From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754834AbdBOXSO (ORCPT ); Wed, 15 Feb 2017 18:18:14 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:53697 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753221AbdBOXSH (ORCPT ); Wed, 15 Feb 2017 18:18:07 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Enric Balletbo Serra" , "Puneet Kumar" , "Andrew Bresticker" , "Kees Cook" Date: Wed, 15 Feb 2017 22:41:40 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 039/306] pstore/ram: Use memcpy_fromio() to save old buffer In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.40-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Andrew Bresticker commit d771fdf94180de2bd811ac90cba75f0f346abf8d upstream. The ramoops buffer may be mapped as either I/O memory or uncached memory. On ARM64, this results in a device-type (strongly-ordered) mapping. Since unnaligned accesses to device-type memory will generate an alignment fault (regardless of whether or not strict alignment checking is enabled), it is not safe to use memcpy(). memcpy_fromio() is guaranteed to only use aligned accesses, so use that instead. Signed-off-by: Andrew Bresticker Signed-off-by: Enric Balletbo Serra Reviewed-by: Puneet Kumar Signed-off-by: Kees Cook Signed-off-by: Ben Hutchings --- fs/pstore/ram_core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/fs/pstore/ram_core.c +++ b/fs/pstore/ram_core.c @@ -286,8 +286,8 @@ void persistent_ram_save_old(struct pers } prz->old_log_size = size; - memcpy(prz->old_log, &buffer->data[start], size - start); - memcpy(prz->old_log + size - start, &buffer->data[0], start); + memcpy_fromio(prz->old_log, &buffer->data[start], size - start); + memcpy_fromio(prz->old_log + size - start, &buffer->data[0], start); } int notrace persistent_ram_write(struct persistent_ram_zone *prz,