Re: 2.5.1-pre5 not easy to boot with devfs

Richard Gooch
2001-12-01T07:01:47Z

Linus Torvalds writes:
> In article <3C085FF3.813BAA57@wanadoo.fr>,
> Pierre Rousselet <pierre.rousselet@wanadoo.fr> wrote:
> >As far as I can see,
> >
> >when CONFIG_DEBUG_KERNEL is set
> > and
> >when devfsd is started at boot time
> >I get an Oops when remounting, rw the root fs :
> >
> >Unable to handle kernel request at va 5a5a5a5e
>
> POISON_BYTE is 0x5a. Something in devfs is using a pointer from a data
> structure that was already free'd, and was thus corrupted by poisoning.
>
> (the above is almost certainly just a pointer dereference off 0x5a5a5a5a
> with an offset of 4 for some entry at the beginning of a structure,
> which is why you get the final "5e" in the page fault address).
>
> >It boots OK with devfsd when CONFIG_DEBUG_KERNEL is not set.
> >It boots OK without devfsd when CONFIG_DEBUG_KERNEL is set (then devfsd
> >can be started after login).
>
> Well, not poisoning the free'd memory makes it "work" only in the sense
> that usually the free'd memory hasn't been re-allocated yet, so you
> don't see the bug even if it is still there.
>
> Richard Gooch probably wants a full stack trace, with symbols. Which
> should show it fairly clearly. At least EIP and the first few "stack
> trace" entries..

Indeed I do. Please Cc: me on devfs related stuff. And please apply
devfs-patch-v200, which fixes a stupid typo. I'd also be interested in
knowing the behaviour with 2.4.17-pre1.

I also need your full .config and boot messages. And booting with
"devfs=dall" is required as well.

Regards,

Richard....
Permanent: rgooch@atnf.csiro.au
Current: rgooch@ras.ucalgary.ca