none/tests/map_unaligned.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include "tests/sys_mman.h"
   4
   5 int main(int argc, char **argv)
   6 {
   7    void *p1;
   8    void *p2;
   9
  10    if ( ( p1 = mmap( 0, 4096, PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0 ) ) == MAP_FAILED )
  11    {
  12       perror( "aligned mmap failed" );
  13       exit( 1 );
  14    }
  15
  16    if ( munmap( p1, 4096 ) != 0 )
  17    {
  18       perror( "aligned munmap failed" );
  19       exit( 1 );
  20    }
  21
  22    // This fails because MAP_FIXED is specified and p1+1 isn't page-aligned.
  23    // (On Linux, just non-page-alignment is enough for failure, but on Darwin
  24    // MAP_FIXED has to also be specified.)
  25    if ( ( p2 = mmap( p1 + 1, 4096, PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0 ) ) == MAP_FAILED )
  26    {
  27       perror( "unaligned mmap failed" );
  28       exit( 1 );
  29    }
  30
  31    if ( munmap( p2, 4096 ) != 0 )
  32    {
  33       perror( "unaligned munmap failed" );
  34       exit( 1 );
  35    }
  36
  37    exit( 0 );
  38 }