linux-kernel - [PATCH 3/4] KVM: x86/vPMU: fix undefined shift in intel_pmu

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Date:   Thu, 18 May 2017 19:37:31 +0200
From:   Radim Krčmář <rkrcmar@...hat.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        Dan Carpenter <dan.carpenter@...cle.com>
Subject: [PATCH 3/4] KVM: x86/vPMU: fix undefined shift in intel_pmu_refresh()

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@...cle.com>
Fixes: 25462f7f5295 ("KVM: x86/vPMU: Define kvm_pmu_ops to support vPMU function dispatch")
Signed-off-by: Radim Krčmář <rkrcmar@...hat.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;
 
-- 
2.13.0