Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934994AbcCPIls (ORCPT ); Wed, 16 Mar 2016 04:41:48 -0400 Received: from mail.kernel.org ([198.145.29.136]:59188 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965962AbcCPIHt (ORCPT ); Wed, 16 Mar 2016 04:07:49 -0400 From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Martin Schwidefsky , Zefan Li Subject: [PATCH 3.4 016/107] s390/sclp: clear upper register halves in _sclp_print_early Date: Wed, 16 Mar 2016 16:05:10 +0800 Message-Id: <1458115601-5762-16-git-send-email-lizf@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1458115541-5712-1-git-send-email-lizf@kernel.org> References: <1458115541-5712-1-git-send-email-lizf@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1445 Lines: 49 From: Martin Schwidefsky 3.4.111-rc1 review patch. If anyone has any objections, please let me know. ------------------ commit f9c87a6f46d508eae0d9ae640be98d50f237f827 upstream. If the kernel is compiled with gcc 5.1 and the XZ compression option the decompress_kernel function calls _sclp_print_early in 64-bit mode while the content of the upper register half of %r6 is non-zero. This causes a specification exception on the servc instruction in _sclp_servc. The _sclp_print_early function saves and restores the upper registers halves but it fails to clear them for the 31-bit code of the mini sclp driver. Signed-off-by: Martin Schwidefsky Signed-off-by: Zefan Li --- arch/s390/kernel/sclp.S | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/s390/kernel/sclp.S b/arch/s390/kernel/sclp.S index 95792d8..51ca1c3 100644 --- a/arch/s390/kernel/sclp.S +++ b/arch/s390/kernel/sclp.S @@ -270,6 +270,8 @@ ENTRY(_sclp_print_early) jno .Lesa2 ahi %r15,-80 stmh %r6,%r15,96(%r15) # store upper register halves + basr %r13,0 + lmh %r0,%r15,.Lzeroes-.(%r13) # clear upper register halves .Lesa2: #endif lr %r10,%r2 # save string pointer @@ -293,6 +295,8 @@ ENTRY(_sclp_print_early) #endif lm %r6,%r15,120(%r15) # restore registers br %r14 +.Lzeroes: + .fill 64,4,0 .LwritedataS4: .long 0x00760005 # SCLP command for write data -- 1.9.1