From: "Bryan O'Donoghue" <pure.logic@nexus-software.ie>
To: Ingo Molnar <mingo@kernel.org>
Cc: linux-kernel@vger.kernel.org, corbet@lwn.net, tglx@linutronix.de,
mingo@redhat.com, hpa@zytor.com, x86@kernel.org,
andriy.shevchenko@linux.intel.com, boon.leong.ong@intel.com,
fengguang.wu@intel.com, linux-doc@vger.kernel.org
Subject: Re: [PATCH] x86/intel/quark: Parameterize the kernel's IMR lock logic
Date: Thu, 18 Feb 2016 10:31:43 +0000 [thread overview]
Message-ID: <1455791503.31619.246.camel@nexus-software.ie> (raw)
In-Reply-To: <20160218075810.GA16041@gmail.com>
On Thu, 2016-02-18 at 08:58 +0100, Ingo Molnar wrote:
> So why not simply do the patch below? Very few people use boot
> parameters, and the
> complexity does not seem to be worth it.
>
> Furthermore I think an IMR range in itself is safe enough - it's not
> like such
> register state is going to be randomly corrupted, even with the
> 'lock' bit unset.
Hi Ingo.
I agree - to flip the lock bit you need to be in ring-0 anyway.
> So it's a perfectly fine protective measure against accidental memory
> corruption
> from the DMA space. It should not try to be more than that.
>
> And once we do this, I suggest we get rid of the 'lock' parameter
> altogether -
> that will further simplify the code.
>
> Thanks,
>
> Ingo
That was the V1 of this patch
https://groups.google.com/forum/#!topic/linux.kernel/6ZuVOF3TJow
Andriy asked for the boot parameter to control the state of the IMR
lock bit, I'm just as happy to go back to that version TBH
next prev parent reply other threads:[~2016-02-18 10:31 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-18 3:29 [PATCH] x86/intel/quark: Parameterize the kernel's IMR lock logic Bryan O'Donoghue
2016-02-18 7:58 ` Ingo Molnar
2016-02-18 10:31 ` Bryan O'Donoghue [this message]
2016-02-18 18:53 ` Ingo Molnar
2016-02-19 1:07 ` Bryan O'Donoghue
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