From 879803c90f8ab13bdb7436dfd966088e9b4d9d53 Mon Sep 17 00:00:00 2001
From: orbitcowboy <orbitcowboy@web.de>
Date: Tue, 25 Sep 2018 09:07:49 +0200
Subject: [PATCH] gnu.cfg: Fixed FP (nullpointer) when third parameter of
 epoll_ctl is set to NULL.

---
 cfg/gnu.cfg    |  1 -
 test/cfg/gnu.c | 14 ++++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/cfg/gnu.cfg b/cfg/gnu.cfg
index 223caef2f..f79789217 100644
--- a/cfg/gnu.cfg
+++ b/cfg/gnu.cfg
@@ -653,7 +653,6 @@
     </arg>
     <arg nr="4">
       <not-bool/>
-      <not-null/>
     </arg>
   </function>
   <!-- int epoll_wait(int epfd, struct epoll_event *events, int maxevents, int timeout); -->
diff --git a/test/cfg/gnu.c b/test/cfg/gnu.c
index 8b1127762..b97f181dd 100644
--- a/test/cfg/gnu.c
+++ b/test/cfg/gnu.c
@@ -8,6 +8,7 @@
 //
 
 #include <string.h>
+#include <sys/epoll.h>
 
 void bufferAccessOutOfBounds()
 {
@@ -37,3 +38,16 @@ void leakReturnValNotUsed()
     if (42 == __builtin_expect(42, 0))
         return;
 }
+
+int nullPointer_epoll_ctl(int epfd, int op, int fd, struct epoll_event *event)
+{
+    // no warning is expected
+    (void)epoll_ctl(epfd, op, fd, event);
+
+    // No nullpointer warning is expected in case op is set to EPOLL_CTL_DEL
+    //   EPOLL_CTL_DEL
+    //          Remove (deregister) the target file descriptor fd from the
+    //          epoll instance referred to by epfd.  The event is ignored and
+    //          can be NULL.
+    return epoll_ctl(epfd, EPOLL_CTL_DEL, fd, NULL);
+}