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Date: Wed, 07 Feb 2024 18:47:39 -0800 (PST)
Subject:     Re: [PATCH v6 0/2] lib: checksum: Fix issues with checksum tests
In-Reply-To: <622b1790-8abb-463c-b6f6-9fb8b4a739cc@roeck-us.net>
CC: Charlie Jenkins <charlie@rivosinc.com>, akpm@linux-foundation.org,
  David.Laight@aculab.com, linux-kernel@vger.kernel.org, lkp@intel.com
From: Palmer Dabbelt <palmer@dabbelt.com>
To: linux@roeck-us.net
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On Wed, 07 Feb 2024 18:44:42 PST (-0800), linux@roeck-us.net wrote:
> On 2/7/24 18:09, Charlie Jenkins wrote:
>> On Wed, Feb 07, 2024 at 05:45:22PM -0800, Andrew Morton wrote:
>>> On Wed, 07 Feb 2024 16:22:49 -0800 Charlie Jenkins <charlie@rivosinc.com> wrote:
>>>
>>>> The ip_fast_csum and csum_ipv6_magic tests did not have the data
>>>> types properly casted, and improperly misaligned data.
>>>
>>> Neither this nor the two patch's changelogs describe *why* these changes
>>> are needed.  They merely assert that we need to do this.
>>>
>>> IOW, when fixing a bug please always describe the user-visible effects
>>> of that bug.
>>>
>>
>> I can add a description that says that the tests are being fixed because
>> they caused failures on systems without misaligned access support. As
>> for the casting patch it's a bit less pertinent but I can add that it
>> allows the code to pass sparse checks.
>>
>> - Charlie
>>
> I don't know exactly what Andrew is asking for, but maybe including the
> error log from the failed selftests and/or the sparse errors would be
> sufficient ?
>
> Not sure though if any of those count as "user visible".

Ya, for compiler warning/error workarounds I usually just include 
something like "without this, I get $ERROR".  Something like 
28ea54bade76 ("RISC-V: Don't rely on positional structure 
initialization").

For the aligned access on there was a fairly interesting discussion on 
why this hadn't tripped up before, I forget if it was on LKML or IRC (or 
Slack or just in the office).  That's worth including...