From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3C59824886C for ; Thu, 7 Aug 2025 20:23:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754598187; cv=none; b=Vb/hBFT9xnkZxziVyCwZtRJyGqyXNFs5bPyeeyEsFIud1m3ISwk7eyY9D9zrqeKE1h7OobQOYGCdFLXy8jzg8qV/BoaeoMe/G6pATq5aNwxH6MPkcANRmQVB9PozMyi2wMwTIf6EMLmrwhTd259SMDR9NZd7yWnT7HXTWoDh06g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754598187; c=relaxed/simple; bh=PhM6aZDLh04KoatxwLiGyayOhIgRFJjx1Ds0aL/u/eQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=QvOmJT54t8hdblWmmDgHuaiHeb8OrA1Mp/4ERR9JagW69GuRSFMqrU7h6mfCNwRiGCfRdjbUTBDyGka4gJTZUD2PHzx8Y1Q3fucywcbi3xhNN93f4Q2TLBaFxcyM1dxCZ0nwmfXTDpYklb6YSe0hRYBxnEV5s0yCNTMvBIoxFnY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PW6kpPyK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="PW6kpPyK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A2659C4CEED; Thu, 7 Aug 2025 20:23:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1754598186; bh=PhM6aZDLh04KoatxwLiGyayOhIgRFJjx1Ds0aL/u/eQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PW6kpPyKjb/lQse8t/X3oFqRMptQB3btY0h+pV7KTEmZeXybod0Cm1be9wgJp2Mln bnaUxMma6x1sd5T3jwpdF9EnzCazxZGSrlKvcPYE3wqCLyNs6gUXysP9QnE7AgRTW9 EQm0lMgARvq0Uc+jarkWtCCEIzEmOMzTW9FfHki5IB4PluYuaiF2zfWbNgJKRDDchc FNW2qVJ6A02pGCOiXlsO83jLJKgJ1wi0eAkZ+qgWfocOUdJoco2YaSSvYqtx2LX+qJ jxL5x0Rkc6mhUi/eTML0RY7GSUzBON2fmWcqjqEyZKM1CNsc34EiHC314qO4tD+Kr4 Ldy38rm8v2qsQ== Date: Thu, 7 Aug 2025 17:23:01 -0300 From: Arnaldo Carvalho de Melo To: Alan Maguire Cc: Andrii Nakryiko , Alexei Starovoitov , Yonghong Song , "Jose E. Marchesi" , Nick Alcock , Jiri Olsa , Namhyung Kim , "bpf@vger.kernel.org Clark Williams" , Kate Carcia , dwarves@vger.kernel.org, Arnaldo Carvalho de Melo Subject: Re: [RFC 0/4] BTF archive with unmodified pahole+toolchain Message-ID: References: <20250807182538.136498-1-acme@kernel.org> Precedence: bulk X-Mailing-List: dwarves@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250807182538.136498-1-acme@kernel.org> On Thu, Aug 07, 2025 at 03:25:34PM -0300, Arnaldo Carvalho de Melo wrote: > If we use completely unmodified libbpf, bpftool, etc, the "BTF archive" > in the resulting vmlinux .BTF ELF section is still consumable, but just > the first "CU" (the first .o .BTF ELF section) is visible, the one for > init/main.o: > acme@number:~/git/linux$ bpftool version > bpftool v7.5.0 > using libbpf v1.5 > features: llvm, skeletons > acme@number:~/git/linux$ > acme@number:~/git/bpf-next$ bpftool btf dump file ~/vmlinux-v6.16.0+.btf_archive format c | wc -l > 11361 > acme@number:~/git/linux$ bpftool btf dump file ../build/v6.16.0+/init/main.o format c | wc -l > 11361 > acme@number:~/git/linux$ > Furthermore: > acme@number:~/git/linux$ bpftool btf dump file ../build/v6.16.0+/init/main.o format c > a > acme@number:~/git/linux$ bpftool btf dump file ~/vmlinux-v6.16.0+.btf_archive format c > b Oops, the expected: acme@number:~/git/linux$ diff a b acme@number:~/git/linux$ > acme@number:~/git/linux$ - Arnaldo