Messages in this thread | | | From | "Kang, Luwei" <> | Subject | RE: [PATCH][next] KVM: x86: Fix bit shifting in update_intel_pt_cfg | Date | Fri, 28 Dec 2018 07:58:06 +0000 |
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> -----Original Message----- > From: Gustavo A. R. Silva [mailto:gustavo@embeddedor.com] > Sent: Thursday, December 27, 2018 4:41 AM > To: Kang, Luwei <luwei.kang@intel.com>; Paolo Bonzini <pbonzini@redhat.com>; Radim Krčmář <rkrcmar@redhat.com>; Thomas Gleixner > <tglx@linutronix.de>; Ingo Molnar <mingo@redhat.com>; Borislav Petkov <bp@alien8.de>; H. Peter Anvin <hpa@zytor.com>; > x86@kernel.org > Cc: kvm@vger.kernel.org; linux-kernel@vger.kernel.org; Gustavo A. R. Silva <gustavo@embeddedor.com> > 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@embeddedor.com> > --- > 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@intel.com>
> > static void vmx_cpuid_update(struct kvm_vcpu *vcpu) > -- > 2.20.1
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