diff options
Diffstat (limited to 'debian/patches-rt/0001-sched-Constrain-locks-in-sched_submit_work.patch')
| -rw-r--r-- | debian/patches-rt/0001-sched-Constrain-locks-in-sched_submit_work.patch | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/debian/patches-rt/0001-sched-Constrain-locks-in-sched_submit_work.patch b/debian/patches-rt/0001-sched-Constrain-locks-in-sched_submit_work.patch new file mode 100644 index 000000000..73828f0ef --- /dev/null +++ b/debian/patches-rt/0001-sched-Constrain-locks-in-sched_submit_work.patch @@ -0,0 +1,49 @@ +From: Peter Zijlstra <peterz@infradead.org> +Date: Fri, 8 Sep 2023 18:22:48 +0200 +Subject: [PATCH 1/7] sched: Constrain locks in sched_submit_work() +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz + +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 +--- + kernel/sched/core.c | 9 +++++++++ + 1 file changed, 9 insertions(+) + +--- a/kernel/sched/core.c ++++ b/kernel/sched/core.c +@@ -6721,11 +6721,18 @@ 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 +@@ -6750,6 +6757,8 @@ static inline void sched_submit_work(str + * 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) |