Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753214AbcD0RpX (ORCPT ); Wed, 27 Apr 2016 13:45:23 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:18568 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752176AbcD0RpW (ORCPT ); Wed, 27 Apr 2016 13:45:22 -0400 Date: Wed, 27 Apr 2016 13:43:56 -0400 From: Sowmini Varadhan To: sowmini.varadhan@oracle.com, tadeusz.struk@intel.com, linux-kernel@vger.kernel.org Cc: herbert@gondor.apana.org.au, smueller@chronox.de, mmarek@suse.com, arnd@arndb.de, andrew.zaborowski@intel.com Subject: [PATCH v2] lib/mpi: Fix kernel unaligned access in mpi_write_to_sgl Message-ID: <20160427174338.GA15460@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: aserv0022.oracle.com [141.146.126.234] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1594 Lines: 55 Commit 2d4d1eea540b ("lib/mpi: Add mpi sgl helpers") added mpi_write_to_sgl() which generates traps due to unaligned access on some platforms like sparc. Fix this by using the get_unaligned* and put_unaligned* functions. Fixes: 2d4d1eea540b ("lib/mpi: Add mpi sgl helpers") Signed-off-by: Sowmini Varadhan --- v2: tadeusz.struk comments: Predicate on BYTES_PER_MPI_LIMB. lib/mpi/mpicoder.c | 21 +++++++++++++++++---- 1 files changed, 17 insertions(+), 4 deletions(-) diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c index eb15e7d..b61eb6b 100644 --- a/lib/mpi/mpicoder.c +++ b/lib/mpi/mpicoder.c @@ -21,6 +21,7 @@ #include #include #include "mpi-internal.h" +#include #define MAX_EXTERN_MPI_BITS 16384 @@ -405,10 +406,22 @@ int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned *nbytes, p -= sizeof(alimb); continue; } else { - mpi_limb_t *limb1 = (void *)p - sizeof(alimb); - mpi_limb_t *limb2 = (void *)p - sizeof(alimb) - + lzeros; - *limb1 = *limb2; + mpi_limb_t tmp; +#if BYTES_PER_MPI_LIMB == 4 + tmp = get_unaligned_be32((void *)p - + sizeof(alimb) + + lzeros); + put_unaligned_be32(tmp, (void *)p - + sizeof(alimb)); +#elif BYTES_PER_MPI_LIMB == 8 + tmp = get_unaligned_be64((void *)p - + sizeof(alimb) + + lzeros); + put_unaligned_be64(tmp, (void *)p - + sizeof(alimb)); +#else +#error please implement for this limb size. +#endif p -= lzeros; y = lzeros; } -- 1.7.1