Re: [PATCH] tpm: Ensure that tpm chip has ops to check if it's defective

[Limonciello, Mario]

On 6/23/2023 1:08 AM, Greg KH wrote:
> On Thu, Jun 22, 2023 at 10:04:27PM -0500, Mario Limonciello wrote:
> > The ibmvtpm doesn't have `chip->ops` set, and so trying to check
> > if it's a defective AMD fTPM doesn't work.
> >
> > Add an extra check to tpm_amd_is_rng_defective() to ensure the
> > TPM being checked has `chip->ops`.
> >
> > Cc: Linux regressions mailing list <regressions@xxxxxxxxxxxxxxx>
> > Reported-by: Aneesh Kumar K. V <aneesh.kumar@xxxxxxxxxxxxx>
> > Reported-by: Sachin Sant <sachinp@xxxxxxxxxxxxx>
> > Link: https://lore.kernel.org/lkml/99B81401-DB46-49B9-B321-CF832B50CAC3@xxxxxxxxxxxxx/
> > Tested-by: Sachin Sant <sachinp@xxxxxxxxxxxxx>
> > Fixes: bd8621ca1510 ("tpm: Add !tpm_amd_is_rng_defective() to the hwrng_unregister() call site")
> > Fixes: f1324bbc4011 ("tpm: disable hwrng for fTPM on some AMD designs")
> > Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> > ---
> >   drivers/char/tpm/tpm-chip.c | 3 +++
> >   1 file changed, 3 insertions(+)
> No cc: stable on that list above?

Good point, my mistake on that miss.

If Jarkko agrees with the direction of this patch, I think
it can be added while committing.

Thanks!