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 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