Re: [PATCH] tpm: Fix TPM 1.2 Shutdown sequence to prevent future TPM operations

[Doug Anderson]

Hi,

On Thu, Jul 11, 2019 at 12:43 PM Jarkko Sakkinen
<jarkko.sakkinen@xxxxxxxxxxxxxxx> wrote:
>
> On Thu, Jul 11, 2019 at 09:35:33PM +0300, Jarkko Sakkinen wrote:
> > > Careful with this, you can't backport this to any kernels that don't
> > > have the sysfs ops locking changes or they will crash in sysfs code.
> >
> > Oops, I was way too fast! Thanks Jason.
>
> Hmm... hold on a second.
>
> How would the crash realize? I mean this is at the point when user space
> should not be active. Secondly, why the crash would not realize with
> TPM2? The only thing the fix is doing is to do the same thing with TPM1
> essentially.

I will continue to remind that I'm pretty TPM-clueless (mostly I just
took someone else's patch and posted it), but I will note that people
on the Chrome OS team seemed concerned by the sysfs locking too.
After seeing Jason's message this morning I dug a little bit and found
<https://crbug.com/819265>

-Doug