sys/sigaction.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved
  25  *
  26  *      @(#)sigaction.c 1.0
  27  */
  28
  29 #include <CrashReporterClient.h>
  30 #include <stdlib.h>
  31 #include <stdio.h>
  32 #include <unistd.h>
  33 #include <signal.h>
  34 #include <sys/signal.h>
  35 #include <errno.h>
  36
  37 /*
  38  *      Intercept the sigaction syscall and use our signal trampoline
  39  *      as the signal handler instead.  The code here is derived
  40  *      from sigvec in sys/kern_sig.c.
  41  */
  42 extern int __sigaction (int, struct __sigaction * __restrict, struct sigaction * __restrict);
  43
  44 int
  45 sigaction (int sig, const struct sigaction * __restrict nsv, struct sigaction * __restrict osv)
  46 {
  47         extern void _sigtramp();
  48         struct __sigaction sa;
  49         struct __sigaction *sap;
  50         int ret;
  51
  52         if (sig <= 0 || sig >= NSIG || sig == SIGKILL || sig == SIGSTOP) {
  53                 errno = EINVAL;
  54                 return (-1);
  55         }
  56         sap = (struct __sigaction *)0;
  57         if (nsv) {
  58                 sa.sa_handler = nsv->sa_handler;
  59                 sa.sa_tramp = _sigtramp;
  60                 sa.sa_mask = nsv->sa_mask;
  61                 sa.sa_flags = nsv->sa_flags;
  62                 sap = &sa;
  63         }
  64         ret = __sigaction(sig, sap, osv);
  65 #ifdef FEATURE_SIGNAL_RESTRICTION
  66         // Note: The "sig != 0" here is to force the compiler to maintain that "sig"
  67         // is live, and in a register, after __sigaction so it is visible in the
  68         // crashing register state.
  69         if (ret == -1 && errno == ENOTSUP && sig != 0) {
  70                 CRSetCrashLogMessage("sigaction on fatal signals is not supported");
  71                 __builtin_trap();
  72         }
  73 #endif
  74         return ret;
  75 }
  76
  77 // XXX
  78 #ifdef __DYNAMIC__
  79
  80 int
  81 _sigaction_nobind (sig, nsv, osv)
  82         int sig;
  83         register const struct sigaction *nsv;
  84         register struct sigaction *osv;
  85 {
  86     return sigaction(sig, nsv, osv);
  87 }
  88 #endif
  89