From mboxrd@z Thu Jan  1 00:00:00 1970
From: catalin.marinas@arm.com (Catalin Marinas)
Date: Tue, 30 Mar 2010 10:31:40 +0100
Subject: [PATCH] ARM: Implement copy_to_user_page() for noMMU
In-Reply-To: <20100330072919.GA14500@n2100.arm.linux.org.uk>
References: <20100329132457.1967.3394.stgit@e102109-lin.cambridge.arm.com>
	<20100330013132.GA15598@shareable.org>
	<20100330072919.GA14500@n2100.arm.linux.org.uk>
Message-ID: <1269941500.17138.38.camel@e102109-lin.cambridge.arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Tue, 2010-03-30 at 08:29 +0100, Russell King - ARM Linux wrote:
> On Tue, Mar 30, 2010 at 02:31:32AM +0100, Jamie Lokier wrote:
> > Other variations such as writing when a mapping is !VM_EXEC and later
> > mapping or mprotecting the same shmem VM_EXEC, but it's even more
> > forbidden semantically to write to a read-only mapping (and just as
> > unchecked on nommu), and conversion of writable to VM_EXEC ought to
> > flush i-cache at mprotect time.
> 
> If NX isn't implemented, then arm_elf_read_implies_exec() must return 1
> for the CPU - so that any region that is marked readable will have
> VM_EXEC set.

If we run uClinux on ARMv6 hardware, we get the above function returning
0. Should we make this function conditional on CONFIG_MMU?

-- 
Catalin