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

From: Christoph Lameter
Date: Wed Apr 23 2008 - 15:05:19 EST


On Wed, 23 Apr 2008, Pekka Enberg wrote:

> fault = check_bytes(start + length, POISON_INUSE, remainder);

fault == NULL if the check was successful. Otherwise it contains the first
address that does not match our expectations.

> if (!fault)
> return 1;
> while (end > fault && end[-1] == POISON_INUSE)
> end--;
>
> slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1);
>
> So how come we're printing out 'fault' as zero and 'end' at 4 GB? Christoph?

We should have returned from the function and not printed this message. If
we somehow skipped the test for !fault then end could have wrapped around
which gets us to 4GB.


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/