lkml.org 
[lkml]   [2018]   [Apr]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: 4.17.0-rc1 doesn't boot.
From
Date
On 04/17/2018 09:00 AM, Mike Galbraith wrote:
> On Tue, 2018-04-17 at 17:31 +0200, Borislav Petkov wrote:
>> On Tue, Apr 17, 2018 at 05:21:30PM +0200, Jörg Otte wrote:
>>> finished bisection.
>>> 39114b7a743e6759bab4d96b7d9651d44d17e3f9 is the first bad commit
>>> (x86/pti: Never implicitly clear _PAGE_GLOBAL for kernel image).
>>
>> Looks like you're not the only one:
>>
>> http://marc.info/?i=20180417150130.GA11166@ak-laptop.emea.nsn-net.net
>
> I'm hitting this too, but only with PREEMPT_RT. I put a bandaid on it
> (tell pti_kernel_image_global_ok() to return true for PREEMPT_RT) while
> waiting to see if it was really really as non-rt as it appeared to be.

It looks like pti_init() is too early for
change_page_attr()/set_memory_nonglobal() because they look for
irqs_off(). This *should* be OK in practice because we only need to
flush the boot CPU, not the others. That's what ends up causing the
BUG_ON().

But, there's apparently something else going on too because things don't
boot even with that BUG_ON() backed out.

The good news is that its easy to reproduce.

\
 
 \ /
  Last update: 2018-04-17 18:48    [W:0.078 / U:0.496 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site