From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932357Ab2LRQxi (ORCPT ); Tue, 18 Dec 2012 11:53:38 -0500 Received: from www84.your-server.de ([213.133.104.84]:40609 "EHLO www84.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932259Ab2LRQxg (ORCPT ); Tue, 18 Dec 2012 11:53:36 -0500 Message-ID: <1355849558.26967.24.camel@wall-e> Subject: Re: [PATCH 6/6] Add 32 bit VDSO support for 32 and 64 bit kernels From: Stefani Seibold To: "H. Peter Anvin" Cc: linux-kernel@vger.kernel.org, x86@kernel.org, tglx@linutronix.de, mingo@redhat.com, ak@linux.intel.com, aarcange@redhat.com, john.stultz@linaro.org, luto@amacapital.net, xemul@parallels.com, gorcunov@openvz.org, andriy.shevchenko@linux.intel.com Date: Tue, 18 Dec 2012 17:52:38 +0100 In-Reply-To: <50D09733.3080502@zytor.com> References: <1355823656-13902-1-git-send-email-stefani@seibold.net> <1355823656-13902-7-git-send-email-stefani@seibold.net> <50D09733.3080502@zytor.com> Content-Type: text/plain; charset="ISO-8859-15" X-Mailer: Evolution 3.4.4 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Authenticated-Sender: stefani@seibold.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Dienstag, den 18.12.2012, 08:17 -0800 schrieb H. Peter Anvin: > On 12/18/2012 01:40 AM, stefani@seibold.net wrote: > > From: Stefani Seibold > > > > This patch adds support for 32 bit VDSO. > > > > For 32 bit programs running on a 32 bit kernel, the same mechanism is > > used as for 64 bit programs running on a 64 bit kernel. > > > > For 32 bit programs running under a 64 bit IA32_EMULATION, it is a > > little bit more tricky. In this case the VVAR and HPET will be mapped > > into the 32 bit address space, by cutting of the upper 32 bit. So the > > address for this will not changed in the view of the 32 bit VDSO. The > > HPET will be mapped in this case at 0xff5fe000 and the VVAR at 0xff5ff000. > > > > The transformation between the in 64 bit kernel representation and the 32 bit > > abi will be also provided. > > > > So we have one VDSO Source for all. > > > > You seem to once again have disregarded the request to make the vvar and > hpet part of the vdso address space proper. If this is not possible or > highly impractical, please extend a technical motivation why that is so, > rather than simply ignoring it. > Pardon, i never disregarded nor i have agreed that this is going to be a part of the VDSO. I currently have also no idea how to do this and i see no need at the moment to do this revamp. The 64 bit VDSO lives since more than 6 years with this kind of implementation. You asked me to do the VDSO 32 bit stuff for the IA32_EMULATION, before it is ready for inclusion into the kernel. Thats exactly what i did. I spend the whole weekend of my spare time to do this implementation. Now we have them all. The patch works perfectly, all issues are solved: - Calling conventions - ABI transformations - System call gateway for X86 32 bit - Mapping of the FIXMAP and HPET into the lower 32 bit address space for IA32_EMULATION - Support for 32 bit programs in 32 kernel and 64 bit kernel - One VDSO source for all If you prefer an other solutions, its okay. There are many ways to code things. But for now i think it is a good step ahead. That is what i currently can provide. - Stefani