linux-kernel - Re: [PATCH v4 7/8] ARM: mm: allow non-text sections to be non-executable

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20140831145921.GA4931@dator>
Date:	Sun, 31 Aug 2014 16:59:21 +0200
From:	Rabin Vincent <rabin@....in>
To:	Kees Cook <keescook@...omium.org>
Cc:	Will Deacon <will.deacon@....com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Rob Herring <robh@...nel.org>,
	Laura Abbott <lauraa@...eaurora.org>,
	Leif Lindholm <leif.lindholm@...aro.org>,
	Stephen Boyd <sboyd@...eaurora.org>,
	"msalter@...hat.com" <msalter@...hat.com>,
	Liu hua <sdu.liu@...wei.com>,
	Nikolay Borisov <Nikolay.Borisov@....com>,
	Nicolas Pitre <nicolas.pitre@...aro.org>,
	Tomasz Figa <t.figa@...sung.com>,
	Doug Anderson <dianders@...gle.com>,
	Jason Wessel <jason.wessel@...driver.com>,
	Catalin Marinas <Catalin.Marinas@....com>,
	Russell King - ARM Linux <linux@....linux.org.uk>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>
Subject: Re: [PATCH v4 7/8] ARM: mm: allow non-text sections to be
 non-executable

On Fri, Aug 29, 2014 at 09:04:41AM -0700, Kees Cook wrote:
> On Tue, Aug 26, 2014 at 7:43 AM, Will Deacon <will.deacon@....com> wrote:
> > Hmm, so do you mandate that preemption is disabled during sections of code
> > where the permissions must be changed after boot? (e.g. ftrace patching)
> 
> I guess it's not enforced (how do I make sure preempt is off?), but
> it's only used during the ftrace patching. I'm open to suggestions! (I
> had avoided going the fixmap route since I would have expected that to
> be much slower.)

For ftrace patching this is called under stop_machine() so preemption is
already off there.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/