From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [Bisected][-next-20130204+] [x86/kvm] udevd:[97]: segfault at ffffffffff5fd020 ip 00007fff069e277f sp 00007fff068c9ef8 error d Date: Mon, 18 Feb 2013 19:59:55 -0300 Message-ID: <20130218225955.GA6166@amt.cnet> References: <1360715210.31472.20.camel@thor.lan> <511AE0A7.2000101@linux.intel.com> <20130213105129.GB9817@redhat.com> <1360756629.4803.5.camel@thor.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Gleb Natapov , "H. Peter Anvin" , linux-kernel@vger.kernel.org, kvm@vger.kernel.org To: Peter Hurley Return-path: Content-Disposition: inline In-Reply-To: <1360756629.4803.5.camel@thor.lan> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Wed, Feb 13, 2013 at 06:57:09AM -0500, Peter Hurley wrote: > On Wed, 2013-02-13 at 12:51 +0200, Gleb Natapov wrote: > > On Tue, Feb 12, 2013 at 04:39:03PM -0800, H. Peter Anvin wrote: > > > On 02/12/2013 04:26 PM, Peter Hurley wrote: > > > > With -next-20130204+ in ubuntu 12.10 VM (so the 80x25 VGA > > > > device/console): > > > > > > > > [ 0.666410] udevd[97]: starting version 175 > > > > [ 0.674043] udevd[97]: udevd:[97]: segfault at ffffffffff5fd020 ip 00007fff069e277f sp 00007fff068c9ef8 error d > > > > > > > > and boots to an initramfs prompt. > > > > > > > > git bisect (log attached) blames: > > > > > > > > commit 7b5c4a65cc27f017c170b025f8d6d75dabb11c6f > > > > Merge: 3596f5b 949db15 > > > > Author: H. Peter Anvin > > > > Date: Fri Jan 25 16:31:21 2013 -0800 > > > > > > > > Merge tag 'v3.8-rc5' into x86/mm > > > > > > > > The __pa() fixup series that follows touches KVM code that is not > > > > present in the existing branch based on v3.7-rc5, so merge in the > > > > current upstream from Linus. > > > > > > > > Signed-off-by: H. Peter Anvin > > > > > > > > > > > > This only happens with the VGA device/console but that is the default > > > > configuration for Ubuntu/KVM because it blacklists pretty much every fb > > > > driver. > > > > > > > > > > I am guessing this is another bad use of __pa()... need to look into that. Can't find this commit on kvm.git or linux-2.6.git. Is it reproducible there? > > He is using 64bit guest and on those __pa() happens to be working. Is it > > possible that slow_virt_to_phys() does not work as expected? Peter (the > > bug reporter :)) can you run your guest kernel with loglevel=7 and > > attach send me console output? > > Attached. > > BTW, this message happens on 'good' boots too: > > [ 0.000000] ------------[ cut here ]------------ > [ 0.000000] WARNING: at /home/peter/src/kernels/next/arch/x86/kernel/pvclock.c:182 pvclock_init_vsyscall+0x22/0x60() > [ 0.000000] Hardware name: Bochs > [ 0.000000] Modules linked in: > [ 0.000000] Pid: 0, comm: swapper Not tainted 3.8.0-next-20130204-xeon #20130204 > [ 0.000000] Call Trace: > [ 0.000000] [] warn_slowpath_common+0x7f/0xc0 > [ 0.000000] [] warn_slowpath_null+0x1a/0x20 > [ 0.000000] [] pvclock_init_vsyscall+0x22/0x60 > [ 0.000000] [] kvm_setup_vsyscall_timeinfo+0x74/0xd8 > [ 0.000000] [] kvm_guest_init+0xd0/0xe9 > [ 0.000000] [] setup_arch+0xbee/0xcaf > [ 0.000000] [] ? printk+0x61/0x63 > [ 0.000000] [] start_kernel+0xd3/0x3f0 > [ 0.000000] [] x86_64_start_reservations+0x2a/0x2c > [ 0.000000] [] x86_64_start_kernel+0xf1/0x100 > [ 0.000000] ---[ end trace b47bb564b2d6ec76 ]--- > > Regards, > Peter Hurley Sending a patch for this, thanks for the report.