linux-kernel - Re: [PATCH bpf] selftests/bpf: DENYLIST.aarch64: Remove fexit

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <890d23f2-636e-12d1-31cc-eb6469f2a9ac@iogearbox.net>
Date: Tue, 9 Jul 2024 19:44:37 +0200
From: Daniel Borkmann <daniel@...earbox.net>
To: KP Singh <kpsingh@...nel.org>
Cc: Puranjay Mohan <puranjay@...nel.org>, Andrii Nakryiko
 <andrii@...nel.org>, Eduard Zingerman <eddyz87@...il.com>,
 Mykola Lysenko <mykolal@...com>, Alexei Starovoitov <ast@...nel.org>,
 Martin KaFai Lau <martin.lau@...ux.dev>, Song Liu <song@...nel.org>,
 Yonghong Song <yonghong.song@...ux.dev>,
 John Fastabend <john.fastabend@...il.com>,
 Stanislav Fomichev <sdf@...gle.com>, Hao Luo <haoluo@...gle.com>,
 Jiri Olsa <jolsa@...nel.org>, Shuah Khan <shuah@...nel.org>,
 bpf@...r.kernel.org, linux-kselftest@...r.kernel.org,
 linux-kernel@...r.kernel.org, Manu Bretelle <chantra@...a.com>,
 Florent Revest <revest@...gle.com>
Subject: Re: [PATCH bpf] selftests/bpf: DENYLIST.aarch64: Remove fexit_sleep

On 7/8/24 6:42 PM, KP Singh wrote:
> On Mon, Jul 8, 2024 at 6:09 PM Daniel Borkmann <daniel@...earbox.net> wrote:
>> On 7/8/24 5:35 PM, Puranjay Mohan wrote:
>>> Daniel Borkmann <daniel@...earbox.net> writes:
>>>> On 7/8/24 5:26 PM, KP Singh wrote:
>>>>> On Mon, Jul 8, 2024 at 5:00 PM Puranjay Mohan <puranjay@...nel.org> wrote:
>>>>>> Daniel Borkmann <daniel@...earbox.net> writes:
>>>>>>> On 7/5/24 4:50 PM, Puranjay Mohan wrote:
>>>>>>>> fexit_sleep test runs successfully now on the CI so remove it from the
>>>>>>>> deny list.
>>>>>>>
>>>>>>> Do you happen to know which commit fixed it? If yes, might be nice to have it
>>>>>>> documented in the commit message.
>>>>>>
>>>>>> Actually, I never saw this test failing on my local setup and yesterday
>>>>>> I tried running it on the CI where it passed as well. So, I assumed that
>>>>>> this would be fixed by some commit. I am not sure which exact commit
>>>>>> might have fixed this.
>>>>>>
>>>>>> Manu, Martin
>>>>>>
>>>>>> When this was added to the deny list was this failing every time and did
>>>>>> you have some reproducer for this. If there is a reproducer, I can try
>>>>>> fixing it but when ran normally this test never fails for me.
>>>>>
>>>>> I think this never worked until
>>>>> https://lore.kernel.org/lkml/20230405180250.2046566-1-revest@chromium.org/
>>>>> was merged, FTrace direct calls was blocking tracing programs on ARM,
>>>>> since then it has always worked.
>>>>
>>>> Awesome, thanks! I'll add this to the commit desc then when applying.
>>>
>>> The commit that added this to the deny list said:
>>> 31f4f810d533 ("selftests/bpf: Add fexit_sleep to DENYLIST.aarch64")
>>>
>>> ```
>>> It is reported that the fexit_sleep never returns in aarch64.
>>> The remaining tests cannot start.
>>> ```
> 
> It may also have something to do with sleepable programs. But I think
> it's generally in the category of "BPF tracing was catching up with
> ARM", it has now.

Hm, the latest run actually hangs in fexit_sleep (which is the test right after
fexit_bpf2bpf). So looks like this was too early. It seems some CI runs pass on
arm64 but others fail:

   https://github.com/kernel-patches/bpf/actions/runs/9859826851/job/27224868398 (fail)
   https://github.com/kernel-patches/bpf/actions/runs/9859837213/job/27224955045 (pass)

Puranjay, do you have a chance to look into this again?

>>> So, if the lack of Ftrace direct calls would be the reason then the
>>> failure would be due to fexit programs not being supported on arm64.
>>>
>>> But this says that the selftest never returns therefore is not related
>>> to ftrace direct call support but another bug?
>>
>> Fwiw, at least it is passing in the BPF CI now.
>>
>> https://github.com/kernel-patches/bpf/actions/runs/9841781347/job/27169610006