Re: [PATCHv2] perf bpf: Fix endianness problem when loading parameters in prologue
From: Thomas-Mich Richter
Date: Tue Aug 15 2017 - 02:42:21 EST
On 08/14/2017 06:39 PM, Arnaldo Carvalho de Melo wrote:
> Em Mon, Aug 14, 2017 at 01:46:44PM +0200, Thomas Richter escreveu:
>> Perf BPF prologue generator unconditionally fetches 8 bytes for function
>> parameters, which causes problem on big endian machine. Thomas gives a
>> detail analysis for this problem:
>>
>> http://lkml.kernel.org/r/968ebda5-abe4-8830-8d69-49f62529d151@xxxxxxxxxxxxxxxxxx
>>
>> This patch parses the type of each argument and converts data from
>> memory to expected type.
>>
>> Now the test runs successfully on 4.13.0-rc5:
>> [root@s8360046 perf]# ./perf test bpf
>> 38: BPF filter :
>> 38.1: Basic BPF filtering : Ok
>> 38.2: BPF pinning : Ok
>> 38.3: BPF prologue generation : Ok
>> 38.4: BPF relocation checker : Ok
>> [root@s8360046 perf]#
>>
>> Signed-off-by: Thomas Richter <tmricht@xxxxxxxxxxxxxxxxxx>
>> Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
>> Acked-by: Wang Nan <wangnan0@xxxxxxxxxx>
>> Tested-by: Wang Nan <wangnan0@xxxxxxxxxx>
>
>
> That is strange, who is the author of the patch? Also I think Tested-by
> is enough, being an even stronger form of Acked-by?
>
> But then you also have Signed-off-by: Wang in there...
>
> From Documentation/process/submitting-patches.rst:
>
> ---------
>
> 12) When to use Acked-by: and Cc:
> ---------------------------------
>
> The Signed-off-by: tag indicates that the signer was involved in the
> development of the patch, or that he/she was in the patch's delivery path.
>
> If a person was not directly involved in the preparation or handling of a
> patch but wishes to signify and record their approval of it then they can
> ask to have an Acked-by: line added to the patch's changelog.
>
> Acked-by: is often used by the maintainer of the affected code when that
> maintainer neither contributed to nor forwarded the patch.
>
> ------------------
>
> If Wang wrote the original patch and you made it better working together
> with him, probably having both of you in Signed-off-by lines should be
> enough?
>
> - Arnaldo
>
Ok, my fault then.
Wang wrote to patch in the first place, I just fixed one line.
Should I resend the patch and delete the Acked-by/Tested-by lines
in the commit message?
Thanks
--
Thomas Richter, Dept 3303, IBM LTC Boeblingen Germany
--
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