locking against myself

[Jerry Toung]

Thanks a lot Andrey.

On Thursday 19 February 2004 12:05 am, Andrey Simonenko wrote:
> On Wed, Feb 18, 2004 at 11:52:26AM -0800, Jerry Toung wrote:
> > Hello hackers,
> > I am constantly getting the following message when I run my KLD:
> >
> > panic: lockmgr: locking against myself
> > Debugger("panic")
> > Stopped at		Debugger+0x54:		xchgl		%ebx,in_Debugger.0
> > db>
> >
> > What could possibly cause this?
> > It seem to say that I'm locking an already locked variable.
>
> Hello Jerry,
>
> According to kern/kern_lock.c:lockmgr() your proc/thread already
> has an exclusive lock and it tries to obtain a recursive exclusive
> lock and lock doesn't have LK_CANRECURSE flag (also you allow to
> sleep in lockmng()).
>
> This is documented in lock(9) manual page:
>
>        LK_EXCLUSIVE    Acquire an exclusive lock.  If an exclusive
> 		       lock is already held, and LK_CANRECURSE is not
> 		       set, the system will panic(9).

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