From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Paul E. McKenney" , Anton Blanchard , Benjamin Herrenschmidt Subject: [ 054/110] powerpc: Fix parameter clobber in csum_partial_copy_generic() Date: Fri, 11 Oct 2013 12:38:34 -0700 Message-Id: <20131011193813.695088632@linuxfoundation.org> In-Reply-To: <20131011193807.584188672@linuxfoundation.org> References: <20131011193807.584188672@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Paul E. McKenney" commit d9813c3681a36774b254c0cdc9cce53c9e22c756 upstream. The csum_partial_copy_generic() uses register r7 to adjust the remaining bytes to process. Unfortunately, r7 also holds a parameter, namely the address of the flag to set in case of access exceptions while reading the source buffer. Lacking a quantum implementation of PowerPC, this commit instead uses register r9 to do the adjusting, leaving r7's pointer uncorrupted. Signed-off-by: Paul E. McKenney Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/lib/checksum_64.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/powerpc/lib/checksum_64.S +++ b/arch/powerpc/lib/checksum_64.S @@ -269,8 +269,8 @@ _GLOBAL(csum_partial_copy_generic) rldicl. r6,r3,64-1,64-2 /* r6 = (r3 & 0x3) >> 1 */ beq .Lcopy_aligned - li r7,4 - sub r6,r7,r6 + li r9,4 + sub r6,r9,r6 mtctr r6 1: