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SubjectRe: [PATCH] tpm: Fix TPM 1.2 Shutdown sequence to prevent future TPM operations
On Thu, Jul 11, 2019 at 01:39:15PM -0300, Jason Gunthorpe wrote:
> On Thu, Jul 11, 2019 at 09:29:19AM -0700, Douglas Anderson wrote:
> > From: Vadim Sukhomlinov <sukhomlinov@google.com>
> >
> > commit db4d8cb9c9f2af71c4d087817160d866ed572cc9 upstream.
> >
> > TPM 2.0 Shutdown involve sending TPM2_Shutdown to TPM chip and disabling
> > future TPM operations. TPM 1.2 behavior was different, future TPM
> > operations weren't disabled, causing rare issues. This patch ensures
> > that future TPM operations are disabled.
> >
> > Fixes: d1bd4a792d39 ("tpm: Issue a TPM2_Shutdown for TPM2 devices.")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Vadim Sukhomlinov <sukhomlinov@google.com>
> > [dianders: resolved merge conflicts with mainline]
> > Signed-off-by: Douglas Anderson <dianders@chromium.org>
> > Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> > This is the backport of the patch referenced above to 4.19 as was done
> > in Chrome OS. See <https://crrev.com/c/1495114> for details. It
> > presumably applies to some older kernels. NOTE that the problem
> > itself has existed for a long time, but continuing to backport this
> > exact solution to super old kernels is out of scope for me. For those
> > truly interested feel free to reference the past discussion [1].
> >
> > Reason for backport: mainline has commit a3fbfae82b4c ("tpm: take TPM
> > chip power gating out of tpm_transmit()") and commit 719b7d81f204
> > ("tpm: introduce tpm_chip_start() and tpm_chip_stop()") and it didn't
> > seem like a good idea to backport 17 patches to avoid the conflict.
>
> 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.

/Jarkko

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