commit d366828bcc93f5411671f8815fbc78066549a84c
Author: evangyzen <eric_van_gyzen@dell.com>
Date:   Sun Feb 22 14:19:07 2015 -0500

    Propagate errors from _thr_umutex_unlock2 through mutex_unlock_common
    
    Errors from _thr_umutex_unlock2 should "never happen" in normal
    circumstances.  If they do, however, return them to the application
    so it can fail early and loudly.  Hiding the errors will only delay
    the inevitable failure, making it harder to find and diagnose.
    
    Submitted by: Eric van Gyzen <eric_van_gyzen@dell.com>
    Obtained from: Dell Inc.

diff --git a/lib/libthr/thread/thr_mutex.c b/lib/libthr/thread/thr_mutex.c
index 61ff077..26e8776 100644
--- a/lib/libthr/thread/thr_mutex.c
+++ b/lib/libthr/thread/thr_mutex.c
@@ -633,7 +633,7 @@ mutex_unlock_common(struct pthread_mutex *m, int cv, int *mtx_defer)
 {
 	struct pthread *curthread = _get_curthread();
 	uint32_t id;
-	int defered;
+	int defered, error;
 
 	if (__predict_false(m <= THR_MUTEX_DESTROYED)) {
 		if (m == THR_MUTEX_DESTROYED)
@@ -647,6 +647,7 @@ mutex_unlock_common(struct pthread_mutex *m, int cv, int *mtx_defer)
 	if (__predict_false(m->m_owner != curthread))
 		return (EPERM);
 
+	error = 0;
 	id = TID(curthread);
 	if (__predict_false(
 		PMUTEX_TYPE(m->m_flags) == PTHREAD_MUTEX_RECURSIVE &&
@@ -660,7 +661,7 @@ mutex_unlock_common(struct pthread_mutex *m, int cv, int *mtx_defer)
 			defered = 0;
 
 		DEQUEUE_MUTEX(curthread, m);
-		_thr_umutex_unlock2(&m->m_lock, id, mtx_defer);
+		error = _thr_umutex_unlock2(&m->m_lock, id, mtx_defer);
 
 		if (mtx_defer == NULL && defered)  {
 			_thr_wake_all(curthread->defer_waiters,
@@ -670,7 +671,7 @@ mutex_unlock_common(struct pthread_mutex *m, int cv, int *mtx_defer)
 	}
 	if (!cv && m->m_flags & PMUTEX_FLAG_PRIVATE)
 		THR_CRITICAL_LEAVE(curthread);
-	return (0);
+	return (error);
 }
 
 int