| |
@@ -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)
|
| |
