On Thu, Dec 06, 2018 at 12:31:15PM +0100, Juergen Gross wrote: > On 06/12/2018 12:13, Greg KH wrote: > > On Thu, Nov 29, 2018 at 02:35:17PM +0100, Juergen Gross wrote: > >> On 29/11/2018 14:26, Kirill A. Shutemov wrote: > >>> On Thu, Nov 29, 2018 at 09:41:25AM +0000, Juergen Gross wrote: > >>>> On 29/11/2018 02:22, Hans van Kranenburg wrote: > >>>>> Hi, > >>>>> > >>>>> As also seen at: > >>>>> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=914951 > >>>>> > >>>>> Attached there are two serial console output logs. One is starting with > >>>>> Xen 4.11 (from debian unstable) as dom0, and the other one without Xen. > >>>>> > >>>>> [ 2.085543] BUG: unable to handle kernel paging request at > >>>>> ffff888d9fffc000 > >>>>> [ 2.085610] PGD 200c067 P4D 200c067 PUD 0 > >>>>> [ 2.085674] Oops: 0000 [#1] SMP NOPTI > >>>>> [ 2.085736] CPU: 1 PID: 1 Comm: swapper/0 Not tainted > >>>>> 4.19.0-trunk-amd64 #1 Debian 4.19.5-1~exp1+pvh1 > >>>>> [ 2.085823] Hardware name: HP ProLiant DL360 G7, BIOS P68 05/21/2018 > >>>>> [ 2.085895] RIP: e030:ptdump_walk_pgd_level_core+0x1fd/0x490 > >>>>> [...] > >>>> > >>>> The offending stable commit is 4074ca7d8a1832921c865d250bbd08f3441b3657 > >>>> ("x86/mm: Move LDT remap out of KASLR region on 5-level paging"), this > >>>> is commit d52888aa2753e3063a9d3a0c9f72f94aa9809c15 upstream. > >>>> > >>>> Current upstream kernel is booting fine under Xen, so in general the > >>>> patch should be fine. Using an upstream kernel built from above commit > >>>> (with the then needed Xen fixup patch 1457d8cf7664f34c4ba534) is fine, > >>>> too. > >>>> > >>>> Kirill, are you aware of any prerequisite patch from 4.20 which could be > >>>> missing in 4.19.5? > >>> > >>> I'm not. > >>> > >>> Let me look into this. > >>> > >> > >> What is making me suspicious is the failure happening just after > >> releasing the init memory. Maybe there is an access to .init.data > >> segment or similar? The native kernel booting could be related to the > >> usage of 2M mappings not being available in a PV-domain. > > > > Did this ever get fixed anywhere that I can properly backport it to the > > 4.19.y tree? > > https://lore.kernel.org/lkml/20181130202328.65359-2-kirill.shutemov@xxxxxxxxxxxxxxx/ > > Still pending upstream. Just pinged tglx. Thanks, it should have gotten a cc: stable@ tag, but I can watch out for it... greg k-h
