Commit 50e81c82 authored by Liam R. Howlett's avatar Liam R. Howlett Committed by Andrew Morton
Browse files

maple_tree: reduce user error potential 

When iterating, a user may operate on the tree and cause the maple state
to be altered and left in an unintuitive state.  Detect this scenario and
correct it by setting to the limit and invalidating the state.

Link: https://lkml.kernel.org/r/20230120162650.984577-4-Liam.Howlett@oracle.com


Signed-off-by: default avatarLiam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 65be6f05

lib/maple_tree.c

+10 −0
Original line number Diff line number Diff line
@@ -4732,6 +4732,11 @@ static inline void *mas_next_entry(struct ma_state *mas, unsigned long limit) 
	unsigned long last;

	enum maple_type mt;



	if (mas->index > limit) {

		mas->index = mas->last = limit;

		mas_pause(mas);

		return NULL;

	}

	last = mas->last;

retry:

	offset = mas->offset;
@@ -4838,6 +4843,11 @@ static inline void *mas_prev_entry(struct ma_state *mas, unsigned long min) 
{

	void *entry;



	if (mas->index < min) {

		mas->index = mas->last = min;

		mas_pause(mas);

		return NULL;

	}

retry:

	while (likely(!mas_is_none(mas))) {

		entry = mas_prev_nentry(mas, min, mas->index);