tree e22ef35623c16784e1a9eb1896d97d3a1512d57b
parent 338e5bd962d8b676845b8cd5cdc056df159c5464
author Marc Zyngier <marc.zyngier@arm.com> 1527595873 +0100
committer Marc Zyngier <marc.zyngier@arm.com> 1532079285 +0100

arm64: ssbd: Introduce thread flag to control userspace mitigation

commit 9dd9614f5476687abbff8d4b12cd08ae70d7c2ad upstream.

In order to allow userspace to be mitigated on demand, let's
introduce a new thread flag that prevents the mitigation from
being turned off when exiting to userspace, and doesn't turn
it on on entry into the kernel (with the assumption that the
mitigation is always enabled in the kernel itself).

This will be used by a prctl interface introduced in a later
patch.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>