On 12/12/2018 08:57 PM, Michael Ellerman wrote: > Frank Rowand <frowand.list@xxxxxxxxx> writes: >> On 12/11/18 8:07 AM, Rob Herring wrote: >>> On Tue, Dec 11, 2018 at 7:29 AM Michael Ellerman <mpe@xxxxxxxxxxxxxx> wrote: > ... >>>> diff --git a/drivers/of/base.c b/drivers/of/base.c >>>> index 09692c9b32a7..d8e4534c0686 100644 >>>> --- a/drivers/of/base.c >>>> +++ b/drivers/of/base.c >>>> @@ -1190,6 +1190,10 @@ struct device_node *of_find_node_by_phandle(phandle handle) >>>> if (phandle_cache[masked_handle] && >>>> handle == phandle_cache[masked_handle]->phandle) >>>> np = phandle_cache[masked_handle]; >>>> + >>>> + /* If we find a detached node, remove it */ >>>> + if (of_node_check_flag(np, OF_DETACHED)) >>>> + np = phandle_cache[masked_handle] = NULL; >> >> The bug you found exposes a couple of different issues, a little bit >> deeper than the proposed fix. I'll work on a fuller fix tonight or >> tomorrow. > > OK thanks. > >>> I'm wondering if we should explicitly remove the node from the cache >>> when we set OF_DETACHED. Otherwise, it could be possible that the node >>> pointer has been freed already. Or maybe we need both? >> >> Yes, it should be explicitly removed. I may also add in a paranoia check in >> of_find_node_by_phandle(). > > That seems best to me. I agree that we should do both. > > cheers Michael -- Michael W. Bringmann Linux I/O, Networking and Security Development IBM Corporation Tie-Line 363-5196 External: (512) 286-5196 Cell: (512) 466-0650 mwb@xxxxxxxxxxxxxxxxxx
