> -----Original Message----- > From: Gustavo A. R. Silva [mailto:gustavo@xxxxxxxxxxxxxx] > Sent: Thursday, December 27, 2018 4:41 AM > To: Kang, Luwei <luwei.kang@xxxxxxxxx>; Paolo Bonzini <pbonzini@xxxxxxxxxx>; Radim Krčmář <rkrcmar@xxxxxxxxxx>; Thomas Gleixner > <tglx@xxxxxxxxxxxxx>; Ingo Molnar <mingo@xxxxxxxxxx>; Borislav Petkov <bp@xxxxxxxxx>; H. Peter Anvin <hpa@xxxxxxxxx>; > x86@xxxxxxxxxx > Cc: kvm@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx> > 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 <gustavo@xxxxxxxxxxxxxx> > --- > 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 <luwei.kang@xxxxxxxxx> > > static void vmx_cpuid_update(struct kvm_vcpu *vcpu) > -- > 2.20.1
