gdb/testsuite/gdb.base/coredump-filter.c

   1 /* Copyright 2015-2018 Free Software Foundation, Inc.
   2
   3    This file is part of GDB.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 #define _GNU_SOURCE
  19 #include <stdlib.h>
  20 #include <assert.h>
  21 #include <unistd.h>
  22 #include <stdio.h>
  23 #include <sys/mman.h>
  24 #include <errno.h>
  25 #include <string.h>
  26
  27 static void *
  28 do_mmap (void *addr, size_t size, int prot, int flags, int fd, off_t offset)
  29 {
  30   void *ret = mmap (addr, size, prot, flags, fd, offset);
  31
  32   assert (ret != NULL);
  33   return ret;
  34 }
  35
  36 int
  37 main (int argc, char *argv[])
  38 {
  39   const size_t size = 10;
  40   const int default_prot = PROT_READ | PROT_WRITE;
  41   char *private_anon, *shared_anon;
  42   char *dont_dump;
  43   int i;
  44
  45   private_anon = do_mmap (NULL, size, default_prot,
  46                           MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  47   memset (private_anon, 0x11, size);
  48
  49   shared_anon = do_mmap (NULL, size, default_prot,
  50                          MAP_SHARED | MAP_ANONYMOUS, -1, 0);
  51   memset (shared_anon, 0x22, size);
  52
  53   dont_dump = do_mmap (NULL, size, default_prot,
  54                        MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  55   memset (dont_dump, 0x55, size);
  56   i = madvise (dont_dump, size, MADV_DONTDUMP);
  57   assert_perror (errno);
  58   assert (i == 0);
  59
  60   return 0; /* break-here */
  61 }
  62
  63 /* Write V to /proc/self/coredump_filter.  Return 0 on success.  */
  64
  65 int
  66 set_coredump_filter (int v)
  67 {
  68   FILE *f = fopen("/proc/self/coredump_filter", "r+");
  69
  70   if (f == NULL)
  71     return 1;
  72
  73   fprintf(f, "%#x", v);
  74
  75   fclose (f);
  76   return 0;
  77 }