[PATCH 2/2] winebus: ignore udev events of devices which do not have devnodes

[Tuomas Räsänen]

From: Tuomas Räsänen

Udev monitor monitors the whole input subsystem, but not all devices
in the input subsystem have devnodes associated to them.

This commit makes the event processing ignore such devices.

All device handling assumes devices have devnodes, so here we just
simply ignore all devices which do not have one.

Previously, udev bus thread aborted when an event for a device without
a devnode was processed:

10111.330:0068:0084:trace:hid:process_monitor_event Received action "remove" for udev device (null)
  10111.330:0068:0084:warn:hid:bus_main_thread L"UDEV" bus wait returned status 0xc0000005

Just plugging in and out a normal mouse was enough cause this.

This was because root input devices (which do not have devnodes) were
handled too and find_device_from_devnode() choked on NULL argument.
---
 dlls/winebus.sys/bus_udev.c | 34 +++++++++++++++++++++++++++++-----
 1 file changed, 29 insertions(+), 5 deletions(-)

diff --git a/dlls/winebus.sys/bus_udev.c b/dlls/winebus.sys/bus_udev.c
index 228d9d8316d..48565ea4d6e 100644
--- a/dlls/winebus.sys/bus_udev.c
+++ b/dlls/winebus.sys/bus_udev.c
@@ -1717,6 +1717,8 @@ static void process_monitor_event(struct udev_monitor *monitor)
     struct base_device *impl;
     struct udev_device *dev;
     const char *action;
+    const char *devnode;
+    const char *syspath;

dev = udev_monitor_receive_device(monitor);
     if (!dev)
@@ -1726,20 +1728,42 @@ static void process_monitor_event(struct udev_monitor *monitor)
     }

action = udev_device_get_action(dev);
-    TRACE("Received action %s for udev device %s\n", debugstr_a(action),
-          debugstr_a(udev_device_get_devnode(dev)));
+    syspath = udev_device_get_syspath(dev);
+    devnode = udev_device_get_devnode(dev);
+    TRACE("Received action %s for udev device %s (%p) devnode %s\n",
+          debugstr_a(action), debugstr_a(syspath), dev, debugstr_a(devnode));
+
+    if (!syspath)
+    {
+        FIXME("udev device %p does not have syspath!\n", dev);
+        goto out;
+    }

if (!action)
-        WARN("No action received\n");
-    else if (strcmp(action, "remove"))
+    {
+        WARN("event for udev device %s does not have any action!\n", syspath);
+        goto out;
+    }
+
+    if (!devnode)
+    {
+        // Pretty normal case, not all devices have associated
+        // devnodes. For example root input devices do not, but
+        // related/child mouse and event devices do.
+        TRACE("udev device %s does not have devnode, ignoring\n", syspath);
+        goto out;
+    }
+
+    if (strcmp(action, "remove"))
         udev_add_device(dev, -1);
     else
     {
-        impl = find_device_from_devnode(udev_device_get_devnode(dev));
+        impl = find_device_from_devnode(devnode);
         if (impl) bus_event_queue_device_removed(&event_queue, &impl->unix_device);
         else WARN("failed to find device for udev device %p\n", dev);
     }

+out:
     udev_device_unref(dev);
 }