From 66c47b63a0df3143fe48d6efc1183eecda2a363d Mon Sep 17 00:00:00 2001
From: David CARLIER <devnexen@gmail.com>
Date: Wed, 29 Dec 2021 13:52:29 +0000
Subject: [PATCH] bpo-46176: mmap module adding MAP_STACK constant. (GH-30252)

---
 Doc/library/mmap.rst                                         | 4 ++++
 .../next/Library/2021-12-25-11-11-21.bpo-46176.EOY9wd.rst    | 1 +
 Modules/mmapmodule.c                                         | 5 +++++
 3 files changed, 10 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Library/2021-12-25-11-11-21.bpo-46176.EOY9wd.rst

diff --git a/Doc/library/mmap.rst b/Doc/library/mmap.rst
index c1ebd80abd9..d19580cd7ee 100644
--- a/Doc/library/mmap.rst
+++ b/Doc/library/mmap.rst
@@ -367,8 +367,12 @@ MAP_* Constants
           MAP_ANON
           MAP_ANONYMOUS
           MAP_POPULATE
+          MAP_STACK
 
     These are the various flags that can be passed to :meth:`mmap.mmap`. Note that some options might not be present on some systems.
 
     .. versionchanged:: 3.10
        Added MAP_POPULATE constant.
+
+    .. versionadded:: 3.11
+       Added MAP_STACK constant.
diff --git a/Misc/NEWS.d/next/Library/2021-12-25-11-11-21.bpo-46176.EOY9wd.rst b/Misc/NEWS.d/next/Library/2021-12-25-11-11-21.bpo-46176.EOY9wd.rst
new file mode 100644
index 00000000000..4a50c261720
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2021-12-25-11-11-21.bpo-46176.EOY9wd.rst
@@ -0,0 +1 @@
+Adding the ``MAP_STACK`` constant for the mmap module.
\ No newline at end of file
diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c
index 399cb0a99ad..742bcb3d145 100644
--- a/Modules/mmapmodule.c
+++ b/Modules/mmapmodule.c
@@ -1637,6 +1637,11 @@ mmap_exec(PyObject *module)
 #endif
 #ifdef MAP_POPULATE
     ADD_INT_MACRO(module, MAP_POPULATE);
+#endif
+#ifdef MAP_STACK
+    // Mostly a no-op on Linux and NetBSD, but useful on OpenBSD
+    // for stack usage (even on x86 arch)
+    ADD_INT_MACRO(module, MAP_STACK);
 #endif
     if (PyModule_AddIntConstant(module, "PAGESIZE", (long)my_getpagesize()) < 0 ) {
         return -1;