xref: /titanic_52/usr/src/cmd/mdb/sparc/kmdb/kmdb_makecontext.c (revision 61679b0b6826b0ae7e3f751acd91412fcfa45d1e)
17c478bd9Sstevel@tonic-gate /*
27c478bd9Sstevel@tonic-gate  * CDDL HEADER START
37c478bd9Sstevel@tonic-gate  *
47c478bd9Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
57c478bd9Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
67c478bd9Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
77c478bd9Sstevel@tonic-gate  * with the License.
87c478bd9Sstevel@tonic-gate  *
97c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
107c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
117c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
127c478bd9Sstevel@tonic-gate  * and limitations under the License.
137c478bd9Sstevel@tonic-gate  *
147c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
157c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
167c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
177c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
187c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
197c478bd9Sstevel@tonic-gate  *
207c478bd9Sstevel@tonic-gate  * CDDL HEADER END
217c478bd9Sstevel@tonic-gate  */
227c478bd9Sstevel@tonic-gate /*
237c478bd9Sstevel@tonic-gate  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
247c478bd9Sstevel@tonic-gate  * Use is subject to license terms.
257c478bd9Sstevel@tonic-gate  */
267c478bd9Sstevel@tonic-gate 
27*61679b0bSGordon Ross #pragma ident	"%Z%%M%	%I%	%E% SMI"
28*61679b0bSGordon Ross 
297c478bd9Sstevel@tonic-gate /*
307c478bd9Sstevel@tonic-gate  * Context-saving routine used for pipelines.  Designed for use only
317c478bd9Sstevel@tonic-gate  * with kmdb_setcontext, and with the assumption that func() will never
327c478bd9Sstevel@tonic-gate  * return.
337c478bd9Sstevel@tonic-gate  */
347c478bd9Sstevel@tonic-gate 
357c478bd9Sstevel@tonic-gate #include <strings.h>
367c478bd9Sstevel@tonic-gate #include <ucontext.h>
377c478bd9Sstevel@tonic-gate #include <sys/types.h>
387c478bd9Sstevel@tonic-gate #include <sys/stack.h>
397c478bd9Sstevel@tonic-gate 
407c478bd9Sstevel@tonic-gate #include <kmdb/kmdb_context_impl.h>
417c478bd9Sstevel@tonic-gate #include <mdb/mdb_kreg.h>
427c478bd9Sstevel@tonic-gate 
437c478bd9Sstevel@tonic-gate void
447c478bd9Sstevel@tonic-gate kmdb_makecontext(ucontext_t *ucp, void (*func)(void *), void *arg, caddr_t stk,
457c478bd9Sstevel@tonic-gate     size_t stksize)
467c478bd9Sstevel@tonic-gate {
477c478bd9Sstevel@tonic-gate 	/*
487c478bd9Sstevel@tonic-gate 	 * Top-of-stack must be rounded down to STACK_ALIGN and
497c478bd9Sstevel@tonic-gate 	 * there must be a minimum frame for the register window.
507c478bd9Sstevel@tonic-gate 	 */
517c478bd9Sstevel@tonic-gate 	uintptr_t stack = (((uintptr_t)stk + stksize - 1) &
527c478bd9Sstevel@tonic-gate 	    ~(STACK_ALIGN - 1)) - SA(MINFRAME);
537c478bd9Sstevel@tonic-gate 
547c478bd9Sstevel@tonic-gate 	/* clear the top stack frame */
557c478bd9Sstevel@tonic-gate 	bzero((void *)stack, SA(MINFRAME));
567c478bd9Sstevel@tonic-gate 
577c478bd9Sstevel@tonic-gate 	/* fill in registers of interest */
587c478bd9Sstevel@tonic-gate 	ucp->uc_mcontext.gregs[REG_PC] = (greg_t)func;
597c478bd9Sstevel@tonic-gate 	ucp->uc_mcontext.gregs[REG_nPC] = (greg_t)func + 4;
607c478bd9Sstevel@tonic-gate 	ucp->uc_mcontext.gregs[REG_O0] = (greg_t)arg;
617c478bd9Sstevel@tonic-gate 	ucp->uc_mcontext.gregs[REG_SP] = (greg_t)(stack - STACK_BIAS);
627c478bd9Sstevel@tonic-gate 	ucp->uc_mcontext.gregs[REG_O7] = NULL;
637c478bd9Sstevel@tonic-gate 	ucp->uc_mcontext.gregs[REG_G7] = NULL;
647c478bd9Sstevel@tonic-gate }
65