From 647d0519b53f440a55df163de21c52a8205431cc Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 29 May 2018 13:11:12 +0100 Subject: arm64: ssbd: Restore mitigation status on CPU resume On a system where firmware can dynamically change the state of the mitigation, the CPU will always come up with the mitigation enabled, including when coming back from suspend. If the user has requested "no mitigation" via a command line option, let's enforce it by calling into the firmware again to disable it. Similarily, for a resume from hibernate, the mitigation could have been disabled by the boot kernel. Let's ensure that it is set back on in that case. Acked-by: Will Deacon Reviewed-by: Mark Rutland Signed-off-by: Marc Zyngier Signed-off-by: Catalin Marinas --- arch/arm64/kernel/suspend.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'arch/arm64/kernel/suspend.c') diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c index a307b9e13392..70c283368b64 100644 --- a/arch/arm64/kernel/suspend.c +++ b/arch/arm64/kernel/suspend.c @@ -62,6 +62,14 @@ void notrace __cpu_suspend_exit(void) */ if (hw_breakpoint_restore) hw_breakpoint_restore(cpu); + + /* + * On resume, firmware implementing dynamic mitigation will + * have turned the mitigation on. If the user has forcefully + * disabled it, make sure their wishes are obeyed. + */ + if (arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE) + arm64_set_ssbd_mitigation(false); } /* -- cgit