From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marc Zyngier <marc.zyngier@arm.com>
Subject: Re: [PATCH] KVM: arm/arm64: fix races in kvm_psci_vcpu_on
Date: Wed, 19 Apr 2017 08:56:20 +0100
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References: <20170418155958.13406-1-drjones@redhat.com>
 <20170418155958.13406-2-drjones@redhat.com>
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To: Andrew Jones <drjones@redhat.com>, kvmarm@lists.cs.columbia.edu
Cc: cdall@linaro.org, lkurusa@redhat.com
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On 18/04/17 16:59, 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: Marc Zyngier <marc.zyngier@arm.com>

	M.
-- 
Jazz is not dead. It just smells funny...