Commit f85c758d authored Jul 17, 2017 by Dan Carpenter Committed by Radim Krčmář Jul 19, 2017

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>

parent 5771a8c0

arch/x86/kvm/x86.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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)