From c4909577da6defa395437f53bba813c654da69c3 Mon Sep 17 00:00:00 2001
From: Petr Viktorin <pviktori@redhat.com>
Date: Thu, 25 Feb 2021 13:14:30 +0100
Subject: [PATCH] Fix alignment issue causing failures on x86-64

---
 ...head-to-16-bytes-on-64-bit-platforms.patch | 63 +++++++++++++++++++
 python3.6.spec                                | 17 ++++-
 2 files changed, 79 insertions(+), 1 deletion(-)
 create mode 100644 00358-align-allocations-and-pygc_head-to-16-bytes-on-64-bit-platforms.patch

diff --git a/00358-align-allocations-and-pygc_head-to-16-bytes-on-64-bit-platforms.patch b/00358-align-allocations-and-pygc_head-to-16-bytes-on-64-bit-platforms.patch
new file mode 100644
index 0000000..063eb4c
--- /dev/null
+++ b/00358-align-allocations-and-pygc_head-to-16-bytes-on-64-bit-platforms.patch
@@ -0,0 +1,63 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Inada Naoki <songofacandy@gmail.com>
+Date: Mon, 3 Jun 2019 10:51:32 +0900
+Subject: [PATCH] 00358: align allocations and PyGC_Head to 16 bytes on 64-bit
+ platforms
+
+Upstream bug: https://bugs.python.org/issue27987
+Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1923658
+
+Combination of two upstream commits:
+- 1b85f4ec45a5d63188ee3866bd55eb29fdec7fbf
+- 8766cb74e186d3820db0a855ccd780d6d84461f7
+---
+ Include/objimpl.h                                           | 6 +++++-
+ .../2019-05-15-18-28-43.bpo-27987.FaxuLy.rst                | 2 ++
+ Objects/obmalloc.c                                          | 6 ++++++
+ 3 files changed, 13 insertions(+), 1 deletion(-)
+ create mode 100644 Misc/NEWS.d/next/Core and Builtins/2019-05-15-18-28-43.bpo-27987.FaxuLy.rst
+
+diff --git a/Include/objimpl.h b/Include/objimpl.h
+index e7a3696d7a..90d71b87ea 100644
+--- a/Include/objimpl.h
++++ b/Include/objimpl.h
+@@ -255,7 +255,11 @@ typedef union _gc_head {
+         union _gc_head *gc_prev;
+         Py_ssize_t gc_refs;
+     } gc;
+-    double dummy;  /* force worst-case alignment */
++    long double dummy;  /* force worst-case alignment */
++    // malloc returns memory block aligned for any built-in types and
++    // long double is the largest standard C type.
++    // On amd64 linux, long double requires 16 byte alignment.
++    // See bpo-27987 for more discussion.
+ } PyGC_Head;
+ 
+ extern PyGC_Head *_PyGC_generation0;
+diff --git a/Misc/NEWS.d/next/Core and Builtins/2019-05-15-18-28-43.bpo-27987.FaxuLy.rst b/Misc/NEWS.d/next/Core and Builtins/2019-05-15-18-28-43.bpo-27987.FaxuLy.rst
+new file mode 100644
+index 0000000000..98073471ca
+--- /dev/null
++++ b/Misc/NEWS.d/next/Core and Builtins/2019-05-15-18-28-43.bpo-27987.FaxuLy.rst	
+@@ -0,0 +1,2 @@
++``PyGC_Head`` structure is aligned to ``long double``.  This is needed to
++ensure GC-ed objects are aligned properly.  Patch by Inada Naoki.
+diff --git a/Objects/obmalloc.c b/Objects/obmalloc.c
+index d46d149311..47283354f4 100644
+--- a/Objects/obmalloc.c
++++ b/Objects/obmalloc.c
+@@ -650,8 +650,14 @@ static int running_on_valgrind = -1;
+  *
+  * You shouldn't change this unless you know what you are doing.
+  */
++
++#if SIZEOF_VOID_P > 4
++#define ALIGNMENT              16               /* must be 2^N */
++#define ALIGNMENT_SHIFT         4
++#else
+ #define ALIGNMENT               8               /* must be 2^N */
+ #define ALIGNMENT_SHIFT         3
++#endif
+ 
+ /* Return the number of bytes in size class I, as a uint. */
+ #define INDEX2SIZE(I) (((uint)(I) + 1) << ALIGNMENT_SHIFT)
diff --git a/python3.6.spec b/python3.6.spec
index c758a54..124193a 100644
--- a/python3.6.spec
+++ b/python3.6.spec
@@ -17,7 +17,7 @@ URL: https://www.python.org/
 #global prerel ...
 %global upstream_version %{general_version}%{?prerel}
 Version: %{general_version}%{?prerel:~%{prerel}}
-Release: 1%{?dist}
+Release: 2%{?dist}
 License: Python
 
 
@@ -437,6 +437,17 @@ Patch343: 00343-faulthandler-gcc10.patch
 # a nightmare because it's basically a binary file.
 Patch353: 00353-architecture-names-upstream-downstream.patch
 
+# 00358 # cd155152db2f3f64831ecc5bd174a72c3bac401f
+# align allocations and PyGC_Head to 16 bytes on 64-bit platforms
+#
+# Upstream bug: https://bugs.python.org/issue27987
+# Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1923658
+#
+# Combination of two upstream commits:
+# - 1b85f4ec45a5d63188ee3866bd55eb29fdec7fbf
+# - 8766cb74e186d3820db0a855ccd780d6d84461f7
+Patch358: 00358-align-allocations-and-pygc_head-to-16-bytes-on-64-bit-platforms.patch
+
 # (New patches go here ^^^)
 #
 # When adding new patches to "python" and "python3" in Fedora, EL, etc.,
@@ -1611,6 +1622,10 @@ CheckPython optimized
 # ======================================================
 
 %changelog
+* Thu Feb 25 2021 Petr Viktorin <pviktori@redhat.com> - 3.6.13-2
+- Fix alignment issue causing failures on x86-64
+  Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1923658
+
 * Tue Feb 16 2021 Tomas Hrnciar <thrnciar@redhat.com> - 3.6.13-1
 - Update to 3.6.13