From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754083AbYLOQD4 (ORCPT ); Mon, 15 Dec 2008 11:03:56 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752419AbYLOQDp (ORCPT ); Mon, 15 Dec 2008 11:03:45 -0500 Received: from h4.dl5rb.org.uk ([81.2.74.4]:36697 "EHLO ditditdahdahdah-dahdahdahditdit.dl5rb.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752437AbYLOQDo (ORCPT ); Mon, 15 Dec 2008 11:03:44 -0500 Date: Mon, 15 Dec 2008 16:03:11 +0000 From: Ralf Baechle To: Gerd Hoffmann Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org Subject: Re: [PATCH v3 0/3] preadv & pwritev syscalls. Message-ID: <20081215160311.GA23153@linux-mips.org> References: <1229340977-24345-1-git-send-email-kraxel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1229340977-24345-1-git-send-email-kraxel@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 15, 2008 at 12:36:14PM +0100, Gerd Hoffmann wrote: > Next revision of the patch series, with the alignment issue fixed by > swapping the last two arguments as suggested by arch maintainers. > > I've dropped the now-obsolete wrappers for mips. Ralf, please > double-check. It fixes the alignment issue but still won't work; on MIPS 32-bit userspace will pass the 64-bit argument in two registers but the 64-bit kernel code will assume it to be passed in a single registers. It'd be ugly but passing a pointer to a 64-bit argument would solve the issue; something like this: sys_preadv(unsigned long fd, const struct iovec __user *vec, unsigned long vlen, loff_t __user *pos); compat_sys_preadv(unsigned long fd, const struct compat_iovec __user *vec, unsigned long vlen, loff_t __user *pos); sys_splice uses loff_t __user * arguments as well and that's why it's doesn't need any compat wrapper. I'm surprised this works for x86; does x86-64 code really expect 64-bit arguments as 2 32-bit arguments? Patch 1/3 looks like it's a bug fix and you may want to submit this separate from the remainder of the series for 2.6.28? Ralf