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 B4788FA3743 for ; Fri, 28 Oct 2022 22:31:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229765AbiJ1Wbj (ORCPT ); Fri, 28 Oct 2022 18:31:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47212 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229678AbiJ1Wbi (ORCPT ); Fri, 28 Oct 2022 18:31:38 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1269BDFB78; Fri, 28 Oct 2022 15:31:36 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 5D94D62AC3; Fri, 28 Oct 2022 22:31:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1A8BFC433D6; Fri, 28 Oct 2022 22:31:33 +0000 (UTC) Date: Fri, 28 Oct 2022 18:31:49 -0400 From: Steven Rostedt To: Linus Torvalds Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , Stephen Boyd , Guenter Roeck , Jesse Brandeburg , Tony Nguyen , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Mirko Lindner , Stephen Hemminger , Martin KaFai Lau , Alexei Starovoitov , Kuniyuki Iwashima , Pavel Begunkov , Menglong Dong , linux-usb@vger.kernel.org, linux-wireless@vger.kernel.org, bridge@lists.linux-foundation.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, lvs-devel@vger.kernel.org, linux-afs@lists.infradead.org, linux-nfs@vger.kernel.org, tipc-discussion@lists.sourceforge.net Subject: Re: [RFC][PATCH v2 19/31] timers: net: Use del_timer_shutdown() before freeing timer Message-ID: <20221028183149.2882a29b@gandalf.local.home> In-Reply-To: <20221027183511.66b058c4@gandalf.local.home> References: <20221027150525.753064657@goodmis.org> <20221027150928.780676863@goodmis.org> <20221027155513.60b211e2@gandalf.local.home> <20221027163453.383bbf8e@gandalf.local.home> <20221027170720.31497319@gandalf.local.home> <20221027183511.66b058c4@gandalf.local.home> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Could someone from networking confirm (or deny) that the timer being removed in sk_stop_timer() will no longer be used even if del_timer() returns false? net/core/sock.c: void sk_stop_timer(struct sock *sk, struct timer_list* timer) { if (del_timer(timer)) __sock_put(sk); } If this is the case, then I'll add the following interface: del_timer_sync_shutdown() // the common case which syncs del_timer_shutdown() // the uncommon case, that returns immediately // used for those cases that add extra code to // handle it, like sk_stop_timer() Which has the same semantics as del_timer_sync() and del_timer() respectively, but will prevent the timer from being rearmed again. This way we can convert the sk_stop_timer() to: void sk_stop_timer(struct sock *sk, struct timer_list* timer) { if (del_timer_shutdown(timer)) __sock_put(sk); } We can also add the del_timer_shutdown() to other locations that need to put a timer into a shutdown state before freeing, and where it's in a context that can not call del_timer_sync_shutdown(). -- Steve