sys.subproj/sigaction.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved
  24  *
  25  *      @(#)sigaction.c 1.0
  26  */
  27
  28 #include <sys/syscall.h>
  29 #include <signal.h>
  30 #include <sys/signal.h>
  31 #include <errno.h>
  32
  33 /*
  34  *      Intercept the sigaction syscall and use our signal trampoline
  35  *      as the signal handler instead.  The code here is derived
  36  *      from sigvec in sys/kern_sig.c.
  37  */
  38
  39 extern void     (*sigcatch[NSIG])();
  40 #if defined(__DYNAMIC__)
  41 extern int __in_sigtramp;
  42 #endif
  43
  44 static int
  45 sigaction__ (sig, nsv, osv, bind)
  46         int sig;
  47         register struct sigaction *nsv, *osv;
  48         int bind;
  49 {
  50         struct sigaction vec;
  51         void (*prevsig)();
  52         extern void _sigtramp();
  53
  54         if (sig <= 0 || sig >= NSIG || sig == SIGKILL || sig == SIGSTOP) {
  55                 errno = EINVAL;
  56                 return (-1);
  57         }
  58         prevsig = sigcatch[sig];
  59         if (nsv) {
  60                 sigcatch[sig] = nsv->sa_handler;
  61                 vec = *nsv;  nsv = &vec;
  62                 if (nsv->sa_handler != (void (*)())SIG_DFL && nsv->sa_handler != (void (*)())SIG_IGN) {
  63                         nsv->sa_handler = _sigtramp;
  64 #ifdef __DYNAMIC__
  65                     if (bind && (__in_sigtramp == 0))                           // XXX
  66                           _dyld_bind_fully_image_containing_address(sigcatch[sig]);
  67 #endif
  68                 }
  69         }
  70         if (syscall (SYS_sigaction, sig, nsv, osv) < 0) {
  71                 sigcatch[sig] = prevsig;
  72                 return (-1);
  73         }
  74         if (osv && prevsig)
  75                 osv->sa_handler = prevsig;
  76         return (0);
  77 }
  78
  79
  80 int
  81 sigaction (sig, nsv, osv)
  82         int sig;
  83         register const struct sigaction *nsv;
  84         register struct sigaction *osv;
  85 {
  86     return sigaction__(sig, nsv, osv, 1);
  87 }
  88
  89 // XXX
  90 #ifdef __DYNAMIC__
  91
  92 int
  93 _sigaction_nobind (sig, nsv, osv)
  94         int sig;
  95         register const struct sigaction *nsv;
  96         register struct sigaction *osv;
  97 {
  98     return sigaction__(sig, nsv, osv, 0);
  99 }
 100 #endif
 101