From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753640AbbCXSXI (ORCPT ); Tue, 24 Mar 2015 14:23:08 -0400 Received: from cantor2.suse.de ([195.135.220.15]:46340 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752298AbbCXSXE (ORCPT ); Tue, 24 Mar 2015 14:23:04 -0400 Message-ID: <5511AB80.3020102@suse.cz> Date: Tue, 24 Mar 2015 19:22:56 +0100 From: Michal Marek User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Jiri Slaby , David Herrmann CC: Greg Kroah-Hartman , Arnd Bergmann , "Eric W. Biederman" , One Thousand Gnomes , Tom Gundersen , Jiri Kosina , Andy Lutomirski , Linux API , linux-kernel , Daniel Mack , Djalal Harouni , linux-kbuild@vger.kernel.org Subject: Re: [PATCH 13/14] kdbus: add walk-through user space example References: <1425906560-13798-1-git-send-email-gregkh@linuxfoundation.org> <1425906560-13798-14-git-send-email-gregkh@linuxfoundation.org> <551194C8.4070707@suse.cz> <5511A0D6.5030606@suse.cz> In-Reply-To: <5511A0D6.5030606@suse.cz> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dne 24.3.2015 v 18:37 Jiri Slaby napsal(a): > On 03/24/2015, 06:15 PM, David Herrmann wrote: >> On Tue, Mar 24, 2015 at 5:46 PM, Jiri Slaby wrote: >>> Errr, no. Not only it causes build failures (even with KDBUS=n), it >>> definitely should not be built for everyone. >> >> It's only built if CONFIG_SAMPLES is set, right? > > Yes, but I build other samples selected with separate CONFIG_ options > like CONFIG_SAMPLE_LIVEPATCH. So this guy should have its own CONFIG_ > option too, because I (and likely others) don't want to build it. All of Definitely. >> It's modeled after the other user-space examples in ./samples/, which >> all use hostprogs (see samples/{bpf,hidraw,seccomp,uhid}/Makefile). I >> have no idea how to build programs that run on the target >> architecture. Documentation/kbuild/makefiles.txt doesn't list it, >> which is, I guess, the reason why everyone used hostprogs so far. And >> given that autotools calls the target architecture "--host", I >> actually thought this is what hostprogs does.. apparently that's not >> the case, sorry. > > Oh, it's cut&paste, I see. This does not look correct though. The hack > inclusive. Host progs are intended to be run on the host where the > kernel is built. During the compilation or such (like x/menuconfig). > Quite misleading naming if you are used to the autotools one. when cross compiling, we are a bit between a rock and a hard place with the sample userspace programs: - The target toolchain might not have libc support - The host toolchain might be lacking recent kernel headers (therefore the need to do make headers_install) - It's not clean whether the samples are meant to be ran on the build host or target. There has been some work by Sam Ravnborg to introduce uapiprogs-y to for sample userspace programs, but for now, please use hostprogs-y, -Iusr/include and make each sample opt-in. Michal