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Date: Thu, 25 Apr 2024 20:19:17 -0400
From: Kent Overstreet <kent.overstreet@linux.dev>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Suren Baghdasaryan <surenb@google.com>, 
	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
Subject: Re: [PATCH] mm/slub: Avoid recursive loop with kmemleak
Message-ID: <t6iykbzqfwt3d7j537shnvebwqy4u5fmzw2gwyeb6a7cosp3hu@eugiwl3t6zfn>
References: <20240425205516.work.220-kees@kernel.org>
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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.com> 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 = kmem_cache_alloc(object_cache, gfp_kmemleak_mask(gfp));
> > > > +             object = kmem_cache_alloc_noprof(object_cache, gfp_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 better
> > 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