1 files changed, 13 insertions, 0 deletions

diff --git a/lib/libpthread/thread/thr_kill.c b/lib/libpthread/thread/thr_kill.c
index 7572c05faff7..c729179c3929 100644
--- a/lib/libpthread/thread/thr_kill.c
+++ b/lib/libpthread/thread/thr_kill.c
@@ -52,6 +52,13 @@ pthread_kill(pthread_t pthread, int sig)
 
 	/* Find the thread in the list of active threads: */
 	else if ((ret = _find_thread(pthread)) == 0) {
+		/*
+		 * Guard against preemption by a scheduling signal.
+		 * A change of thread state modifies the waiting
+		 * and priority queues.
+		 */
+		_thread_kern_sched_defer();
+
 		switch (pthread->state) {
 		case PS_SIGSUSPEND:
 			/*
@@ -108,6 +115,12 @@ pthread_kill(pthread_t pthread, int sig)
 			sigaddset(&pthread->sigpend,sig);
 			break;
 		}
+
+		/*
+		 * Reenable preemption and yield if a scheduling signal
+		 * occurred while in the critical region.
+		 */
+		_thread_kern_sched_undefer();
 	}
 
 	/* Return the completion status: */