Re: tip -ENOBOOT - bisected to locking/refcounts, x86/asm: Implement fast refcount overflow protection

[Kees Cook]

On Tue, Aug 29, 2017 at 3:03 AM, Mike Galbraith <efault@xxxxxx> wrote:
> On Tue, 2017-08-29 at 11:27 +0200, Ingo Molnar wrote:
>> * Mike Galbraith <efault@xxxxxx> wrote:
>>
>> > On Tue, 2017-08-29 at 10:58 +0200, Ingo Molnar wrote:
>> > > * Mike Galbraith <efault@xxxxxx> wrote:
>> > >
>> > > > Greetings,
>> > > >
>> > > > Take 2 of KVM bisect as you work fingered $subject.  Take 1 was stymied
>> > > > by build dependencies (aa5d1b81, df340524) which I foolishly tried to
>> > > > skip, leading git bisect to end up handing me a list of commits that
>> > > > might be busted.  During take 2, I added those two as required.
>> > > >
>> > > > Symptom is a few splats as below, with box finally hanging.  Network
>> > > > comes up, but neither ssh nor console login is possible.
>> > >
>> > > Just to double check, does the patch below also cure the regression?
>> > > If we don't find the bug it might be safer than a full revert.
>> >
>> > I reverted it, and vbox now boots.  Should I still try the below?
>>
>> Would be nice, so I can stick a Tested-by on it and such!
>
> Done, works.

Was this the x86 refcount implementation, or a atomic -> refcount conversion?

-Kees

-- 
Kees Cook
Pixel Security