diff options
| author | SeongJae Park <sj@kernel.org> | 2023-12-08 20:50:18 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-01-01 15:42:23 +0300 |
| commit | e93bcaebda90c237b2ce2b4e0ee7897b83b5cbf0 (patch) | |
| tree | 427c7677252f59042ee674e6a6f5bfaa65b28c8d /include/linux | |
| parent | c708a5e51b43797539d787f27ee947d95986c382 (diff) | |
| download | linux-e93bcaebda90c237b2ce2b4e0ee7897b83b5cbf0.tar.xz | |
mm/damon/core: make damon_start() waits until kdamond_fn() starts
[ Upstream commit 6376a824595607e99d032a39ba3394988b4fce96 ]
The cleanup tasks of kdamond threads including reset of corresponding
DAMON context's ->kdamond field and decrease of global nr_running_ctxs
counter is supposed to be executed by kdamond_fn(). However, commit
0f91d13366a4 ("mm/damon: simplify stop mechanism") made neither
damon_start() nor damon_stop() ensure the corresponding kdamond has
started the execution of kdamond_fn().
As a result, the cleanup can be skipped if damon_stop() is called fast
enough after the previous damon_start(). Especially the skipped reset
of ->kdamond could cause a use-after-free.
Fix it by waiting for start of kdamond_fn() execution from
damon_start().
Link: https://lkml.kernel.org/r/20231208175018.63880-1-sj@kernel.org
Fixes: 0f91d13366a4 ("mm/damon: simplify stop mechanism")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reported-by: Jakub Acs <acsjakub@amazon.de>
Cc: Changbin Du <changbin.du@intel.com>
Cc: Jakub Acs <acsjakub@amazon.de>
Cc: <stable@vger.kernel.org> # 5.15.x
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/damon.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/damon.h b/include/linux/damon.h index 506118916378..a953d7083cd5 100644 --- a/include/linux/damon.h +++ b/include/linux/damon.h @@ -534,6 +534,8 @@ struct damon_ctx { * update */ unsigned long next_ops_update_sis; + /* for waiting until the execution of the kdamond_fn is started */ + struct completion kdamond_started; /* public: */ struct task_struct *kdamond; |