Re: [PATCH 3/4] KVM: x86/vPMU: fix undefined shift in intel_pmu_refresh()

From	David Hildenbrand <david@redhat.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 3/4] KVM: x86/vPMU: fix undefined shift in intel_pmu_refresh()
Date	2017-05-19 15:40 +0200
Message-ID	<tIQil-2MD-3@gated-at.bofh.it> (permalink)
References	<tIxz3-5R2-3@gated-at.bofh.it> <tIxz3-5R2-15@gated-at.bofh.it>
Organization	Red Hat GmbH

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On 18.05.2017 19:37, Radim Krčmář wrote:
> Static analysis noticed that pmu->nr_arch_gp_counters can be 32
> (INTEL_PMC_MAX_GENERIC) and therefore cannot be used to shift 'int'.
> 
> I didn't add BUILD_BUG_ON for it as we have a better checker.
> 
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Fixes: 25462f7f5295 ("KVM: x86/vPMU: Define kvm_pmu_ops to support vPMU function dispatch")
> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
> ---
>  arch/x86/kvm/pmu_intel.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kvm/pmu_intel.c b/arch/x86/kvm/pmu_intel.c
> index 9d4a8504a95a..5ab4a364348e 100644
> --- a/arch/x86/kvm/pmu_intel.c
> +++ b/arch/x86/kvm/pmu_intel.c
> @@ -294,7 +294,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
>  			((u64)1 << edx.split.bit_width_fixed) - 1;
>  	}
>  
> -	pmu->global_ctrl = ((1 << pmu->nr_arch_gp_counters) - 1) |
> +	pmu->global_ctrl = ((1ull << pmu->nr_arch_gp_counters) - 1) |
>  		(((1ull << pmu->nr_arch_fixed_counters) - 1) << INTEL_PMC_IDX_FIXED);
>  	pmu->global_ctrl_mask = ~pmu->global_ctrl;
>  
> 

Reviewed-by: David Hildenbrand <david@redhat.com>

-- 

Thanks,

David

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[PATCH 3/4] KVM: x86/vPMU: fix undefined shift in intel_pmu_refresh() Radim Krčmář <rkrcmar@redhat.com> - 2017-05-18 19:40 +0200
  Re: [PATCH 3/4] KVM: x86/vPMU: fix undefined shift in  intel_pmu_refresh() David Hildenbrand <david@redhat.com> - 2017-05-19 15:40 +0200

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