1 files changed, 12 insertions, 0 deletions
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index 10d90d1783..88dda9cd39 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -244,7 +244,19 @@ void qemu_set_nonblock(int fd)
     f = fcntl(fd, F_GETFL);
     assert(f != -1);
     f = fcntl(fd, F_SETFL, f | O_NONBLOCK);
+#ifdef __OpenBSD__
+    if (f == -1) {
+        /*
+         * Previous to OpenBSD 6.3, fcntl(F_SETFL) is not permitted on
+         * memory devices and sets errno to ENODEV.
+         * It's OK if we fail to set O_NONBLOCK on devices like /dev/null,
+         * because they will never block anyway.
+         */
+        assert(errno == ENODEV);
+    }
+#else
     assert(f != -1);
+#endif
 }
 
 int socket_set_fast_reuse(int fd)