root/maint/gnulib/tests/test-sigsegv-catch-segv2.c

/* */

DEFINITIONS

1. handler_continuation
2. handler
3. crasher
4. main
5. main

   1 /* Test that the handler can be exited multiple times.
   2    Copyright (C) 2002-2021 Free Software Foundation, Inc.
   3 
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2 of the License, or
   7    (at your option) any later version.
   8 
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13 
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16 
  17 /* Written by Bruno Haible.  */
  18 
  19 #include <config.h>
  20 
  21 /* Specification.  */
  22 #include "sigsegv.h"
  23 
  24 #include <stdint.h>
  25 #include <stdio.h>
  26 
  27 #if HAVE_SIGSEGV_RECOVERY
  28 
  29 # if defined _WIN32 && !defined __CYGWIN__
  30   /* Windows doesn't have sigset_t.  */
  31   typedef int sigset_t;
  32 #  define sigemptyset(set)
  33 #  define sigprocmask(how,set,oldset)
  34 # endif
  35 
  36 # include "mmap-anon-util.h"
  37 # include <stdlib.h> /* for abort, exit */
  38 # include <signal.h>
  39 # include <setjmp.h>
  40 
  41 # if SIGSEGV_FAULT_ADDRESS_ALIGNMENT > 1UL
  42 #  include <unistd.h>
  43 #  define SIGSEGV_FAULT_ADDRESS_ROUNDOFF_BITS (getpagesize () - 1)
  44 # else
  45 #  define SIGSEGV_FAULT_ADDRESS_ROUNDOFF_BITS 0
  46 # endif
  47 
  48 jmp_buf mainloop;
  49 sigset_t mainsigset;
  50 
  51 volatile int pass = 0;
  52 uintptr_t page;
  53 
  54 volatile int handler_called = 0;
  55 
  56 static void
  57 handler_continuation (void *arg1, void *arg2, void *arg3)
     /*  */
  58 {
  59   longjmp (mainloop, pass);
  60 }
  61 
  62 int
  63 handler (void *fault_address, int serious)
     /*  */
  64 {
  65   handler_called++;
  66   if (handler_called > 10)
  67     abort ();
  68   if (fault_address
  69       != (void *)((page + 0x678 + 8 * pass) & ~SIGSEGV_FAULT_ADDRESS_ROUNDOFF_BITS))
  70     abort ();
  71   pass++;
  72   printf ("Fault %d caught.\n", pass);
  73   sigprocmask (SIG_SETMASK, &mainsigset, NULL);
  74   return sigsegv_leave_handler (handler_continuation, NULL, NULL, NULL);
  75 }
  76 
  77 void
  78 crasher (uintptr_t p)
     /*  */
  79 {
  80   *(volatile int *) (p + 0x678 + 8 * pass) = 42;
  81 }
  82 
  83 int
  84 main ()
     /*  */
  85 {
  86   int prot_unwritable;
  87   void *p;
  88   sigset_t emptyset;
  89 
  90   /* Preparations.  */
  91 # if !HAVE_MAP_ANONYMOUS
  92   zero_fd = open ("/dev/zero", O_RDONLY, 0644);
  93 # endif
  94 
  95 # if defined __linux__ && defined __sparc__
  96   /* On Linux 2.6.26/SPARC64, PROT_READ has the same effect as
  97      PROT_READ | PROT_WRITE.  */
  98   prot_unwritable = PROT_NONE;
  99 # else
 100   prot_unwritable = PROT_READ;
 101 # endif
 102 
 103   /* Setup some mmaped memory.  */
 104   p = mmap_zeromap ((void *) 0x12340000, 0x4000);
 105   if (p == (void *)(-1))
 106     {
 107       fprintf (stderr, "mmap_zeromap failed.\n");
 108       exit (2);
 109     }
 110   page = (uintptr_t) p;
 111 
 112   /* Make it read-only.  */
 113   if (mprotect ((void *) page, 0x4000, prot_unwritable) < 0)
 114     {
 115       fprintf (stderr, "mprotect failed.\n");
 116       exit (2);
 117     }
 118 
 119   /* Install the SIGSEGV handler.  */
 120   if (sigsegv_install_handler (&handler) < 0)
 121     exit (2);
 122 
 123   /* Save the current signal mask.  */
 124   sigemptyset (&emptyset);
 125   sigprocmask (SIG_BLOCK, &emptyset, &mainsigset);
 126 
 127   /* Provoke two SIGSEGVs in a row.  */
 128   switch (setjmp (mainloop))
 129     {
 130     case 0: case 1:
 131       printf ("Doing SIGSEGV pass %d.\n", pass + 1);
 132       crasher (page);
 133       printf ("no SIGSEGV?!\n"); exit (1);
 134     case 2:
 135       break;
 136     default:
 137       abort ();
 138     }
 139 
 140   /* Test passed!  */
 141   printf ("Test passed.\n");
 142   return 0;
 143 }
 144 
 145 #else
 146 
 147 int
 148 main ()
     /*  */
 149 {
 150   return 77;
 151 }
 152 
 153 #endif

/* */