Re: [PATCH v2 2/3] efi: arm64: Wire up BTI annotation in memory attributes table
From: Ard Biesheuvel <ardb@kernel.org>
Date: 2023-02-20 16:48:00
Also in:
linux-efi
On Mon, 20 Feb 2023 at 16:53, Mark Brown [off-list ref] wrote:
On Wed, Feb 08, 2023 at 03:36:40PM +0100, Ard Biesheuvel wrote:quoted
OTOH, what is the penalty for setting the GP attribute and using the translation table on a core that does not implement BTI?The concern with doing that for Linux was what would happen if someone implemented a system with mixed BTI/no BTI support and then a task got preempted and moved between the two, you might end up with PSTATE.BTYPE incorrectly set and trigger a spurious fault. That shouldn't be an issue for EFI runtime services.
Right, I hadn't figured that. But as you say, this shouldn't affect EFI runtime services, as they are non-preemptible and therefore non-migratable. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel