lkml.org 
[lkml]   [2018]   [Nov]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2] arm64: Make kpti command line options x86 compatible
On Tue, Nov 13, 2018 at 04:29:06PM +0100, Alexander Graf wrote:
> I've already stumbled over 2 cases where people got confused about how to
> disable kpti on AArch64. In both cases, they used existing x86_64 options
> and just applied that to an AArch64 system, expecting it to work.
>
> I think it makes a lot of sense to have compatible kernel command line
> parameters whenever we can have them be compatible.
>
> So this patch adds the pti= and no_pti kernel command line options, mapping
> them into the existing kpti= command line framework. It preserves the old
> syntax to maintain compatibility with older command lines.
>
> While at it, the patch also marks the respective options as dual-arch.
>
> Reported-by: Richard Brown <rbrown@suse.de>
> Signed-off-by: Alexander Graf <agraf@suse.de>
>
> ---
>
> v1 -> v2:
>
> - Actually make it compile. Sorry for the sloppy v1.
> ---
> Documentation/admin-guide/kernel-parameters.txt | 6 +++---
> arch/arm64/kernel/cpufeature.c | 20 +++++++++++++++++++-
> 2 files changed, 22 insertions(+), 4 deletions(-)

This patch doesn't help though, right, because kpti= has already been
included with backports etc so the ship has sailed? Yeah, it's not ideal,
but we went over this before:

http://lists.infradead.org/pipermail/linux-arm-kernel/2018-August/598395.html

The thing we really need is the sysfs interface hooking up so you can easily
check the state of the mitigation. Still waiting for a follow-up on that ;)

http://lists.infradead.org/pipermail/linux-arm-kernel/2018-September/603412.html

Will

\
 
 \ /
  Last update: 2018-11-15 16:47    [W:0.174 / U:10.724 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site