> -----Original Message-----
> From: Gustavo A. R. Silva [mailto:[email protected]]
> Sent: Thursday, December 27, 2018 4:41 AM
> To: Kang, Luwei <[email protected]>; Paolo Bonzini <[email protected]>;
> Radim Krčmář <[email protected]>; Thomas Gleixner
> <[email protected]>; Ingo Molnar <[email protected]>; Borislav Petkov
> <[email protected]>; H. Peter Anvin <[email protected]>;
> [email protected]
> Cc: [email protected]; [email protected]; Gustavo A. R. Silva
> <[email protected]>
> Subject: [PATCH][next] KVM: x86: Fix bit shifting in update_intel_pt_cfg
>
> ctl_bitmask in pt_desc is of type u64. When an integer like 0xf is being left
> shifted more than 32 bits, the behavior is undefined.
>
> Fix this by adding suffix ULL to integer 0xf.
>
> Addresses-Coverity-ID: 1476095 ("Bad bit shift operation")
> Fixes: 6c0f0bba85a0 ("KVM: x86: Introduce a function to initialize the PT
> configuration")
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
> arch/x86/kvm/vmx/vmx.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index
> cbd55e7aeae5..251c68a74bbe 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -7012,7 +7012,7 @@ static void update_intel_pt_cfg(struct kvm_vcpu *vcpu)
>
> /* unmask address range configure area */
> for (i = 0; i < vmx->pt_desc.addr_range; i++)
> - vmx->pt_desc.ctl_bitmask &= ~(0xf << (32 + i * 4));
> + vmx->pt_desc.ctl_bitmask &= ~(0xfULL << (32 + i * 4));
> }
Looks good to me, thanks.
Reviewed-by: Luwei Kang <[email protected]>
>
> static void vmx_cpuid_update(struct kvm_vcpu *vcpu)
> --
> 2.20.1
