From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f52.google.com ([74.125.82.52]:34987 "EHLO mail-wm0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750765AbdAWRG5 (ORCPT ); Mon, 23 Jan 2017 12:06:57 -0500 Received: by mail-wm0-f52.google.com with SMTP id r126so142923389wmr.0 for ; Mon, 23 Jan 2017 09:06:56 -0800 (PST) Reply-To: nicolas.dichtel@6wind.com Subject: Re: [PATCH v4 3/7] x86: put msr-index.h in uapi References: <1484304406-10820-1-git-send-email-nicolas.dichtel@6wind.com> <1485183521-13002-1-git-send-email-nicolas.dichtel@6wind.com> <1485183521-13002-4-git-send-email-nicolas.dichtel@6wind.com> <20170123165245.7zy7nf3cx5o4vvh3@pd.tnic> From: Nicolas Dichtel Message-ID: Date: Mon, 23 Jan 2017 18:06:52 +0100 MIME-Version: 1.0 In-Reply-To: <20170123165245.7zy7nf3cx5o4vvh3@pd.tnic> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Borislav Petkov Cc: arnd@arndb.de, mmarek@suse.com, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, airlied@linux.ie, davem@davemloft.net, linux@armlinux.org.uk, slash.tmp@free.fr, daniel.vetter@ffwll.ch, rmk+kernel@armlinux.org.uk, msalter@redhat.com, jengelh@inai.de, hch@infradead.org, tklauser@distanz.ch, mpe@ellerman.id.au, mingo@kernel.org, hpa@zytor.com + Peter Anvin and Ingo Molnar Le 23/01/2017 à 17:52, Borislav Petkov a écrit : > On Mon, Jan 23, 2017 at 03:58:37PM +0100, Nicolas Dichtel wrote: >> This header file is exported, thus move it to uapi. > > Why? Why is this damn thing exported in the first place? It is exported because it is listed in arch/x86/include/uapi/asm/Kbuild: header-y += msr-index.h (see also patch #4). > > The moment we decide to change an MSR name or even remove it from that > file, we break userspace. And what for, because userspace is using some > arbitrary header file which was meant to be for the kernel solely. I understand your concerns but my patch does not change anything. And I think David's comment is right: if I remove it, I break the uapi. After digging a bit, it seems you have already tried to remove it in commit b72e7464e4cf ("x86/uapi: Do not export as part of the user API headers"), but because this file is still listed in the Kbuild file, it is still exported. It would be great if we could find a consensus about what to do with this file because it blocks patch #4 and the rest of the series. Thank you, Nicolas