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[PATCH] NEWS: Add comment about S/390 ABI changes
- From: Andreas Krebbel <krebbel at linux dot vnet dot ibm dot com>
- To: libc-alpha at sourceware dot org
- Cc: allan at archlinux dot org
- Date: Tue, 8 Apr 2014 16:35:18 +0200
- Subject: [PATCH] NEWS: Add comment about S/390 ABI changes
- Authentication-results: sourceware.org; auth=none
Hi,
the attached patch adds the text Carlos added to:
https://sourceware.org/glibc/wiki/Release/2.19#Packaging_Changes
to the glibc NEWS file. Thanks to Carlos for writing it!
Alan, is that ok for 2.19 branch as well?
Bye,
-Andreas-
>From aae3aab214438c4e3e09daba41f62a9ad3fbc4df Mon Sep 17 00:00:00 2001
From: Andreas Krebbel <krebbel@linux.vnet.ibm.com>
Date: Tue, 8 Apr 2014 16:30:07 +0200
Subject: [PATCH] NEWS: Add comment about changed ABI on s390 and s390x.
---
NEWS | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/NEWS b/NEWS
index db8cc10..0f86584 100644
--- a/NEWS
+++ b/NEWS
@@ -151,6 +151,20 @@ Version 2.19
* Preliminary documentation about Multi-Thread, Async-Signal and
Async-Cancel Safety has been added.
+
+* Change of ABI data structures for s390 and s390x:
+ On s390 and s390x the size of struct ucontext and jmp_buf was increased to
+ allow for future hardware extensions. All library functions that accept or
+ return these structures were versioned in order to provide backwards
+ compatibility with existing code. However, not all cases can be handled
+ with interface versioning. If an application embeds either structure into
+ another structure and that structure is passed to another compilation unit
+ which expects the newer larger-sized object then any access to the new
+ fields will result in undefined behaviour. Similarly any access to fields
+ that were moved by the enlarging of the structures will cause undefined
+ behaviour. To fix the undefined behaviour all objects that are part of the
+ final in-memory image must agree on the size of structures, and this may
+ require recompilation.
Version 2.18
--
1.8.5.5