strncpy_from_user.S (1220B)
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 <asm/asmmacro.h> 21#include <asm/export.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)