From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6BE1FC4360C for ; Tue, 8 Oct 2019 17:06:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 337A5217D7 for ; Tue, 8 Oct 2019 17:06:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726254AbfJHRG4 (ORCPT ); Tue, 8 Oct 2019 13:06:56 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:60104 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725917AbfJHRG4 (ORCPT ); Tue, 8 Oct 2019 13:06:56 -0400 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.2 #3 (Red Hat Linux)) id 1iHswm-0005iH-Jz; Tue, 08 Oct 2019 17:06:53 +0000 Date: Tue, 8 Oct 2019 18:06:52 +0100 From: Al Viro To: Greg KH Cc: Linus Torvalds , Guenter Roeck , Linux Kernel Mailing List , linux-fsdevel Subject: Re: [PATCH] Convert filldir[64]() from __put_user() to unsafe_put_user() Message-ID: <20191008170652.GU26530@ZenIV.linux.org.uk> References: <20191007025046.GL26530@ZenIV.linux.org.uk> <20191008032912.GQ26530@ZenIV.linux.org.uk> <20191008045712.GR26530@ZenIV.linux.org.uk> <20191008131416.GA2860109@kroah.com> <20191008152900.GT26530@ZenIV.linux.org.uk> <20191008153831.GA2881123@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191008153831.GA2881123@kroah.com> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Tue, Oct 08, 2019 at 05:38:31PM +0200, Greg KH wrote: > On Tue, Oct 08, 2019 at 04:29:00PM +0100, Al Viro wrote: > > On Tue, Oct 08, 2019 at 03:14:16PM +0200, Greg KH wrote: > > > On Tue, Oct 08, 2019 at 05:57:12AM +0100, Al Viro wrote: > > > > > > > > OK... BTW, do you agree that the use of access_ok() in > > > > drivers/tty/n_hdlc.c:n_hdlc_tty_read() is wrong? It's used as an early > > > > cutoff, so we don't bother waiting if user has passed an obviously bogus > > > > address. copy_to_user() is used for actual copying there... > > > > > > Yes, it's wrong, and not needed. I'll go rip it out unless you want to? > > > > I'll throw it into misc queue for now; it has no prereqs and nothing is going > > to depend upon it. > > Great, thanks. > > > While looking for more of the same pattern: usb_device_read(). Frankly, > > usb_device_dump() calling conventions look ugly - it smells like it > > would be much happier as seq_file. Iterator would take some massage, > > but that seems to be doable. Anyway, that's a separate story... > > That's just a debugfs file, and yes, it should be moved to seq_file. I > think I tried it a long time ago, but given it's just a debugging thing, > I gave up as it wasn't worth it. > > But yes, the access_ok() there also seems odd, and should be dropped. I'm almost tempted to keep it there as a reminder/grep fodder ;-) Seriously, though, it might be useful to have a way of marking the places in need of gentle repair of retrocranial inversions _without_ attracting the "checkpatch warning of the week" crowd...