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Date:   Tue, 6 Jun 2023 15:46:49 -0700
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Subject: Re: [PATCH 1/2] [v3] bpf: hide unused bpf_patch_call_args
To:     Arnd Bergmann <arnd@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>
Cc:     Arnd Bergmann <arnd@arndb.de>,
        John Fastabend <john.fastabend@gmail.com>,
        Martin KaFai Lau <martin.lau@linux.dev>,
        Song Liu <song@kernel.org>, Yonghong Song <yhs@fb.com>,
        KP Singh <kpsingh@kernel.org>,
        Stanislav Fomichev <sdf@google.com>,
        Hao Luo <haoluo@google.com>, Jiri Olsa <jolsa@kernel.org>,
        "Jason A. Donenfeld" <Jason@zx2c4.com>, bpf@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20230602135128.1498362-1-arnd@kernel.org>
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From:   Yonghong Song <yhs@meta.com>
In-Reply-To: <20230602135128.1498362-1-arnd@kernel.org>
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On 6/2/23 6:50 AM, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> This function is only used when CONFIG_BPF_JIT_ALWAYS_ON is disabled,
> but CONFIG_BPF_SYSCALL is enabled. When both are turned off, the
> prototype is missing but the unused function is still compiled,
> as seen from this W=1 warning:
> 
> kernel/bpf/core.c:2075:6: error: no previous prototype for 'bpf_patch_call_args' [-Werror=missing-prototypes]
> 
> Add a matching #ifdef for the definition to leave it out.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Acked-by: Yonghong Song <yhs@fb.com>