From patchwork Wed Oct 16 08:49:02 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 3051491 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 04DF09F2B6 for ; Wed, 16 Oct 2013 09:25:58 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id EC6DC201CD for ; Wed, 16 Oct 2013 09:25:56 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 05D6920237 for ; Wed, 16 Oct 2013 09:25:55 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id EFDDF4382E for ; Wed, 16 Oct 2013 02:25:54 -0700 (PDT) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org X-Greylist: delayed 980 seconds by postgrey-1.32 at gabe; Wed, 16 Oct 2013 02:05:40 PDT Received: from relay.fireflyinternet.com (server109-228-28-164.live-servers.net [109.228.28.164]) by gabe.freedesktop.org (Postfix) with ESMTP id BE1F5E6688 for ; Wed, 16 Oct 2013 02:05:40 -0700 (PDT) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.73.22; Received: from haswell.alporthouse.com (unverified [78.156.73.22]) by relay.fireflyinternet.com (FireflyRelay1) with ESMTP id 9827281-2000100 for multiple; Wed, 16 Oct 2013 09:49:10 +0100 From: Chris Wilson To: dri-devel@lists.freedesktop.org Subject: [PATCH] drm: Pad drm_mode_get_connector to 64-bit boundary Date: Wed, 16 Oct 2013 09:49:02 +0100 Message-Id: <1381913342-17634-1-git-send-email-chris@chris-wilson.co.uk> X-Mailer: git-send-email 1.8.4.rc3 X-Authenticated-User: chris.alporthouse@surfanytime.net Cc: Dave Airlie , stable@vger.kernel.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: , MIME-Version: 1.0 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=-4.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD,UNPARSEABLE_RELAY autolearn=ham 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 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 Cc: stable@vger.kernel.org --- include/uapi/drm/drm_mode.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h index 550811712f78..28acbaf4a81e 100644 --- a/include/uapi/drm/drm_mode.h +++ b/include/uapi/drm/drm_mode.h @@ -223,6 +223,8 @@ 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)