kern/59182: ugen(4) should always attach with device-specific drivers as children

[campbell+netbsd%mumble.net@localhost]

>Number:         59182
>Category:       kern
>Synopsis:       ugen(4) should always attach with device-specific drivers as children
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Mar 16 15:55:00 +0000 2025
>Originator:     Taylor R Campbell
>Release:        current, 10, 9, ...
>Organization:
The NetUSB Generation
>Environment:
>Description:
ugen(4) should always attach, with device-specific drivers attaching as children, so that userland can always do certain ugen(4) ioctls like getting device descriptors, and it should sprout a new ioctl command for userland to claim the device and kick out the kernel driver if needed.
>How-To-Repeat:
try to use tools like usbgen(8) from sysutils/usbutil to print the device descriptors of a USB device with a kernel driver, or generally try to get userland access to a device that has a kernel driver without rebooting
>Fix:
Yes, please!