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Date: Thu, 10 Sep 2015 13:01:42 -0500 (CDT)
From: Christoph Lameter <cl@linux.com>
Subject: Re: Is it OK to pass non-acquired objects to kfree?
In-Reply-To: <20150910171333.GD4029@linux.vnet.ibm.com>
Message-ID: <alpine.DEB.2.11.1509101301010.10131@east.gentwo.org>
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To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>, Pekka Enberg <penberg@kernel.org>, David Rientjes <rientjes@google.com>, Joonsoo Kim <iamjoonsoo.kim@lge.com>, Andrew Morton <akpm@linux-foundation.org>, "linux-mm@kvack.org" <linux-mm@kvack.org>, Andrey Konovalov <andreyknvl@google.com>, Alexander Potapenko <glider@google.com>

On Thu, 10 Sep 2015, Paul E. McKenney wrote:

> The reason we poked at this was to see if any of SLxB touched the
> memory being freed.  If none of them touched the memory being freed,
> and if that was a policy, then the idiom above would be legal.  However,
> one of them does touch the memory being freed, so, yes, the above code
> needs to be fixed.

The one that touches the object has a barrier() before it touches the
memory.

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