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From: Christoffer Dall <cdall@linaro.org>
To: Andrew Jones <drjones@redhat.com>
Cc: marc.zyngier@arm.com, lkurusa@redhat.com, kvmarm@lists.cs.columbia.edu
Subject: Re: [PATCH] KVM: arm/arm64: fix races in kvm_psci_vcpu_on
Date: Wed, 19 Apr 2017 12:25:19 +0200	[thread overview]
Message-ID: <20170419102519.GC4104@cbox> (raw)
In-Reply-To: <20170418155958.13406-2-drjones@redhat.com>

On Tue, Apr 18, 2017 at 05:59:58PM +0200, Andrew Jones wrote:
> Fix potential races in kvm_psci_vcpu_on() by taking the kvm->lock
> mutex.  In general, it's a bad idea to allow more than one PSCI_CPU_ON
> to process the same target VCPU at the same time.  One such problem
> that may arise is that one PSCI_CPU_ON could be resetting the target
> vcpu, which fills the entire sys_regs array with a temporary value
> including the MPIDR register, while another looks up the VCPU based
> on the MPIDR value, resulting in no target VCPU found.  Resolves both
> races found with the kvm-unit-tests/arm/psci unit test.
> 
> Reported-by: Levente Kurusa <lkurusa@redhat.com>
> Suggested-by: Christoffer Dall <cdall@linaro.org>
> Signed-off-by: Andrew Jones <drjones@redhat.com>

Reviewed-by: Christoffer Dall <cdall@linaro.org>


Applied to kvmarm/queue.

Thanks,
-Christoffer

      parent reply	other threads:[~2017-04-19 10:22 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-18 15:59 [PATCH] KVM: arm/arm64: fix races in psci emulation Andrew Jones
2017-04-18 15:59 ` [PATCH] KVM: arm/arm64: fix races in kvm_psci_vcpu_on Andrew Jones
2017-04-19  7:56   ` Marc Zyngier
2017-04-19 10:25   ` Christoffer Dall [this message]

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