Hi Tony,
Am 14.06.2018 um 14:01 schrieb Tony Lindgren tony@atomide.com:
- H. Nikolaus Schaller hns@goldelico.com [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 pinctrl_generic_add_group()?
Yes, that could be. I didn't research the call path, just the one of devm_pinctrl_get(). That uses a mutex in
https://elixir.bootlin.com/linux/v4.17.1/source/drivers/pinctrl/core.c#L1021
Maybe a similar mutex is missing elsewhere.
BR, Nikolaus