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Date: Tue, 12 Jul 2016 23:08:53 +0100
From: Russell King - ARM Linux <linux@armlinux.org.uk>
Subject: Re: [PATCH v2 1/3] Add the initify gcc plugin
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To: Kees Cook <keescook@chromium.org>
Cc: Emese Revfy <re.emese@gmail.com>, "kernel-hardening@lists.openwall.com" <kernel-hardening@lists.openwall.com>, PaX Team <pageexec@freemail.hu>, Brad Spengler <spender@grsecurity.net>, Michal Marek <mmarek@suse.com>, LKML <linux-kernel@vger.kernel.org>, Masahiro Yamada <yamada.masahiro@socionext.com>, linux-kbuild <linux-kbuild@vger.kernel.org>, minipli@ld-linux.so, Catalin Marinas <catalin.marinas@arm.com>, Rasmus Villemoes <linux@rasmusvillemoes.dk>, David Brown <david.brown@linaro.org>, "benh@kernel.crashing.org" <benh@kernel.crashing.org>, Thomas Gleixner <tglx@linutronix.de>, Andrew Morton <akpm@linux-foundation.org>, Jeff Layton <jlayton@poochiereds.net>, Arnd Bergmann <arnd@arndb.de>, Sam Ravnborg <sam@ravnborg.org>, Karsten Keil <isdn@linux-pingi.de>

On Tue, Jul 12, 2016 at 03:45:56PM -0400, Kees Cook wrote:
> On Mon, Jul 4, 2016 at 7:40 PM, Emese Revfy <re.emese@gmail.com> wrote:
> > If a function is called by __init and __exit functions as well then
> > the plugin moves it to the __exit section. This causes false positive
> > section mismatch errors/warnings that I don't know how to handle yet.
> 
> Should the mismatch checker be updated to recognize this case? Without
> the plugin, I assume these kinds of functions would only ever be
> marked for __exit? If so, should the plugin strip the __init marking
> and only add __exit?

That sounds like a problem for architectures that still discard the
__exit section at link time to reduce the size of the linked kernel
image - though, obviously, if using the plugin results in a smaller
kernel image _with_ the exit sections, then there's a net benefit
size-wise.

-- 
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