Re: BUG: drivers/pinctrl/core: races in pinctrl_groups and deferred probing

From: Tony Lindgren
Date: Thu Jun 14 2018 - 08:02:05 EST

* H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> [180613 12:41]:
> Now if I look into pinctrl_generic_add_group() and pinctrl_generic_get_group_name(),
> pctldev->num_groups++ is not protected if pinctrl_generic_add_group() may be called by
> two threads in parallel for the same pctldev. Hence a second thread may try to insert
> a different node into the radix tree at the same selector index. This fails but there
> is no error check - and the second entry is completely missing (but probably assumed to
> be there).

Sounds like pinctrl-single.c is missing mutex around calls to