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Date:   Wed, 29 Jun 2022 10:36:50 -0700
From:   Martin KaFai Lau <kafai@fb.com>
To:     Jules Irenge <jbi.octave@gmail.com>
Cc:     Elana.Copperman@mobileye.com, Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>, netdev@vger.kernel.org,
        bpf@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] btf: Fix error of Macros with multiple statements
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On Wed, Jun 29, 2022 at 06:19:30PM +0100, Jules Irenge wrote:
> This patch fixes an error reported by checkpatch.pl
No.  It is not a fix.

Have you at least compiler tested it ?

> 
> ERROR: Macros with multiple statements should be
> enclosed in a do while loop
> 
> To fix this a do while(0) loop is used
> to encloses the multiple statements.
> 
> Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
> ---
>  kernel/bpf/btf.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
> index 1bc496162572..95c1ee525e28 100644
> --- a/kernel/bpf/btf.c
> +++ b/kernel/bpf/btf.c
> @@ -5057,8 +5057,10 @@ extern struct btf *btf_vmlinux;
>  static union {
>  	struct bpf_ctx_convert {
>  #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
> -	prog_ctx_type _id##_prog; \
> -	kern_ctx_type _id##_kern;
> +		do { \
> +			prog_ctx_type _id##_prog; \
> +			kern_ctx_type _id##_kern; \
> +		} while (0)
>  #include <linux/bpf_types.h>
>  #undef BPF_PROG_TYPE
>  	} *__t;
> -- 
> 2.36.1
>