Re: [PATCH v2 bpf-next] selftests/bpf: Fix failure paths in send_signal test

[Eduard Zingerman <eddyz87@gmail.com>]

On Thu, 2025-11-13 at 09:11 -0800, Alexei Starovoitov wrote:
> From: Alexei Starovoitov <ast@kernel.org>
>
> When test_send_signal_kern__open_and_load() fails parent closes the
> pipe which cases ASSERT_EQ(read(pipe_p2c...)) to fail, but child
> continues and enters infinite loop, while parent is stuck in wait(NULL).
> Other error paths have similar issue, so kill the child before waiting on it.
>
> The bug was discovered while compiling all of selftests with -O1 instead of -O2
> which caused progs/test_send_signal_kern.c to fail to load.
>
> Fixes: ab8b7f0cb358 ("tools/bpf: Add self tests for bpf_send_signal_thread()")
> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
> ---

Acked-by: Eduard Zingerman <eddyz87@gmail.com>

From the same test:

                 /* wait a little for signal handler */
                 for (int i = 0; i < 1000000000 && !sigusr1_received; i++) {
                         j /= i + j + 1;
                         if (remote)
                                 sleep(seconds: 1);
                         else
                                 if (!attr)
                                         /* trigger the nanosleep tracepoint program. */
                                         usleep(useconds: 1);
                 }

Constants are probably a bit too high: from 10**3 to 10**9 seconds.