7.0 CURRENT kernel's ath driver causes page fault, kernel panic (debugging kernel)

[Garrett Cooper]

On Sat, Jul 19, 2008 at 8:57 AM, Edward Ruggeri <smallhand at crawblog.com> wrote:
> On Fri, Jul 18, 2008 at 7:29 PM, Edward Ruggeri <smallhand at crawblog.com> wrote:
>>> As for the actual debug process, there's a spot in the dev handbook
>>> about it (http://www.freebsd.org/doc/en/books/developers-handbook/kerneldebug.html),
>>> but when I tried debugging my issue with NTFS and SMB I didn't really
>>> find it helpful to be honest...
>
> AND
>
>>> You may also have to compile without SMP and with the 4BSD scheduler
>>> just to see whether or not it's an issue reproducible with the ULE
>>> scheduler, the driver, or something else...
>
> I have a couple dumps now, with different kernel configurations.  In
> addition to the debugging options Garrett has recommended, I've
> switched from the ULE to the 4BSD scheduler and removed SMP support.
> The error persists.
>
> The backtrace in kgdb says that panic is called from the function
> ath_start at line 1748 in ath_start.c.  Here is a snippet:
>
> bf = STAILQ_FIRST(&frags);
> KASSERT(bf != NULL, ("no buf for txfrag"));
>
> Does that sound like enough to file a problem report with?  What other
> information would be desired?

You might want to first update the kernel and userland to 7-RELENG
first. If the issue persists in 7-RELENG, I'd file a PR. Regardless of
whether or not the issue persists I would contact the maintainer to
let them know about the bug.
Cheers,
-Garrett