posix/src/sigaction.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup POSIXAPI
0007  *
0008  * @brief Allows calling process to examine action of a Specific Signal
0009  */
0010
0011 /*
0012  *  3.3.4 Examine and Change Signal Action, P1003.1b-1993, p. 70
0013  *
0014  *  COPYRIGHT (c) 1989-1999.
0015  *  On-Line Applications Research Corporation (OAR).
0016  *
0017  * Redistribution and use in source and binary forms, with or without
0018  * modification, are permitted provided that the following conditions
0019  * are met:
0020  * 1. Redistributions of source code must retain the above copyright
0021  *    notice, this list of conditions and the following disclaimer.
0022  * 2. Redistributions in binary form must reproduce the above copyright
0023  *    notice, this list of conditions and the following disclaimer in the
0024  *    documentation and/or other materials provided with the distribution.
0025  *
0026  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0027  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0028  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0029  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0030  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0031  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0032  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0033  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0034  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0035  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0036  * POSSIBILITY OF SUCH DAMAGE.
0037  */
0038
0039 #ifdef HAVE_CONFIG_H
0040 #include "config.h"
0041 #endif
0042
0043 #include <pthread.h>
0044 #include <signal.h>
0045 #include <errno.h>
0046
0047 #include <rtems/posix/psignalimpl.h>
0048 #include <rtems/seterr.h>
0049
0050 int sigaction(
0051   int                     sig,
0052   const struct sigaction *__restrict act,
0053   struct sigaction       *__restrict oact
0054 )
0055 {
0056   Thread_queue_Context queue_context;
0057
0058   if ( !sig )
0059     rtems_set_errno_and_return_minus_one( EINVAL );
0060
0061   if ( !is_valid_signo(sig) )
0062     rtems_set_errno_and_return_minus_one( EINVAL );
0063
0064   /*
0065    *  Some signals cannot be ignored (P1003.1b-1993, pp. 70-72 and references.
0066    *
0067    *  NOTE: Solaris documentation claims to "silently enforce" this which
0068    *        contradicts the POSIX specification.
0069    */
0070
0071   if ( sig == SIGKILL )
0072     rtems_set_errno_and_return_minus_one( EINVAL );
0073
0074   _Thread_queue_Context_initialize( &queue_context );
0075   _POSIX_signals_Acquire( &queue_context );
0076
0077   if ( oact )
0078     *oact = _POSIX_signals_Vectors[ sig ];
0079
0080   /*
0081    *  Evaluate the new action structure and set the global signal vector
0082    *  appropriately.
0083    */
0084
0085   if ( act ) {
0086
0087     /*
0088      *  Unless the user is installing the default signal actions, then
0089      *  we can just copy the provided sigaction structure into the vectors.
0090      */
0091
0092     if ( act->sa_handler == SIG_DFL ) {
0093       _POSIX_signals_Vectors[ sig ] = _POSIX_signals_Default_vectors[ sig ];
0094     } else {
0095        _POSIX_signals_Clear_process_signals( sig );
0096        _POSIX_signals_Vectors[ sig ] = *act;
0097     }
0098   }
0099
0100   _POSIX_signals_Release( &queue_context );
0101
0102   return 0;
0103 }