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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 932E5C5519F for ; Fri, 20 Nov 2020 09:53:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2A5632222F for ; Fri, 20 Nov 2020 09:53:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="IoAvqT5J" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727123AbgKTJxI (ORCPT ); Fri, 20 Nov 2020 04:53:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45604 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726293AbgKTJxI (ORCPT ); Fri, 20 Nov 2020 04:53:08 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 07FAAC0613CF for ; Fri, 20 Nov 2020 01:53:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=taXbEmbJ23h3ZZoR5OLcqyWWYe4ykcWqY5PbOPgOoY4=; b=IoAvqT5JWJK7x+dMpKMaAuGydq G4FcNPnbsRwQ6AtQydMVRwpmh/lvKLzoJVmmVJIzPvAmg20Wb1l+hoj/X/SepMWCYW2C0Z1FCziCR c2ioRfn782gePuDnDG6O/1T67Gv+8nwljg7cnr/TpBYYu2l4MGzgJwqw3IdJmmUq39WcVLx2tKa4p q7gfo8oucyXhLZOfxFOluVd/j0N9PzdCXCPaHs17yu5whsKzxrWBet1YfWCTvPjjFfBkTsurVj7nx BCRjXOn2nqJUDvme30ZEDri9bZMAreTxOxNRXQIbqyBvIaibqZEBpzLcs49SF2JZ4D4B4J0LYMYMf 3bwBBdRQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kg36E-0006ez-Fm; Fri, 20 Nov 2020 09:53:02 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 18164304D28; Fri, 20 Nov 2020 10:53:02 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 02B692B06A309; Fri, 20 Nov 2020 10:53:01 +0100 (CET) Date: Fri, 20 Nov 2020 10:53:01 +0100 From: Peter Zijlstra To: subashab@codeaurora.org Cc: Florian Westphal , Will Deacon , pablo@netfilter.org, Sean Tranchetti , netfilter-devel@vger.kernel.org, tglx@linutronix.de Subject: Re: [PATCH nf] x_tables: Properly close read section with read_seqcount_retry Message-ID: <20201120095301.GB3092@hirez.programming.kicks-ass.net> References: <983d178e6f3aac81d491362ab60db61f@codeaurora.org> <20201116182028.GE22792@breakpoint.cc> <20201118121322.GA1821@willie-the-truck> <20201118124228.GJ22792@breakpoint.cc> <20201118125406.GA2029@willie-the-truck> <20201118131419.GK22792@breakpoint.cc> <7d52f54a7e3ebc794f0b775e793ab142@codeaurora.org> <20201118211007.GA15137@breakpoint.cc> <7d8bc917b7a6790fa789085ba8324b08@codeaurora.org> <20201120094413.GA3040@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201120094413.GA3040@hirez.programming.kicks-ass.net> Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org On Fri, Nov 20, 2020 at 10:44:13AM +0100, Peter Zijlstra wrote: > On Thu, Nov 19, 2020 at 10:53:13PM -0700, subashab@codeaurora.org wrote: > > +struct xt_table_info > > +*xt_table_get_private_protected(const struct xt_table *table) > > +{ > > + return rcu_dereference_protected(table->private, > > + mutex_is_locked(&xt[table->af].mutex)); > > +} > > +EXPORT_SYMBOL(xt_table_get_private_protected); > > In all debug builds this function compiles to a single memory ! went missing... :/ > dereference. Do you really want that out-of-line?