From: Will Deacon <will.deacon@arm.com>
To: Alexander Graf <agraf@suse.de>
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
Catalin Marinas <catalin.marinas@arm.com>,
Richard Brown <rbrown@suse.de>,
Matthias Brugger <mbrugger@suse.com>
Subject: Re: [PATCH v2] arm64: Make kpti command line options x86 compatible
Date: Thu, 15 Nov 2018 15:47:39 +0000 [thread overview]
Message-ID: <20181115154738.GB2062@brain-police> (raw)
In-Reply-To: <20181113152906.55802-1-agraf@suse.de>
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
next prev parent reply other threads:[~2018-11-15 15:47 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-13 15:29 [PATCH v2] arm64: Make kpti command line options x86 compatible Alexander Graf
2018-11-15 15:47 ` Will Deacon [this message]
2018-11-15 16:49 ` Alexander Graf
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