From d3700649c0c078ab0eaeb594a0df4e6ac5d90653 Mon Sep 17 00:00:00 2001
From: Yoshinori Sugino <ysgn0101@gmail.com>
Date: Fri, 6 Nov 2020 15:37:05 +0900
Subject: [PATCH] sched/sched/sched_waitid.c: Allow WNOHANG

In the current implementation of waitid, WEXITED is mandatory and WNOHANG is optional.
---
 sched/sched/sched_waitid.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/sched/sched/sched_waitid.c b/sched/sched/sched_waitid.c
index a03cbe2edb..b8fb630b9c 100644
--- a/sched/sched/sched_waitid.c
+++ b/sched/sched/sched_waitid.c
@@ -127,7 +127,12 @@ int nx_waitid(int idtype, id_t id, FAR siginfo_t *info, int options)
    * distinguish any other events.
    */
 
-  if (options != WEXITED)
+  if ((options & WEXITED) == 0)
+    {
+      return -ENOSYS;
+    }
+
+  if ((options & ~(WEXITED | WNOHANG)) != 0)
     {
       return -ENOSYS;
     }