kern_context.c revision 112888
1106977Sdeischen/*- 2106977Sdeischen * Copyright (c) 2002 Daniel M. Eischen <deischen@freebsd.org> 3106977Sdeischen * All rights reserved. 4106977Sdeischen * 5106977Sdeischen * Redistribution and use in source and binary forms, with or without 6106977Sdeischen * modification, are permitted provided that the following conditions 7106977Sdeischen * are met: 8106977Sdeischen * 1. Redistributions of source code must retain the above copyright 9106977Sdeischen * notice, this list of conditions and the following disclaimer. 10106977Sdeischen * 2. Redistributions in binary form must reproduce the above copyright 11106977Sdeischen * notice, this list of conditions and the following disclaimer in the 12106977Sdeischen * documentation and/or other materials provided with the distribution. 13106977Sdeischen * 14106977Sdeischen * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15106977Sdeischen * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16106977Sdeischen * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17106977Sdeischen * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18106977Sdeischen * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19106977Sdeischen * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20106977Sdeischen * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21106977Sdeischen * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22106977Sdeischen * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23106977Sdeischen * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24106977Sdeischen * SUCH DAMAGE. 25106977Sdeischen * 26106977Sdeischen */ 27106977Sdeischen/* 28106977Sdeischen * $FreeBSD: head/sys/kern/kern_context.c 112888 2003-03-31 22:49:17Z jeff $ 29106977Sdeischen */ 30106977Sdeischen 31106977Sdeischen#include <sys/param.h> 32106977Sdeischen#include <sys/kernel.h> 33106977Sdeischen#include <sys/lock.h> 34106977Sdeischen#include <sys/mutex.h> 35106977Sdeischen#include <sys/proc.h> 36106977Sdeischen#include <sys/sysent.h> 37106977Sdeischen#include <sys/systm.h> 38106977Sdeischen#include <sys/sysproto.h> 39106977Sdeischen#include <sys/signalvar.h> 40106977Sdeischen#include <sys/ucontext.h> 41106977Sdeischen 42106977Sdeischen/* 43106977Sdeischen * The first two fields of a ucontext_t are the signal mask and 44106977Sdeischen * the machine context. The next field is uc_link; we want to 45106977Sdeischen * avoid destroying the link when copying out contexts. 46106977Sdeischen */ 47106977Sdeischen#define UC_COPY_SIZE (sizeof(sigset_t) + sizeof(mcontext_t)) 48106977Sdeischen 49106977Sdeischen 50106977Sdeischen#ifndef _SYS_SYSPROTO_H_ 51106977Sdeischenstruct getcontext_args { 52106977Sdeischen struct __ucontext *ucp; 53106977Sdeischen} 54106977Sdeischenstruct setcontext_args { 55106977Sdeischen const struct __ucontext_t *ucp; 56106977Sdeischen} 57106977Sdeischenstruct swapcontext_args { 58106977Sdeischen struct __ucontext *oucp; 59106977Sdeischen const struct __ucontext_t *ucp; 60106977Sdeischen} 61106977Sdeischen#endif 62106977Sdeischen 63106977Sdeischen/* 64106977Sdeischen * MPSAFE 65106977Sdeischen */ 66106977Sdeischenint 67106977Sdeischengetcontext(struct thread *td, struct getcontext_args *uap) 68106977Sdeischen{ 69106977Sdeischen ucontext_t uc; 70106977Sdeischen int ret; 71106977Sdeischen 72106977Sdeischen if (uap->ucp == NULL) 73106977Sdeischen ret = EINVAL; 74106977Sdeischen else { 75106977Sdeischen get_mcontext(td, &uc.uc_mcontext); 76112888Sjeff uc.uc_sigmask = td->td_sigmask; 77106977Sdeischen ret = copyout(&uc, uap->ucp, UC_COPY_SIZE); 78106977Sdeischen } 79106977Sdeischen return (ret); 80106977Sdeischen} 81106977Sdeischen 82106977Sdeischen/* 83106977Sdeischen * MPSAFE 84106977Sdeischen */ 85106977Sdeischenint 86106977Sdeischensetcontext(struct thread *td, struct setcontext_args *uap) 87106977Sdeischen{ 88106977Sdeischen ucontext_t uc; 89106977Sdeischen int ret; 90106977Sdeischen 91106977Sdeischen if (uap->ucp == NULL) 92106977Sdeischen ret = EINVAL; 93106977Sdeischen else { 94106977Sdeischen ret = copyin(uap->ucp, &uc, UC_COPY_SIZE); 95106977Sdeischen if (ret == 0) { 96106977Sdeischen ret = set_mcontext(td, &uc.uc_mcontext); 97106977Sdeischen if (ret == 0) { 98106977Sdeischen SIG_CANTMASK(uc.uc_sigmask); 99106977Sdeischen PROC_LOCK(td->td_proc); 100112888Sjeff td->td_sigmask = uc.uc_sigmask; 101106977Sdeischen PROC_UNLOCK(td->td_proc); 102106977Sdeischen } 103106977Sdeischen } 104106977Sdeischen } 105106977Sdeischen return (ret); 106106977Sdeischen} 107106977Sdeischen 108106977Sdeischenint 109106977Sdeischenswapcontext(struct thread *td, struct swapcontext_args *uap) 110106977Sdeischen{ 111106977Sdeischen ucontext_t uc; 112106977Sdeischen int ret; 113106977Sdeischen 114106977Sdeischen if (uap->oucp == NULL || uap->ucp == NULL) 115106977Sdeischen ret = EINVAL; 116106977Sdeischen else { 117106977Sdeischen get_mcontext(td, &uc.uc_mcontext); 118112888Sjeff uc.uc_sigmask = td->td_sigmask; 119106977Sdeischen ret = copyout(&uc, uap->oucp, UC_COPY_SIZE); 120106977Sdeischen if (ret == 0) { 121106977Sdeischen ret = copyin(uap->ucp, &uc, UC_COPY_SIZE); 122106977Sdeischen if (ret == 0) { 123106977Sdeischen ret = set_mcontext(td, &uc.uc_mcontext); 124106977Sdeischen if (ret == 0) { 125106977Sdeischen SIG_CANTMASK(uc.uc_sigmask); 126106977Sdeischen PROC_LOCK(td->td_proc); 127112888Sjeff td->td_sigmask = uc.uc_sigmask; 128106977Sdeischen PROC_UNLOCK(td->td_proc); 129106977Sdeischen } 130106977Sdeischen } 131106977Sdeischen } 132106977Sdeischen } 133106977Sdeischen return (ret); 134106977Sdeischen} 135