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 2005 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 #include <sys/types.h> 30 #include <sys/systm.h> 31 #include <sys/door.h> 32 #include <sys/stack.h> 33 #include <sys/errno.h> 34 #include <sys/sysmacros.h> 35 36 int 37 door_finish_dispatch(caddr_t newsp) 38 { 39 void lwp_setsp(klwp_t *, caddr_t); 40 void lwp_clear_uwin(void); 41 42 char bytes[MAX(MINFRAME, MINFRAME32)]; 43 size_t count; 44 caddr_t biased_sp; 45 46 if (get_udatamodel() == DATAMODEL_NATIVE) { 47 count = MINFRAME; 48 biased_sp = newsp - STACK_BIAS; 49 } else { 50 count = MINFRAME32; 51 biased_sp = newsp; 52 } 53 54 /* 55 * We carefully zero out the stack frame we're pointing %sp at. 56 * This means that, upon returning to userland, the ins and locals 57 * will be zeroed, instead of acquiring whatever garbage was on the 58 * stack previously. In particular, this makes sure %fp is NULL, 59 * so that stack traces are properly terminated. 60 */ 61 bzero(bytes, count); 62 if (copyout(bytes, newsp, count) != 0) 63 return (E2BIG); 64 65 /* 66 * There may be some user register windows stashed away 67 * because our user thread stack wasn't available during some 68 * kernel overflows. We don't care about this saved user 69 * state since we are resetting our stack. Make sure we 70 * don't try to push these registers out to our stack 71 * later on when returning from this system call. 72 * 73 * We have guaranteed that no new user windows will be stored 74 * to the pcb save area at this point since a door server 75 * thread always does a full context switch (shuttle_switch, 76 * shuttle_resume) before making itself available for a door 77 * invocation. 78 */ 79 lwp_clear_uwin(); 80 lwp_setsp(ttolwp(curthread), biased_sp); 81 return (0); 82 } 83 84 uintptr_t 85 door_final_sp(uintptr_t resultsp, size_t align, int datamodel) 86 { 87 size_t minframe = (datamodel == DATAMODEL_NATIVE)? 88 MINFRAME : MINFRAME32; 89 return (P2ALIGN(resultsp - minframe, align)); 90 } 91