diff options
| -rw-r--r-- | kernel/bpf/rqspinlock.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/kernel/bpf/rqspinlock.c b/kernel/bpf/rqspinlock.c index e35b06fcf9ee..f7d0c8d4644e 100644 --- a/kernel/bpf/rqspinlock.c +++ b/kernel/bpf/rqspinlock.c @@ -437,6 +437,19 @@ int __lockfunc resilient_queued_spin_lock_slowpath(rqspinlock_t *lock, u32 val) * queuing. */ queue: + /* + * Do not queue if we're a waiter and someone is attempting this lock on + * the same CPU. In case of NMIs, this prevents long timeouts where we + * interrupt the pending waiter, and the owner, that will eventually + * signal the head of our queue, both of which are logically but not + * physically part of the queue, hence outside the scope of the idx > 0 + * check above for the trylock fallback. + */ + if (check_deadlock_AA(lock)) { + ret = -EDEADLK; + goto err_release_entry; + } + lockevent_inc(lock_slowpath); /* Deadlock detection entry already held after failing fast path. */ node = this_cpu_ptr(&rqnodes[0].mcs); |