Messages in this thread | | | Subject | Re: [PATCH 4.4 00/37] 4.4.110-stable review | From | Pavel Tatashin <> | Date | Fri, 5 Jan 2018 20:16:09 -0500 |
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Hi Hugh,
Thank you very much for your very thoughtful input.
I quiet positive this problem is PTI regression, because exactly the same problem I see with kernel 4.1 to which I back-ported all the necessary PTI patches from 4.4.110. I will provide this thread with more information as I collect it. I will also try to root cause the problem.
The bug has memory corruption behavior, but with both 4.1 and 4.4 kernels problem goes away when I boot with noefi parameter. So, EFI + PTI is the culprit for this memory corruption.
Thank you, Pavel
On 01/05/2018 06:15 PM, Hugh Dickins wrote: > On Fri, Jan 5, 2018 at 1:03 PM, Pavel Tatashin > <pasha.tatashin@oracle.com> wrote: >> The hardware works :) I meant that before the patch linked in >> https://lkml.org/lkml/2018/1/5/534, I was never able to boot 4.4.110. But >> with that patch applied, I was able to boot it at least once, but it could >> be accidental. The hang/panic does not happen at the same time on every >> boot. > > I get the feeling that it was accidental: it seems to me that you have > a memory corruption problem, that gets shifted around by the different > patches (or "noefi" or "nopti"). > > Because yesterday your boots were able to get way beyond the "EFI > Variables Facility" message, and I can't imagine why the EFI issue > would not have been equally debilitating on yesterday's 110-rc, if it > were in play. > > I did intend to ask you to send your System.map, for us to scan > through: maybe some variable is marked __init and should not be, then > the "Freeing unused kernel memory" frees it for random reuse. > > But today you didn't get anywhere near the "Freeing unused kernel > memory", so that can't be it - or do you sometimes get that far today? > > You mention that the hang/panic does not happen at the same time on > every boot: I think all I can ask is for you to keep supplying us with > different examples (console messages) of where it occurs, in the hope > that one of them will point us in the right direction. > > And it even seems possible that this has nothing to do with the > 4.4.110 changes - that 4.4.109 plus some other random patches would > unleash similar corruption. Though on balance that does seem unlikely. > > Hugh
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