1/* 2 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au> 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 * 3. Neither the name of the author nor the names of any co-contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $FreeBSD$ 30 */ 31 32#include "namespace.h" 33#include <signal.h> 34#include <errno.h> 35#include <pthread.h> 36#include "un-namespace.h" 37#include "thr_private.h" 38 39__weak_reference(_sigaction, sigaction); 40 41int 42_sigaction(int sig, const struct sigaction * act, struct sigaction * oact) 43{ 44 int ret = 0; 45 int err = 0; 46 struct sigaction newact, oldact; 47 struct pthread *curthread; 48 kse_critical_t crit; 49 50 /* Check if the signal number is out of range: */ 51 if (sig < 1 || sig > _SIG_MAXSIG) { 52 /* Return an invalid argument: */ 53 errno = EINVAL; 54 ret = -1; 55 } else { 56 if (act) 57 newact = *act; 58 59 crit = _kse_critical_enter(); 60 curthread = _get_curthread(); 61 KSE_LOCK_ACQUIRE(curthread->kse, &_thread_signal_lock); 62 63 oldact = _thread_sigact[sig - 1]; 64 65 /* Check if a signal action was supplied: */ 66 if (act != NULL) { 67 /* Set the new signal handler: */ 68 _thread_sigact[sig - 1] = newact; 69 } 70 71 /* 72 * Check if the kernel needs to be advised of a change 73 * in signal action: 74 */ 75 if (act != NULL) { 76 77 newact.sa_flags |= SA_SIGINFO; 78 79 /* 80 * Check if the signal handler is being set to 81 * the default or ignore handlers: 82 */ 83 if (newact.sa_handler != SIG_DFL && 84 newact.sa_handler != SIG_IGN) { 85 /* 86 * Specify the thread kernel signal 87 * handler: 88 */ 89 newact.sa_sigaction = _thr_sig_handler; 90 } 91 /* 92 * Install libpthread signal handler wrapper 93 * for SIGINFO signal if threads dump enabled 94 * even if a user set the signal handler to 95 * SIG_DFL or SIG_IGN. 96 */ 97 if (sig == SIGINFO && _thr_dump_enabled()) { 98 newact.sa_sigaction = _thr_sig_handler; 99 } 100 /* Change the signal action in the kernel: */ 101 if (__sys_sigaction(sig, &newact, NULL) != 0) { 102 _thread_sigact[sig - 1] = oldact; 103 /* errno is in kse, will copy it to thread */ 104 err = errno; 105 ret = -1; 106 } 107 } 108 KSE_LOCK_RELEASE(curthread->kse, &_thread_signal_lock); 109 _kse_critical_leave(crit); 110 /* 111 * Check if the existing signal action structure contents are 112 * to be returned: 113 */ 114 if (oact != NULL) { 115 /* Return the existing signal action contents: */ 116 *oact = oldact; 117 } 118 if (ret != 0) { 119 /* Return errno to thread */ 120 errno = err; 121 } 122 } 123 124 /* Return the completion status: */ 125 return (ret); 126} 127