Hi Arnaldo,
On Wed, May 22, 2019 at 10:18:32AM -0300, Arnaldo Carvalho de Melo wrote:
> Em Wed, May 22, 2019 at 02:32:48PM +0900, Namhyung Kim escreveu:
> > It seems that the current code lacks holding the namespace lock in
> > thread__namespaces(). Otherwise it can see inconsistent results.
> >
> > Signed-off-by: Namhyung Kim <namhy...@kernel.org>
> > ---
> > tools/perf/util/thread.c | 15 +++++++++++++--
> > 1 file changed, 13 insertions(+), 2 deletions(-)
> >
> > diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
> > index 403045a2bbea..b413ba5b9835 100644
> > --- a/tools/perf/util/thread.c
> > +++ b/tools/perf/util/thread.c
> > @@ -133,7 +133,7 @@ void thread__put(struct thread *thread)
> > }
> > }
> >
> > -struct namespaces *thread__namespaces(const struct thread *thread)
> > +static struct namespaces *__thread__namespaces(const struct thread *thread)
> > {
> > if (list_empty(&thread->namespaces_list))
> > return NULL;
> > @@ -141,10 +141,21 @@ struct namespaces *thread__namespaces(const struct
> > thread *thread)
> > return list_first_entry(&thread->namespaces_list, struct namespaces,
> > list);
> > }
> >
> > +struct namespaces *thread__namespaces(const struct thread *thread)
> > +{
> > + struct namespaces *ns;
> > +
> > + down_read((struct rw_semaphore *)&thread->namespaces_lock);
> > + ns = __thread__namespaces(thread);
> > + up_read((struct rw_semaphore *)&thread->namespaces_lock);
> > +
>
> Humm, so we need to change thread__namespaces() to remove that const
> instead of throwing it away with that cast, right?
Yes, that's possible too. Note that thread__comm_str() has the same issue
as well.
Thanks,
Namhyung
