Re: [libvirt] [PATCHv5 2/8] qemu: bulk stats: implement CPU stats group
----- Original Message -----
From: "Peter Krempa" <pkrempa(a)redhat.com>
To: "Francesco Romani" <fromani(a)redhat.com>, libvir-list(a)redhat.com
Sent: Monday, September 15, 2014 2:49:50 PM
Subject: Re: [libvirt] [PATCHv5 2/8] qemu: bulk stats: implement CPU stats group
> +static int
> +qemuDomainGetStatsCpu(virQEMUDriverPtr driver ATTRIBUTE_UNUSED,
> + virDomainObjPtr dom,
> + virDomainStatsRecordPtr record,
> + int *maxparams,
> + unsigned int privflags ATTRIBUTE_UNUSED)
> +{
> + qemuDomainObjPrivatePtr priv = dom->privateData;
> + unsigned long long cpu_time = 0;
> + unsigned long long user_time = 0;
> + unsigned long long sys_time = 0;
> + int err = 0;
> +
> + err = virCgroupGetCpuacctUsage(priv->cgroup, &cpu_time);
This code doesn't check if priv->cgroup isn't NULL and dereferences it
unconditionally. This would crash with shutoff machines.
Ouch. Right, of course. I tested on running VMs actually, and that explains
why I haven't catched it :(
I'll add an
if (priv->group)
return 0;
right at the beginning.
You mean
if (!priv->cgroup)
return 0;
I believe
--
Francesco Romani
RedHat Engineering Virtualization R & D
Phone: 8261328
IRC: fromani