From mboxrd@z Thu Jan 1 00:00:00 1970 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 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Torvalds Subject: Re: [4.2.0-rc1-00201-g59c3cb5] Regression: kernel NULL pointer dereference Date: Sun, 12 Jul 2015 09:52:51 -0700 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mail-ie0-f180.google.com (mail-ie0-f180.google.com [209.85.223.180]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5DE356E1C3 for ; Sun, 12 Jul 2015 09:52:52 -0700 (PDT) Received: by iebmu5 with SMTP id mu5so221457381ieb.1 for ; Sun, 12 Jul 2015 09:52:51 -0700 (PDT) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: =?UTF-8?Q?J=C3=B6rg_Otte?= , Daniel Vetter Cc: Linux Kernel Mailing List , DRI List-Id: dri-devel@lists.freedesktop.org T24gU3VuLCBKdWwgMTIsIDIwMTUgYXQgMTowMyBBTSwgSsO2cmcgT3R0ZSA8anJnLm90dGVAZ21h aWwuY29tPiB3cm90ZToKPgo+IEJVRzogdW5hYmxlIHRvIGhhbmRsZSBrZXJuZWwgTlVMTCBwb2lu dGVyIGRlcmVmZXJlbmNlIGF0IDAwMDAwMDAwMDAwMDAwMDkKPiBJUDogWzxmZmZmZmZmZmJkMzQ0 N2JiPl0gMHhmZmZmZmZmZmJkMzQ0N2JiCgpVZ2guIFBsZWFzZSBlbmFibGUgS0FMTFNZTVMgdG8g Z2V0IHNhbmUgc3ltYm9scy4KCkJ1dCB5ZXMsICJjcnRjX3N0YXRlLT5iYXNlLmFjdGl2ZSIgaXMg YXQgb2Zmc2V0IDkgZnJvbSAiY3J0Y19zdGF0ZSIsCnNvIGl0J3MgcHJldHR5IGNsZWFybHkganVz dCB0aGF0IGNoYW5nZSBmcm0KCi0gICAgICAgaWYgKGludGVsX2NydGMtPmFjdGl2ZSkgeworICAg ICAgIGlmIChjcnRjX3N0YXRlLT5iYXNlLmFjdGl2ZSkgewoKYW5kICJjcnRjX3N0YXRlIiBpcyBO VUxMLgoKQW5kIHRoZSBjb2RlIHZlcnkgbXVjaCBrbm93cyB0aGF0IGNydGNfc3RhdGUgY2FuIGJl IE5VTEwsIHNpbmNlIGl0J3MKaW5pdGlhbGl6ZWQgd2l0aAoKICAgICAgICBjcnRjX3N0YXRlID0g c3RhdGUtPmJhc2Uuc3RhdGUgPwogICAgICAgICAgICAgICAgaW50ZWxfYXRvbWljX2dldF9jcnRj X3N0YXRlKHN0YXRlLT5iYXNlLnN0YXRlLAppbnRlbF9jcnRjKSA6IE5VTEw7CgpUc3NrLiBEYW5p ZWw/IFNob3VsZCBJIGp1c3QgcmV2ZXJ0IHRoYXQgY29tbWl0IGRlYzRmNzk5ZDBhNAooImRybS9p OTE1OiBVc2UgY3J0Y19zdGF0ZS0+YWN0aXZlIGluIHByaW1hcnkgY2hlY2tfcGxhbmUgZnVuYyIp IGZvcgpub3csIG9yIGlzIHRoZXJlIGEgYmV0dGVyIGZpeD8gTGlrZSBqdXN0IGNoZWNraW5nIGNy dGNfc3RhdGUgZm9yIE5VTEw/CgogICAgICAgICAgICAgICAgICAgIExpbnVzCl9fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCmRyaS1kZXZlbCBtYWlsaW5nIGxp c3QKZHJpLWRldmVsQGxpc3RzLmZyZWVkZXNrdG9wLm9yZwpodHRwOi8vbGlzdHMuZnJlZWRlc2t0 b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVsCg==