On Wed, Feb 20, 2013 at 07:09:36PM +0200, Andy Shevchenko wrote: > The guilty commit is cc5b5f6 "events: convert to idr_alloc()" together with > f49318a "idr: implement lookup hint". In our case the idr_alloc is never > called, but idr_find is. The hint field is never initialized and could not be > dereferenced.
Ah, right, ->hint is uninitialized at the beginning. > The proposed fix uses the idr_slowpath call which reflects old behaviour. > > Signed-off-by: Andy Shevchenko <[email protected]> > Reported-by: Kirill A. Shutemov <[email protected]> > --- > kernel/events/core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/events/core.c b/kernel/events/core.c > index 624e53f..20421ea 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -6076,7 +6076,7 @@ struct pmu *perf_init_event(struct perf_event *event) > idx = srcu_read_lock(&pmus_srcu); > > rcu_read_lock(); > - pmu = idr_find(&pmu_idr, event->attr.type); > + pmu = idr_find_slowpath(&pmu_idr, event->attr.type); But I don't think this is the right thing to do. I'm working on proper fix for idr_find(). Will post soon. Thanks! -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
