diff options
| author | SeongJae Park | 2023-12-08 17:50:18 +0000 |
|---|---|---|
| committer | Andrew Morton | 2023-12-12 17:20:17 -0800 |
| commit | 6376a824595607e99d032a39ba3394988b4fce96 (patch) | |
| tree | 7176ac63c877da843207b5799f76b4c0cf51a743 /include | |
| parent | a6fcd57cf2df409d35e9225b8dbad6f937b28df0 (diff) | |
mm/damon/core: make damon_start() waits until kdamond_fn() starts
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>
Diffstat (limited to 'include')
| -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 ab2f17d9926b..e00ddf1ed39c 100644 --- a/include/linux/damon.h +++ b/include/linux/damon.h @@ -559,6 +559,8 @@ 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; |