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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 494FFC43331 for ; Tue, 24 Mar 2020 15:37:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1F9E5208CA for ; Tue, 24 Mar 2020 15:37:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585064245; bh=hsEWh4lkEZJj8SgPovkPJPa8VD6fGH33UAu8+iJ0v3Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uA+IxxBIkwMk38Byp0aEVa+u+7G+N3hujh0yQNsA0ErOq4kulOFnbmsK2YIWrM/Q5 kUmh/BO2HorWVQ0lrc+9HN1CBmNCp4nFOwbNPX+MSH6WEgP2+et8/kW8FYzsLisA44 Vaq8f0pFCln7av2u+y4KXduyx4yHqH2iyZ5+eTbs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728589AbgCXPhX (ORCPT ); Tue, 24 Mar 2020 11:37:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:59988 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728501AbgCXPhN (ORCPT ); Tue, 24 Mar 2020 11:37:13 -0400 Received: from localhost.localdomain (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 220872137B; Tue, 24 Mar 2020 15:37:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585064233; bh=hsEWh4lkEZJj8SgPovkPJPa8VD6fGH33UAu8+iJ0v3Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sh+iGzEj3EFKgcy1Fl5LykZI4hKr6kfQvQMK1zjUj9XrGmYyiVbiPkykjJ8oa7kcv 2hyjEQEDZo3ISlrHu8UFUARgGL47vL7/K/5qVrrBL853pxxr3ZjrYkJlSSruOY+cHe Eizev4Onuh72ciaMDl/jVo8Fmg9r5oEA5OiZpPPo= From: Will Deacon To: linux-kernel@vger.kernel.org Cc: Will Deacon , Eric Dumazet , Jann Horn , Kees Cook , Maddie Stone , Marco Elver , "Paul E . McKenney" , Peter Zijlstra , Thomas Gleixner , kernel-team@android.com, kernel-hardening@lists.openwall.com Subject: [RFC PATCH 09/21] list: Remove unnecessary WRITE_ONCE() from hlist_bl_add_before() Date: Tue, 24 Mar 2020 15:36:31 +0000 Message-Id: <20200324153643.15527-10-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200324153643.15527-1-will@kernel.org> References: <20200324153643.15527-1-will@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There is no need to use WRITE_ONCE() when inserting into a non-RCU protected list. Cc: Paul E. McKenney Cc: Peter Zijlstra Signed-off-by: Will Deacon --- include/linux/list_bl.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/include/linux/list_bl.h b/include/linux/list_bl.h index 1804fdb84dda..c93e7e3aa8fc 100644 --- a/include/linux/list_bl.h +++ b/include/linux/list_bl.h @@ -91,15 +91,15 @@ static inline void hlist_bl_add_before(struct hlist_bl_node *n, struct hlist_bl_node *next) { struct hlist_bl_node **pprev = next->pprev; + unsigned long val; n->pprev = pprev; n->next = next; next->pprev = &n->next; /* pprev may be `first`, so be careful not to lose the lock bit */ - WRITE_ONCE(*pprev, - (struct hlist_bl_node *) - ((uintptr_t)n | ((uintptr_t)*pprev & LIST_BL_LOCKMASK))); + val = (unsigned long)n | ((unsigned long)*pprev & LIST_BL_LOCKMASK); + *pprev = (struct hlist_bl_node *)val; } static inline void hlist_bl_add_behind(struct hlist_bl_node *n, -- 2.20.1