| Message ID | 20171212125032.6292-1-christoffer.dall@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v3.18,backport] arm64: KVM: fix VTTBR_BADDR_MASK BUG_ON off-by-one | expand |
On Tue, Dec 12, 2017 at 01:50:31PM +0100, Christoffer Dall wrote: > From: Kristina Martsenko <kristina.martsenko@arm.com> > > Commit 26aa7b3b1c0fb3f1a6176a0c1847204ef4355693 upstream. Please disregard this, I accidentally backported the arm64 patch instead of the arm patch. Another one (the correct one, hopefully) incoming, which backports 5553b142be11e794ebc0805950b2e8313f93d718 instead. Thanks (and sorry about the noise), -Christoffer > > 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 47-bit addresses (instead of 48-bit) and also > insufficiently checking the alignment. This patch fixes it. > > As an example, with 4k pages, before this patch we have: > > PHYS_MASK_SHIFT = 48 > VTTBR_X = 37 - 24 = 13 > VTTBR_BADDR_SHIFT = 13 - 1 = 12 > VTTBR_BADDR_MASK = ((1 << 35) - 1) << 12 = 0x00007ffffffff000 > > Which is wrong, because the mask doesn't allow bit 47 of the VTTBR > address to be set, and only requires the address to be 12-bit (4k) > aligned, while it actually needs to be 13-bit (8k) aligned because we > concatenate two 4k tables. > > With this patch, the mask becomes 0x0000ffffffffe000, which is what we > want. > > Fixes: 0369f6a34b9f ("arm64: KVM: EL2 register definitions") > Cc: <stable@vger.kernel.org> # 3.11.x > Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> > Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> > Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> > Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> > --- > arch/arm64/include/asm/kvm_arm.h | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h > index 8afb863f5a9e..333ddd45dd1f 100644 > --- a/arch/arm64/include/asm/kvm_arm.h > +++ b/arch/arm64/include/asm/kvm_arm.h > @@ -160,8 +160,7 @@ > #define VTTBR_X (37 - VTCR_EL2_T0SZ_40B) > #endif > > -#define VTTBR_BADDR_SHIFT (VTTBR_X - 1) > -#define VTTBR_BADDR_MASK (((UL(1) << (PHYS_MASK_SHIFT - VTTBR_X)) - 1) << VTTBR_BADDR_SHIFT) > +#define VTTBR_BADDR_MASK (((UL(1) << (PHYS_MASK_SHIFT - VTTBR_X)) - 1) << VTTBR_X) > #define VTTBR_VMID_SHIFT (UL(48)) > #define VTTBR_VMID_MASK (UL(0xFF) << VTTBR_VMID_SHIFT) > > -- > 2.14.2 >
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 8afb863f5a9e..333ddd45dd1f 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -160,8 +160,7 @@ #define VTTBR_X (37 - VTCR_EL2_T0SZ_40B) #endif -#define VTTBR_BADDR_SHIFT (VTTBR_X - 1) -#define VTTBR_BADDR_MASK (((UL(1) << (PHYS_MASK_SHIFT - VTTBR_X)) - 1) << VTTBR_BADDR_SHIFT) +#define VTTBR_BADDR_MASK (((UL(1) << (PHYS_MASK_SHIFT - VTTBR_X)) - 1) << VTTBR_X) #define VTTBR_VMID_SHIFT (UL(48)) #define VTTBR_VMID_MASK (UL(0xFF) << VTTBR_VMID_SHIFT)