[PATCH v5 0/1] MR5385: winebus: ignore udev events of devices which do not have devnodes

[Tuomas Räsänen (＠tuomasjjrasanen)]

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

This MR 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. They are irrelevant.

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.

--
  v5: winebus: ignore udev events of devices which do not have devnodes

https://gitlab.winehq.org/wine/wine/-/merge_requests/5385

[PATCH v5 1/1] 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 | 28 ++++++++++++++++++++--------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/dlls/winebus.sys/bus_udev.c b/dlls/winebus.sys/bus_udev.c
index 419de2e7af3..2cd995a4178 100644
--- a/dlls/winebus.sys/bus_udev.c
+++ b/dlls/winebus.sys/bus_udev.c
@@ -1710,26 +1710,38 @@ static void process_monitor_event(struct udev_monitor *monitor)
 {
     struct base_device *impl;
     struct udev_device *dev;
-    const char *action;
+    const char *action, *devnode, *syspath;

dev = udev_monitor_receive_device(monitor);
     if (!dev)
     {
-        FIXME("Failed to get device that has changed\n");
+        ERR("Failed to get device that has changed\n");
         return;
     }

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)));
-
-    if (!action)
-        WARN("No action received\n");
+    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)
+        ERR("udev device %p does not have syspath!\n", dev);
+    else if (!action)
+        ERR("event for udev device %s does not have any action!\n", syspath);
+    else 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);
+    }
     else 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);
     }

[Tuomas Räsänen (＠tuomasjjrasanen)]

On Tue Mar 26 09:55:05 2024 +0000, Tuomas Räsänen wrote:
> changed this line in [version 5 of the diff](/wine/wine/-/merge_requests/5385/diffs?diff_id=107188&start_sha=de37140811ab6b769232a13f6a7ceb9c23b399d4#ebaa042208adccc6698dd3a945f8af16313b1b63_272_267)

Dropped.

[Tuomas Räsänen (＠tuomasjjrasanen)]

On Mon Mar 25 18:55:49 2024 +0000, Tuomas Räsänen wrote:
> I just fixed the commit to not use "on error goto out" -pattern but use
> ERR for `!syspath` case.
> I also added a commit which changes WARN to ERR on in `!action` case.

All changes squashed together into a single commit.

[PATCH v5 0/1] MR5385: winebus: ignore udev events of devices which do not have devnodes - approved

[Rémi Bernon (＠rbernon)]

This merge request was approved by Rémi Bernon.