From patchwork Mon Nov 25 13:44:29 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Hutchings X-Patchwork-Id: 3231031 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 8B27BC045B for ; Mon, 25 Nov 2013 13:54:30 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D0062202F0 for ; Mon, 25 Nov 2013 13:54:25 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 7A7E8202EA for ; Mon, 25 Nov 2013 13:54:20 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 84201105762 for ; Mon, 25 Nov 2013 05:54:20 -0800 (PST) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from shadbolt.e.decadent.org.uk (shadbolt.e.decadent.org.uk [88.96.1.126]) by gabe.freedesktop.org (Postfix) with ESMTP id 35B57FA7B5 for ; Mon, 25 Nov 2013 05:54:01 -0800 (PST) Received: from [192.168.4.212] (helo=deadeye.wl.decadent.org.uk) by shadbolt.decadent.org.uk with esmtps (TLS1.2:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.80) (envelope-from ) id 1VkwbT-0002oF-92; Mon, 25 Nov 2013 13:53:31 +0000 Received: from ben by deadeye.wl.decadent.org.uk with local (Exim 4.80) (envelope-from ) id 1VkwbR-0003K4-Hq; Mon, 25 Nov 2013 13:53:29 +0000 Content-Disposition: inline MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Date: Mon, 25 Nov 2013 13:44:29 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 75/87] drm: Pad drm_mode_get_connector to 64-bit boundary In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.212 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Cc: Dave Airlie , akpm@linux-foundation.org, Pavel Roskin , dri-devel@lists.freedesktop.org X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces+patchwork-dri-devel=patchwork.kernel.org@lists.freedesktop.org Errors-To: dri-devel-bounces+patchwork-dri-devel=patchwork.kernel.org@lists.freedesktop.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 3.2.53-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Chris Wilson commit bc5bd37ce48c66e9192ad2e7231e9678880f6f8e upstream. Pavel Roskin reported that DRM_IOCTL_MODE_GETCONNECTOR was overwritting the 4 bytes beyond the end of its structure with a 32-bit userspace running on a 64-bit kernel. This is due to the padding gcc inserts as the drm_mode_get_connector struct includes a u64 and its size is not a natural multiple of u64s. 64-bit kernel: sizeof(drm_mode_get_connector)=80, alignof=8 sizeof(drm_mode_get_encoder)=20, alignof=4 sizeof(drm_mode_modeinfo)=68, alignof=4 32-bit userspace: sizeof(drm_mode_get_connector)=76, alignof=4 sizeof(drm_mode_get_encoder)=20, alignof=4 sizeof(drm_mode_modeinfo)=68, alignof=4 Fortuituously we can insert explicit padding to the tail of our structures without breaking ABI. Reported-by: Pavel Roskin Signed-off-by: Chris Wilson Cc: Dave Airlie Cc: dri-devel@lists.freedesktop.org Signed-off-by: Dave Airlie [bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings --- include/uapi/drm/drm_mode.h | 2 ++ 1 file changed, 2 insertions(+) --- a/include/drm/drm_mode.h +++ b/include/drm/drm_mode.h @@ -184,6 +184,8 @@ struct drm_mode_get_connector { __u32 connection; __u32 mm_width, mm_height; /**< HxW in millimeters */ __u32 subpixel; + + __u32 pad; }; #define DRM_MODE_PROP_PENDING (1<<0)