Re: [PATCH v3] tpm: Disable RNG for all AMD fTPMs

[Mario Limonciello <mario.limonciello@amd.com>]

On 8/7/23 17:28, Jason A. Donenfeld wrote:
> On Sat, Aug 05, 2023 at 02:39:11AM +0300, Jarkko Sakkinen wrote:
>> On Sat Aug 5, 2023 at 2:21 AM EEST, Mario Limonciello wrote:
>>> On 8/4/23 17:54, Jarkko Sakkinen wrote:
>>>> On Thu Aug 3, 2023 at 9:24 PM EEST, Mario Limonciello wrote:
>>>>> The TPM RNG functionality is not necessary for entropy when the CPU
>>>>> already supports the RDRAND instruction. The TPM RNG functionality
>>>>> was previously disabled on a subset of AMD fTPM series, but reports
>>>>> continue to show problems on some systems causing stutter root caused
>>>>> to TPM RNG functionality.
>>>>>
>>>>> Expand disabling TPM RNG use for all AMD fTPMs whether they have versions
>>>>> that claim to have fixed or not. To accomplish this, move the detection
>>>>> into part of the TPM CRB registration and add a flag indicating that
>>>>> the TPM should opt-out of registration to hwrng.
>>>>>
>>>>> Cc: stable@vger.kernel.org # 5.5+
>>>>> Fixes: b006c439d58d ("hwrng: core - start hwrng kthread also for untrusted sources")
>>>>> Fixes: f1324bbc4011 ("tpm: disable hwrng for fTPM on some AMD designs")
>>>>> Fixes: 3ef193822b25 ("tpm_crb: fix fTPM on AMD Zen+ CPUs")
>>>>> Reported-by: daniil.stas@posteo.net
>>>>> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217719
>>>>> Reported-by: bitlord0xff@gmail.com
>>>>> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217212
>>>>> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
>>>>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
>>>>
>>>> I will skip rc5 and send this for rc6 on Monday.
>>>>
>>>> Has anyone with suitable AMD system tested this?
>>>
>>> Probably obvious; but I tested with a system that can support both dTPM
>>> and fTPM and swapped between the two before I sent it.
>>
>> Ok, great. I've tested that with non-AMD system things continue to
>> work so I guess that is sufficient enough for:
>>
>> Tested-by: Jarkko Sakkinen <jarkko@kernel.org>
>>
>> BR, Jarkko
> 
> Why is
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=554b841d470338a3b1d6335b14ee1cd0c8f5d754
> in Linus' tree? After we told you on several email threads to take the
> v3, and you said you would, you still took the v2? What are you doing?
> I'm frustrated because this is not the first time you've been out
> to lunch about this stuff. Now there's the wrong stable metadata and the
> fix is incomplete. Shame.

I guess that means I need to re-send out the other fixup that was missed 
in v3 separately and with a new fixes tag against that hash that landed 
in Linus' tree?  Or Jarkko are you going to resolve the differences?