locking/mutex: Add p->blocked_on wrappers for correctness checks

This lets us assert mutex::wait_lock is held whenever we access
p->blocked_on, as well as warn us for unexpected state changes.

[fix conflicts, call in more places]
[jstultz: tweaked commit subject, reworked a good bit]
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Connor O'Brien <connoro@google.com>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://lkml.kernel.org/r/20250712033407.2383110-4-jstultz@google.com
This commit is contained in:
Valentin Schneider
2025-07-12 03:33:44 +00:00
committed by Peter Zijlstra
parent 44e4e0297c
commit a4f0b6fef4
4 changed files with 81 additions and 27 deletions

View File

@@ -54,13 +54,13 @@ void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
lockdep_assert_held(&lock->wait_lock);
/* Current thread can't be already blocked (since it's executing!) */
DEBUG_LOCKS_WARN_ON(task->blocked_on);
DEBUG_LOCKS_WARN_ON(__get_task_blocked_on(task));
}
void debug_mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
struct task_struct *task)
{
struct mutex *blocked_on = READ_ONCE(task->blocked_on);
struct mutex *blocked_on = __get_task_blocked_on(task);
DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
DEBUG_LOCKS_WARN_ON(waiter->task != task);