From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Fri, 12 Apr 2013 18:13:48 +0100 Subject: [PATCH] ARM: KVM: fix unbalanced get_cpu() in access_dcsw Message-ID: <1365786828-548-1-git-send-email-marc.zyngier@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org In the very unlikely event where a guest would be foolish enough to *read* from a write-only cache maintainance register, we end up with preemption disabled, due to a misplaced get_cpu(). Just move the "is_write" test outside of the critical section. Signed-off-by: Marc Zyngier --- arch/arm/kvm/coproc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c index 94eee8b..8eea97b 100644 --- a/arch/arm/kvm/coproc.c +++ b/arch/arm/kvm/coproc.c @@ -79,11 +79,11 @@ static bool access_dcsw(struct kvm_vcpu *vcpu, unsigned long val; int cpu; - cpu = get_cpu(); - if (!p->is_write) return read_from_write_only(vcpu, p); + cpu = get_cpu(); + cpumask_setall(&vcpu->arch.require_dcache_flush); cpumask_clear_cpu(cpu, &vcpu->arch.require_dcache_flush); -- 1.8.1.4