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From:   Alexei Starovoitov <alexei.starovoitov@gmail.com>
Date:   Thu, 13 Apr 2023 21:56:00 -0700
Message-ID: <CAADnVQJ00Npkp=+XYaTybzaPnrcfK0nKrePAktVNBt2-YqWdEg@mail.gmail.com>
Subject: Re: [PATCH] selftests/bpf: ignore pointer types check with clang
To:     Andrea Righi <andrea.righi@canonical.com>
Cc:     Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <martin.lau@linux.dev>,
        Song Liu <song@kernel.org>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>, Hao Luo <haoluo@google.com>,
        Jiri Olsa <jolsa@kernel.org>, Mykola Lysenko <mykolal@fb.com>,
        Shuah Khan <shuah@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>,
        Paolo Pisati <paolo.pisati@canonical.com>,
        bpf <bpf@vger.kernel.org>,
        "open list:KERNEL SELFTEST FRAMEWORK" 
        <linux-kselftest@vger.kernel.org>,
        clang-built-linux <llvm@lists.linux.dev>,
        LKML <linux-kernel@vger.kernel.org>
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On Wed, Apr 12, 2023 at 2:59=E2=80=AFAM Andrea Righi <andrea.righi@canonica=
l.com> wrote:
>
> Building bpf selftests with clang can trigger errors like the following:
>
>   CLNG-BPF [test_maps] bpf_iter_netlink.bpf.o
> progs/bpf_iter_netlink.c:32:4: error: incompatible pointer types assignin=
g to 'struct sock *' from 'struct sock___17 *' [-Werror,-Wincompatible-poin=
ter-types]
>         s =3D &nlk->sk;
>           ^ ~~~~~~~~
> 1 error generated.

I cannot reproduce this and BPF CI doesn't complain about it either.
What kind of clang do you use?
Some special version and build flags?