1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Just like strncpy() except that if a fault occurs during copying,
4 * -EFAULT is returned.
5 *
6 * Inputs:
7 *	in0:	address of destination buffer
8 *	in1:	address of string to be copied
9 *	in2:	length of buffer in bytes
10 * Outputs:
11 *	r8:	-EFAULT in case of fault or number of bytes copied if no fault
12 *
13 * Copyright (C) 1998-2001 Hewlett-Packard Co
14 * Copyright (C) 1998-2001 David Mosberger-Tang <davidm@hpl.hp.com>
15 *
16 * 00/03/06 D. Mosberger Fixed to return proper return value (bug found by
17 *			 by Andreas Schwab <schwab@suse.de>).
18 */
19
20#include <linux/export.h>
21#include <asm/asmmacro.h>
22
23GLOBAL_ENTRY(__strncpy_from_user)
24	alloc r2=ar.pfs,3,0,0,0
25	mov r8=0
26	mov r9=in1
27	;;
28	add r10=in1,in2
29	cmp.eq p6,p0=r0,in2
30(p6)	br.ret.spnt.many rp
31
32	// XXX braindead copy loop---this needs to be optimized
33.Loop1:
34	EX(.Lexit, ld1 r8=[in1],1)
35	;;
36	EX(.Lexit, st1 [in0]=r8,1)
37	cmp.ne p6,p7=r8,r0
38	;;
39(p6)	cmp.ne.unc p8,p0=in1,r10
40(p8)	br.cond.dpnt.few .Loop1
41	;;
42(p6)	mov r8=in2		// buffer filled up---return buffer length
43(p7)	sub r8=in1,r9,1		// return string length (excluding NUL character)
44[.Lexit:]
45	br.ret.sptk.many rp
46END(__strncpy_from_user)
47EXPORT_SYMBOL(__strncpy_from_user)
48