From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47428 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726584AbgIUPHv (ORCPT ); Mon, 21 Sep 2020 11:07:51 -0400 Date: Mon, 21 Sep 2020 16:07:45 +0100 From: Al Viro Subject: Re: [PATCH 04/11] iov_iter: explicitly check for CHECK_IOVEC_ONLY in rw_copy_check_uvector Message-ID: <20200921150745.GT3421308@ZenIV.linux.org.uk> References: <20200921143434.707844-1-hch@lst.de> <20200921143434.707844-5-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200921143434.707844-5-hch@lst.de> Sender: Al Viro List-ID: To: Christoph Hellwig Cc: Andrew Morton , Jens Axboe , Arnd Bergmann , David Howells , David Laight , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, io-uring@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, keyrings@vger.kernel.org, linux-security-module@vger.kernel.org On Mon, Sep 21, 2020 at 04:34:27PM +0200, Christoph Hellwig wrote: > Explicitly check for the magic value insted of implicitly relying on > its numeric representation. Also drop the rather pointless unlikely > annotation. See above - I would rather have CHECK_IOVEC_ONLY gone. The reason for doing these access_ok() in the same loop is fairly weak, especially since you are checking type on each iteration. Might as well do that in a separate loop afterwards.