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From:   Andrii Nakryiko <andrii.nakryiko@gmail.com>
Date:   Tue, 5 Apr 2022 16:52:02 -0700
Message-ID: <CAEf4BzZLw-QeXgb1HRR-b3D5NqQRs_iqOFcZmokvmf6rXTy-iw@mail.gmail.com>
Subject: Re: [PATCH bpf-next] selftests/bpf: Remove redundant checks in get_stack_print_output()
To:     Yuntao Wang <ytcoode@gmail.com>
Cc:     Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>, Shuah Khan <shuah@kernel.org>,
        Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>,
        "open list:KERNEL SELFTEST FRAMEWORK" 
        <linux-kselftest@vger.kernel.org>
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On Tue, Apr 5, 2022 at 9:39 AM Yuntao Wang <ytcoode@gmail.com> wrote:
>
> The checks preceding CHECK macro are redundant, remove them.
>
> Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
> ---
>  tools/testing/selftests/bpf/prog_tests/get_stack_raw_tp.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/get_stack_raw_tp.c b/tools/testing/selftests/bpf/prog_tests/get_stack_raw_tp.c
> index 16048978a1ef..5f2ab720dabd 100644
> --- a/tools/testing/selftests/bpf/prog_tests/get_stack_raw_tp.c
> +++ b/tools/testing/selftests/bpf/prog_tests/get_stack_raw_tp.c
> @@ -76,10 +76,8 @@ static void get_stack_print_output(void *ctx, int cpu, void *data, __u32 size)
>                         good_user_stack = true;
>         }
>
> -       if (!good_kern_stack)
> -           CHECK(!good_kern_stack, "kern_stack", "corrupted kernel stack\n");
> -       if (!good_user_stack)
> -           CHECK(!good_user_stack, "user_stack", "corrupted user stack\n");
> +       CHECK(!good_kern_stack, "kern_stack", "corrupted kernel stack\n");
> +       CHECK(!good_user_stack, "user_stack", "corrupted user stack\n");

I suspect it was to avoid super long verbose logs, as each CHECK()
emits one line into output and here we might be getting a lot of
samples. So let's keep it as is. But for the future let's try getting
rid of CHECK()s as much as possible in favor of ASSERT_xxx(). Thanks.

>  }
>
>  void test_get_stack_raw_tp(void)
> --
> 2.35.1
>