On Thu Jan 17 13, Tejun Heo wrote: > Hello, Jerry. > > Can you please also cc cgroups@xxxxxxxxxxxxxxx and Aristeu Rozanski > <aris@xxxxxxxxxx>? > > On Thu, Jan 17, 2013 at 03:00:18PM -0700, Jerry Snitselaar wrote: > > devcgroup_css_free() calls dev_exception_clean() without the > > devcgroup_mutex being held. > > > > Shutting down a kvm virt was giving me the following trace: > > Hmm... > > > Signed-off-by: Jerry Snitselaar <jerry.snitselaar@xxxxxxxxxx> > > --- > > security/device_cgroup.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/security/device_cgroup.c b/security/device_cgroup.c > > index 19ecc8d..d794abc 100644 > > --- a/security/device_cgroup.c > > +++ b/security/device_cgroup.c > > @@ -215,7 +215,9 @@ static void devcgroup_css_free(struct cgroup *cgroup) > > struct dev_cgroup *dev_cgroup; > > > > dev_cgroup = cgroup_to_devcgroup(cgroup); > > + mutex_lock(&devcgroup_mutex); > > You can't grab mutex from rcu callback. It seems like the lockdep > assertion isn't necessary in this case as the free callback should be > the last remaining user of the dev_cgroup. Maybe factor out > __devcgroup_css_free() which doesn't have lockdep assertion? > Ok. I was wondering if it was really needed since it was freeing dev_cgroup right after that. I probably would have never noticed the trace if hadn't been checking to see if a fix for ttm stopped it from spamming me with them for trying to sleep in an invalid context. Jerry > > dev_exception_clean(dev_cgroup); > > + mutex_unlock(&devcgroup_mutex); > > kfree(dev_cgroup); > > Thanks. > > -- > tejun -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
