Messages in this thread | | | Date | Mon, 18 Jun 2018 11:17:44 -0700 | From | Tony Lindgren <> | Subject | Re: [Letux-kernel] BUG: drivers/pinctrl/core: races in pinctrl_groups and deferred probing |
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* H. Nikolaus Schaller <hns@goldelico.com> [180618 16:46]:
> > I can also demonstrate that the duplication has gone:
OK good to hear.
> And I was no longer able to reproduce the strcmp(NULL) issue. So it is either better hidden > or gone.
It should not be possible with checks preventing registering a group or function with no name. I'll try to repost the whole series tomorrow with that added.
> So code just needs group cleanup on failed probing and fixing the mutex around pinctrl_generic_add_group(). > > I think we need the mutex because a race still can happen when create_pinctrl() is calling pcs_dt_node_to_map() > and pinctrl_generic_add_group() w/o being locked on pinctrl_maps_mutex. > > The race I suspect is that two drivers are trying to insert the same name and may come > both to the conclusion that it does not yet exist. And both insert into the radix tree. > > The window of risk is small though... It is in pinctrl_generic_add_group() between calling > pinctrl_generic_group_name_to_selector() and radix_tree_insert() so we probably won't > see it in real hardware tests.
Hmm but that race should be already fixed with mutex held by the pin controller drivers with these fixes? Or am I missing something still?
Regards,
Tony
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