diff -r 027494c8ddaf Lib/test/test_os.py
--- a/Lib/test/test_os.py	Mon Jul 07 15:18:52 2014 +0300
+++ b/Lib/test/test_os.py	Mon Jul 07 17:23:19 2014 +0300
@@ -43,6 +43,10 @@
     import _winapi
 except ImportError:
     _winapi = None
+try:
+    from _testcapi import INT_MAX, PY_SSIZE_T_MAX
+except ImportError:
+    INT_MAX = PY_SSIZE_T_MAX = sys.maxsize
 
 from test.script_helper import assert_python_ok
 
@@ -119,6 +123,23 @@
             self.assertEqual(type(s), bytes)
             self.assertEqual(s, b"spam")
 
+    @support.cpython_only
+    @unittest.skipIf(sys.platform == "win32", "Posix specific tests")
+    @unittest.skipUnless(INT_MAX < PY_SSIZE_T_MAX,
+                         "needs INT_MAX < PY_SSIZE_T_MAX")
+    @support.bigmemtest(size=INT_MAX + 1, memuse=1, dry_run=False)
+    def test_large_read(self, size):
+        try:
+            fd = os.open('/dev/zero', os.O_RDONLY)
+        except OSError:
+            self.skipTest('needs /dev/zero')
+        try:
+            s = os.read(fd, size)
+        finally:
+            os.close(fd)
+        self.assertEqual(type(s), bytes)
+        self.assertEqual(len(s), size)
+
     def test_write(self):
         # os.write() accepts bytes- and buffer-like objects but not strings
         fd = os.open(support.TESTFN, os.O_CREAT | os.O_WRONLY)