diff options
Diffstat (limited to 'debian/patches-rt/0057-sched-avoid-false-lockdep-splat-in-put_task_struct.patch')
| -rw-r--r-- | debian/patches-rt/0057-sched-avoid-false-lockdep-splat-in-put_task_struct.patch | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/debian/patches-rt/0057-sched-avoid-false-lockdep-splat-in-put_task_struct.patch b/debian/patches-rt/0057-sched-avoid-false-lockdep-splat-in-put_task_struct.patch new file mode 100644 index 000000000..9da36bc08 --- /dev/null +++ b/debian/patches-rt/0057-sched-avoid-false-lockdep-splat-in-put_task_struct.patch @@ -0,0 +1,52 @@ +From 5c27e6fdf46d68180a46fdf7944aa7e4668680c3 Mon Sep 17 00:00:00 2001 +From: Wander Lairson Costa <wander@redhat.com> +Date: Wed, 14 Jun 2023 09:23:22 -0300 +Subject: [PATCH 57/62] sched: avoid false lockdep splat in put_task_struct() +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.1/older/patches-6.1.69-rt21.tar.xz + +In put_task_struct(), a spin_lock is indirectly acquired under the kernel +stock. When running the kernel in real-time (RT) configuration, the +operation is dispatched to a preemptible context call to ensure +guaranteed preemption. However, if PROVE_RAW_LOCK_NESTING is enabled +and __put_task_struct() is called while holding a raw_spinlock, lockdep +incorrectly reports an "Invalid lock context" in the stock kernel. + +This false splat occurs because lockdep is unaware of the different +route taken under RT. To address this issue, override the inner wait +type to prevent the false lockdep splat. + +Signed-off-by: Wander Lairson Costa <wander@redhat.com> +Suggested-by: Oleg Nesterov <oleg@redhat.com> +Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Suggested-by: Peter Zijlstra <peterz@infradead.org> +Cc: Steven Rostedt <rostedt@goodmis.org> +Cc: Luis Goncalves <lgoncalv@redhat.com> +Link: https://lore.kernel.org/r/20230614122323.37957-3-wander@redhat.com +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +(cherry picked from commit a5e446e728e89d5f5c5e427cc919bc7813c64c28) +Signed-off-by: Clark Williams <clark.williams@gmail.com> +--- + include/linux/sched/task.h | 6 +++++- + 1 file changed, 5 insertions(+), 1 deletion(-) + +diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h +index 7291fb6399d2..de7ebd2bf3ba 100644 +--- a/include/linux/sched/task.h ++++ b/include/linux/sched/task.h +@@ -141,8 +141,12 @@ static inline void put_task_struct(struct task_struct *t) + */ + if (IS_ENABLED(CONFIG_PREEMPT_RT) && !preemptible()) + call_rcu(&t->rcu, __put_task_struct_rcu_cb); +- else ++ else { ++ static DEFINE_WAIT_OVERRIDE_MAP(put_task_map, LD_WAIT_SLEEP); ++ lock_map_acquire_try(&put_task_map); + __put_task_struct(t); ++ lock_map_release(&put_task_map); ++ } + } + + static inline void put_task_struct_many(struct task_struct *t, int nr) +-- +2.43.0 + |