Kernel panic during boot in usb_add_task

Michael Neumann mneumann at
Wed Nov 28 07:53:35 PST 2007

Matthew Dillon wrote:
:More specifically:
:   *(head)->tqh_last = (elm);
:This expands to:
:   *(&taskq->tasks)->tgh_last = task;
:There a NULL pointer is dereferenced somehow.
     It looks like memory corruption.  USB may be issuing duplicate TAILQ
     operations on its taskq structure(s).
     Please try this patch.  If it doesn't work then one or more task
     structure is probably being ripped out from under the usb code,
     probably by somthing related to uhci_timeout() as you previously
     reported.  My guess is that uhci_detach() is ripping the structure
     out without waiting for the abort to finish but lets see if this
     patch has any effect first.
Thank you very much! An ISO image for testing it would be great, as I 
can't compile it myself (no DF system running). Hum, I don't want to ask 
for too much :). BTW, is it possible to cross-compile DF on FreeBSD?



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