From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from
 uninitialized memory in __alloc_skb
Date: Wed, 20 Apr 2011 16:26:31 +0200
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References: <bug-33502-10286@https.bugzilla.kernel.org/>
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Cc: Pekka Enberg <penberg@cs.helsinki.fi>, casteyde.christian@free.fr,
	Andrew Morton <akpm@linux-foundation.org>,
	netdev@vger.kernel.org, bugzilla-daemon@bugzilla.kernel.org,
	bugme-daemon@bugzilla.kernel.org,
	Vegard Nossum <vegardno@ifi.uio.no>
To: Christoph Lameter <cl@linux.com>
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Le mercredi 20 avril 2011 =C3=A0 09:05 -0500, Christoph Lameter a =C3=A9=
crit :
> On Wed, 20 Apr 2011, Eric Dumazet wrote:
>=20
> > > Then, just disable SLUB_CMPXCHG_DOUBLE if KMEMCHECK is defined, a=
s I did in my first patch.
>=20
> Ok your first patch seems to be the sanest approach.
>=20
> >  {
> > @@ -1889,16 +1895,18 @@ static __always_inline void *slab_alloc(str=
uct 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
> >
>=20
> 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.