Received-SPF: pass (google.com: domain of linux-kernel+bounces-148024-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99;
Date: Wed, 17 Apr 2024 09:05:12 +0200
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>,
	Naresh Kamboju <naresh.kamboju@linaro.org>,
	Mark Brown <broonie@kernel.org>, stable@vger.kernel.org,
	patches@lists.linux.dev, linux-kernel@vger.kernel.org,
	torvalds@linux-foundation.org, akpm@linux-foundation.org,
	linux@roeck-us.net, shuah@kernel.org, patches@kernelci.org,
	lkft-triage@lists.linaro.org, pavel@denx.de, jonathanh@nvidia.com,
	f.fainelli@gmail.com, sudipm.mukherjee@gmail.com,
	srw@sladewatkins.net, rwarsow@gmx.de, conor@kernel.org,
	allen.lkml@gmail.com, Yihuang Yu <yihyu@redhat.com>,
	Gavin Shan <gshan@redhat.com>, Ryan Roberts <ryan.roberts@arm.com>,
	Anshuman Khandual <anshuman.khandual@arm.com>,
	Shaoqin Huang <shahuang@redhat.com>, Will Deacon <will@kernel.org>,
	linux-arm-kernel@lists.infradead.org,
	Anders Roxell <anders.roxell@linaro.org>
Subject: Re: [PATCH 6.6 000/122] 6.6.28-rc1 review
Message-ID: <2024041744-pretender-clutter-7d4d@gregkh>
References: <20240415141953.365222063@linuxfoundation.org>
 <Zh5UJh31PlBkpZWd@finisterre.sirena.org.uk>
 <CA+G9fYu-AjRm-BBA=8fWS8oCbBJ5W443JHPh3uddD7ea7MY-YA@mail.gmail.com>
 <86y19dqw74.wl-maz@kernel.org>
 <Zh61KobDt_y1O46-@arm.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <Zh61KobDt_y1O46-@arm.com>

On Tue, Apr 16, 2024 at 06:28:10PM +0100, Catalin Marinas wrote:
> On Tue, Apr 16, 2024 at 02:22:07PM +0100, Marc Zyngier wrote:
> > On Tue, 16 Apr 2024 14:07:30 +0100,
> > Naresh Kamboju <naresh.kamboju@linaro.org> wrote:
> > > On Tue, 16 Apr 2024 at 16:04, Mark Brown <broonie@kernel.org> wrote:
> > > > On Mon, Apr 15, 2024 at 04:19:25PM +0200, Greg Kroah-Hartman wrote:
> > > > > This is the start of the stable review cycle for the 6.6.28 release.
> > > > > There are 122 patches in this series, all will be posted as a response
> > > > > to this one.  If anyone has any issues with these being applied, please
> > > > > let me know.
> > > >
> > > > The bisect of the boot issue that's affecting the FVP in v6.6 (only)
> > > > landed on c9ad150ed8dd988 (arm64: tlb: Fix TLBI RANGE operand),
> > > > e3ba51ab24fdd in mainline, as being the first bad commit - it's also in
> > > > the -rc for v6.8 but that seems fine.  I've done no investigation beyond
> > > > the bisect and looking at the commit log to pull out people to CC and
> > > > note that the fix was explicitly targeted at v6.6.
> > > 
> > > Anders investigated this reported issues and bisected and also found
> > > the missing commit for stable-rc 6.6 is
> > > e2768b798a19 ("arm64/mm: Modify range-based tlbi to decrement scale")
> > 
> > Which is definitely *not* stable candidate. We need to understand why
> > the invalidation goes south when the scale go up instead of down.
> 
> If you backport e3ba51ab24fd ("arm64: tlb: Fix TLBI RANGE operand")
> which fixes 117940aa6e5f ("KVM: arm64: Define
> kvm_tlb_flush_vmid_range()") but without the newer e2768b798a19
> ("arm64/mm: Modify range-based tlbi to decrement scale"), it looks like
> "scale" in __flush_tlb_range_op() goes out of range to 4. Tested on my
> CBMC model, not on the actual kernel. It may be worth adding some
> WARN_ONs in __flush_tlb_range_op() if scale is outside the 0..3 range or
> num greater than 31.
> 
> I haven't investigated properly (and I'm off tomorrow, back on Thu) but
> it's likely the original code was not very friendly to the maximum
> range, never tested. Anyway, if one figures out why it goes out of
> range, I think the solution is to also backport e2768b798a19 to stable.

How about I drop the offending commit from stable and let you all figure
out what needs to be added before applying anything else :)

thanks,

greg k-h