On Mon, Oct 15, 2018 at 09:41:23AM -0700, Jim Mattson wrote:
> x86_exception_has_error_code should deterministically return false if
> its operand is greater than 32.
>
> Fixes: 0447378a4a793 ("kvm: vmx: Nested VM-entry prereqs for event inj.")
> Cc: Marc Orr <marcorr@xxxxxxxxxx>
> Cc: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
> Reviewed-by: Marc Orr <marcorr@xxxxxxxxxx>
> ---
> arch/x86/kvm/x86.h | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
> index 67b9568613f3..152b20d06a48 100644
> --- a/arch/x86/kvm/x86.h
> +++ b/arch/x86/kvm/x86.h
> @@ -116,7 +116,8 @@ static inline bool x86_exception_has_error_code(unsigned int vector)
> BIT(NP_VECTOR) | BIT(SS_VECTOR) | BIT(GP_VECTOR) |
> BIT(PF_VECTOR) | BIT(AC_VECTOR);
>
> - return (1U << vector) & exception_has_error_code;
> + WARN_ON_ONCE(vector >= 32);
> + return vector < 32 && (1U << vector) & exception_has_error_code;
WARN_ON_ONCE always returns the condition, even after warning. I.e.:
if (WARN_ON_ONCE(vector >= 32))
return false;
return (1U << vector) & exception_has_error_code;
> }
>
> static inline bool mmu_is_nested(struct kvm_vcpu *vcpu)
> --
> 2.19.1.331.ge82ca0e54c-goog
>
