From ee4ec1d7f9bdbdfc87117133478cfb2f6653e65c Mon Sep 17 00:00:00 2001 From: Andreas Krebbel 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 441eae3be1..c751491b81 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