Re: [PATCH v3 0/1] arm64: Add workaround for Fujitsu A64FX erratum 010001

[Will Deacon]

On Fri, Feb 01, 2019 at 05:53:50AM +0000, Zhang, Lei wrote:
> > -----Original Message-----
> > From: linux-arm-kernel
> > [mailto:linux-arm-kernel-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of
> > James Morse
> > Sent: Thursday, January 31, 2019 12:00 AM
> > To: Zhang, Lei/å é
> > Cc: 'Mark Rutland'; 'Catalin Marinas'; 'will.deacon@xxxxxxx';
> > 'linux-kernel@xxxxxxxxxxxxxxx';
> > 'linux-arm-kernel@xxxxxxxxxxxxxxxxxxx'
> > Subject: Re: [PATCH v3 0/1] arm64: Add workaround for Fujitsu A64FX
> > erratum 010001
> > 
> > 
> > e03e61c3173c ("arm64: kaslr: Set TCR_EL1.NFD1 when
> > CONFIG_RANDOMIZE_BASE=y") ?
> > 
> > So you'd never see it if you disabled CONFIG_RANDOMIZE_BASE?
> For security, it is necessary to set CONFIG_RANDOMIZE_BASE=y.

So I guess we should boot with NFD1 clear, and then set it only when we
realise we're not on an A64FX?

Will