Re: kmemcheck caught read from freed memory (cfq_free_io_context)

[Christoph Lameter]

On Wed, 2 Apr 2008, Pekka Enberg wrote:

> On Wed, Apr 2, 2008 at 2:08 PM, Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote:
> >  but what holds off the slab allocator re-issueing that same object and
> >  someone else writing other stuff into it?
> 
> Nothing. So you cannot access the object at all after you've called
> kmem_cache_free(). SLAB_RCU or no SLAB_RCU.

You can of course access the object. And if you establish a definite state 
of locks on free (and through a ctor) then its even okay to take locks.
 
--
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/