Copyright (C) 1998-2001 Hewlett-Packard Co
13 * Copyright (C) 1998-2001 David Mosberger-Tang <davidm@hpl.hp.com>
14 *
15 * 00/03/06 D. Mosberger Fixed to return proper return value (bug found by
16 *			 by Andreas Schwab <schwab@suse.de>).
17 */
18
19#include <asm/asmmacro.h>
20
21GLOBAL_ENTRY(__strncpy_from_user)
22	alloc r2=ar.pfs,3,0,0,0
23	mov r8=0
24	mov r9=in1
25	;;
26	add r10=in1,in2
27	cmp.eq p6,p0=r0,in2
28(p6)	br.ret.spnt.many rp
29
30	// XXX braindead copy loop---this needs to be optimized
31.Loop1:
32	EX(.Lexit, ld1 r8=[in1],1)
33	;;
34	EX(.Lexit, st1 [in0]=r8,1)
35	cmp.ne p6,p7=r8,r0
36	;;
37(p6)	cmp.ne.unc p8,p0=in1,r10
38(p8)	br.cond.dpnt.few .Loop1
39	;;
40(p6)	mov r8=in2		// buffer filled up---return buffer length
41(p7)	sub r8=in1,r9,1		// return string length (excluding NUL character)
42[.Lexit:]
43	br.ret.sptk.many rp
44END(__strncpy_from_user)