From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-6.1 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 6F7377D04D for ; Wed, 27 Mar 2019 17:31:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729404AbfC0RbH (ORCPT ); Wed, 27 Mar 2019 13:31:07 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:39876 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729355AbfC0RbH (ORCPT ); Wed, 27 Mar 2019 13:31:07 -0400 Received: by mail-pg1-f195.google.com with SMTP id k3so6565357pga.6 for ; Wed, 27 Mar 2019 10:31:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=Wze83KFIvJTV8YI9HnSthl69lDUr/t9qneSOCvDPwuo=; b=SdOOU2hawDlo5SMbEn9D2CIF+57XHG+Np+8/YOU8jfYrzQb9EtsEViDRR6QVjuczdq vwD1JMvisVX+L2XBmIrDJid9FKifEg/6SxMp3r9GC0seMybpj53JzUliGn+EiaFYb1mp 40b/KVkkbOV9eLTG1ErMds04ybgFDOSahHxNY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=Wze83KFIvJTV8YI9HnSthl69lDUr/t9qneSOCvDPwuo=; b=LQmMUdk4rxzZF1WuzJ2gxYrVKW9Vm1N3uVpIfuQKy5U1BpFgTDllPqGurJzhXBaI10 7HV31kD525qwpMzzyLg73wzgyOMMCTGI/zcf+5OzWtoQR8YApe1/iPef79DrKyf/8Xjf 3sCRqUlocztSrtBO60cUyZ+LAjEcjx73Fap86f+u6rzcUpATCQmAGsYhNvJiuY3O8ihz 61kh+rr/zjS/HeGEXWZTO743K7VeOAMW3BHgPmtadCFHW1eG6XLA1VfcDJRpjUJy6LGQ K+WSPa/Sy+r/rOeWyjwlGCwHfLC/Q429JDjuNozj5FcI9qj1/N+1WE+NmHv15arccRO2 8VEA== X-Gm-Message-State: APjAAAUQcnqftlvA/HhSul3XOs3adaIDrscxAQQbm6tZ/rTGk/yHIU/V vettW1+CerR4TGwjRKWxlSSgbQ== X-Google-Smtp-Source: APXvYqxfzd5JrLje0ulUoGoeoWa0jegNU5VZnyBKdl4S9CJ1ugHkq+sCNO41wLB6Z/a+lVS1qV2Xpg== X-Received: by 2002:a62:14d7:: with SMTP id 206mr8302102pfu.162.1553707866476; Wed, 27 Mar 2019 10:31:06 -0700 (PDT) Received: from localhost ([2620:15c:6:12:9c46:e0da:efbf:69cc]) by smtp.gmail.com with ESMTPSA id d69sm28438011pfg.26.2019.03.27.10.31.04 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 27 Mar 2019 10:31:04 -0700 (PDT) Date: Wed, 27 Mar 2019 13:31:03 -0400 From: Joel Fernandes To: Alexei Starovoitov Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Andrew Morton , ast@kernel.org, atishp04@gmail.com, dancol@google.com, Dan Williams , gregkh@linuxfoundation.org, Jonathan Corbet , karim.yaghmour@opersys.com, Kees Cook , linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, Manoj Rao , Masahiro Yamada , rdunlap@infradead.org Subject: Re: [PATCH v2 1/2] Provide in-kernel headers for making it easy to extend the kernel Message-ID: <20190327173103.GA205980@google.com> References: <20190211143600.15021-1-joel@joelfernandes.org> <20190215031926.ljzluy2cfxp64u6o@ast-mbp> <20190325134947.GA187133@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190325134947.GA187133@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Mon, Mar 25, 2019 at 09:49:47AM -0400, Joel Fernandes wrote: > On Thu, Feb 14, 2019 at 07:19:29PM -0800, Alexei Starovoitov wrote: > > On Mon, Feb 11, 2019 at 09:35:59AM -0500, Joel Fernandes (Google) wrote: > > > Introduce in-kernel headers and other artifacts which are made available > > > as an archive through proc (/proc/kheaders.txz file). This archive makes > > > it possible to build kernel modules, run eBPF programs, and other > > > tracing programs that need to extend the kernel for tracing purposes > > > without any dependency on the file system having headers and build > > > artifacts. > > > > > > On Android and embedded systems, it is common to switch kernels but not > > > have kernel headers available on the file system. Raw kernel headers > > > also cannot be copied into the filesystem like they can be on other > > > distros, due to licensing and other issues. There's no linux-headers > > > package on Android. Further once a different kernel is booted, any > > > headers stored on the file system will no longer be useful. By storing > > > the headers as a compressed archive within the kernel, we can avoid these > > > issues that have been a hindrance for a long time. > > > > The set looks good to me and since the main use case is building bpf progs > > I can route it via bpf-next tree if there are no objections. > > Masahiro, could you please ack it? > > FYI, Masahiro's comments were all address by v5: > https://lore.kernel.org/patchwork/project/lkml/list/?series=387311 > > I believe aren't more outstanding concerns. Could we consider it for v5.2? Just to highlight the problem, today I booted v5.0 on an emulated Android device for some testing, that didn't have a set of prebuilt headers that we have been packaging on well known kernels, to get around this issue. This caused great pain and issues with what I was doing. I know me and many others really want this. With this I can boot an emulated Android device with IKCONFIG_PROC=y and run BCC with that that. Also I want to do the BCC side of the development, but first want to know if we can merge this upstream. Masahiro, I believe due diligence has been done in solidifying it as posted in the v5. Anything else we need to do here? Are you with the patches? thanks! - Joel