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From: Suren Baghdasaryan <surenb@google.com>
Date: Thu, 25 Apr 2024 20:46:13 -0700
Message-ID: <CAJuCfpGLZ88KMTH93gxfFC++AMCEcObyS1FG_S_w6Ce+koai9A@mail.gmail.com>
Subject: Re: [PATCH] mm/slub: Avoid recursive loop with kmemleak
To: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Andrew Morton <akpm@linux-foundation.org>, Kees Cook <keescook@chromium.org>, 
	Catalin Marinas <catalin.marinas@arm.com>, Christoph Lameter <cl@linux.com>, 
	Pekka Enberg <penberg@kernel.org>, David Rientjes <rientjes@google.com>, 
	Joonsoo Kim <iamjoonsoo.kim@lge.com>, Vlastimil Babka <vbabka@suse.cz>, 
	Roman Gushchin <roman.gushchin@linux.dev>, Hyeonggon Yoo <42.hyeyoo@gmail.com>, linux-mm@kvack.org, 
	linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
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On Thu, Apr 25, 2024 at 5:19=E2=80=AFPM Kent Overstreet
<kent.overstreet@linux.dev> wrote:
>
> On Thu, Apr 25, 2024 at 04:49:17PM -0700, Andrew Morton wrote:
> > On Thu, 25 Apr 2024 14:30:55 -0700 Suren Baghdasaryan <surenb@google.co=
m> wrote:
> >
> > > > > --- a/mm/kmemleak.c
> > > > > +++ b/mm/kmemleak.c
> > > > > @@ -463,7 +463,7 @@ static struct kmemleak_object *mem_pool_alloc=
(gfp_t gfp)
> > > > >
> > > > >       /* try the slab allocator first */
> > > > >       if (object_cache) {
> > > > > -             object =3D kmem_cache_alloc(object_cache, gfp_kmeml=
eak_mask(gfp));
> > > > > +             object =3D kmem_cache_alloc_noprof(object_cache, gf=
p_kmemleak_mask(gfp));
> > > >
> > > > What do these get accounted to, or does this now pop a warning with
> > > > CONFIG_MEM_ALLOC_PROFILING_DEBUG?
> > >
> > > Thanks for the fix, Kees!
> > > I'll look into this recursion more closely to see if there is a bette=
r
> > > way to break it. As a stopgap measure seems ok to me. I also think
> > > it's unlikely that one would use both tracking mechanisms on the same
> > > system.
> >
> > I'd really like to start building mm-stable without having to route
> > around memprofiling.  How about I include Kees's patch in that for now?
>
> Agreed

Yes, please. When I figure out a better way, I'll post a separate patch. Th=
anks!