On Mon, 2020-09-28 at 15:33 -0300, Jason Gunthorpe wrote: > On Mon, Sep 28, 2020 at 11:00:12AM -0700, James Bottomley wrote: > > Some TIS based TPMs can return 0xff to status reads if the locality > > hasn't been properly requested. Detect this condition by checking > > the bits that the TIS spec specifies must return zero are clear and > > return zero in that case. Also drop a warning so the problem can > > be identified in the calling path and fixed (usually a missing > > try_get_ops()). > > > > Signed-off-by: James Bottomley < > > James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> > > > > This is the patch I've been using to catch and kill all the points > > in the stack where we're not properly using get/put ops on the tpm > > chip. > > If this is a problem add a lockdep on ops_sem in various places too? It's not really possible because of the init issue with checking the interrupt. That originally had no locking at all (it doesn't need any because the TPM device isn't publicly exposed at the point the check is done). If the patch to add get/put around the tpm2_get_tpm_pt is acceptable, then perhaps we could because I think that's the last unguarded use of tpm_tis_status. James
