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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6477CEB64D9 for ; Mon, 26 Jun 2023 18:35:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232370AbjFZSfz (ORCPT ); Mon, 26 Jun 2023 14:35:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49544 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232372AbjFZSfy (ORCPT ); Mon, 26 Jun 2023 14:35:54 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6880394 for ; Mon, 26 Jun 2023 11:35:53 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 05D7560F30 for ; Mon, 26 Jun 2023 18:35:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 111EAC433C9; Mon, 26 Jun 2023 18:35:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1687804552; bh=v7pmnwCE80ZhgGzf3m+4GZLv86wicdfa/gHJOKXld+k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mwne/lCdyzprHzuR25v4CdqqOV1+pxLO+qidNEPa1swMiYJTEwBlPOOYnA1y0Ewwm DelSeH4EdntByEqnDRHQaagSykzeQfKodqAyjz/1lNbDZuYlBcSeKOp/NF6yeIUeh3 8DDju6bgvQVTSPgpRU0Q4/jWTpvgCOKojZ6yK+os= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ben Segall , Al Viro , Christian Brauner , Andrew Morton , Sasha Levin Subject: [PATCH 5.4 04/60] epoll: ep_autoremove_wake_function should use list_del_init_careful Date: Mon, 26 Jun 2023 20:11:43 +0200 Message-ID: <20230626180739.725179251@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230626180739.558575012@linuxfoundation.org> References: <20230626180739.558575012@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Benjamin Segall [ Upstream commit 2192bba03d80f829233bfa34506b428f71e531e7 ] autoremove_wake_function uses list_del_init_careful, so should epoll's more aggressive variant. It only doesn't because it was copied from an older wait.c rather than the most recent. [bsegall@google.com: add comment] Link: https://lkml.kernel.org/r/xm26bki0ulsr.fsf_-_@google.com Link: https://lkml.kernel.org/r/xm26pm6hvfer.fsf@google.com Fixes: a16ceb139610 ("epoll: autoremove wakers even more aggressively") Signed-off-by: Ben Segall Cc: Al Viro Cc: Christian Brauner Cc: Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin --- fs/eventpoll.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 877f9f61a4e8d..8c0e94183186f 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -1814,7 +1814,11 @@ static int ep_autoremove_wake_function(struct wait_queue_entry *wq_entry, { int ret = default_wake_function(wq_entry, mode, sync, key); - list_del_init(&wq_entry->entry); + /* + * Pairs with list_empty_careful in ep_poll, and ensures future loop + * iterations see the cause of this wakeup. + */ + list_del_init_careful(&wq_entry->entry); return ret; } -- 2.39.2