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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 6B29AC49ED6 for ; Thu, 12 Sep 2019 02:54:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 47A412075C for ; Thu, 12 Sep 2019 02:54:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729068AbfILCyq (ORCPT ); Wed, 11 Sep 2019 22:54:46 -0400 Received: from mga11.intel.com ([192.55.52.93]:7906 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727576AbfILCyq (ORCPT ); Wed, 11 Sep 2019 22:54:46 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Sep 2019 19:54:45 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,492,1559545200"; d="scan'208";a="197089492" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by orsmga002.jf.intel.com with ESMTP; 11 Sep 2019 19:54:44 -0700 Date: Thu, 12 Sep 2019 10:54:24 +0800 From: Wei Yang To: Wei Yang Cc: linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] fs/userfaultfd.c: simplify the calculation of new_flags Message-ID: <20190912025424.GB25169@richard> Reply-To: Wei Yang References: <20190806053859.2374-1-richardw.yang@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190806053859.2374-1-richardw.yang@linux.intel.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ping~ On Tue, Aug 06, 2019 at 01:38:59PM +0800, Wei Yang wrote: >Finally new_flags equals old vm_flags *OR* vm_flags. > >It is not necessary to mask them first. > >Signed-off-by: Wei Yang >--- > fs/userfaultfd.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > >diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c >index ccbdbd62f0d8..653d8f7c453c 100644 >--- a/fs/userfaultfd.c >+++ b/fs/userfaultfd.c >@@ -1457,7 +1457,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, > start = vma->vm_start; > vma_end = min(end, vma->vm_end); > >- new_flags = (vma->vm_flags & ~vm_flags) | vm_flags; >+ new_flags = vma->vm_flags | vm_flags; > prev = vma_merge(mm, prev, start, vma_end, new_flags, > vma->anon_vma, vma->vm_file, vma->vm_pgoff, > vma_policy(vma), >-- >2.17.1 -- Wei Yang Help you, Help me