Re: [PATCH RFC 5/5] arm64/speculation: Add support for 'cpu_spec_mitigations=' cmdline options

Josh Poimboeuf
2019-04-05T16:03:51Z

On Fri, Apr 05, 2019 at 03:44:14PM +0100, Will Deacon wrote:
> Hi Josh,
>
> On Thu, Apr 04, 2019 at 11:44:15AM -0500, Josh Poimboeuf wrote:
> > Configure arm64 runtime CPU speculation bug mitigations in accordance
> > with the 'cpu_spec_mitigations=' cmdline options. This affects
> > Meltdown and Speculative Store Bypass.
> >
> > The default behavior is unchanged.
> >
> > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
> > ---
> > Documentation/admin-guide/kernel-parameters.txt | 2 ++
> > arch/arm64/kernel/cpu_errata.c | 4 ++++
> > arch/arm64/kernel/cpufeature.c | 6 ++++++
> > 3 files changed, 12 insertions(+)
>
> Just wanted to make you aware that this is probably going to conflict badly
> with some patches we have pending to hook up the sysfs entries:
>
> http://lists.infradead.org/pipermail/linux-arm-kernel/2019-March/640326.html
>
> That patch series isn't quite there yet, so I'm expecting a v7, but I think
> it will change the shape of this patch quite a lot.

Thanks for the heads up Will. I will drop the arm64 patch for now then.

--
Josh