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=-8.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 671CDC2D0E8 for ; Tue, 31 Mar 2020 11:40:00 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id BB69020838 for ; Tue, 31 Mar 2020 11:39:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="S3uI88bT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BB69020838 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-18330-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 5576 invoked by uid 550); 31 Mar 2020 11:39:31 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Received: (qmail 7990 invoked from network); 30 Mar 2020 23:25:17 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585610705; bh=CW5W2odPF+X6jORiftGFOScxeCEkL8MSvWI5irb+e0o=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=S3uI88bTqKZzYLy91vMNO4bJJddG5wvwNkFYadqaAnLjdYEI1HOJpNNh5J3gcaMC/ fy1/ClnNa5Z/pAnSs+HlhN4Krzrb31JVlXehWbfGMx2Gtay+NQuLppE85lYZHzvlAq ydJTWEGKQA5K4jY4Ot9epYlD8hijT2IaSAolkQW8= Date: Mon, 30 Mar 2020 16:25:05 -0700 From: "Paul E. McKenney" To: Will Deacon Cc: linux-kernel@vger.kernel.org, Eric Dumazet , Jann Horn , Kees Cook , Maddie Stone , Marco Elver , Peter Zijlstra , Thomas Gleixner , kernel-team@android.com, kernel-hardening@lists.openwall.com Subject: Re: [RFC PATCH 08/21] Revert "list: Use WRITE_ONCE() when initializing list_head structures" Message-ID: <20200330232505.GD19865@paulmck-ThinkPad-P72> References: <20200324153643.15527-1-will@kernel.org> <20200324153643.15527-9-will@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200324153643.15527-9-will@kernel.org> User-Agent: Mutt/1.9.4 (2018-02-28) On Tue, Mar 24, 2020 at 03:36:30PM +0000, Will Deacon wrote: > This reverts commit 2f073848c3cc8aff2655ab7c46d8c0de90cf4e50. > > There is no need to use WRITE_ONCE() to initialise a non-RCU 'list_head'. > > Cc: Paul E. McKenney > Cc: Peter Zijlstra > Signed-off-by: Will Deacon And attention to lockless uses of list_empty() here, correct? Depending on the outcome of discussions on 3/21, I should have added in all three cases. Thanx, Paul > --- > include/linux/list.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/list.h b/include/linux/list.h > index c7331c259792..b86a3f9465d4 100644 > --- a/include/linux/list.h > +++ b/include/linux/list.h > @@ -32,7 +32,7 @@ > */ > static inline void INIT_LIST_HEAD(struct list_head *list) > { > - WRITE_ONCE(list->next, list); > + list->next = list; > list->prev = list; > } > > -- > 2.20.1 >