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| author | SeongJae Park <sj@kernel.org> | 2023-12-08 17:50:18 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-01-01 12:39:08 +0000 |
| commit | ec7b81b0abcde34ac75a4b02239aa88306feab67 (patch) | |
| tree | 139ebf25bd9d1859dd0f489f6498c8df3820035f /include | |
| parent | 41f4ff9fe22c4b83e8d6978118c3d89767b3438d (diff) | |
| download | linux-stable-ec7b81b0abcde34ac75a4b02239aa88306feab67.tar.gz linux-stable-ec7b81b0abcde34ac75a4b02239aa88306feab67.tar.bz2 linux-stable-ec7b81b0abcde34ac75a4b02239aa88306feab67.zip | |
mm/damon/core: make damon_start() waits until kdamond_fn() starts
commit 6376a824595607e99d032a39ba3394988b4fce96 upstream.
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: SeongJae Park <sj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/damon.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/damon.h b/include/linux/damon.h index b13be7ae2275..e6941b239f44 100644 --- a/include/linux/damon.h +++ b/include/linux/damon.h @@ -8,6 +8,7 @@ #ifndef _DAMON_H_ #define _DAMON_H_ +#include <linux/completion.h> #include <linux/mutex.h> #include <linux/time64.h> #include <linux/types.h> @@ -452,6 +453,8 @@ struct damon_ctx { /* private: internal use only */ struct timespec64 last_aggregation; struct timespec64 last_ops_update; + /* for waiting until the execution of the kdamond_fn is started */ + struct completion kdamond_started; /* public: */ struct task_struct *kdamond; |