[PATCH] rcu_torture_lock deadlock fix

rcu_torture_lock is used in a softirq-unsafe manner, but it is also
taken by rcu_torture_cb(), which may execute in softirq-context,
resulting in potential deadlocks.

The fix is to acquire rcu_torture_lock in a softirq-safe manner.  With
this fix applied, the rcu-torture code passes validation.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Ingo Molnar 2006-01-25 19:50:12 +01:00 committed by Linus Torvalds
parent f6bc2666ed
commit adac166523

View file

@ -114,16 +114,16 @@ rcu_torture_alloc(void)
{
struct list_head *p;
spin_lock(&rcu_torture_lock);
spin_lock_bh(&rcu_torture_lock);
if (list_empty(&rcu_torture_freelist)) {
atomic_inc(&n_rcu_torture_alloc_fail);
spin_unlock(&rcu_torture_lock);
spin_unlock_bh(&rcu_torture_lock);
return NULL;
}
atomic_inc(&n_rcu_torture_alloc);
p = rcu_torture_freelist.next;
list_del_init(p);
spin_unlock(&rcu_torture_lock);
spin_unlock_bh(&rcu_torture_lock);
return container_of(p, struct rcu_torture, rtort_free);
}
@ -134,9 +134,9 @@ static void
rcu_torture_free(struct rcu_torture *p)
{
atomic_inc(&n_rcu_torture_free);
spin_lock(&rcu_torture_lock);
spin_lock_bh(&rcu_torture_lock);
list_add_tail(&p->rtort_free, &rcu_torture_freelist);
spin_unlock(&rcu_torture_lock);
spin_unlock_bh(&rcu_torture_lock);
}
static void