text: /* Verifies that overlapping memory mappings are disallowed. */
  
  #include <syscall.h>
  #include "tests/vm/sample.inc"
  #include "tests/lib.h"
  #include "tests/main.h"
  
  void
  test_main (void)
  {
    char *start = (char *) 0x10000000;
    int fd[2];
  
    CHECK ((fd[0] = open ("zeros")) > 1, "open \"zeros\" once");
    CHECK (mmap (fd[0], start) != MAP_FAILED, "mmap \"zeros\"");
    CHECK ((fd[1] = open ("zeros")) > 1 && fd[0] != fd[1],
           "open \"zeros\" again");
    CHECK (mmap (fd[1], start + 4096) == MAP_FAILED,
           "try to mmap \"zeros\" again");
  }
  