KVM: x86: masking out upper bits

kvm_read_cr3() returns an unsigned long and gfn is a u64.  We intended
to mask out the bottom 5 bits but because of the type issue we mask the
top 32 bits as well.  I don't know if this is a real problem, but it
causes static checker warnings.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5b8f07889f6a591f4e23ac69c6bb9656e7bc0a31..82a63c59f77b52fb7a9fa6ce49513c77ce7c21fa 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -597,8 +597,8 @@ bool pdptrs_changed(struct kvm_vcpu *vcpu)
                      (unsigned long *)&vcpu->arch.regs_avail))
                return true;
 
-       gfn = (kvm_read_cr3(vcpu) & ~31u) >> PAGE_SHIFT;
-       offset = (kvm_read_cr3(vcpu) & ~31u) & (PAGE_SIZE - 1);
+       gfn = (kvm_read_cr3(vcpu) & ~31ul) >> PAGE_SHIFT;
+       offset = (kvm_read_cr3(vcpu) & ~31ul) & (PAGE_SIZE - 1);
        r = kvm_read_nested_guest_page(vcpu, gfn, pdpte, offset, sizeof(pdpte),
                                       PFERR_USER_MASK | PFERR_WRITE_MASK);
        if (r < 0)