Messages in this thread | | | Date | Tue, 21 Oct 2014 15:02:15 -0600 | From | Jason Gunthorpe <> | Subject | Re: [tpmdd-devel] [PATCH] tpm: fix multiple race conditions in tpm_ppi.c |
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On Tue, Oct 21, 2014 at 11:42:51PM +0300, Jarkko Sakkinen wrote:
> > 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? > > This has realized in Intel NUCs where there is PTT and dTPM module. Even > when PTT is selected there is still ACPI device for dTPM so three is a > race condition and PPI is unusable. I think that it's not good that code is > not robust enough to deal with this.
Oh OK, you should probably explain in the commit log that this is a bug fix that impacts real hardware, that qualifies it for the -stable tree.
Assuming two-phase commit is nearly ready to go, I'd still sequence this fix after two-phase for mainline and then use this patch as-is for the 3.17 -stable backport of the mainline commit.
> Even if you forget the race condition it feels waste to lookup a handle > that is already known.
There is no doubt that this new arrangement is much better than what was there before!
Thanks, Jason
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