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References: <20220112002503.115968-1-connoro@google.com>
In-Reply-To: <20220112002503.115968-1-connoro@google.com>
From:   Song Liu <song@kernel.org>
Date:   Wed, 12 Jan 2022 10:18:07 -0800
Message-ID: <CAPhsuW4T4DDPaiF0zUyxN4nUX-a9OWYd0OLMGLjCnUO38-d74g@mail.gmail.com>
Subject: Re: [PATCH bpf] tools/resolve_btfids: build with host flags
To:     "Connor O'Brien" <connoro@google.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>,
        Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
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On Tue, Jan 11, 2022 at 4:25 PM Connor O'Brien <connoro@google.com> wrote:
>
> resolve_btfids is built using $(HOSTCC) and $(HOSTLD) but does not
> pick up the corresponding flags. As a result, host-specific settings
> (such as a sysroot specified via HOSTCFLAGS=--sysroot=..., or a linker
> specified via HOSTLDFLAGS=-fuse-ld=...) will not be respected.
>
> Fix this by setting CFLAGS to KBUILD_HOSTCFLAGS and LDFLAGS to
> KBUILD_HOSTLDFLAGS.
>
> Also pass the cflags through to libbpf via EXTRA_CFLAGS to ensure that
> the host libbpf is built with flags consistent with resolve_btfids.
>
> Signed-off-by: Connor O'Brien <connoro@google.com>

I guess this should go to bpf-next tree?

Other than that,

Acked-by: Song Liu <songliubraving@fb.com>