From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E345B22339; Thu, 9 Oct 2025 13:31:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760016681; cv=none; b=X8fUWDzwGuMpX2vsKX9PDO9AIrk8LAPwS1kqnE6FiqpP38O0TmBsAM5hkApZJYw6jCjbTOrbmmKQK3rXPf8G1fPg8EZK95h9/9HAXuLYLojwpC6MBAG0AmElnSEeQ18FCQodr1yMyGh6HlfitWM363jKBrwWkfyVcjvY4Mpbinw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760016681; c=relaxed/simple; bh=0IFvkQnMAy8Uc538u+cckdX0F9rDkpNjw/fh01Zt8cQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Wd0WwX4KN0ob8qy3SGs7wykif8RsD3vZGx5xc10Mr8IdNsfnJ9a1LhGXkldHARTUxf9aDfWd46fCMo0W9jtC6QZJolYYfNeJzUz/b+P87FhFmwJxY7qtFBc0ATOXTkaWqevhePEFIONNVHnC48JHM6ceBuxTqVmnEJ2wb07/BcU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=dk5Ibfxv; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="dk5Ibfxv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD2BFC4CEF8; Thu, 9 Oct 2025 13:31:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760016680; bh=0IFvkQnMAy8Uc538u+cckdX0F9rDkpNjw/fh01Zt8cQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dk5IbfxvMT7GhrRDbmHiSxM69xDcMSZxr5UkSf42vP3DoEHjiBN/eKM9RXAY1+ecg FaV8VlAeUUiWUkhAcG7zMcIN3Vf/PGNALp/UapmU/jZgkcYMKod4dWaqoO9OneAVnL X+NZdIvMFf/RjrN5k/+f4SikQ11rbcAx9ySt6Aio= Date: Thu, 9 Oct 2025 15:31:17 +0200 From: Greg KH To: Vivian Wang Cc: Albert Ou , Inochi Amaoto , Han Gao , Charlie Jenkins , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Meng Zhuo , Yangyu Chen , Palmer Dabbelt , Palmer Dabbelt , Paul Walmsley , Guo Ren , Paul Walmsley , linux-riscv@lists.infradead.org, Yao Zi Subject: Re: [PATCH 6.6.y 0/2] riscv: mm: Backport of mmap hint address fixes Message-ID: <2025100931-carefully-exerciser-5d26@gregkh> References: <20251008-riscv-mmap-addr-space-6-6-v1-0-9f47574a520f@iscas.ac.cn> <2025100812-raven-goes-4fd8@gregkh> <187fe5a3-99b9-49b6-be49-3d4f6f1fb16b@iscas.ac.cn> <2025100920-riverbank-congress-c7ee@gregkh> <87d603ce-578d-46a7-87b1-54befccc6fad@iscas.ac.cn> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87d603ce-578d-46a7-87b1-54befccc6fad@iscas.ac.cn> On Thu, Oct 09, 2025 at 01:50:11PM +0800, Vivian Wang wrote: > > On 10/9/25 13:00, Greg KH wrote: > > On Thu, Oct 09, 2025 at 12:19:46PM +0800, Vivian Wang wrote: > >> [...] > > Ok, that makes a bit more sense, but again, why is this just showing up > > now? What changed to cause this to be noticed at and needed to be fixed > > at this moment in time and not before? > > As of why this came quite late in the lifetime of the 6.6.y branch, I > believe it's a combination of two factors. > > Firstly, actual Sv48-capable RISC-V hardware came fairly late. Milk-V > Megrez (with Eswin EIC7700X), on which the Go TSAN thing ran, was > shipped only early this year. The DC ROMA II laptop (EIC7702X) and > Framework mainboard with the same SoC has not even shipped yet, or maybe > only shipped to developers - I'm not so certain. Most other RISC-V > machines only have Sv39. > > Secondly, there is interest among some Chinese software vendors to ship > Linux distros based on a 6.6.y LTS kernel. The "RISC-V Common Kernel" > (RVCK) project [1], with support from openEuler and various HW vendors, > maintains backports on top of a 6.6.y kernel. "RockOS" [2] is a distro > maintained by PLCT Lab, ISCAS, for EIC770{0,2}X-based boards, and it has > a 6.6.y kernel branch. Both have cherry-picked the mmap patches for now. > > We operate with the understanding that the official stable kernel will > not be accepting new major features and drivers, but fixes do belong in > stable, and at least from the perspective of PLCT Lab we generally try > to send patches instead of hoarding them. Hence, the earlier backport > request and this backport series. > > I hope this explanation is acceptable. Thanks for the detailed explaination. I've queued these up now. But wow, shipping new products on a 2 year old kernel feels very risky to me, but hey, what do I know? :) > PS: This 6.6 kernel thing isn't just a RISC-V thing, by the way. KylinOS > V11 has shipped in August with a 6.6 kernel. Deepin and UOS will be > shipping with 6.6, with UOS "25" shipping maybe late this year or early > 2026. That too is crazy. They should know better. Just to give a bit of context for this, for the latest 6.6.y release, 6.6.110, there are currently over 300 documented unfixed CVE items in that branch. Feels rough to be doing a new release based on that... good luck! greg k-h