1 /*- 2 * Copyright (c) 2002 Daniel M. Eischen <deischen@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 */ 27 /* 28 * $FreeBSD$ 29 */ 30 31 #include <sys/param.h> 32 #include <sys/kernel.h> 33 #include <sys/lock.h> 34 #include <sys/mutex.h> 35 #include <sys/proc.h> 36 #include <sys/sysent.h> 37 #include <sys/systm.h> 38 #include <sys/sysproto.h> 39 #include <sys/signalvar.h> 40 #include <sys/ucontext.h> 41 42 /* 43 * The first two fields of a ucontext_t are the signal mask and 44 * the machine context. The next field is uc_link; we want to 45 * avoid destroying the link when copying out contexts. 46 */ 47 #define UC_COPY_SIZE (sizeof(sigset_t) + sizeof(mcontext_t)) 48 49 50 #ifndef _SYS_SYSPROTO_H_ 51 struct getcontext_args { 52 struct __ucontext *ucp; 53 } 54 struct setcontext_args { 55 const struct __ucontext_t *ucp; 56 } 57 struct swapcontext_args { 58 struct __ucontext *oucp; 59 const struct __ucontext_t *ucp; 60 } 61 #endif 62 63 /* 64 * MPSAFE 65 */ 66 int 67 getcontext(struct thread *td, struct getcontext_args *uap) 68 { 69 ucontext_t uc; 70 int ret; 71 72 if (uap->ucp == NULL) 73 ret = EINVAL; 74 else { 75 get_mcontext(td, &uc.uc_mcontext); 76 uc.uc_sigmask = td->td_proc->p_sigmask; 77 ret = copyout(&uc, uap->ucp, UC_COPY_SIZE); 78 } 79 return (ret); 80 } 81 82 /* 83 * MPSAFE 84 */ 85 int 86 setcontext(struct thread *td, struct setcontext_args *uap) 87 { 88 ucontext_t uc; 89 int ret; 90 91 if (uap->ucp == NULL) 92 ret = EINVAL; 93 else { 94 ret = copyin(uap->ucp, &uc, UC_COPY_SIZE); 95 if (ret == 0) { 96 ret = set_mcontext(td, &uc.uc_mcontext); 97 if (ret == 0) { 98 SIG_CANTMASK(uc.uc_sigmask); 99 PROC_LOCK(td->td_proc); 100 td->td_proc->p_sigmask = uc.uc_sigmask; 101 PROC_UNLOCK(td->td_proc); 102 } 103 } 104 } 105 return (ret); 106 } 107 108 int 109 swapcontext(struct thread *td, struct swapcontext_args *uap) 110 { 111 ucontext_t uc; 112 int ret; 113 114 if (uap->oucp == NULL || uap->ucp == NULL) 115 ret = EINVAL; 116 else { 117 get_mcontext(td, &uc.uc_mcontext); 118 uc.uc_sigmask = td->td_proc->p_sigmask; 119 ret = copyout(&uc, uap->oucp, UC_COPY_SIZE); 120 if (ret == 0) { 121 ret = copyin(uap->ucp, &uc, UC_COPY_SIZE); 122 if (ret == 0) { 123 ret = set_mcontext(td, &uc.uc_mcontext); 124 if (ret == 0) { 125 SIG_CANTMASK(uc.uc_sigmask); 126 PROC_LOCK(td->td_proc); 127 td->td_proc->p_sigmask = uc.uc_sigmask; 128 PROC_UNLOCK(td->td_proc); 129 } 130 } 131 } 132 } 133 return (ret); 134 } 135