Panic in 6.2-PRERELEASE with bge on amd64

[John Baldwin]

On Monday 08 January 2007 00:06, Bruce Evans wrote:
> On Sun, 7 Jan 2007, Sven Willenberger wrote:
> 
> > I am starting a new thread on this as what I had assumed was a panic in
> > nfsd turns out to be an issue with the bge driver. This is an amd64 box,
> > dual processor (SMP kernel) that happens to be running nfsd. About every
> > 3-5 days the kernel panics and I have finally managed to get a core
> > dump.
> > The system: FreeBSD 6.2-PRERELEASE #8: Tue Jan  2 10:57:39 EST 2007
> 
> Like most NIC drivers, bge unlocks and re-locks around its call to
> ether_input() in its interrupt handler.  This isn't very safe, and it
> certainly causes panics for bge.  I often see it panic when bringing
> the interface down and up while input is arriving, on a non-SMP non-amd64
> (actually i386) non-6.x (actually -current) system.  Bringing the
> interface down is probably the worst case.  It creates a null pointer
> for bge_intr() to follow.

Why do you feel that it is unsafe to drop the lock around if_input()?

-- 
John Baldwin