From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3sLP3L6BTRzDrK1 for ; Sat, 27 Aug 2016 00:45:18 +1000 (AEST) From: Christophe Leroy Subject: [PATCH] powerpc/32: fix again csum_partial_copy_generic() To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Scott Wood Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Alessio Igor Bogani , Antoine Blangy , stable@vger.kernel.org Message-Id: <20160826144513.A71561A245B@localhost.localdomain> Date: Fri, 26 Aug 2016 16:45:13 +0200 (CEST) List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , commit 7aef4136566b0 ("powerpc32: rewrite csum_partial_copy_generic() based on copy_tofrom_user()") introduced a bug when destination address is odd and len is lower than cacheline size. In that case the resulting csum value doesn't have to be rotated one byte because the cache-aligned copy part is skipped so no alignment is performed. Fixes: 7aef4136566b0 ("powerpc32: rewrite csum_partial_copy_generic() based on copy_tofrom_user()") Cc: stable@vger.kernel.org Reported-by: Alessio Igor Bogani Signed-off-by: Christophe Leroy Tested-by: Alessio Igor Bogani --- arch/powerpc/lib/checksum_32.S | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/lib/checksum_32.S b/arch/powerpc/lib/checksum_32.S index 0a57fe6..aa8214f 100644 --- a/arch/powerpc/lib/checksum_32.S +++ b/arch/powerpc/lib/checksum_32.S @@ -127,18 +127,19 @@ _GLOBAL(csum_partial_copy_generic) stw r7,12(r1) stw r8,8(r1) - rlwinm r0,r4,3,0x8 - rlwnm r6,r6,r0,0,31 /* odd destination address: rotate one byte */ - cmplwi cr7,r0,0 /* is destination address even ? */ addic r12,r6,0 addi r6,r4,-4 neg r0,r4 addi r4,r3,-4 andi. r0,r0,CACHELINE_MASK /* # bytes to start of cache line */ + crset 4*cr7+eq beq 58f cmplw 0,r5,r0 /* is this more than total to do? */ blt 63f /* if not much to do */ + rlwinm r7,r6,3,0x8 + rlwnm r12,r12,r7,0,31 /* odd destination address: rotate one byte */ + cmplwi cr7,r7,0 /* is destination address even ? */ andi. r8,r0,3 /* get it word-aligned first */ mtctr r8 beq+ 61f -- 2.1.0