Openwall GNU/*/Linux - a small security-enhanced Linux distro for servers
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Mon, 4 Sep 2017 18:30:26 +0100
From: Ard Biesheuvel <ard.biesheuvel@...aro.org>
To: Nicolas Pitre <nicolas.pitre@...aro.org>
Cc: "linux-arm-kernel@...ts.infradead.org" <linux-arm-kernel@...ts.infradead.org>, 
	Kernel Hardening <kernel-hardening@...ts.openwall.com>, Arnd Bergmann <arnd@...db.de>, 
	Russell King <linux@...linux.org.uk>, Kees Cook <keescook@...omium.org>, 
	Thomas Garnier <thgarnie@...gle.com>, Marc Zyngier <marc.zyngier@....com>, 
	Mark Rutland <mark.rutland@....com>, Tony Lindgren <tony@...mide.com>, 
	Matt Fleming <matt@...eblueprint.co.uk>, Dave Martin <dave.martin@....com>
Subject: Re: [PATCH v2 16/29] ARM: kernel: switch to relative exception tables

On 4 September 2017 at 18:17, Nicolas Pitre <nicolas.pitre@...aro.org> wrote:
> On Sun, 3 Sep 2017, Ard Biesheuvel wrote:
>
>> To avoid having to relocate the contents of extable entries at
>> runtime when running with KASLR enabled, wire up the existing
>> support for emitting them as relative references. This ensures
>> these quantities are invariant under runtime relocation.
>>
>> Cc: Russell King <linux@...linux.org.uk>
>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@...aro.org>
>
> Could it be better to have a macro that encapsulates exception entries
> e.g.:
>
>         .macro ex_entry insn fixup
>         .long   \insn - ., \fixup - .
>         .endif
>
> so that if ever this changes again or for whatever reason someone needs
> absolute entries then this won't have to be done everywhere. The section
> switch could be included in such a macro too. And it is so easy to
> forget to do the "- ." when adding new entries.
>

Good point. I will change that.

Powered by blists - more mailing lists

Your e-mail address:

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.