Liam R. Howlett 2780b421b8 maple_tree: fix write memory barrier of nodes once dead for RCU mode ... [ Upstream commit c13af03de4 ] During the development of the maple tree, the strategy of freeing multiple nodes changed and, in the process, the pivots were reused to store pointers to dead nodes. To ensure the readers see accurate pivots, the writers need to mark the nodes as dead and call smp_wmb() to ensure any readers can identify the node as dead before using the pivot values. There were two places where the old method of marking the node as dead without smp_wmb() were being used, which resulted in RCU readers seeing the wrong pivot value before seeing the node was dead. Fix this race condition by using mte_set_node_dead() which has the smp_wmb() call to ensure the race is closed. Add a WARN_ON() to the ma_free_rcu() call to ensure all nodes being freed are marked as dead to ensure there are no other call paths besides the two updated paths. This is necessary for the RCU mode of the maple tree. Link: https://lkml.kernel.org/r/20230227173632.3292573-6-surenb@google.com Fixes: 54a611b605 ("Maple Tree: add new data structure") Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>		2023-04-20 12:36:58 +02:00
..
generated	maple_tree: reorganize testing to restore module testing	2022-11-08 15:57:22 -08:00
linux	radix tree test suite: add lockdep_is_held to header	2022-09-26 19:46:14 -07:00
trace/events	Maple Tree: add new data structure	2022-09-26 19:46:13 -07:00
.gitignore	maple_tree: reorganize testing to restore module testing	2022-11-08 15:57:22 -08:00
benchmark.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288	2019-06-05 17:36:37 +02:00
bitmap.c
idr-test.c	idr test suite: Improve reporting from idr_find_test_1	2021-04-01 07:50:42 -04:00
iteration_check.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288	2019-06-05 17:36:37 +02:00
iteration_check_2.c	xarray: Fix early termination of xas_for_each_marked	2020-03-12 17:42:08 -04:00
linux.c	maple_tree: reorganize testing to restore module testing	2022-11-08 15:57:22 -08:00
main.c	xarray: Fix early termination of xas_for_each_marked	2020-03-12 17:42:08 -04:00
Makefile	maple_tree: reorganize testing to restore module testing	2022-11-08 15:57:22 -08:00
maple.c	maple_tree: fix write memory barrier of nodes once dead for RCU mode	2023-04-20 12:36:58 +02:00
multiorder.c	radix tree test suite: Register the main thread with the RCU library	2021-04-01 07:41:30 -04:00
regression.h
regression1.c
regression2.c
regression3.c
regression4.c
tag_check.c
test.c
test.h	radix tree test suite: Fix compilation	2020-10-07 09:07:49 -04:00
xarray.c	radix tree test suite: Register the main thread with the RCU library	2021-04-01 07:41:30 -04:00