Comment 0 for bug 1550468

== Comment: #0 - Hendrik Brueckner - 2016-02-26 11:02:00 ==
Please backport Linux kernel upstream commit ID:

commit 342300cc9cd3428bc6bfe5809bfcc1b9a0f06702
Author: Martin Schwidefsky <email address hidden>
Date: Fri Feb 19 14:44:14 2016 +0100

    s390/compat: correct restore of high gprs on signal return

    git commit 8070361799ae1e3f4ef347bd10f0a508ac10acfb
    "s390: add support for vector extension"
    broke 31-bit compat processes in regard to signal handling.

    The restore_sigregs_ext32() function is used to restore the additional
    elements from the user space signal frame. Among the additional elements
    are the upper registers halves for 64-bit register support for 31-bit
    processes. The copy_from_user that is used to retrieve the high-gprs
    array from the user stack uses an incorrect length, 8 bytes instead of
    64 bytes. This causes incorrect upper register halves to get loaded.

    Cc: <email address hidden> # 3.8+
    Signed-off-by: Martin Schwidefsky <email address hidden>