commit 8a25d5debff2daee280e83e09d8c25d67c26a972
author Ingo Molnar <mingo@elte.hu> Mon Jul 03 00:24:54 2006 -0700
committer Linus Torvalds <torvalds@g5.osdl.org> Mon Jul 03 15:27:04 2006 -0700
tree 3bccfef9acb66fc62863bfd6c16493c5e8c8e394
parent 4ea2176dfa714882e88180b474e4cbcd888b70af

[PATCH] lockdep: prove spinlock rwlock locking correctness

Use the lock validator framework to prove spinlock and rwlock locking
correctness.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/sched.c

diff --git a/kernel/sched.c b/kernel/sched.c
index 9118299..ae4db01 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -308,6 +308,13 @@
 	/* this is a valid case when another task releases the spinlock */
 	rq->lock.owner = current;
 #endif
+	/*
+	 * If we are tracking spinlock dependencies then we have to
+	 * fix up the runqueue lock - which gets 'carried over' from
+	 * prev into current:
+	 */
+	spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_);
+
 	spin_unlock_irq(&rq->lock);
 }
 
@@ -1778,6 +1785,7 @@
 		WARN_ON(rq->prev_mm);
 		rq->prev_mm = oldmm;
 	}
+	spin_release(&rq->lock.dep_map, 1, _THIS_IP_);
 
 	/* Here we just switch the register state and the stack. */
 	switch_to(prev, next, prev);
@@ -4384,6 +4392,7 @@
 	 * no need to preempt or enable interrupts:
 	 */
 	__release(rq->lock);
+	spin_release(&rq->lock.dep_map, 1, _THIS_IP_);
 	_raw_spin_unlock(&rq->lock);
 	preempt_enable_no_resched();
 
@@ -4447,6 +4456,7 @@
 		spin_lock(lock);
 	}
 	if (need_resched() && __resched_legal()) {
+		spin_release(&lock->dep_map, 1, _THIS_IP_);
 		_raw_spin_unlock(lock);
 		preempt_enable_no_resched();
 		__cond_resched();