2 files changed, 16 insertions, 0 deletions

diff --git a/lib/libkse/kse.map b/lib/libkse/kse.map
index 94f6dd958188..a6eed6980e67 100644
--- a/lib/libkse/kse.map
+++ b/lib/libkse/kse.map
@@ -256,6 +256,7 @@ FBSDprivate_1.0 {
 	_pthread_mutex_getprioceiling;
 	_pthread_mutex_init;
 	_pthread_mutex_init_calloc_cb;
+	_pthread_mutex_isowned_np;
 	_pthread_mutex_lock;
 	_pthread_mutex_setprioceiling;
 	_pthread_mutex_timedlock;
@@ -360,3 +361,7 @@ FBSDprivate_1.0 {
 	_thread_state_running;
 	_thread_state_zoombie;
 };
+
+FBSD_1.1 {
+	pthread_mutex_isowned_np;
+};
diff --git a/lib/libkse/thread/thr_mutex.c b/lib/libkse/thread/thr_mutex.c
index fe101c784313..fe733b1643be 100644
--- a/lib/libkse/thread/thr_mutex.c
+++ b/lib/libkse/thread/thr_mutex.c
@@ -36,6 +36,7 @@
 #include <sys/param.h>
 #include <sys/queue.h>
 #include <pthread.h>
+#include <pthread_np.h>
 #include "un-namespace.h"
 #include "thr_private.h"
 
@@ -127,6 +128,7 @@ __weak_reference(__pthread_mutex_trylock, pthread_mutex_trylock);
 /* No difference between libc and application usage of these: */
 __weak_reference(_pthread_mutex_destroy, pthread_mutex_destroy);
 __weak_reference(_pthread_mutex_unlock, pthread_mutex_unlock);
+__weak_reference(_pthread_mutex_isowned_np, pthread_mutex_isowned_np);
 
 static int
 thr_mutex_init(pthread_mutex_t *mutex,
@@ -1866,3 +1868,12 @@ mutex_queue_enq(pthread_mutex_t mutex, pthread_t pthread)
 	}
 	pthread->sflags |= THR_FLAGS_IN_SYNCQ;
 }
+
+int
+_pthread_mutex_isowned_np(pthread_mutex_t *mutex)
+{
+	struct pthread	*curthread = _get_curthread();
+
+	return ((*mutex)->m_owner == curthread);
+}
+