diff options
| author | SeongJae Park <sj@kernel.org> | 2023-10-07 20:04:32 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-11-02 09:37:00 +0100 |
| commit | cdb4daffc2d428f2ea5ffa7fb388e82792eeb518 (patch) | |
| tree | b7c5998f72290e0593467a3b3b6e4d8eff006ba6 | |
| parent | a5c9f62896253d8d83bb674c7eaadc18ff23780c (diff) | |
mm/damon/sysfs: check DAMOS regions update progress from before_terminate()
commit 76b7069bcc89dec33f03eb08abee165d0306b754 upstream.
DAMON_SYSFS can receive DAMOS tried regions update request while kdamond
is already out of the main loop and before_terminate callback
(damon_sysfs_before_terminate() in this case) is not yet called. And
damon_sysfs_handle_cmd() can further be finished before the callback is
invoked. Then, damon_sysfs_before_terminate() unlocks damon_sysfs_lock,
which is not locked by anyone. This happens because the callback function
assumes damon_sysfs_cmd_request_callback() should be called before it.
Check if the assumption was true before doing the unlock, to avoid this
problem.
Link: https://lkml.kernel.org/r/20231007200432.3110-1-sj@kernel.org
Fixes: f1d13cacabe1 ("mm/damon/sysfs: implement DAMOS tried regions update command")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> [6.2.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | mm/damon/sysfs.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c index 33e1d5c9cb54..df165820c605 100644 --- a/mm/damon/sysfs.c +++ b/mm/damon/sysfs.c @@ -1202,6 +1202,8 @@ static int damon_sysfs_set_targets(struct damon_ctx *ctx, return 0; } +static bool damon_sysfs_schemes_regions_updating; + static void damon_sysfs_before_terminate(struct damon_ctx *ctx) { struct damon_target *t, *next; @@ -1209,10 +1211,12 @@ static void damon_sysfs_before_terminate(struct damon_ctx *ctx) /* damon_sysfs_schemes_update_regions_stop() might not yet called */ kdamond = damon_sysfs_cmd_request.kdamond; - if (kdamond && damon_sysfs_cmd_request.cmd == + if (kdamond && (damon_sysfs_cmd_request.cmd == DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS && + damon_sysfs_schemes_regions_updating) && ctx == kdamond->damon_ctx) { damon_sysfs_schemes_update_regions_stop(ctx); + damon_sysfs_schemes_regions_updating = false; mutex_unlock(&damon_sysfs_lock); } @@ -1331,7 +1335,6 @@ static int damon_sysfs_commit_input(struct damon_sysfs_kdamond *kdamond) static int damon_sysfs_cmd_request_callback(struct damon_ctx *c) { struct damon_sysfs_kdamond *kdamond; - static bool damon_sysfs_schemes_regions_updating; int err = 0; /* avoid deadlock due to concurrent state_store('off') */ |