Commit 24f69c0f authored by David Brazdil's avatar David Brazdil Committed by Marc Zyngier
Browse files

KVM: arm64: Make nVHE ASLR conditional on RANDOMIZE_BASE 



If there are spare bits in non-VHE hyp VA, KVM unconditionally replaces them
with a random tag chosen at init. Disable this if the kernel is built without
RANDOMIZE_BASE to align with kernel behavior.

Signed-off-by: default avatarDavid Brazdil <dbrazdil@google.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200721094445.82184-2-dbrazdil@google.com
parent 3a949f4c

arch/arm64/kvm/va_layout.c

+1 −1
Original line number Diff line number Diff line
@@ -48,7 +48,7 @@ __init void kvm_compute_layout(void) 
	va_mask = GENMASK_ULL(tag_lsb - 1, 0);

	tag_val = hyp_va_msb;



	if (tag_lsb != (vabits_actual - 1)) {

	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && tag_lsb != (vabits_actual - 1)) {

		/* We have some free bits to insert a random tag. */

		tag_val |= get_random_long() & GENMASK_ULL(vabits_actual - 2, tag_lsb);

	}