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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 32030C3A589 for ; Thu, 15 Aug 2019 21:38:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EF792206C1 for ; Thu, 15 Aug 2019 21:38:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=netronome-com.20150623.gappssmtp.com header.i=@netronome-com.20150623.gappssmtp.com header.b="H9ze0nzk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731539AbfHOVi0 (ORCPT ); Thu, 15 Aug 2019 17:38:26 -0400 Received: from mail-qt1-f196.google.com ([209.85.160.196]:37066 "EHLO mail-qt1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728283AbfHOViZ (ORCPT ); Thu, 15 Aug 2019 17:38:25 -0400 Received: by mail-qt1-f196.google.com with SMTP id y26so3958978qto.4 for ; Thu, 15 Aug 2019 14:38:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netronome-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :organization:mime-version:content-transfer-encoding; bh=7RjFhH6dS5ryo8FppK0a6qd+bmHzUr1mS9Tjvl8f9Xg=; b=H9ze0nzk6Ys63BibLvJCx1XQtGLvrmRz0XBkMa0V38lvqjiKhq+YyTYWMt/fFtchDW KRu7+T413iq15r7Jw7+O5apzJJi/hptumY/OrV6VVQDtaJGj2/j4XVWDu1QCZivQKYe9 mBymRihkyxBP73gFi8mi+bZG7WbPfnwT0A7EhJqrr1ZXalJxAoSkDQWFvmR774999xvt RBAElb1pbQSANNGpyzGJOJu7cRMMvgLKwSto3eQkL4VK38/bH5UFjJmg2dQSlyUxSZBp TnmhipB/hLDYVJTetxOjj9oZA+nWrja3I8vjgGtb6ipW+WtbGr8whLNEsAQTijndbTTO BIAA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:organization:mime-version:content-transfer-encoding; bh=7RjFhH6dS5ryo8FppK0a6qd+bmHzUr1mS9Tjvl8f9Xg=; b=bW8kgdU99eOGVK+lmiv6f2Evmeb21uI1wMBkv5E8NMzidkS7dBhNhIa5JJhMbErSih ePNxmuzz3zB3fbwvLyVczeyjxb2pgi2XD46eLfpzUHN2EKsTOg7xfyAKMh/6ClfQG8hG 2pvDArna8VciatXVQI8CAgD6pmdPTaudCkTjoxTwdMF3XsWd3nck5RFCGQgyj6VeK34X Le5M0m5QrBAFjpOA446pzpyX5QDtf+fxFDH7AZwGGBrMmOhuM/gXORyYY68S84RTr7LP qzNuFLDQiZjKk63UesJpDftKoJsibbtKhZdHTKor9EiEoozjuS4wdrXCTFAIgqhTPAQz mebw== X-Gm-Message-State: APjAAAXl31tGZi92Fp+oSbk7ZyHDkw1m51ASg5+UtDHomUKSkUa84ORO AOMgYbolJOLtb8NOhnHA3qXmVg== X-Google-Smtp-Source: APXvYqzMHgW4n4enlc9GDOdNi5gmHUYqKqHG+9ImxJBV701czliMZZ4iivhk7+rOfTatE8GIfPwEZg== X-Received: by 2002:ac8:550f:: with SMTP id j15mr5923046qtq.25.1565905104815; Thu, 15 Aug 2019 14:38:24 -0700 (PDT) Received: from cakuba.netronome.com ([66.60.152.14]) by smtp.gmail.com with ESMTPSA id u23sm2059600qkj.98.2019.08.15.14.38.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 15 Aug 2019 14:38:24 -0700 (PDT) Date: Thu, 15 Aug 2019 14:38:10 -0700 From: Jakub Kicinski To: Eric Dumazet Cc: Davide Caratti , Boris Pismenny , John Fastabend , Dave Watson , Aviad Yehezkel , "David S. Miller" , netdev@vger.kernel.org Subject: Re: [PATCH net-next 2/3] tcp: ulp: add functions to dump ulp-specific information Message-ID: <20190815143810.3a190c81@cakuba.netronome.com> In-Reply-To: <228db5cc-9b10-521f-9031-e0f86f5ded3e@gmail.com> References: <228db5cc-9b10-521f-9031-e0f86f5ded3e@gmail.com> Organization: Netronome Systems, Ltd. MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, 15 Aug 2019 20:46:01 +0200, Eric Dumazet wrote: > On 8/15/19 6:00 PM, Davide Caratti wrote: > > > > > + if (net_admin) { > > + const struct tcp_ulp_ops *ulp_ops; > > + > > + rcu_read_lock(); > > + ulp_ops = icsk->icsk_ulp_ops; > > + if (ulp_ops) > > + err = tcp_diag_put_ulp(skb, sk, ulp_ops); > > + rcu_read_unlock(); > > + if (err) > > + return err; > > + } > > return 0; > > > Why is rcu_read_lock() and rcu_read_unlock() used at all ? > > icsk->icsk_ulp_ops does not seem to be rcu protected ? > > If this was, then an rcu_dereference() would be appropriate. Indeed it's ulp_data not ulp_ops that are protected. Davide, perhaps we could push the RCU lock into tls_get_info(), after all? And tls_context has to use rcu_deference there, as Eric points out, plus we should probably NULL-check it.