| /* This testcase is part of GDB, the GNU debugger. | 
 |  | 
 |    Copyright 2004-2022 Free Software Foundation, Inc. | 
 |  | 
 |    This program is free software; you can redistribute it and/or modify | 
 |    it under the terms of the GNU General Public License as published by | 
 |    the Free Software Foundation; either version 3 of the License, or | 
 |    (at your option) any later version. | 
 |  | 
 |    This program is distributed in the hope that it will be useful, | 
 |    but WITHOUT ANY WARRANTY; without even the implied warranty of | 
 |    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the | 
 |    GNU General Public License for more details. | 
 |  | 
 |    You should have received a copy of the GNU General Public License | 
 |    along with this program.  If not, see <http://www.gnu.org/licenses/>. | 
 |  | 
 | */ | 
 |  | 
 | #include <signal.h> | 
 | #include <stdio.h> | 
 | #include <stdlib.h> | 
 | #include <string.h> | 
 | #include <sys/mman.h> | 
 | #include <unistd.h> | 
 |  | 
 | static void *p; | 
 |  | 
 | void | 
 | pass (void) | 
 | { | 
 | } | 
 |  | 
 | static void | 
 | handler (int sig, siginfo_t *info, void *context) | 
 | { | 
 |   if (info->si_addr == p) | 
 |     pass (); | 
 |   _exit (0); | 
 | } | 
 |  | 
 | int | 
 | main (void) | 
 | { | 
 |   /* Set up unwritable memory.  */ | 
 |   { | 
 |     size_t len; | 
 |     len = sysconf(_SC_PAGESIZE); | 
 |     p = mmap (0, len, PROT_NONE, MAP_ANON|MAP_PRIVATE, -1, 0); | 
 |     if (p == MAP_FAILED) | 
 |       { | 
 | 	perror ("mmap"); | 
 | 	return 1; | 
 |       } | 
 |   } | 
 |   /* Set up the signal handler.  */ | 
 |   { | 
 |     struct sigaction action; | 
 |     memset (&action, 0, sizeof (action)); | 
 |     action.sa_sigaction = handler; | 
 |     action.sa_flags |= SA_SIGINFO; | 
 |     if (sigaction (SIGSEGV, &action, NULL)) | 
 |       { | 
 | 	perror ("sigaction"); | 
 | 	return 1; | 
 |       } | 
 |   } | 
 |   /* Trigger SIGSEGV.  */ | 
 |   *(int *)p = 0; | 
 |   return 0; | 
 | } |