From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753620Ab2HUUON (ORCPT ); Tue, 21 Aug 2012 16:14:13 -0400 Received: from moutng.kundenserver.de ([212.227.126.171]:57799 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751978Ab2HUUOI (ORCPT ); Tue, 21 Aug 2012 16:14:08 -0400 From: Arnd Bergmann To: Catalin Marinas Subject: Re: [PATCH v2 17/31] arm64: System calls handling Date: Tue, 21 Aug 2012 20:14:01 +0000 User-Agent: KMail/1.12.2 (Linux/3.5.0; KDE/4.3.2; x86_64; ; ) Cc: "linux-arch@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Will Deacon References: <1344966752-16102-1-git-send-email-catalin.marinas@arm.com> <201208151422.16335.arnd@arndb.de> <20120821175122.GI12708@arm.com> In-Reply-To: <20120821175122.GI12708@arm.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201208212014.01837.arnd@arndb.de> X-Provags-ID: V02:K0:rbRO7pcLsYNCZVZjsHdIPRuSekleqQK3wmA2M1aZ1bD T8i+I1VZ2sDvVlZW8vlpOYjsVFkIY7NgZHf1lSsFpIfYAG9mzr 7QlitrFvv15WzGdf1gdhwU6emtOzDsvpTkPemfTuOHz9M1aK3H ga3CbLZRmY3jdZeJnxY6/gzzrvXV/uqG4moKGkpR3UD1faxyF6 DBK/RV1YmR+6jqFAe2RRDeR9niLP9n3JC9+w0qTmjUvylEaFzJ RXlzF+8Q7NMj9/q/X+C8FI25n7IsjLy4zvJwRC4fMLvSoW6zdJ Raw4SnVOmCTfbhSS+qtr2SKRt2YI0zBEg3oZSIEPmK28xsQhkC SGwibACZtFwVsNXavQh8= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 21 August 2012, Catalin Marinas wrote: > > > +asmlinkage long sys_mmap(unsigned long addr, unsigned long len, > > > + unsigned long prot, unsigned long flags, > > > + unsigned long fd, off_t off) > > > +{ > > > + if (offset_in_page(off) != 0) > > > + return -EINVAL; > > > + > > > + return sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT); > > > +} > > > > I think > > > > #define sys_mmap sys_mmap_pgoff > > There are slightly different semantics with the last argument of > sys_mmap() which takes a byte offset. The sys_mmap_pgoff() function > takes the offset shifted by PAGE_SHIFT (which is the same as sys_mmap2). > > Looking at the other architectures, it makes sense to use a generic > sys_mmap() implementation similar to the one above (or the ia-64, seems > to be the most complete). > Why that? The generic sys_mmap_pgoff was specifically added so new architectures could just use that instead of having their own wrappers, see f8b72560. Arnd