Date: Wed, 8 Oct 2014 12:21:55 +0100
From: Will Deacon <will.deacon@arm.com>
To: Arun Chandran <achandran@mvista.com>
Cc: Mark Rutland <Mark.Rutland@arm.com>,
        Catalin Marinas <Catalin.Marinas@arm.com>,
        "linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Anton Blanchard <anton@samba.org>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Heiko Carstens <heiko.carstens@de.ibm.com>,
        Martin Schwidefsky <schwidefsky@de.ibm.com>
Subject: Re: [PATCH v1] Arm64: ASLR: fix text randomization
Message-ID: <20141008112154.GF26140@arm.com>
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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
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