From mboxrd@z Thu Jan 1 00:00:00 1970 From: rabin@rab.in (Rabin Vincent) Date: Sun, 31 Aug 2014 16:59:21 +0200 Subject: [PATCH v4 7/8] ARM: mm: allow non-text sections to be non-executable In-Reply-To: References: <1407949593-16121-1-git-send-email-keescook@chromium.org> <1407949593-16121-8-git-send-email-keescook@chromium.org> <20140819123342.GJ23128@arm.com> <20140826144303.GX23445@arm.com> Message-ID: <20140831145921.GA4931@dator> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Aug 29, 2014 at 09:04:41AM -0700, Kees Cook wrote: > On Tue, Aug 26, 2014 at 7:43 AM, Will Deacon 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.