I am having a problem with passing LK_SPIN as a flag to lockmgr(). It
raises a panic in the following code section, src/sys/kern/kern_lock.c,
1.72, in lockmgr() (current kernel is compiled with diagnostic):

#ifdef DIAGNOSTIC /* { */
	/*
	 * Don't allow spins on sleep locks and don't allow sleeps
	 * on spin locks.
	 */
	if ((flags ^ lkp->lk_flags) & LK_SPIN)
		panic("lockmgr: sleep/spin mismatch");
#endif /* } */


The flag is LK_SPIN|LK_EXCLUSIVE|LK_RECURSEFAIL. lkp->lk_flags is equal
to 0. 
(LK_SPIN|LK_...) ^ 0 = (LK_SPIN|LK_...)
(LK_SPIN|LK_...) & LK_SPIN = nonzero
And so the panic is called.

I call lockinit using something similar to:
lockinit(lkp, prio, wmesg, (1 * hz), 0);

Which is why lkp->lk_flags is 0. I then call lockmgr with something
similar to:
lockmgr(lkp, LK_SPIN|LK_EXCLUSIVE|LK_RECURSEFAIL, NULL);

It seems perfectly legal to call lockinit() with a 0 flag. I need to do
this because the thread calling lockmgr() may need to sleep or spin
depending on the situation (the spin case is in a network ioctl for a
device: is sleeping safe?). Is this behaviour possible? I have not
actually found code in the tree that uses LK_SPIN though, so could this
be a genuine error that has not been found until now?

Should the code be:

#ifdef DIAGNOSTIC /* { */
	/*
	 * Don't allow spins on sleep locks and don't allow sleeps
	 * on spin locks.
	 */
	if (((flags|lkp->lk_flags) & LK_SPIN) && 
                ((flags|lkp->lk_flags) & LK_SLEEPFAIL)))
		panic("lockmgr: sleep/spin mismatch");
#endif /* } */

?

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