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From: Marcelo Tosatti <mtosatti@redhat.com>
To: kvm <kvm@vger.kernel.org>
Subject: KVM: PIT: fix kpit_elapsed division by zero
Date: Thu, 2 Jul 2009 20:02:15 -0300	[thread overview]
Message-ID: <20090702230215.GA25347@amt.cnet> (raw)


Fix division by zero triggered by latch count command on uninitialized
counter.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>


diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index 14bbaae..8c3ac30 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -104,6 +104,9 @@ static s64 __kpit_elapsed(struct kvm *kvm)
 	ktime_t remaining;
 	struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state;
 
+	if (!ps->pit_timer.period)
+		return 0;
+
 	/*
 	 * The Counter does not stop when it reaches zero. In
 	 * Modes 0, 1, 4, and 5 the Counter ``wraps around'' to

             reply	other threads:[~2009-07-02 23:02 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-07-02 23:02 Marcelo Tosatti [this message]
2009-07-06  7:44 ` KVM: PIT: fix kpit_elapsed division by zero Avi Kivity

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