From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755248AbdJLJV6 (ORCPT ); Thu, 12 Oct 2017 05:21:58 -0400 Received: from mga14.intel.com ([192.55.52.115]:55856 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751932AbdJLJV5 (ORCPT ); Thu, 12 Oct 2017 05:21:57 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.43,365,1503385200"; d="scan'208";a="909219645" Date: Thu, 12 Oct 2017 17:21:55 +0800 From: Fengguang Wu To: Peter Zijlstra Cc: Byungchul Park , Ingo Molnar , linux-kernel@vger.kernel.org, LKP , Josh Poimboeuf Subject: Re: [lockdep] b09be676e0 BUG: unable to handle kernel NULL pointer dereference at 000001f2 Message-ID: <20171012092155.eujxes7f5k2fcjhp@wfg-t540p.sh.intel.com> References: <20171003140634.r2jzujgl62ox4uzh@wfg-t540p.sh.intel.com> <20171012084725.zclmk65qvym5xek7@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20171012084725.zclmk65qvym5xek7@hirez.programming.kicks-ass.net> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 12, 2017 at 10:47:25AM +0200, Peter Zijlstra wrote: >On Tue, Oct 03, 2017 at 10:06:34PM +0800, Fengguang Wu wrote: > >> #!/bin/bash >> >> kernel=$1 >> initrd=openwrt-trinity-i386.cgz >> >> wget --no-clobber https://github.com/fengguang/reproduce-kernel-bug/raw/master/initrd/$initrd >> >> kvm=( >> qemu-system-x86_64 >> -enable-kvm >> -cpu Haswell,+smep >> -kernel $kernel >> -initrd $initrd >> -m 256 >> -smp 1 >> -device e1000,netdev=net0 >> -netdev user,id=net0 >> -boot order=nc >> -no-reboot >> -watchdog i6300esb >> -watchdog-action debug >> -rtc base=localtime >> -serial stdio >> -display none >> -monitor null >> ) >> >> append=( >> root=/dev/ram0 >> hung_task_panic=1 >> debug >> apic=debug >> sysrq_always_enabled >> rcupdate.rcu_cpu_stall_timeout=100 >> net.ifnames=0 >> printk.devkmsg=on >> panic=-1 >> softlockup_panic=1 >> nmi_watchdog=panic >> oops=panic >> load_ramdisk=2 >> prompt_ramdisk=0 >> drbd.minor_count=8 >> systemd.log_level=err >> ignore_loglevel >> console=tty0 >> earlyprintk=ttyS0,115200 >> console=ttyS0,115200 >> vga=normal >> rw >> drbd.minor_count=8 >> ) >> >> "${kvm[@]}" -append "${append[*]}" > > >So I was wanting to go chase that one splat you triggered, but the above >(after s/Haswell,+smep/host/) boots right up until it wants an init: > >[ 0.000000] Kernel command line: root=/dev/ram0 hung_task_panic=1 debug apic=debug sysrq_always_enabled rcupdate.rcu_cpu_stall_timeout=100 net.ifnames=0 printk.devkmsg=on panic=-1 softlockup_panic=1 nmi_watchdog=panic oops=panic load_ramdisk=2 prompt_ramdisk=0 drbd.minor_count=8 systemd.log_level=err ignore_loglevel console=tty0 earlyprintk=ttyS0,115200 console=ttyS0,115200 vga=normal rw drbd.minor_count=8 > >[ 35.721719] Kernel panic - not syncing: No working init found. Try passing init= option to kernel. See Linux Documentation/admin-guide/init.rst for guidance. Well I got the same result. The script and initrd image matches well with my local version. I'll dig what goes wrong. >And it did download that initrd thingy... > >$ shasum openwrt-trinity-i386.cgz >0a405d02a162defd82a5ffd556fd24e0ee2f994a openwrt-trinity-i386.cgz > > >Anything else I need? >