From f7f83b90a0eb5a15480334a3e4e911101e1b2573 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Thu, 16 Nov 2017 17:58:21 +0000 Subject: [PATCH] arm: KVM: Fix VTTBR_BADDR_MASK BUG_ON off-by-one commit 5553b142be11e794ebc0805950b2e8313f93d718 upstream. VTTBR_BADDR_MASK is used to sanity check the size and alignment of the VTTBR address. It seems to currently be off by one, thereby only allowing up to 39-bit addresses (instead of 40-bit) and also insufficiently checking the alignment. This patch fixes it. This patch is the 32bit pendent of Kristina's arm64 fix, and she deserves the actual kudos for pinpointing that one. Fixes: f7ed45be3ba52 ("KVM: ARM: World-switch implementation") Reported-by: Kristina Martsenko Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- arch/arm/include/asm/kvm_arm.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h index 816db0bf2dd8..46b336df4ec1 100644 --- a/arch/arm/include/asm/kvm_arm.h +++ b/arch/arm/include/asm/kvm_arm.h @@ -161,8 +161,7 @@ #else #define VTTBR_X (5 - KVM_T0SZ) #endif -#define VTTBR_BADDR_SHIFT (VTTBR_X - 1) -#define VTTBR_BADDR_MASK (((1LLU << (40 - VTTBR_X)) - 1) << VTTBR_BADDR_SHIFT) +#define VTTBR_BADDR_MASK (((1LLU << (40 - VTTBR_X)) - 1) << VTTBR_X) #define VTTBR_VMID_SHIFT (48LLU) #define VTTBR_VMID_MASK (0xffLLU << VTTBR_VMID_SHIFT)