From mboxrd@z Thu Jan  1 00:00:00 1970
From: will.deacon@arm.com (Will Deacon)
Date: Wed, 8 Oct 2014 12:21:55 +0100
Subject: [PATCH v1] Arm64: ASLR: fix text randomization
In-Reply-To: <CAFdej01hex6aeNNjdA1uDodEQ-d=JhsoqFJHkPvnKY+xbzZmxw@mail.gmail.com>
References: <1412685628-27178-1-git-send-email-achandran@mvista.com>
 <20141007134349.GR24725@leverpostej>
 <CAFdej01hex6aeNNjdA1uDodEQ-d=JhsoqFJHkPvnKY+xbzZmxw@mail.gmail.com>
Message-ID: <20141008112154.GF26140@arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Wed, Oct 08, 2014 at 07:51:54AM +0100, Arun Chandran wrote:
> On Tue, Oct 7, 2014 at 7:13 PM, Mark Rutland <mark.rutland@arm.com> wrote:
> > I wasn't able to spot where the randomness came from in the
> > ARCH_BINFMT_ELF_RANDOMIZE_PIE case, so it's not clear to me if the
> > generic implementation behaves identically other than disabling
> > randomization when told to via proc.
> 
> I also don't know from where it is coming; but it works on arm and x86 :)

The randomness will come from elf_map, since that will descend into the mmap
code and end up with a randomised base address (see mmap_base and
arch_pick_mmap_layout).

Will