1 files changed, 20 insertions, 0 deletions

diff --git a/tests/vm/mmap-overlap.c b/tests/vm/mmap-overlap.c
new file mode 100644
index 0000000..668ae5f
--- /dev/null
+++ b/tests/vm/mmap-overlap.c
@@ -0,0 +1,20 @@
+/* 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");
+}