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From:   David Howells <dhowells@redhat.com>
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To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     dhowells@redhat.com, Joe Perches <joe@perches.com>,
        Waiman Long <longman@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
        James Morris <jmorris@namei.org>,
        "Serge E. Hallyn" <serge@hallyn.com>,
        Linux-MM <linux-mm@kvack.org>, keyrings@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Matthew Wilcox <willy@infradead.org>,
        David Rientjes <rientjes@google.com>, law@redhat.com
Subject: Re: [PATCH v2] mm: Add kvfree_sensitive() for freeing sensitive data objects
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Date:   Tue, 07 Apr 2020 23:54:10 +0100
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Linus Torvalds <torvalds@linux-foundation.org> wrote:

> > It might be worth asking the compiler folks to give us an __attribute_=
_ for
> > that - even if they don't do anything with it immediately.  So we migh=
t have
> > something like:
> >
> >         void free(const volatile void *ptr) __attribute__((free(1)));
> =

> Yeah, that sounds sane.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D94527

> Even if it wasn't initially used for anything it wouldn't hurt, and mayb=
e
> some day it would improve warnings (and allow the compiler to do the dea=
d
> store elimination that started this whole long set of threads in the fir=
st
> place..)

With regard to this, I've got back "not sure what Linus was talking about =
WRT
DSE, if he's got examples he could pass along, they'd be appreciated"

David