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References: <20240117111000.12763-1-yangtiezhu@loongson.cn> <20240117111000.12763-3-yangtiezhu@loongson.cn>
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From: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Date: Fri, 19 Jan 2024 13:18:27 -0800
Message-ID: <CAEf4BzYXayB91cXKktBXe_SMDLXhjNo3DGML6DuakLOysZ5jbA@mail.gmail.com>
Subject: Re: [PATCH bpf-next v5 2/3] libbpf: Move insn_is_pseudo_func() to libbpf_internal.h
To: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Alexei Starovoitov <ast@kernel.org>, Daniel Borkmann <daniel@iogearbox.net>, 
	Andrii Nakryiko <andrii@kernel.org>, Eduard Zingerman <eddyz87@gmail.com>, 
	John Fastabend <john.fastabend@gmail.com>, Jiri Olsa <jolsa@kernel.org>, 
	Hou Tao <houtao@huaweicloud.com>, Song Liu <song@kernel.org>, bpf@vger.kernel.org, 
	linux-kernel@vger.kernel.org
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On Wed, Jan 17, 2024 at 3:10=E2=80=AFAM Tiezhu Yang <yangtiezhu@loongson.cn=
> wrote:
>
> Currently, insn_is_pseudo_func() is only used in libbpf.c, move it
> to libbpf_internal.h so that it can be used in test_verifier, this
> is preparation for later patch.
>
> Suggested-by: Song Liu <song@kernel.org>
> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
> ---
>  tools/lib/bpf/libbpf.c          | 5 -----
>  tools/lib/bpf/libbpf_internal.h | 5 +++++
>  2 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index c5a42ac309fd..259d585d6ff5 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -748,11 +748,6 @@ static bool is_call_insn(const struct bpf_insn *insn=
)
>         return insn->code =3D=3D (BPF_JMP | BPF_CALL);
>  }
>
> -static bool insn_is_pseudo_func(struct bpf_insn *insn)
> -{
> -       return is_ldimm64_insn(insn) && insn->src_reg =3D=3D BPF_PSEUDO_F=
UNC;
> -}
> -
>  static int
>  bpf_object__init_prog(struct bpf_object *obj, struct bpf_program *prog,
>                       const char *name, size_t sec_idx, const char *sec_n=
ame,
> diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_inter=
nal.h
> index 27e4e320e1a6..a9c337345aff 100644
> --- a/tools/lib/bpf/libbpf_internal.h
> +++ b/tools/lib/bpf/libbpf_internal.h
> @@ -532,6 +532,11 @@ static inline bool is_ldimm64_insn(struct bpf_insn *=
insn)
>         return insn->code =3D=3D (BPF_LD | BPF_IMM | BPF_DW);
>  }
>
> +static inline bool insn_is_pseudo_func(struct bpf_insn *insn)
> +{
> +       return is_ldimm64_insn(insn) && insn->src_reg =3D=3D BPF_PSEUDO_F=
UNC;
> +}
> +

This just adds more internal code of libbpf used by selftests. While
we've allowed it in some cases to avoid duplication of more complex
logic, I don't feel like it's justified in this case. These helpers
are trivial enough to copy/paste somewhere into selftests helpers
header, so please do that instead.

>  /* if fd is stdin, stdout, or stderr, dup to a fd greater than 2
>   * Takes ownership of the fd passed in, and closes it if calling
>   * fcntl(fd, F_DUPFD_CLOEXEC, 3).
> --
> 2.42.0
>