Messages in this thread | | | Subject | Re: [PATCH] ima: optimize ima_pcr_extend function by asynchronous | From | Tianjia Zhang <> | Date | Wed, 15 Apr 2020 10:53:06 +0800 |
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On 2020/4/15 2:07, Ken Goldman wrote: > I wonder if there's a different issue? I just ran selftest with > fullTest = yes in two different TPM vendors. > > One took 230 msec, the other 320 msec. > > I've never seen anything near 10 seconds. > > Note that this is worse than the worst case because it's forcing a full > retest. The TPM typically starts its self test immediately at power up > and could be complete by the time the OS starts to boot. > > When I run selftest with fullTest = no, I get 30 msec, probably > because it's not doing anything. > > On 4/14/2020 7:50 AM, Tianjia Zhang wrote: >> Because ima_pcr_extend() to operate the TPM chip, this process is >> very time-consuming, for IMA, this is a blocking action, especially >> when the TPM is in self test state, this process will block for up >> to ten seconds. >
Ten seconds is an extreme scenario, and I haven't seen this worst case, but the TPM driver will fail to return in this scenario.
Thanks and best, Tianjia
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