tests/test-vma-prot.c

   1 /* Test of getting protection of a virtual memory area.
   2    Copyright (C) 2024-2025 Free Software Foundation, Inc.
   3
   4    This file is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published
   6    by the Free Software Foundation, either version 3 of the License,
   7    or (at your option) any later version.
   8
   9    This file 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 <bruno@clisp.org>, 2024.  */
  18
  19 #include <config.h>
  20
  21 #include "vma-prot.h"
  22
  23 #include <stdlib.h>
  24
  25 #if HAVE_MAP_ANONYMOUS
  26 # include <sys/mman.h>
  27 # include <unistd.h>
  28 #endif
  29
  30 #include "macros.h"
  31
  32 int dummy;
  33
  34 int
  35 f (int x)
  36 {
  37   return x;
  38 }
  39
  40 int
  41 main (void)
  42 {
  43   int prot;
  44
  45   /* Test on memory allocated through malloc().  */
  46   {
  47     char *mem = malloc (10);
  48     prot = get_vma_prot (mem + 2, 5);
  49     ASSERT (prot != -1);
  50     ASSERT (((VMA_PROT_READ | VMA_PROT_WRITE) & ~prot) == 0);
  51   }
  52   {
  53     char *mem = malloc (1000000);
  54     prot = get_vma_prot (mem, 1000000);
  55     ASSERT (prot != -1);
  56     ASSERT (((VMA_PROT_READ | VMA_PROT_WRITE) & ~prot) == 0);
  57   }
  58
  59 #if HAVE_MAP_ANONYMOUS
  60   /* Test on memory allocated through mmap().  */
  61   {
  62     char *mem = mmap (NULL, 1024*1024, PROT_READ | PROT_WRITE,
  63                       MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
  64     if (mem != (char *)(-1))
  65       {
  66         prot = get_vma_prot (mem, 1024*1024);
  67         ASSERT (prot != -1);
  68         ASSERT (prot == (VMA_PROT_READ | VMA_PROT_WRITE));
  69
  70         size_t pagesize = sysconf (_SC_PAGESIZE);
  71         if (pagesize <= 512*1024
  72             && munmap (mem + pagesize, pagesize) >= 0)
  73           {
  74             prot = get_vma_prot (mem, 1024*1024);
  75             ASSERT (prot != -1);
  76             ASSERT (prot == 0);
  77           }
  78       }
  79   }
  80 #endif
  81
  82   /* Test on a global variable.  */
  83   prot = get_vma_prot (&dummy, sizeof (dummy));
  84   ASSERT (prot != -1);
  85   ASSERT (((VMA_PROT_READ | VMA_PROT_WRITE) & ~prot) == 0);
  86
  87   /* Test on a function.  */
  88   prot = get_vma_prot (&f, 1);
  89   ASSERT (prot != -1);
  90 #if (defined __hppa || defined __hppa64__ \
  91      || defined __ia64__ \
  92      || defined _AIX \
  93      || (defined __powerpc64__ && defined __linux__ && _CALL_ELF != 2))
  94   /* On these platforms, a function pointer is actually a pointer to
  95      a struct of pointers.  */
  96 #else
  97   /* On these platforms, a function pointer is a pointer to or into some
  98      machine instruction.  */
  99   ASSERT ((VMA_PROT_EXECUTE & ~prot) == 0);
 100 #endif
 101 #if !defined __OpenBSD__
 102   /* Except on OpenBSD/arm64, the machine instructions are also readable.  */
 103   ASSERT ((VMA_PROT_READ & ~prot) == 0);
 104 #endif
 105
 106   return test_exit_status;
 107 }