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From:   Joel Fernandes <joel@joelfernandes.org>
Date:   Wed, 5 Feb 2020 08:41:55 -0800
Message-ID: <CAEXW_YTxcqdqTC_+-n_Zqvn1sfDX04Y=CVgqMvPc_27qUMw=HA@mail.gmail.com>
Subject: Re: [PATCH] Revert kheaders feature
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Alexei Starovoitov <ast@kernel.org>
Cc:     Olof Johansson <olof.johansson@gmail.com>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Michal Marek <michal.lkml@markovi.net>,
        Jonathan Corbet <corbet@lwn.net>,
        Thomas Gleixner <tglx@linutronix.de>,
        Tejun Heo <tj@kernel.org>,
        Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
        David Howells <dhowells@redhat.com>,
        Patrick Bellasi <patrick.bellasi@arm.com>,
        Krzysztof Kozlowski <krzk@kernel.org>,
        linux-kbuild@vger.kernel.org,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Wed, Feb 5, 2020 at 8:02 AM Joel Fernandes <joel@joelfernandes.org> wrote:
>
> On Wed, Feb 05, 2020 at 03:46:29PM +0000, Greg Kroah-Hartman wrote:
> > Now that BPF does not need a copy of the kernel headers anymore in order
> > to build programs, there's no real need for putting the kernel headers
> > into a kernel module.  So drop the feature quick, before someone starts
> > using it :)
>
> Temporary Nack. Adding Alexei to the thread.
>
> I believe at the time of this going in, the BPF's BTF feature was not fully
> ready or able to support the usecases. Especially because BPF programs can
> call or use macros in kernel headers as well.
>
> Also, now BCC project does depend on this and so does bpftrace. Have both
> of these tools migrated to use BTF and don't need CONFIG_KHEADERS to be
> compiled? Sorry if I lost track.
>

Sorry to call it CONFIG_KHEADERS, obviously I mean CONFIG_IKHEADERS.

thanks,

 - Joel