From: Greg KH <gregkh@linuxfoundation.org>
To: Vivian Wang <wangruikang@iscas.ac.cn>
Cc: Albert Ou <aou@eecs.berkeley.edu>,
Inochi Amaoto <inochiama@gmail.com>,
Han Gao <rabenda.cn@gmail.com>,
Charlie Jenkins <charlie@rivosinc.com>,
linux-kernel@vger.kernel.org, stable@vger.kernel.org,
Meng Zhuo <mengzhuo@iscas.ac.cn>, Yangyu Chen <cyy@cyyself.name>,
Palmer Dabbelt <palmer@dabbelt.com>,
Palmer Dabbelt <palmer@rivosinc.com>,
Paul Walmsley <paul.walmsley@sifive.com>,
Guo Ren <guoren@kernel.org>, Paul Walmsley <pjw@kernel.org>,
linux-riscv@lists.infradead.org, Yao Zi <ziyao@disroot.org>
Subject: Re: [PATCH 6.6.y 0/2] riscv: mm: Backport of mmap hint address fixes
Date: Thu, 9 Oct 2025 15:31:17 +0200 [thread overview]
Message-ID: <2025100931-carefully-exerciser-5d26@gregkh> (raw)
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
prev parent reply other threads:[~2025-10-09 13:31 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-08 7:50 [PATCH 6.6.y 0/2] riscv: mm: Backport of mmap hint address fixes Vivian Wang
2025-10-08 7:50 ` [PATCH 6.6.y 1/2] riscv: mm: Use hint address in mmap if available Vivian Wang
2025-10-08 7:50 ` [PATCH 6.6.y 2/2] riscv: mm: Do not restrict mmap address based on hint Vivian Wang
2025-10-08 10:20 ` [PATCH 6.6.y 0/2] riscv: mm: Backport of mmap hint address fixes Greg KH
2025-10-09 4:19 ` Vivian Wang
2025-10-09 5:00 ` Greg KH
2025-10-09 5:50 ` Vivian Wang
2025-10-09 13:31 ` Greg KH [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2025100931-carefully-exerciser-5d26@gregkh \
--to=gregkh@linuxfoundation.org \
--cc=aou@eecs.berkeley.edu \
--cc=charlie@rivosinc.com \
--cc=cyy@cyyself.name \
--cc=guoren@kernel.org \
--cc=inochiama@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-riscv@lists.infradead.org \
--cc=mengzhuo@iscas.ac.cn \
--cc=palmer@dabbelt.com \
--cc=palmer@rivosinc.com \
--cc=paul.walmsley@sifive.com \
--cc=pjw@kernel.org \
--cc=rabenda.cn@gmail.com \
--cc=stable@vger.kernel.org \
--cc=wangruikang@iscas.ac.cn \
--cc=ziyao@disroot.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox