From 4fb15021890d327023aefd95f5a84ac33b037d19 Mon Sep 17 00:00:00 2001
From: Lihua Zhao <44661095+LihuaZhao@users.noreply.github.com>
Date: Tue, 21 May 2019 18:50:14 +0800
Subject: [PATCH] bpo-36648: fix mmap issue for VxWorks (GH-12394)

The mmap module set MAP_SHARED flag when map anonymous memory, however VxWorks
only support MAP_PRIVATE when map anonymous memory, this commit clear MAP_SHARED
and set MAP_PRIVATE.
---
 .../next/Library/2019-03-18-14-25-36.bpo-31904.ds3d67.rst  | 1 +
 Modules/mmapmodule.c                                       | 7 +++++++
 2 files changed, 8 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Library/2019-03-18-14-25-36.bpo-31904.ds3d67.rst

diff --git a/Misc/NEWS.d/next/Library/2019-03-18-14-25-36.bpo-31904.ds3d67.rst b/Misc/NEWS.d/next/Library/2019-03-18-14-25-36.bpo-31904.ds3d67.rst
new file mode 100644
index 0000000000..fd82fe086f
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2019-03-18-14-25-36.bpo-31904.ds3d67.rst
@@ -0,0 +1 @@
+Fix mmap fail for VxWorks
diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c
index 33366b2d93..917c6362c1 100644
--- a/Modules/mmapmodule.c
+++ b/Modules/mmapmodule.c
@@ -1164,6 +1164,13 @@ new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict)
 #ifdef MAP_ANONYMOUS
         /* BSD way to map anonymous memory */
         flags |= MAP_ANONYMOUS;
+
+        /* VxWorks only supports MAP_ANONYMOUS with MAP_PRIVATE flag */
+#ifdef __VXWORKS__
+        flags &= ~MAP_SHARED;
+        flags |= MAP_PRIVATE;
+#endif
+
 #else
         /* SVR4 method to map anonymous memory is to open /dev/zero */
         fd = devzero = _Py_open("/dev/zero", O_RDWR);
-- 
2.40.0