From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from terminus.zytor.com ([198.137.202.10]:50574 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757264Ab1BKUIS (ORCPT ); Fri, 11 Feb 2011 15:08:18 -0500 Message-ID: <4D55972E.90506@zytor.com> Date: Fri, 11 Feb 2011 12:08:14 -0800 From: "H. Peter Anvin" MIME-Version: 1.0 Subject: Re: Specific processing during user space header generation References: <4D532BEF.1040602@zytor.com> <20110210055459.GA31333@merkur.ravnborg.org> <4D547B0C.9020508@zytor.com> <20110211191430.GA6227@merkur.ravnborg.org> In-Reply-To: <20110211191430.GA6227@merkur.ravnborg.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Sam Ravnborg Cc: linux-kbuild@vger.kernel.org On 02/11/2011 11:14 AM, Sam Ravnborg wrote: > > The purpose of headers_install is to install the existing kernel headers > and during the installation process do some minimal adjustments to make > then suit userspace consumption. > > What you suggest smells like something else - care to explain what > you have in mind? > I am working with H.J. Lu on an experimental native 32-bit ABI for x86-64. As a result, we are adding an for new system call numbers. Now, the kernel needs to use both and , since as far as the kernel are concerned they are both 64-bit system calls. As such, the latter contains symbols like: __NR_x32_ioctl ... however, when used in user space, we want it to look like __NR_ioctl ... just like any other ABI. Incidentally we have a similar situation with the i386 ABI, but that one is sort of backwards -- since unistd_32.h is also used by native 32 bits, we can't just make the transformation for userspace there. The alternative, of course (which would also work for the native 32 bit case, now when I think about it) is for the human-written file to be the user space version, and use a script to generate the kernel version. -hpa