From: Paul Mackerras Date: Thu, 16 Jul 2015 07:11:13 +0000 (+1000) Subject: KVM: PPC: Book3S HV: Fix preempted vcore list locking X-Git-Tag: firefly_0821_release~176^2~1087^2~12^2~2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=402813fe39db66e8f3be2a1b5b62dd664e33f6b8;p=firefly-linux-kernel-4.4.55.git KVM: PPC: Book3S HV: Fix preempted vcore list locking When a vcore gets preempted, we put it on the preempted vcore list for the current CPU. The runner task then calls schedule() and comes back some time later and takes itself off the list. We need to be careful to lock the list that it was put onto, which may not be the list for the current CPU since the runner task may have moved to another CPU. Signed-off-by: Paul Mackerras Signed-off-by: Alexander Graf --- diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 6e3ef308b4c5..3d022766294a 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -1962,10 +1962,11 @@ static void kvmppc_vcore_preempt(struct kvmppc_vcore *vc) static void kvmppc_vcore_end_preempt(struct kvmppc_vcore *vc) { - struct preempted_vcore_list *lp = this_cpu_ptr(&preempted_vcores); + struct preempted_vcore_list *lp; kvmppc_core_end_stolen(vc); if (!list_empty(&vc->preempt_list)) { + lp = &per_cpu(preempted_vcores, vc->pcpu); spin_lock(&lp->lock); list_del_init(&vc->preempt_list); spin_unlock(&lp->lock);