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From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] arm64: kpti: Use early_param for kpti= command-line option
Date: Wed, 20 Jun 2018 16:44:26 +0100	[thread overview]
Message-ID: <20180620154426.GC27776@arm.com> (raw)
In-Reply-To: <20180620154032.kwhvuwibustjqmwz@armageddon.cambridge.arm.com>

On Wed, Jun 20, 2018 at 04:40:32PM +0100, Catalin Marinas wrote:
> On Wed, Jun 20, 2018 at 04:23:47PM +0100, Will Deacon wrote:
> > We inspect __kpti_forced early on as part of the cpufeature enable
> > callback which remaps the swapper page table using non-global entries.
> > 
> > Ensure that __kpti_forced has been updated to reflect the kpti=
> > command-line option before we start using it.
> > 
> > Reported-by: Wei Xu <xuwei5@hisilicon.com>
> > Signed-off-by: Will Deacon <will.deacon@arm.com>
> 
> Does it need a fixes tag?
> 
> Fixes: ea1e3de85e94 ("arm64: entry: Add fake CPU feature for unmapping the kernel at EL0")

Perhaps, but really this is just a performance optimisation for the kpti=off
case where we don't actually need to put the nG mappings down.

Will

  reply	other threads:[~2018-06-20 15:44 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-20 15:23 [PATCH] arm64: kpti: Use early_param for kpti= command-line option Will Deacon
2018-06-20 15:40 ` Catalin Marinas
2018-06-20 15:44   ` Will Deacon [this message]
2018-06-20 15:46 ` Wei Xu

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