From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753577AbcHAM5M (ORCPT ); Mon, 1 Aug 2016 08:57:12 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:18675 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753337AbcHAM5J (ORCPT ); Mon, 1 Aug 2016 08:57:09 -0400 From: Christophe Leroy Subject: [PATCH] powerpc/32: fix csum_partial_copy_generic() To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Scott Wood Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, stable@vger.kernel.org, antoine.blangy@c-s.fr Message-Id: <20160801125605.410371A23A2@localhost.localdomain> Date: Mon, 1 Aug 2016 14:56:05 +0200 (CEST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org commit 7aef4136566b0 ("powerpc32: rewrite csum_partial_copy_generic() based on copy_tofrom_user()") introduced a bug when destination address is odd and initial csum is not null In that (rare) case the initial csum value has to be rotated one byte as well as the resulting value is Fixes: 7aef4136566b0 ("powerpc32: rewrite csum_partial_copy_generic() based on copy_tofrom_user()") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy --- arch/powerpc/lib/checksum_32.S | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/lib/checksum_32.S b/arch/powerpc/lib/checksum_32.S index d90870a..ad0870a 100644 --- a/arch/powerpc/lib/checksum_32.S +++ b/arch/powerpc/lib/checksum_32.S @@ -127,7 +127,8 @@ _GLOBAL(csum_partial_copy_generic) stw r7,12(r1) stw r8,8(r1) - andi. r0,r4,1 /* is destination address even ? */ + rlwinm r0,r4,3,0x8 /* is destination address even ? */ + rlwnm r6,r6,r0,0,31 /* swap bytes for odd destination */ cmplwi cr7,r0,0 addic r12,r6,0 addi r6,r4,-4 -- 2.1.0