Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb

Eric Dumazet
2011-04-20T14:26:36Z

Le mercredi 20 avril 2011 à 09:05 -0500, Christoph Lameter a écrit :
> On Wed, 20 Apr 2011, Eric Dumazet wrote:
>
> > > Then, just disable SLUB_CMPXCHG_DOUBLE if KMEMCHECK is defined, as I did in my first patch.
>
> Ok your first patch seems to be the sanest approach.
>
> > {
> > @@ -1889,16 +1895,18 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
> > struct kmem_cache_cpu *c;
> > #ifdef CONFIG_CMPXCHG_LOCAL
> > unsigned long tid;
> > -#else
> > +#endif
> > +#ifdef MASK_IRQ_IN_SLAB_ALLOC
> > unsigned long flags;
> > #endif
> >
>
> Yea well that does not bring us much.

Well, we keep the fast free path ?

only slab_alloc() would have to disable irqs for ~20 instructions.