3.12.38-rt53-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Gustavo Bittencourt <gbitten@xxxxxxxxx> 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@xxxxxxxxxxxxxxx Signed-off-by: Gustavo Bittencourt <gbitten@xxxxxxxxx> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> --- kernel/rtmutex.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c index 76cb88027fc2..e8a6555a670a 100644 --- a/kernel/rtmutex.c +++ b/kernel/rtmutex.c @@ -2166,7 +2166,8 @@ __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) @@ -2184,7 +2185,8 @@ __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) -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe stable-rt" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
