lib/libc_r/uthread/uthread_sigaction.c

   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. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by John Birrell.
  16  * 4. Neither the name of the author nor the names of any co-contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * $FreeBSD: src/lib/libc_r/uthread/uthread_sigaction.c,v 1.11.2.3 2002/10/22 14:44:03 fjoe Exp $
  33  * $DragonFly: src/lib/libc_r/uthread/uthread_sigaction.c,v 1.2 2003/06/17 04:26:48 dillon Exp $
  34  */
  35 #include <signal.h>
  36 #include <errno.h>
  37 #include <pthread.h>
  38 #include "pthread_private.h"
  39
  40 int
  41 _sigaction(int sig, const struct sigaction * act, struct sigaction * oact)
  42 {
  43         int ret = 0;
  44         struct sigaction gact;
  45
  46         /* Check if the signal number is out of range: */
  47         if (sig < 1 || sig > NSIG) {
  48                 /* Return an invalid argument: */
  49                 errno = EINVAL;
  50                 ret = -1;
  51         } else {
  52                 if (_thread_initial == NULL)
  53                         _thread_init();
  54
  55                 /*
  56                  * Check if the existing signal action structure contents are
  57                  * to be returned:
  58                  */
  59                 if (oact != NULL) {
  60                         /* Return the existing signal action contents: */
  61                         oact->sa_handler = _thread_sigact[sig - 1].sa_handler;
  62                         oact->sa_mask = _thread_sigact[sig - 1].sa_mask;
  63                         oact->sa_flags = _thread_sigact[sig - 1].sa_flags;
  64                 }
  65
  66                 /* Check if a signal action was supplied: */
  67                 if (act != NULL) {
  68                         /* Set the new signal handler: */
  69                         _thread_sigact[sig - 1].sa_mask = act->sa_mask;
  70                         _thread_sigact[sig - 1].sa_flags = act->sa_flags;
  71                         _thread_sigact[sig - 1].sa_handler = act->sa_handler;
  72                 }
  73
  74                 /*
  75                  * Check if the kernel needs to be advised of a change
  76                  * in signal action:
  77                  */
  78                 if (act != NULL && sig != _SCHED_SIGNAL && sig != SIGCHLD &&
  79                     sig != SIGINFO) {
  80                         /*
  81                          * Ensure the signal handler cannot be interrupted
  82                          * by other signals.  Always request the POSIX signal
  83                          * handler arguments.
  84                          */
  85                         sigfillset(&gact.sa_mask);
  86                         gact.sa_flags = SA_SIGINFO | SA_RESTART;
  87
  88                         /*
  89                          * Check if the signal handler is being set to
  90                          * the default or ignore handlers:
  91                          */
  92                         if (act->sa_handler == SIG_DFL ||
  93                             act->sa_handler == SIG_IGN)
  94                                 /* Specify the built in handler: */
  95                                 gact.sa_handler = act->sa_handler;
  96                         else
  97                                 /*
  98                                  * Specify the thread kernel signal
  99                                  * handler:
 100                                  */
 101                                 gact.sa_handler = (void (*) ()) _thread_sig_handler;
 102
 103                         /* Change the signal action in the kernel: */
 104                         if (__sys_sigaction(sig,&gact,NULL) != 0)
 105                                 ret = -1;
 106                 }
 107         }
 108
 109         /* Return the completion status: */
 110         return (ret);
 111 }
 112
 113 __strong_reference(_sigaction, sigaction);