Re: [PATCH bpf-next v2] selftests/bpf: Report the real error from libarena parallel workers

[Jiayuan Chen <jiayuan.chen@linux.dev>]

On 7/23/26 2:24 PM, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Medium] Skipping `-EINTR` completely causes interrupted tests to falsely pass.
> --
>
> --- Patch [1]: [PATCH bpf-next v2] selftests/bpf: Report the real error from libarena parallel workers ---
> commit a35a4526e56449664def8e15919986cc43126b84
> Author: Jiayuan Chen <jiayuan.chen@linux.dev>
>
> selftests/bpf: Report the real error from libarena parallel workers
>
> This commit updates the error collection logic in the libarena parallel
> tests to skip -EINTR. The goal is to ensure the real failure is reported
> rather than losing it when another worker thread bails out early.
>
> Link: https://github.com/kernel-patches/bpf/actions/runs/29867905253/job/88764463566
> Link: https://github.com/kernel-patches/bpf/actions/runs/29878191901/job/88794845824
>
>> diff --git a/tools/testing/selftests/bpf/prog_tests/libarena.c b/tools/testing/selftests/bpf/prog_tests/libarena.c
>> index df7e4b8dc3945..daade4150af66 100644
>> --- a/tools/testing/selftests/bpf/prog_tests/libarena.c
>> +++ b/tools/testing/selftests/bpf/prog_tests/libarena.c
> [ ... ]
>
>> @@ -118,7 +119,22 @@ static int run_libarena_parallel_test_workers(struct libarena *skel,
>>   			continue;
>>   		}
>>   
>> -		err = err ?: (long)thread_ret;
>> +		worker_err = (long)thread_ret;
>> +
>> +		/*
>> +		 * A worker that bails out because another one already gave up
>> +		 * reports -EINTR. It is collateral damage that carries no
>> +		 * information, so skip it entirely: never let it become the
>> +		 * reported error, and don't log it either.
>> +		 */
>> +		if (!worker_err || worker_err == -EINTR)
>> +			continue;
>> +
>> +		if (!err)
>> +			err = worker_err;
> [Severity: Medium]
> If all worker threads return -EINTR due to a process-wide signal, such as a
> global CI timeout or user SIGINT, does this loop leave err initialized to 0
> and falsely report the test as passed?


The bpf_prog_test_run_syscall() path has no way to return -EINTR; a 
worker returns -EINTR only
when test_abort is true, and test_abort is never set without another 
worker returning the
real error, so the workers can never all return -EINTR.

And even if some future signal-based exit were added to the syscall 
path, by then correctness
is already moot....