Index: sys/kern/kern_umtx.c
===================================================================
--- sys/kern/kern_umtx.c
+++ sys/kern/kern_umtx.c
@@ -2262,6 +2262,21 @@
 			break;
 		}
 
+		/*
+		 * Nobody owns it, but the acquire failed. On architectures
+		 * that implement casueword32 using Load Linked/Store
+		 * Conditional operations it may have failed due to another
+		 * thread acquiring the mutex or because of to a store to a
+		 * different address. Check for pending signals and
+		 * retry the operation.
+		 */
+		if (owner == UMUTEX_UNOWNED) {
+			error = thread_check_susp(td, true);
+			if (error != 0)
+				break;
+			continue;
+		}
+
 		/*
 		 * Avoid overwriting a possible error from sleep due
 		 * to the pending signal with suspension check result.