Re: [tpmdd-devel] [PATCH] tpm: fix multiple race conditions in tpm_ppi.c

From: Jason Gunthorpe
Date: Tue Oct 21 2014 - 12:56:20 EST


On Tue, Oct 21, 2014 at 11:22:41AM +0300, Jarkko Sakkinen wrote:
> * Traversal of the ACPI device tree was not done right. It should lookup
> PPI only under the ACPI device that it is associated. Otherwise, it could
> match to a wrong PPI interface if there are two TPM devices in the device
> tree.
> * Removed global ACPI handle and version string from tpm_ppi.c as this
> is racy. Instead they should be associated with the chip.
> * Moved code just a tiny bit towards two-phase allocation to implement
> fix for the PPI race conditions.
> * Added missing copyright platter in tpm_ppi.c.

The PPI parts of this look fine to me, and are a really nice cleanup,
thanks!

Personally, I'd sequence this commit right after your 'tpm: two-phase
chip management functions' commit because it makes it much saner (no
half step toward the new functions). I assume this is a theoretical
problem? Or do you have a two TPM system?

Jason
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