On 25.03.19 10:04, Dan Carpenter wrote:
> This code generates a Smatch warning:
>
> arch/x86/kvm/vmx/nested.c:4828 handle_vmfunc() warn: should '(1 << function)' be a 64 bit type?
>
> The warning is generated because "vmcs12->vm_function_control" is a u64
> but the shift can only test the lower 32 bits. This doesn't cause a
> problem in the current code because we only use BIT(0). This patch just
> silences the static checker warning.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> ---
> arch/x86/kvm/vmx/nested.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> index f24a2c225070..1f4398246bd9 100644
> --- a/arch/x86/kvm/vmx/nested.c
> +++ b/arch/x86/kvm/vmx/nested.c
> @@ -4825,7 +4825,7 @@ static int handle_vmfunc(struct kvm_vcpu *vcpu)
> }
>
> vmcs12 = get_vmcs12(vcpu);
> - if ((vmcs12->vm_function_control & (1 << function)) == 0)
> + if ((vmcs12->vm_function_control & (1ULL << function)) == 0)
I guess one set of parentheses could be dropped here, while touching the
line.
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
> goto fail;
>
> switch (function) {
>
--
Thanks,
David / dhildenb
