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

[Limonciello, Mario]

> -----Original Message-----
> From: Limonciello, Mario
> Sent: Friday, June 23, 2023 8:42 AM
> To: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: peterhuewe@xxxxxx; jarkko@xxxxxxxxxx; jgg@xxxxxxxx; linux-
> integrity@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Linux regressions
> mailing list <regressions@xxxxxxxxxxxxxxx>; Aneesh Kumar K . V
> <aneesh.kumar@xxxxxxxxxxxxx>; Sachin Sant <sachinp@xxxxxxxxxxxxx>
> Subject: Re: [PATCH] tpm: Ensure that tpm chip has ops to check if it's
> defective
> 
> 
> 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!

Since then, a much better patch was suggested.
Please discard this one.
https://lkml.org/lkml/2023/6/29/898