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Date:   Tue, 8 Aug 2023 07:52:43 +0200
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To:     Mark Brown <broonie@kernel.org>, Will Deacon <will@kernel.org>
Cc:     Hugh Dickins <hughd@google.com>,
        Lorenzo Stoakes <lstoakes@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Mike Rapoport <rppt@kernel.org>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Matthew Wilcox <willy@infradead.org>,
        David Hildenbrand <david@redhat.com>,
        Suren Baghdasaryan <surenb@google.com>,
        Qi Zheng <zhengqi.arch@bytedance.com>,
        Yang Shi <shy828301@gmail.com>,
        Mel Gorman <mgorman@techsingularity.net>,
        Peter Xu <peterx@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Yu Zhao <yuzhao@google.com>,
        Alistair Popple <apopple@nvidia.com>,
        Ralph Campbell <rcampbell@nvidia.com>,
        Ira Weiny <ira.weiny@intel.com>,
        Steven Price <steven.price@arm.com>,
        SeongJae Park <sj@kernel.org>,
        Huang Ying <ying.huang@intel.com>,
        Naoya Horiguchi <naoya.horiguchi@nec.com>,
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        Zack Rusin <zackr@vmware.com>, Jason Gunthorpe <jgg@ziepe.ca>,
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        Pasha Tatashin <pasha.tatashin@soleen.com>,
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        Song Liu <song@kernel.org>,
        Thomas Hellstrom <thomas.hellstrom@linux.intel.com>,
        Ryan Roberts <ryan.roberts@arm.com>,
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        linux-arm-kernel@lists.infradead.org,
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From:   "Linux regression tracking (Thorsten Leemhuis)" 
        <regressions@leemhuis.info>
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On 20.07.23 14:06, Mark Brown wrote:
> On Thu, Jul 20, 2023 at 11:32:28AM +0100, Will Deacon wrote:
>> On Tue, Jul 11, 2023 at 06:57:33PM +0100, Mark Brown wrote:
> 
>>> Still investigating but I'm pretty convinced this is nothing to do with
>>> your commit/series and is just common or garden memory corruption that
>>> just happens to get tickled by your changes.  Sorry for the noise.
> 
>> Did you get to the bottom of this? If not, do you have a reliable way to
>> reproduce the problem? I don't like the sound of memory corruption :(
> 
> Not to the bottom of it, but getting there - I isolated the issue to
> something in the unregistration path for thermal zones but didn't manage
> to figure out exactly what.

Hi Mark, just wondering did anything come out of this and is this still
happening? I'm just wondering, as I still have this on my list of
tracked regressions.

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
--
Everything you wanna know about Linux kernel regression tracking:
https://linux-regtracking.leemhuis.info/about/#tldr
If I did something stupid, please tell me, as explained on that page.

#regzbot poke
>  There was some indication it might be a use
> after free but I'm not convinced.
> 
> I have a reliable way to reproduce this if you have a pine64plus, it
> also shows up a lot on the Libretech Tritium but not quite so reliably
> as pine64plus since Hugh's changes.  Equally pine64plus was rock solid
> until those so there's some timing/environment thing going on which
> makes the issue manifest obviously, I expect you should be able to
> trigger the issue by unregistering a thermal driver but the effects
> might not be visible.
> 
> There is a change on the list to make the Allwinner SoCs not trigger the
> issue during boot (their thermal driver refuses to register if any one
> zone fails but most of their SoCs have multiple thermal zones with only
> one fully described) but it needs fixing either way.