From mboxrd@z Thu Jan  1 00:00:00 1970
From: Pekka Enberg <penberg@kernel.org>
Subject: Re: ia64 dies in slab code on next-20120906
Date: Mon, 10 Sep 2012 09:59:26 +0300 (EEST)
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References: <CA+8MBbKmaaiEJ363E2PU-=6KJ4u+ZsQ1ywjb0nWMrp4xaSCeLw@mail.gmail.com> <20120907112606.7d09e84c4782b748a95e1946@canb.auug.org.au> <00000139a722a761-bafedf19-81a0-4922-a522-a2bb0fbb951a-000000@email.amazonses.com>
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To: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Christoph Lameter <cl@linux.com>, Tony Luck <tony.luck@intel.com>, linux-next@vger.kernel.org, Sedat Dilek <sedat.dilek@gmail.com>, Hugh Dickins <hughd@google.com>

On Mon, 10 Sep 2012, Stephen Rothwell wrote:

> Hi Christoph,
> 
> On Sat, 8 Sep 2012 18:27:10 +0000 Christoph Lameter <cl@linux.com> wrote:
> >
> > Thanks Tony for the additional information regarding the pointer. That got
> > me thinking about something different.
> > 
> > Try the following fix:
> > 
> > Subject: slub: Zero initial memory segment for kmem_cache and kmem_cache_node
> > 
> > Earlier patches in the common set moved the zeroing of the kmem_cache structure
> > into common code. See "Move allocation of kmem_cache into common code".
> > 
> > The allocation for the two special structures is still done
> > from slub specific code but no zeroing is done since the cache creation functions
> > used to zero. This now needs to be updated so that the structures
> > are zeroed during allocation in kmem_cache_init().
> > Otherwise random pointer values may be followed.
> > 
> > Signed-off-by: Christoph Lameter <cl@linux.com>
> > 
> > Index: linux/mm/slub.c
> > ===================================================================
> > --- linux.orig/mm/slub.c	2012-09-08 13:21:33.523056357 -0500
> > +++ linux/mm/slub.c	2012-09-08 13:22:12.483056947 -0500
> > @@ -3705,7 +3705,7 @@
> >  	/* Allocate two kmem_caches from the page allocator */
> >  	kmalloc_size = ALIGN(kmem_size, cache_line_size());
> >  	order = get_order(2 * kmalloc_size);
> > -	kmem_cache = (void *)__get_free_pages(GFP_NOWAIT, order);
> > +	kmem_cache = (void *)__get_free_pages(GFP_NOWAIT|__GFP_ZERO, order);
> > 
> >  	/*
> >  	 * Must first have the slab cache available for the allocations of the
> > 
> 
> I have added this as a merge fix patch to linux-next today in the
> anticipation that it will be added to the slab tree ASAP.

I've applied the patch. Thanks everyone!