1/* $NetBSD: strlcpy.S,v 1.5 2020/05/05 06:20:55 skrll Exp $ */ 2 3/* 4 * Copyright (c) 2002 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Matthew Fredette. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32#include <machine/asm.h> 33 34#if defined(LIBC_SCCS) && !defined(lint) 35 RCSID("$NetBSD: strlcpy.S,v 1.5 2020/05/05 06:20:55 skrll Exp $") 36#endif /* LIBC_SCCS and not lint */ 37 38/* 39 * size_t strlcpy(char *dst, const char *src, size_t size); 40 */ 41LEAF_ENTRY(_strlcpy) 42 .weak strlcpy 43 strlcpy = _strlcpy 44 45 /* Always load the first byte of the source string. */ 46 ldbs,ma 1(%arg1), %r1 47 48 /* 49 * If our dst buffer is zero bytes, branch immediately 50 * to the code that counts the (remaining) length 51 * of the src string. 52 */ 53 comb,= %r0, %arg2, $strlcpy_dst_done 54 copy %arg1, %ret0 55 56 /* 57 * If our dst buffer is one byte, branch immediately 58 * to the code that NUL-terminates the dst buffer and 59 * counts the (remaining) length of the src string. 60 */ 61 addib,=,n -1, %arg2, $strlcpy_dst_full 62 63 /* 64 * Loop copying bytes. At the top of this loop, 65 * %arg2 is always the number of bytes we can still 66 * store, and %r1 holds the next byte to store. 67 */ 68$strlcpy_loop: 69 comb,= %r0, %r1, $strlcpy_exit 70 stbs,ma %r1, 1(%arg0) 71 addib,<> -1, %arg2, $strlcpy_loop 72 ldbs,ma 1(%arg1), %r1 73 74$strlcpy_dst_full: 75 stbs,ma %r0, 1(%arg0) 76 77$strlcpy_dst_done: 78 comb,<>,n %r0, %r1, $strlcpy_dst_done 79 ldbs,ma 1(%arg1), %r1 80 81$strlcpy_exit: 82 bv %r0(%rp) 83 sub %arg1, %ret0, %ret0 84EXIT(strlcpy) 85