Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751432AbbGLQwx (ORCPT ); Sun, 12 Jul 2015 12:52:53 -0400 Received: from mail-ig0-f172.google.com ([209.85.213.172]:35784 "EHLO mail-ig0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751131AbbGLQww convert rfc822-to-8bit (ORCPT ); Sun, 12 Jul 2015 12:52:52 -0400 MIME-Version: 1.0 In-Reply-To: References: Date: Sun, 12 Jul 2015 09:52:51 -0700 X-Google-Sender-Auth: vKK5gkOq9NFcdl5cgtIPIMkgZEU Message-ID: Subject: Re: [4.2.0-rc1-00201-g59c3cb5] Regression: kernel NULL pointer dereference From: Linus Torvalds To: =?UTF-8?Q?J=C3=B6rg_Otte?= , Daniel Vetter Cc: David Airlie , DRI , Linux Kernel Mailing List , Maarten Lankhorst Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1146 Lines: 32 On Sun, Jul 12, 2015 at 1:03 AM, Jörg Otte wrote: > > BUG: unable to handle kernel NULL pointer dereference at 0000000000000009 > IP: [] 0xffffffffbd3447bb Ugh. Please enable KALLSYMS to get sane symbols. But yes, "crtc_state->base.active" is at offset 9 from "crtc_state", so it's pretty clearly just that change frm - if (intel_crtc->active) { + if (crtc_state->base.active) { and "crtc_state" is NULL. And the code very much knows that crtc_state can be NULL, since it's initialized with crtc_state = state->base.state ? intel_atomic_get_crtc_state(state->base.state, intel_crtc) : NULL; Tssk. Daniel? Should I just revert that commit dec4f799d0a4 ("drm/i915: Use crtc_state->active in primary check_plane func") for now, or is there a better fix? Like just checking crtc_state for NULL? Linus -- 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/