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Subject: Re: [BUG bpf-next] bpf/net: Hitting gpf when running selftests
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To: Eduard Zingerman <eddyz87@gmail.com>, Jiri Olsa <olsajiri@gmail.com>
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On 8/31/2023 11:03 PM, Eduard Zingerman wrote:
> On Thu, 2023-08-31 at 13:52 +0300, Eduard Zingerman wrote:
>> On Wed, 2023-08-30 at 23:07 +0200, Jiri Olsa wrote:
>>> On Wed, Aug 30, 2023 at 08:58:11PM +0200, Jiri Olsa wrote:
>>>> hi,
>>>> I'm hitting crash below on bpf-next/master when running selftests,
>>>> full log and config attached
>>>
>>> it seems to be 'test_progs -t sockmap_listen' triggering that
>>
>> Hi,
>>
>> I hit it as well, use the following command to reproduce:
>>
>>    for i in $(seq 1 100); do \
>>      ./test_progs -a 'sockmap_listen/sockmap VSOCK test_vsock_redir' \
>>      | grep Summary; \
>>    done
>>
> 
> For what its worth, bisect points to the following commit:
> 147f3efaa241 ("sched/fair: Implement an EEVDF-like scheduling policy")
> 
> Which was merged into bpf-next 3 days ago as a part of:
> 3ca9a836ff53 ("Merge tag 'sched-core-2023-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip")
> 
> Scheduling changes uncovered some old race condition?
>

As replied in another mail, I think the issue is introduced by this commit:

405df89dd52c ("bpf, sockmap: Improved check for empty queue")


> [...]
> 
> 
> .