From: Marc Zyngier Date: Thu, 16 Nov 2017 17:58:21 +0000 (+0000) Subject: arm: KVM: Fix VTTBR_BADDR_MASK BUG_ON off-by-one X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=5553b142be11e794ebc0805950b2e8313f93d718;p=linux.git arm: KVM: Fix VTTBR_BADDR_MASK BUG_ON off-by-one 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") Cc: # 3.9 Reported-by: Kristina Martsenko Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h index c8781450905be..3ab8b3781bfec 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 (((_AC(1, ULL) << (40 - VTTBR_X)) - 1) << VTTBR_BADDR_SHIFT) +#define VTTBR_BADDR_MASK (((_AC(1, ULL) << (40 - VTTBR_X)) - 1) << VTTBR_X) #define VTTBR_VMID_SHIFT _AC(48, ULL) #define VTTBR_VMID_MASK(size) (_AT(u64, (1 << size) - 1) << VTTBR_VMID_SHIFT)