Re: [PATCH Linux-next] perf test: Fix test case perf trace BTF general tests

Thomas Richter
2025-11-26T07:13:14Z

On 11/20/25 01:52, Namhyung Kim wrote:
> On Wed, Nov 19, 2025 at 12:59:03PM -0500, Steven Rostedt wrote:
>> On Tue, 18 Nov 2025 20:36:46 -0800
>> Namhyung Kim <namhyung@kernel.org> wrote:
>>
>>>> Really? It still uses libtraceevent right? I made sure that this didn't
>>>> break trace-cmd and thought that perf would work too.
>>>
>>> It doesn't completely break perf trace but added new parameter for the
>>> write syscall at the end. IIUC perf trace iterates the format fields
>>> after __syscall_nr and take them all as syscall parameters.
>>
>> Is this a regression? Or can perf be fixed?
>>
>> I just ran it and I have this:
>>
>> 542.337 ( 0.131 ms): sshd-session/1189 write(fd: 7<socket:[9749]>, buf: , count: 268) = 268
>>
>> I haven't tried it without the patches. Does it usually show what "buf" is?
>> Now with the reading of user space, it can show the content too!
>
> Yep, it reads the content using BPF. This is on my 6.16 kernel.
>
> $ sudo perf trace -e write -- /bin/echo hello
> hello
> 0.000 ( 0.014 ms): echo/61922 write(fd: 1, buf: hello\10, count: 6) = 6
>
> Thanks,
> Namhyung
>
>

Hello Namhyung, Steven,

friendly ping... any progress here?

--
Thomas Richter, Dept 3303, IBM s390 Linux Development, Boeblingen, Germany
--
IBM Deutschland Research & Development GmbH

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