Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753152AbeADUnp (ORCPT + 1 other); Thu, 4 Jan 2018 15:43:45 -0500 Received: from mail-pg0-f46.google.com ([74.125.83.46]:37725 "EHLO mail-pg0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752550AbeADUnn (ORCPT ); Thu, 4 Jan 2018 15:43:43 -0500 X-Google-Smtp-Source: ACJfBovc22TpAx75OGr7dyoBnTfiZt2jw4Ge9l04zlEXekDu50wLiyRKVQL4UDSaktbxw+9lamcyiw== Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (1.0) Subject: Re: [PATCH 4.4 00/37] 4.4.110-stable review From: Andy Lutomirski X-Mailer: iPhone Mail (15C153) In-Reply-To: Date: Thu, 4 Jan 2018 12:43:41 -0800 Cc: Thomas Voegtle , Greg Kroah-Hartman , Linux Kernel Mailing List , Andrew Morton , Guenter Roeck , Shuah Khan , patches@kernelci.org, Ben Hutchings , lkft-triage@lists.linaro.org, stable Content-Transfer-Encoding: 8BIT Message-Id: References: <20180103195056.837404126@linuxfoundation.org> <20180104195055.GA29809@kroah.com> To: Linus Torvalds Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: > On Jan 4, 2018, at 12:29 PM, Linus Torvalds wrote: > >> On Thu, Jan 4, 2018 at 12:16 PM, Thomas Voegtle wrote: >> >> Attached a screenshot. >> Is that useful? Are there some debug options I can add? > > Not much of an oops, because the SIGSEGV happens in user space. The > only reason you get any kernel stack printout at all is because 'init' > dying will make the kernel print that out. > > The segfault address for init looks like the fixmap area to me (first > byte in the last page of the fixmap?). "Error 5" means that it's a > user-space read that got a protection fault. So it's not a LDT of GDT > update or anything like that, it's a normal access from user space (or > a qemu emulation bug, but that sounds unlikely). > > Is that the vsyscall page? > > Adding Luto to the participants. I think he noticed one of the > vsyscall patches missing earlier in the 4.9 series. Maybe the 4.4 > series had something similar.. > That's almost certainly it. I'll try to find some time today or tomorrow to add a proper selftest. > Linus