From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ralf Baechle Subject: Re: [PATCH v3 0/3] preadv & pwritev syscalls. Date: Mon, 15 Dec 2008 16:03:11 +0000 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 Return-path: Content-Disposition: inline In-Reply-To: <1229340977-24345-1-git-send-email-kraxel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Gerd Hoffmann Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-api@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 -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html