Re: [PATCH] radix-tree: Fix private list warnings

From: Johannes Weiner
Date: Sat Jan 14 2017 - 11:01:06 EST


On Thu, Jan 12, 2017 at 05:28:23PM -0800, Matthew Wilcox wrote:
> From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
>
> The newly introduced warning in radix_tree_free_nodes() was testing the
> wrong variable; it should have been 'old' instead of 'node'. Rather
> than replace that one instance, I noticed that we can simply put the
> WARN_ON_ONCE in radix_tree_node_free() and it will be just as effective.
>
> Fixes: ea07b862ac8e ("mm: workingset: fix use-after-free in shadow node shrinker")
> Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>

Thanks for the fix in radix_tree_free_nodes(). But I intentionally
spread out the warnings to retain the line numbers. The inlining in
that code will obscure which tree operation ends up triggering.