diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2023-09-08 18:22:48 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2023-09-20 09:31:11 +0200 |
| commit | 28bc55f654de49f6122c7475b01b5d5ef4bdf0d4 (patch) | |
| tree | e64652db817f2983d86425749a8f712de5886067 | |
| parent | a432b7c0cf420dbf2448c6bda6a6697afbb153d5 (diff) | |
sched: Constrain locks in sched_submit_work()
Even though sched_submit_work() is ran from preemptible context,
it is discouraged to have it use blocking locks due to the recursion
potential.
Enforce this.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230908162254.999499-2-bigeasy@linutronix.de
| -rw-r--r-- | kernel/sched/core.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 2299a5cfbfb9..d55564097bd8 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6720,11 +6720,18 @@ void __noreturn do_task_dead(void) static inline void sched_submit_work(struct task_struct *tsk) { + static DEFINE_WAIT_OVERRIDE_MAP(sched_map, LD_WAIT_CONFIG); unsigned int task_flags; if (task_is_running(tsk)) return; + /* + * Establish LD_WAIT_CONFIG context to ensure none of the code called + * will use a blocking primitive -- which would lead to recursion. + */ + lock_map_acquire_try(&sched_map); + task_flags = tsk->flags; /* * If a worker goes to sleep, notify and ask workqueue whether it @@ -6749,6 +6756,8 @@ static inline void sched_submit_work(struct task_struct *tsk) * make sure to submit it to avoid deadlocks. */ blk_flush_plug(tsk->plug, true); + + lock_map_release(&sched_map); } static void sched_update_worker(struct task_struct *tsk) |