1 /* $NetBSD: kcopy.c,v 1.3 2020/07/06 09:34:16 rin Exp $ */ 2 /*- 3 * Copyright (c) 2010, 2011 The NetBSD Foundation, Inc. 4 * All rights reserved. 5 * 6 * This code is derived from software contributed to The NetBSD Foundation 7 * by Raytheon BBN Technologies Corp and Defense Advanced Research Projects 8 * Agency and which was developed by Matt Thomas of 3am Software Foundry. 9 * 10 * This material is based upon work supported by the Defense Advanced Research 11 * Projects Agency and Space and Naval Warfare Systems Center, Pacific, under 12 * Contract No. N66001-09-C-2073. 13 * Approved for Public Release, Distribution Unlimited 14 * 15 * Redistribution and use in source and binary forms, with or without 16 * modification, are permitted provided that the following conditions 17 * are met: 18 * 1. Redistributions of source code must retain the above copyright 19 * notice, this list of conditions and the following disclaimer. 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in the 22 * documentation and/or other materials provided with the distribution. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 25 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 26 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 27 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 28 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 34 * POSSIBILITY OF SUCH DAMAGE. 35 */ 36 37 #include <sys/cdefs.h> 38 __KERNEL_RCSID(0, "$NetBSD: kcopy.c,v 1.3 2020/07/06 09:34:16 rin Exp $"); 39 40 #include <sys/param.h> 41 #include <sys/cpu.h> 42 43 #include <machine/pcb.h> 44 45 /* 46 * kcopy(const void *src, void *dst, size_t len); 47 * 48 * Copy len bytes from src to dst, aborting if we encounter a fatal 49 * page fault. 50 * 51 * kcopy() _must_ save and restore the old fault handler since it is 52 * called by uiomove(), which may be in the path of servicing a non-fatal 53 * page fault. 54 */ 55 int 56 kcopy(const void *src, void *dst, size_t len) 57 { 58 struct pcb * const pcb = lwp_getpcb(curlwp); 59 struct faultbuf * const saved_onfault = pcb->pcb_onfault; 60 struct faultbuf env; 61 62 const int rv = setfault(&env); 63 if (__predict_true(rv == 0)) 64 memcpy(dst, src, len); 65 66 pcb->pcb_onfault = saved_onfault; 67 return rv; 68 } 69