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

Jarkko Sakkinen
2019-07-12T03:31:47Z

On Thu, Jul 11, 2019 at 04:46:26PM -0300, Jason Gunthorpe wrote:
> On Thu, Jul 11, 2019 at 10:43:13PM +0300, Jarkko Sakkinen 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.
>
> Not strictly, AFAIK
>
> > 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.
>
> TPM2 doesn't use the unlocked sysfs path

Gah, sorry :-) I should have known that.

I can go through the patches needed when I come back from my leave after
two weeks.

/Jarkko