Re: [PATCH v2 2/3] efi: call get_event_log before ExitBootServices

From: Jarkko Sakkinen
Date: Thu Sep 14 2017 - 14:43:42 EST


On Mon, Sep 11, 2017 at 12:00:21PM +0200, Thiebaud Weksteen wrote:
> With TPM 2.0 specification, the event logs may only be accessible by
> calling an EFI Boot Service. Modify the EFI stub to copy the log area to
> a new Linux-specific EFI configuration table so it remains accessible
> once booted.
>
> When calling this service, it is possible to specify the expected format
> of the logs: TPM 1.2 (SHA1) or TPM 2.0 ("Crypto Agile"). For now, only the
> first format is retrieved.
>
> Signed-off-by: Thiebaud Weksteen <tweek@xxxxxxxxxx>

With a quick skim the code change looks good but I remember from
Matthew's talk that there was this issue that ExitBootServices() would
cause a yet another event?

I guess you could manually synthetize that event by reading the PCR
values right after ExitBootServices()?

Anyway, great work, thanks for making this effort.

/Jarkko