[PATCH]locking:mutex Print warning if trylock in irq context

[gaurav jindal]

Since mutex_trylock must not be called from interrupt context, a robustness
can be added to this function by throwing a warning if it is called in
interrupt context.
It would help to make debugging easier in case of undesired calling of this
function.

Signed-off-by: gaurav jindal<gauravjindal1...@gmail.com>

---

diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index 858a075..fe1cace 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -1176,7 +1176,10 @@ void __sched mutex_lock_io(struct mutex *lock)
  */
 int __sched mutex_trylock(struct mutex *lock)
 {
-       bool locked = __mutex_trylock(lock);
+       bool locked;
+
+       WARN_ONCE(in_irq(), "%s wrongly called in irq context", __func__);
+       locked = __mutex_trylock(lock);

        if (locked)
                mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_);