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From: Sasha Levin <sashal@kernel.org>
To: Conor Dooley <conor@kernel.org>
Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org,
	Lucas Tanure <tanure@linux.com>, Rob Herring <robh@kernel.org>,
	robh+dt@kernel.org, frowand.list@gmail.com,
	devicetree@vger.kernel.org
Subject: Re: [PATCH AUTOSEL 6.3 06/11] of: fdt: Scan /memreserve/ last
Date: Thu, 1 Jun 2023 05:54:28 -0400	[thread overview]
Message-ID: <ZHhq1DKT1CBSTQlz@sashalap> (raw)
In-Reply-To: <20230515-headroom-swirl-a0a845584a58@spud>

On Mon, May 15, 2023 at 09:21:04PM +0100, Conor Dooley wrote:
>Hey Sasha,
>
>On Thu, May 11, 2023 at 03:37:49PM -0400, Sasha Levin wrote:
>> From: Lucas Tanure <tanure@linux.com>
>>
>> [ Upstream commit b413281876292de44ae84e9a9ce9d62e47f266e9 ]
>>
>> Change the scanning /memreserve/ and /reserved-memory node order to fix
>> Kernel panic on Khadas Vim3 Board.
>>
>> If /memreserve/ goes first, the memory is reserved, but nomap can't be
>> applied to the region. So the memory won't be used by Linux, but it is
>> still present in the linear map as normal memory, which allows
>> speculation. Legitimate access to adjacent pages will cause the CPU
>> to end up prefetching into them leading to Kernel panic.
>>
>> So /reserved-memory node should go first, as it has a more updated
>> description of the memory regions and can apply flags, like nomap.
>>
>> Link: https://lore.kernel.org/all/CAJX_Q+1Tjc+-TjZ6JW9X0NxEdFe=82a9626yL63j7uVD4LpxEA@mail.gmail.com/
>> Signed-off-by: Lucas Tanure <tanure@linux.com>
>> Link: https://lore.kernel.org/r/20230424113846.46382-1-tanure@linux.com
>> Signed-off-by: Rob Herring <robh@kernel.org>
>> Signed-off-by: Sasha Levin <sashal@kernel.org>
>
>Rob requested that this patch (and it's bretheren in other AUTOSEL
>series) not be backported immediately:
>| Going to let this sit in linux-next for a bit. I also didn't tag for
>| stable kernels. I want it to get some exposure in mainline at least for
>| a few -rc releases rather than getting backported right away. Please
>| help ensure that happens if you see stable review emails. I'm going to
>| be offline most of the next month.
>https://lore.kernel.org/linux-devicetree/168262872454.3491083.6407810340850053636.robh@kernel.org/
>
>Perhaps delaying it for another couple of weeks, since we have only just
>had -rc2, is a good idead?

I'll drop it, let me know when you want it included back. Thanks!

-- 
Thanks,
Sasha

      reply	other threads:[~2023-06-01  9:55 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20230511193757.623114-1-sashal@kernel.org>
2023-05-11 19:37 ` [PATCH AUTOSEL 6.3 06/11] of: fdt: Scan /memreserve/ last Sasha Levin
2023-05-15 20:21   ` Conor Dooley
2023-06-01  9:54     ` Sasha Levin [this message]

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