kern/47682: panic in ohci_free_std

[Simon Burge <simonb%NetBSD.org@localhost>]

>Number:         47682
>Category:       kern
>Synopsis:       panic in ohci_free_std
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Mar 22 09:45:00 +0000 2013
>Originator:     Simon Burge
>Release:        NetBSD 6.0
>Organization:
>Environment:
        System: NetBSD athlon.thistledown.com.au 6.0 NetBSD 6.0 (THOREAU) #0: 
Sat Nov 24 09:37:16 EST 2012 
simonb%thoreau.thistledown.com.au@localhost:/NetBSD/src6/sys/arch/amd64/compile/THOREAU
 amd64
        Architecture: x86_64
        Machine: amd64
>Description:
        I have a program that opens a usb temperature device via the
        ugen driver, and after a "while" (anywhere from a day or two up
        to two or so weeks) I get the following panic (via ten finger
        copy):

                uvm_fault(...)
                fatal page fault in supervisor mode
                trap type 6 code 0 ...
                kernel: page fault trap, code=0
                ..
                ohci_free.std.clone.3() at netbsd:ohci_free.std.clone.3+0x17
                ohci_device_ctrl_start() ...
                usbd_transfer() ...
                usbd_do_request_flags_pipe() ...
                usbd_do_request_flags() ...
                ugenioctl() ...
                cdev_ioctl() ...
                VOP_IOCTL() ...
                vn_ioctl() ...
                sys_ioctl() ...
                syscall() ..
                db{1} >

        Note that the USB keyboard doesn't work in ddb, so please
        don't ask for more from ddb unless I can squeeze it into
        ddb.commandonenter.

>How-To-Repeat:
        Repeatedly open a ugen device?

>Fix:
        Non given.