Subject: Re: Simple way to panic arm kernels
To: Steve Woodford <firstname.lastname@example.org>
From: Richard Earnshaw <Richard.Earnshaw@arm.com>
Date: 04/26/2004 10:44:56
On Mon, 2004-04-26 at 10:42, Steve Woodford wrote:
> On Monday 26 April 2004 10:17 am, Richard Earnshaw wrote:
> > On Sun, 2004-04-25 at 21:50, Richard Earnshaw wrote:
> > > I've finally managed to track this down to revision 1.8 of
> > > arch/arm/include/arm32/frame.h
> > A 'current' kernel with frame.h backed off to revision 1.7 ran the
> > above test for 9 hours last night without panicing. That's about 9
> > times longer than I've ever seen a broken kernel manage.
> Thanks for tracking this down. I'll look into the problem RSN.
> Cheers, Steve
I think I've spotted the difference in behaviour.
The change is in the case where we are NOT returning to user mode. In
that case the new sequence completes with IRQs preserved in the new
code, but blocked in the old.