Re: [PATCH v5 1/3] of: cache phandle nodes to reduce cost of of_find_node_by_phandle()

From: Alan Tull
Date: Wed Jun 13 2018 - 10:43:36 EST


On Tue, Jun 12, 2018 at 1:16 PM, Alan Tull <atull@xxxxxxxxxx> wrote:
> On Sun, Mar 4, 2018 at 6:14 PM, <frowand.list@xxxxxxxxx> wrote:
>
> Hi Frank,
>
> I'm investigating a refcount use-after-free warning that happens after
> overlays are applied, removed, reapplied a few (typically three) times
> (see below). This is new in v4.17, didn't happen in v4.16. As I was
> investigating I found that rebuilding the phandle_cache after overlays
> are applied or removed seems to help.

I was probably wrong about this. The more I look at the phandle_cache code,
the more it looks looks good and straightforward. Probably disabling
phandle_cache is 'fixing' things through some weird side effect. I'll
keep investigating. Sorry for the noise.

Alan