From eb9e99cbf79c494fc374644592f86430ee87c3a2 Mon Sep 17 00:00:00 2001 From: Gustavo Bittencourt Date: Tue, 20 Jan 2015 18:02:29 -0200 Subject: rtmutex: enable deadlock detection in ww_mutex_lock functions The functions ww_mutex_lock_interruptible and ww_mutex_lock should return -EDEADLK when faced with a deadlock. To do so, the paramenter detect_deadlock in rt_mutex_slowlock must be TRUE. This patch corrects potential deadlocks when running PREEMPT_RT with nouveau driver. Cc: stable-rt@vger.kernel.org Signed-off-by: Gustavo Bittencourt Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Steven Rostedt --- kernel/locking/rtmutex.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index 1794fae96a2a..27a1993111f9 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -2239,7 +2239,8 @@ __ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ww_c might_sleep(); mutex_acquire_nest(&lock->base.dep_map, 0, 0, &ww_ctx->dep_map, _RET_IP_); - ret = rt_mutex_slowlock(&lock->base.lock, TASK_INTERRUPTIBLE, NULL, 0, ww_ctx); + ret = rt_mutex_slowlock(&lock->base.lock, TASK_INTERRUPTIBLE, NULL, + RT_MUTEX_FULL_CHAINWALK, ww_ctx); if (ret) mutex_release(&lock->base.dep_map, 1, _RET_IP_); else if (!ret && ww_ctx->acquired > 1) @@ -2257,7 +2258,8 @@ __ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ww_ctx) might_sleep(); mutex_acquire_nest(&lock->base.dep_map, 0, 0, &ww_ctx->dep_map, _RET_IP_); - ret = rt_mutex_slowlock(&lock->base.lock, TASK_UNINTERRUPTIBLE, NULL, 0, ww_ctx); + ret = rt_mutex_slowlock(&lock->base.lock, TASK_UNINTERRUPTIBLE, NULL, + RT_MUTEX_FULL_CHAINWALK, ww_ctx); if (ret) mutex_release(&lock->base.dep_map, 1, _RET_IP_); else if (!ret && ww_ctx->acquired > 1) -- cgit v1.2.3