Re: [PATCH] arm64: Implement branch predictor hardening for Falkor

From: Shanker Donthineni <shankerd@codeaurora.org>
To: Will Deacon <will.deacon@arm.com>
Cc: Sean Campbell <scampbel@codeaurora.org>,
	Marc Zyngier <marc.zyngier@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	kvmarm <kvmarm@lists.cs.columbia.edu>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] arm64: Implement branch predictor hardening for Falkor
Date: Mon, 8 Jan 2018 15:44:24 -0600	[thread overview]
Message-ID: <fa96f638-075e-10a0-d764-9c24b50fcf13@codeaurora.org> (raw)
In-Reply-To: <01fe1f41-ac45-0c19-a502-77b915c48fcf@codeaurora.org>

Hi Will/Catalin,

Please drop https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/commit/?h=kpti&id=79ad24ef6c260efa0614896b15e67f4829448e32 in which you've removed FALKOR MIDR change. I've posted
v2 patch series including typo fix & FALKOR MIDR patch which is already available in upstream v4.15-rc7
branch. Please merge v2 patch.

On 01/08/2018 01:10 PM, Shanker Donthineni wrote:
> Hi Will,
> 
> On 01/08/2018 12:44 PM, Will Deacon wrote:
>> On Mon, Jan 08, 2018 at 05:09:33PM +0000, Will Deacon wrote:
>>> On Fri, Jan 05, 2018 at 02:28:59PM -0600, Shanker Donthineni wrote:
>>>> Falkor is susceptible to branch predictor aliasing and can
>>>> theoretically be attacked by malicious code. This patch
>>>> implements a mitigation for these attacks, preventing any
>>>> malicious entries from affecting other victim contexts.
>>>
>>> Thanks, Shanker. I'll pick this up (fixing the typo pointed out by Drew).
>>
>> Note that MIDR_FALKOR doesn't exist in mainline, so I had to drop those
>> changes too. See the kpti branch for details.
>>
> 
> The FALKOR MIDR patch is already available in the upstream kernel v4.15-rc7
>     https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/arch/arm64?h=v4.15-rc7&id=c622cc013cece073722592cff1ac6643a33b1622
> 
> If you want I can resend the above patch in v2 series including typo fix.
> 
>> If you'd like anything else done here, please send additional patches to me
>> and Catalin that we can apply on top of what we currently have. Note that
>> I'm in the air tomorrow, so won't be picking up email.
>>
>> Cheers,
>>
>> Will
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>
> 

-- 
Shanker Donthineni
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.