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 27116182Sobrien#include <sys/cdefs.h> 28116182Sobrien__FBSDID("$FreeBSD: stable/11/sys/kern/kern_context.c 338983 2018-09-27 18:42:40Z gordon $"); 29116182Sobrien 30106977Sdeischen#include <sys/param.h> 31106977Sdeischen#include <sys/kernel.h> 32106977Sdeischen#include <sys/lock.h> 33106977Sdeischen#include <sys/mutex.h> 34106977Sdeischen#include <sys/proc.h> 35209613Sjhb#include <sys/syscallsubr.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/* 43167232Srwatson * The first two fields of a ucontext_t are the signal mask and the machine 44167232Srwatson * context. The next field is uc_link; we want to avoid destroying the link 45167232Srwatson * when copying out contexts. 46106977Sdeischen */ 47112962Sjake#define UC_COPY_SIZE offsetof(ucontext_t, uc_link) 48106977Sdeischen 49106977Sdeischen#ifndef _SYS_SYSPROTO_H_ 50106977Sdeischenstruct getcontext_args { 51106977Sdeischen struct __ucontext *ucp; 52106977Sdeischen} 53106977Sdeischenstruct setcontext_args { 54106977Sdeischen const struct __ucontext_t *ucp; 55106977Sdeischen} 56106977Sdeischenstruct swapcontext_args { 57106977Sdeischen struct __ucontext *oucp; 58106977Sdeischen const struct __ucontext_t *ucp; 59106977Sdeischen} 60106977Sdeischen#endif 61106977Sdeischen 62106977Sdeischenint 63225617Skmacysys_getcontext(struct thread *td, struct getcontext_args *uap) 64106977Sdeischen{ 65106977Sdeischen ucontext_t uc; 66113626Sjhb int ret; 67106977Sdeischen 68106977Sdeischen if (uap->ucp == NULL) 69106977Sdeischen ret = EINVAL; 70106977Sdeischen else { 71338983Sgordon bzero(&uc, sizeof(ucontext_t)); 72122364Smarcel get_mcontext(td, &uc.uc_mcontext, GET_MC_CLEAR_RET); 73113626Sjhb PROC_LOCK(td->td_proc); 74112888Sjeff uc.uc_sigmask = td->td_sigmask; 75113626Sjhb PROC_UNLOCK(td->td_proc); 76218327Skib bzero(uc.__spare__, sizeof(uc.__spare__)); 77106977Sdeischen ret = copyout(&uc, uap->ucp, UC_COPY_SIZE); 78106977Sdeischen } 79106977Sdeischen return (ret); 80106977Sdeischen} 81106977Sdeischen 82106977Sdeischenint 83225617Skmacysys_setcontext(struct thread *td, struct setcontext_args *uap) 84106977Sdeischen{ 85106977Sdeischen ucontext_t uc; 86106977Sdeischen int ret; 87106977Sdeischen 88106977Sdeischen if (uap->ucp == NULL) 89106977Sdeischen ret = EINVAL; 90106977Sdeischen else { 91106977Sdeischen ret = copyin(uap->ucp, &uc, UC_COPY_SIZE); 92106977Sdeischen if (ret == 0) { 93106977Sdeischen ret = set_mcontext(td, &uc.uc_mcontext); 94106977Sdeischen if (ret == 0) { 95198507Skib kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, 96198507Skib NULL, 0); 97106977Sdeischen } 98106977Sdeischen } 99106977Sdeischen } 100112962Sjake return (ret == 0 ? EJUSTRETURN : ret); 101106977Sdeischen} 102106977Sdeischen 103106977Sdeischenint 104225617Skmacysys_swapcontext(struct thread *td, struct swapcontext_args *uap) 105106977Sdeischen{ 106106977Sdeischen ucontext_t uc; 107106977Sdeischen int ret; 108106977Sdeischen 109106977Sdeischen if (uap->oucp == NULL || uap->ucp == NULL) 110106977Sdeischen ret = EINVAL; 111106977Sdeischen else { 112338983Sgordon bzero(&uc, sizeof(ucontext_t)); 113122364Smarcel get_mcontext(td, &uc.uc_mcontext, GET_MC_CLEAR_RET); 114218327Skib bzero(uc.__spare__, sizeof(uc.__spare__)); 115113626Sjhb PROC_LOCK(td->td_proc); 116112888Sjeff uc.uc_sigmask = td->td_sigmask; 117113626Sjhb PROC_UNLOCK(td->td_proc); 118106977Sdeischen ret = copyout(&uc, uap->oucp, UC_COPY_SIZE); 119106977Sdeischen if (ret == 0) { 120106977Sdeischen ret = copyin(uap->ucp, &uc, UC_COPY_SIZE); 121106977Sdeischen if (ret == 0) { 122106977Sdeischen ret = set_mcontext(td, &uc.uc_mcontext); 123106977Sdeischen if (ret == 0) { 124198507Skib kern_sigprocmask(td, SIG_SETMASK, 125198507Skib &uc.uc_sigmask, NULL, 0); 126106977Sdeischen } 127106977Sdeischen } 128106977Sdeischen } 129106977Sdeischen } 130112962Sjake return (ret == 0 ? EJUSTRETURN : ret); 131106977Sdeischen} 132