On Wed, Jun 05, 2019 at 11:05:15AM -0700, Matthew Garrett wrote: > After the first call to GetEventLog() on UEFI systems using the TCG2 > crypto agile log format, any further log events (other than those > triggered by ExitBootServices()) will be logged in both the main log and > also in the Final Events Log. While the kernel only calls GetEventLog() > immediately before ExitBootServices(), we can't control whether earlier > parts of the boot process have done so. This will result in log entries > that exist in both logs, and so the current approach of simply appending > the Final Event Log to the main log will result in events being > duplicated. > > We can avoid this problem by looking at the size of the Final Event Log > just before we call ExitBootServices() and exporting this to the main > kernel. The kernel can then skip over all events that occured before > ExitBootServices() and only append events that were not also logged to > the main log. > > Signed-off-by: Matthew Garrett <mjg59@xxxxxxxxxx> > Reported-by: Joe Richey <joerichey@xxxxxxxxxx> > Suggested-by: Joe Richey <joerichey@xxxxxxxxxx> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx> /Jarkko
