Re: 2.6.25-git2: BUG: unable to handle kernel paging request at ffffffffffffffff

[David Miller <davem@davemloft.net>]

From: Jiri Slaby <jirislaby@gmail.com>
Date: Fri, 25 Apr 2008 09:41:12 +0200

> Added 3 80211 experts.
> 
> On 04/25/2008 03:57 AM, David Miller wrote:
> > From: Linus Torvalds <torvalds@linux-foundation.org>
> > Date: Thu, 24 Apr 2008 18:48:32 -0700 (PDT)
> > 
> >> But that 0xf0 definitely has shown up before. It's not the *only* 
> >> corruption, but it's definitely a very interesting pattern. And the other 
> >> ones that didn't show the 0xf0 pattern could obviously be due to pointers 
> >> that were corrupted by 0xf0 in low bytes, so it _may_ be the source of the 
> >> other corruptions too that didn't have an obvious 0xf0 directly in them.
> > 
> > Ok.
> > 
> > Do we know of any pattern of the wireless device type in use?
> > If there is a pattern to that, it would be a huge clue.
> > 
> > And if it is predominantly one particular wireless device type, we
> > should be able to come up with a patch to test.
> 
> Johannes, Michael, Jiri? Someone writes to freed memory patterns 0xf0 (not 
> aligned to anything, addressed per byte), one of suspects is mac80211, don't you 
> know that pattern from anywhere?

I notice Jiri, in your hardware list, you have an ath5k Atheros AR5212 chip
in there.

I took a look at the resume code for ath5k but nothing really suspicious
there except:

	err = pci_enable_device(pdev);
	if (err)
		return err;

	pci_restore_state(pdev);

Shouldn't we restore state before we turn the chip back on and thus
potentially let it start DMA'ing all over the place?