Re: [v8 09/10] arm64: add sysfs vulnerability show for speculative store bypass

From: Stefan Wahren
Date: Thu Apr 25 2019 - 13:11:31 EST



> Jeremy Linton <jeremy.linton@xxxxxxx> hat am 15. April 2019 um 23:21 geschrieben:
>
>
> Return status based on ssbd_state and __ssb_safe. If the
> mitigation is disabled, or the firmware isn't responding then
> return the expected machine state based on a whitelist of known
> good cores.
>
> Given a heterogeneous machine, the overall machine vulnerability
> defaults to safe but is reset to unsafe when we miss the whitelist
> and the firmware doesn't explicitly tell us the core is safe.
> In order to make that work we delay transitioning to vulnerable
> until we know the firmware isn't responding to avoid a case
> where we miss the whitelist, but the firmware goes ahead and
> reports the core is not vulnerable. If all the cores in the
> machine have SSBS, then __ssb_safe will remain true.
>
> Signed-off-by: Jeremy Linton <jeremy.linton@xxxxxxx>

Tested-by: Stefan Wahren <stefan.wahren@xxxxxxxx>

on a Raspberry Pi 3 B