1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 #pragma ident "%Z%%M% %I% %E% SMI"
28
29 /*
30 * Context-saving routine used for pipelines. Designed for use only
31 * with kmdb_setcontext, and with the assumption that func() will never
32 * return.
33 */
34
35 #include <strings.h>
36 #include <ucontext.h>
37 #include <sys/types.h>
38 #include <sys/stack.h>
39
40 #include <kmdb/kmdb_context_impl.h>
41 #include <mdb/mdb_kreg.h>
42
43 void
kmdb_makecontext(ucontext_t * ucp,void (* func)(void *),void * arg,caddr_t stk,size_t stksize)44 kmdb_makecontext(ucontext_t *ucp, void (*func)(void *), void *arg, caddr_t stk,
45 size_t stksize)
46 {
47 /*
48 * Top-of-stack must be rounded down to STACK_ALIGN and
49 * there must be a minimum frame for the register window.
50 */
51 uintptr_t stack = (((uintptr_t)stk + stksize - 1) &
52 ~(STACK_ALIGN - 1)) - SA(MINFRAME);
53
54 /* clear the top stack frame */
55 bzero((void *)stack, SA(MINFRAME));
56
57 /* fill in registers of interest */
58 ucp->uc_mcontext.gregs[REG_PC] = (greg_t)func;
59 ucp->uc_mcontext.gregs[REG_nPC] = (greg_t)func + 4;
60 ucp->uc_mcontext.gregs[REG_O0] = (greg_t)arg;
61 ucp->uc_mcontext.gregs[REG_SP] = (greg_t)(stack - STACK_BIAS);
62 ucp->uc_mcontext.gregs[REG_O7] = NULL;
63 ucp->uc_mcontext.gregs[REG_G7] = NULL;
64 }
65