PROBLEM: memory corrupting bug, bisected to 6dda9d55

[Thomas Gleixner]

On Mon, 18 Oct 2010, Andrew Morton wrote:

> On Mon, 18 Oct 2010 12:33:31 +0100
> Mel Gorman <mel at csn.ul.ie> wrote:
> 
> > A bit but I still don't know why it would cause corruption. Maybe this is still
> > a caching issue but the difference in timing between list_add and list_add_tail
> > is enough to hide the bug. It's also possible there are some registers
> > ioremapped after the memmap array and reading them is causing some
> > problem.
> > 
> > Andrew, what is the right thing to do here? We could flail around looking
> > for explanations as to why the bug causes a user buffer corruption but never
> > get an answer or do we go with this patch, preferably before 2.6.36 releases?
> 
> Well, you've spotted a bug so I'd say we fix it asap.
> 
> It's a bit of a shame that we lose the only known way of reproducing a
> different bug, but presumably that will come back and bite someone else
> one day, and we'll fix it then :(

I might be completely one off as usual, but this thing reminds me of a
bug I stared at yesterday night:

    http://permalink.gmane.org/gmane.linux.kernel/1049605

Reporter Cc'ed

Thanks,

	tglx