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_lwp.c revision 1.3 
      1 /*	$NetBSD: _lwp.c,v 1.3 2005/06/12 05:21:27 lukem Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2001 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Nathan J. Williams.
      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  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *        This product includes software developed by the NetBSD
     21  *        Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 #include <sys/cdefs.h>
     40 #if defined(LIBC_SCCS) && !defined(lint)
     41 __RCSID("$NetBSD: _lwp.c,v 1.3 2005/06/12 05:21:27 lukem Exp $");
     42 #endif /* LIBC_SCCS and not lint */
     43 
     44 #include "namespace.h"
     45 #include <sys/types.h>
     46 #include <inttypes.h>
     47 #include <ucontext.h>
     48 #include <lwp.h>
     49 #include <stdlib.h>
     50 
     51 void
     52 _lwp_makecontext(ucontext_t *u, void (*start)(void *),
     53     void *arg, void *private, caddr_t stack_base, size_t stack_size)
     54 {
     55 	void **sp;
     56 
     57 	getcontext(u);
     58 	u->uc_link = NULL;
     59 
     60 	u->uc_stack.ss_sp = stack_base;
     61 	u->uc_stack.ss_size = stack_size;
     62 
     63 	/* LINTED uintptr_t is safe */
     64 	u->uc_mcontext.__gregs[_REG_RIP] = (uintptr_t)start;
     65 
     66 	sp = (void **) (((uintptr_t)(stack_base + stack_size) & ~15) - 8);
     67 
     68 	/* LINTED __greg_t is safe */
     69 	u->uc_mcontext.__gregs[_REG_RDI] = (__greg_t)arg;
     70 	*--sp = (void *) _lwp_exit;
     71 
     72 	/* LINTED uintptr_t is safe */
     73 	u->uc_mcontext.__gregs[_REG_URSP] = (uintptr_t) sp;
     74 
     75 	/* LINTED private is currently unused */
     76 }
     77