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Sender: Guenter Roeck <groeck7@gmail.com>
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Date:   Sat, 8 Jul 2023 06:20:12 -0700
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Subject: Re: [PATCH v2 04/27] locking/atomic: make atomic*_{cmp,}xchg optional
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To:     Linux regressions mailing list <regressions@lists.linux.dev>,
        Mark Rutland <mark.rutland@arm.com>
Cc:     linux-kernel@vger.kernel.org, akiyks@gmail.com,
        boqun.feng@gmail.com, corbet@lwn.net, keescook@chromium.org,
        linux@armlinux.org.uk, linux-doc@vger.kernel.org,
        mchehab@kernel.org, paulmck@kernel.org, peterz@infradead.org,
        rdunlap@infradead.org, sstabellini@kernel.org, will@kernel.org
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 <20230605070124.3741859-5-mark.rutland@arm.com>
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 <a94334d8-0a9a-1cbc-ebfe-1825abfb8307@leemhuis.info>
From:   Guenter Roeck <linux@roeck-us.net>
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On 7/8/23 06:07, Linux regression tracking (Thorsten Leemhuis) wrote:
> On 27.06.23 19:07, Guenter Roeck wrote:
>> On Mon, Jun 05, 2023 at 08:01:01AM +0100, Mark Rutland wrote:
>>> Most architectures define the atomic/atomic64 xchg and cmpxchg
>>> operations in terms of arch_xchg and arch_cmpxchg respectfully.
>>>
>>> Add fallbacks for these cases and remove the trivial cases from arch
>>> code. On some architectures the existing definitions are kept as these
>>> are used to build other arch_atomic*() operations.
>>>
>>> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
>> [...]
>>
>> This patch results in:
>>
>> ERROR: modpost: "__xchg_called_with_bad_pointer" [lib/atomic64_test.ko] undefined!
>>
>> when trying to build sparc64:allmodconfig.
> 
> Guenter, please correct me if I'm wrong:
> 
> This is fixed by Arnd's patch "sparc: mark __arch_xchg() as
> __always_inline", but that afaics sadly hasn't even reached -next yet.
> https://lore.kernel.org/all/20230628094938.2318171-1-arnd@kernel.org/
> 
> Hence adding it to the tracking now that the end of the merge window is
> near:
> 
> #regzbot ^introduced d12157efc8e083c7
> #regzbot title locking/atomic: build error on sparc64:allmodconfig
> #regzbot ignore-activity
> 

Yes, this is correct.

Guenter