From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934439AbXEMQpm (ORCPT ); Sun, 13 May 2007 12:45:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934423AbXEMQpe (ORCPT ); Sun, 13 May 2007 12:45:34 -0400 Received: from x35.xmailserver.org ([64.71.152.41]:2558 "EHLO x35.xmailserver.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934131AbXEMQpd (ORCPT ); Sun, 13 May 2007 12:45:33 -0400 X-AuthUser: davidel@xmailserver.org Date: Sun, 13 May 2007 09:44:43 -0700 (PDT) From: Davide Libenzi X-X-Sender: davide@alien.or.mcafeemobile.com To: Andrew Morton cc: Geert Uytterhoeven , Linux Kernel Mailing List , Linus Torvalds , Oleg Nesterov , "Eric W. Biederman" Subject: Re: undefined reference to `__clear_user' (was: Re: [patch 2/13] signal/timer/event fds v10 - signalfd core ...) In-Reply-To: <20070513034442.52f81fff.akpm@linux-foundation.org> Message-ID: References: <20070513034442.52f81fff.akpm@linux-foundation.org> X-GPG-FINGRPRINT: CFAE 5BEE FD36 F65E E640 56FE 0974 BF23 270F 474E X-GPG-PUBLIC_KEY: http://www.xmailserver.org/davidel.asc MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 13 May 2007, Andrew Morton wrote: > On Sun, 13 May 2007 12:28:23 +0200 (CEST) Geert Uytterhoeven wrote: > > > Hi Davide, > > > > On Mon, 2 Apr 2007, Davide Libenzi wrote: > > > --- /dev/null 1970-01-01 00:00:00.000000000 +0000 > > > +++ linux-2.6.21-rc5.fds/fs/signalfd.c 2007-04-02 15:06:29.000000000 -0700 > > > > > +/* > > > + * Copied from copy_siginfo_to_user() in kernel/signal.c > > > + */ > > > +static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo, > > > + siginfo_t const *kinfo) > > > +{ > > > + long err; > > > + > > > + BUILD_BUG_ON(sizeof(struct signalfd_siginfo) != 128); > > > + > > > + /* > > > + * Unused memebers should be zero ... > > > + */ > > > + err = __clear_user(uinfo, sizeof(*uinfo)); > > ^^^^^^^^^^^^ > > > > Shouldn't this be `clear_user()'? I don't see any access_ok() calls > > before this call (I do see them in copy_siginfo_to_user() in > > kernel/signal.c), but of course I may miss something... > > > > I only noticed because m68k doesn't have __clear_user(), as this routine > > was never needed by generic code before your change. > > > > The vfs does the access_ok() checking on entry to read, write, readv, > writev, pread and pwrite. Maybe deserves a comment? Given that even Al "VFS" Viro missed that at first sight yesterday :) Al was also mentioning that some archs (among them FRV, IIRC) do not have __clear_user, so we may want to align them to all the other ones. - Davide