Hi Andrew,
On 2020-06-15 09:48, Andrew Scull wrote:
On Mon, Jun 15, 2020 at 09:19:51AM +0100, Marc Zyngier wrote:
While initializing EL2, switch Pointer Authentication if detected
^ nit: on?
Yes.
from EL1. We use the EL1-provided keys though.
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
arch/arm64/kvm/hyp-init.S | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S
index 6e6ed5581eed..81732177507d 100644
--- a/arch/arm64/kvm/hyp-init.S
+++ b/arch/arm64/kvm/hyp-init.S
@@ -104,6 +104,17 @@ alternative_else_nop_endif
*/
mov_q x4, (SCTLR_EL2_RES1 | (SCTLR_ELx_FLAGS & ~SCTLR_ELx_A))
CPU_BE( orr x4, x4, #SCTLR_ELx_EE)
+alternative_if ARM64_HAS_ADDRESS_AUTH_ARCH
+ b 1f
+alternative_else_nop_endif
+alternative_if_not ARM64_HAS_ADDRESS_AUTH_IMP_DEF
+ b 2f
+alternative_else_nop_endif
+1:
+ orr x4, x4, #(SCTLR_ELx_ENIA | SCTLR_ELx_ENIB)
+ orr x4, x4, #SCTLR_ELx_ENDA
+ orr x4, x4, #SCTLR_ELx_ENDB
mm/proc.S builds the mask with ldr and ors it in one go, would be nice
to use the same pattern.
Do you actually mean kernel/head.S, or even __ptrauth_keys_init_cpu in
asm/asm_pointer_auth.h?
If so, I agree that it'd be good to make it look similar by using the
mov_q macro, at the expense of a spare register (which we definitely can
afford here).
Thanks,
M.
--
Jazz is not dead. It just smells funny...
