1/* 2 * Copyright (c) 2001 Daniel M. Eischen <deischen@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Neither the name of the author nor the names of its contributors 11 * may be used to endorse or promote products derived from this software 12 * without specific prior written permission. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD$"); 29 30#include <sys/param.h> 31#include <sys/signal.h> 32#include <sys/ucontext.h> 33 34#include <errno.h> 35#include <stddef.h> 36 37__weak_reference(__swapcontext, swapcontext); 38 39int 40__swapcontext(ucontext_t *oucp, const ucontext_t *ucp) 41{ 42 int ret; 43 44 if ((oucp == NULL) || (ucp == NULL)) { 45 errno = EINVAL; 46 return (-1); 47 } 48 oucp->uc_flags &= ~UCF_SWAPPED; 49 ret = getcontext(oucp); 50 if ((ret == 0) && !(oucp->uc_flags & UCF_SWAPPED)) { 51 oucp->uc_flags |= UCF_SWAPPED; 52 ret = setcontext(ucp); 53 } 54 return (ret); 55} 56