From f3b05a74bbff88e0d1b7310618f10b6c2f85ea32 Mon Sep 17 00:00:00 2001
From: Xiang Fan <sfanxiang@gmail.com>
Date: Sun, 21 Jan 2018 00:14:49 +0800
Subject: [PATCH] kernel: devfs: don't notify output-only select events by
 default

Output-only events (B_EVENT_ERROR, B_EVENT_DISCONNECTED and
B_EVENT_INVALID, with B_EVENT_INVALID masked out before passing down
events) are used to indicate error, so they should not be notified if
the device does not have Select().

Bug: 13965
---
 src/system/kernel/device_manager/devfs.cpp | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/system/kernel/device_manager/devfs.cpp b/src/system/kernel/device_manager/devfs.cpp
index c0139f3fe3..4fc5d3102d 100644
--- a/src/system/kernel/device_manager/devfs.cpp
+++ b/src/system/kernel/device_manager/devfs.cpp
@@ -35,6 +35,7 @@
 #include <util/AutoLock.h>
 #include <vfs.h>
 #include <vm/vm.h>
+#include <wait_for_objects.h>
 
 #include "BaseDevice.h"
 #include "FileDevice.h"
@@ -1552,8 +1553,12 @@ devfs_select(fs_volume* _volume, fs_vnode* _vnode, void* _cookie,
 		return B_NOT_ALLOWED;
 
 	// If the device has no select() hook, notify select() now.
-	if (!vnode->stream.u.dev.device->HasSelect())
-		return notify_select_event((selectsync*)sync, event);
+	if (!vnode->stream.u.dev.device->HasSelect()) {
+		if (!SELECT_TYPE_IS_OUTPUT_ONLY(event))
+			return notify_select_event((selectsync*)sync, event);
+		else
+			return B_OK;
+	}
 
 	return vnode->stream.u.dev.device->Select(cookie->device_cookie, event,
 		(selectsync*)sync);