lkml.org 
[lkml]   [2017]   [Nov]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [crash] PANIC: double fault, error_code: 0x0

* Ingo Molnar <mingo@kernel.org> wrote:

> > diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
> > index 4ac952080869..ea992ca4e74f 100644
> > --- a/arch/x86/entry/entry_64.S
> > +++ b/arch/x86/entry/entry_64.S
> > @@ -547,6 +547,8 @@ END(irq_entries_start)
> > ud2
> > .Lokay_\@:
> > addq $8, %rsp
> > +#else
> > + .rep 64; nop; .endr
>
> Also note that turning off CONFIG_UNWINDER_ORC also solves the crash. I did that
> in an attempt to get a different backtrace.
>
> So it's either unwinder related, or seemingly minor changes to code
> alignment/placement will make the bug go away.

Ok, I think the Orc unwinder is innocent: I just forced a build with frame
pointers but with ORC debuginfo and unwinder, and that is booting fine too.

So it's the specific code size and alignment present in the config I sent that is
triggering the bug. Fudging that alignment/sizing with the workaround patch above
makes the crash go away.

Thanks,

Ingo

\
 
 \ /
  Last update: 2017-11-25 10:40    [W:1.016 / U:2.044 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site