Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761470AbaJDAzb (ORCPT ); Fri, 3 Oct 2014 20:55:31 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:44731 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754881AbaJCVcb (ORCPT ); Fri, 3 Oct 2014 17:32:31 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Shobhit Kumar , Rafael Barbalho , Daniel Vetter Subject: [PATCH 3.16 024/357] drm/i915: Fix crash when failing to parse MIPI VBT Date: Fri, 3 Oct 2014 14:26:50 -0700 Message-Id: <20141003212934.189784276@linuxfoundation.org> X-Mailer: git-send-email 2.1.2 In-Reply-To: <20141003212933.458851516@linuxfoundation.org> References: <20141003212933.458851516@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Rafael Barbalho commit ed3b6679936801fa2dab47e7a6ef74e383400ed9 upstream. This particular nasty presented itself while trying to register the intelfb device (intel_fbdev.c). During the process of registering the device the driver will disable the crtc via i9xx_crtc_disable. These will also disable the panel using the generic mipi panel functions in dsi_mod_vbt_generic.c. The stale MIPI generic data sequence pointers would cause a crash within those functions. However, all of this is happening while console_lock is held from do_register_framebuffer inside fbcon.c. Which means that you got kernel log and just the device appearing to reboot/hang for no apparent reason. The fault started from the FB_EVENT_FB_REGISTERED event using the fb_notifier_call_chain call in fbcon.c. This regression has been introduced in commit d3b542fcfc72d7724585e3fd2c5e75351bc3df47 Author: Shobhit Kumar Date: Mon Apr 14 11:00:34 2014 +0530 drm/i915: Add parsing support for new MIPI blocks in VBT Cc: Shobhit Kumar Signed-off-by: Rafael Barbalho Reviewed-by: Shobhit Kumar [danvet: Add regression citation.] Signed-off-by: Daniel Vetter Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/intel_bios.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/gpu/drm/i915/intel_bios.c +++ b/drivers/gpu/drm/i915/intel_bios.c @@ -877,7 +877,7 @@ err: /* error during parsing so set all pointers to null * because of partial parsing */ - memset(dev_priv->vbt.dsi.sequence, 0, MIPI_SEQ_MAX); + memset(dev_priv->vbt.dsi.sequence, 0, sizeof(dev_priv->vbt.dsi.sequence)); } static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/