From: Ingo Molnar Date: Wed, 25 Jan 2006 18:50:12 +0000 (+0100) Subject: [PATCH] rcu_torture_lock deadlock fix X-Git-Tag: v2.6.16-rc2~246 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=adac1665234dd966990af846eccd20b7f4923279;p=linux-2.6 [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 Acked-by: Paul E. McKenney Signed-off-by: Linus Torvalds --- diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index 773219907d..7712912dbc 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -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