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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 27B34C433E1 for ; Wed, 27 May 2020 17:08:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0717520873 for ; Wed, 27 May 2020 17:08:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=cloudflare.com header.i=@cloudflare.com header.b="UbtuMdTd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731132AbgE0RIt (ORCPT ); Wed, 27 May 2020 13:08:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41134 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729875AbgE0RIq (ORCPT ); Wed, 27 May 2020 13:08:46 -0400 Received: from mail-ej1-x643.google.com (mail-ej1-x643.google.com [IPv6:2a00:1450:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 124BCC03E97D for ; Wed, 27 May 2020 10:08:46 -0700 (PDT) Received: by mail-ej1-x643.google.com with SMTP id x1so28949265ejd.8 for ; Wed, 27 May 2020 10:08:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=4aNYzFZ3HQztQJxIHCfXbNBHtKfIZ7aoRnKs0QLw/oE=; b=UbtuMdTdaVEj1t1nuIVBixpqHZcjOrac9qGZFczd4DtMvVa+hiueDk/NSOW5GT8KRZ YqwyEP2w42/7XndFUvr6Cn4+/LAKTrUD/GMxTlcMgoxZ4I4VQCtBAjZrJzl8VCUmISrP rhm+Cu02/+iztj1R2eXop3lJwrDBagqKqUKpk= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=4aNYzFZ3HQztQJxIHCfXbNBHtKfIZ7aoRnKs0QLw/oE=; b=bXAP+ElFEHfcCpUjan/mz1ZVheYZiww13NdB5aTGdwhLdqHu4Am/XrsPRpLtRH5YkG Vov+NUwpcsShaLh6L2LAVqImZLXmR61ttY0zt0oWdE3FPFY5+LUm4uTZu8KphUuUBHTO +24XCblrXStevTNrd4fuX/125G2Tafsh2aGu3cg19CviwbtjArTJJ1QKLoUihUM4pVxe Wx9OF4y52FrxvfBueSev/UrASpycSJpLsEvBq2kS/EMjETxQ/cKXz1QKy2QxoZPPawco yjYeoV6iT66uzBUQkkYZSiKunskIm9RoyTdZ6P9f+UOnniPbNY1tHRPfpnWssh/dTa/C /vug== X-Gm-Message-State: AOAM533X96wBVUFJr89UHzpUEJ6nnUZ1ivLlOeZ8m4Cxi7za8TgXlfMD a30fj1xfdgxbuzEcYVqWckWAZS/6FSg= X-Google-Smtp-Source: ABdhPJxM1aq2ausULE8+zhL4DTIGQiqUBoIXA++dwmTCA8sckm6c+YMf2xtAt2Xwf/NVatKH5l7TYg== X-Received: by 2002:a17:906:eda5:: with SMTP id sa5mr6871910ejb.289.1590599324729; Wed, 27 May 2020 10:08:44 -0700 (PDT) Received: from cloudflare.com ([2a02:a310:c262:aa00:b35e:8938:2c2a:ba8b]) by smtp.gmail.com with ESMTPSA id e9sm2716447edl.25.2020.05.27.10.08.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 27 May 2020 10:08:44 -0700 (PDT) From: Jakub Sitnicki To: bpf@vger.kernel.org Cc: netdev@vger.kernel.org, kernel-team@cloudflare.com Subject: [PATCH bpf-next 2/8] flow_dissector: Pull locking up from prog attach callback Date: Wed, 27 May 2020 19:08:34 +0200 Message-Id: <20200527170840.1768178-3-jakub@cloudflare.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20200527170840.1768178-1-jakub@cloudflare.com> References: <20200527170840.1768178-1-jakub@cloudflare.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Split out the part of attach callback that happens with attach/detach lock acquired. This structures the prog attach callback similar to prog detach, and opens up doors for moving the locking out of flow_dissector and into generic callbacks for attaching/detaching progs to netns in subsequent patches. Signed-off-by: Jakub Sitnicki --- net/core/flow_dissector.c | 40 +++++++++++++++++++-------------------- 1 file changed, 20 insertions(+), 20 deletions(-) diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 73cc085dc2b7..4f73f6c51602 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -109,15 +109,10 @@ int skb_flow_dissector_prog_query(const union bpf_attr *attr, return 0; } -int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr, - struct bpf_prog *prog) +static int flow_dissector_bpf_prog_attach(struct net *net, + struct bpf_prog *prog) { struct bpf_prog *attached; - struct net *net; - int ret = 0; - - net = current->nsproxy->net_ns; - mutex_lock(&flow_dissector_mutex); if (net == &init_net) { /* BPF flow dissector in the root namespace overrides @@ -130,33 +125,38 @@ int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr, for_each_net(ns) { if (ns == &init_net) continue; - if (rcu_access_pointer(ns->flow_dissector_prog)) { - ret = -EEXIST; - goto out; - } + if (rcu_access_pointer(ns->flow_dissector_prog)) + return -EEXIST; } } else { /* Make sure root flow dissector is not attached * when attaching to the non-root namespace. */ - if (rcu_access_pointer(init_net.flow_dissector_prog)) { - ret = -EEXIST; - goto out; - } + if (rcu_access_pointer(init_net.flow_dissector_prog)) + return -EEXIST; } attached = rcu_dereference_protected(net->flow_dissector_prog, lockdep_is_held(&flow_dissector_mutex)); - if (attached == prog) { + if (attached == prog) /* The same program cannot be attached twice */ - ret = -EINVAL; - goto out; - } + return -EINVAL; + rcu_assign_pointer(net->flow_dissector_prog, prog); if (attached) bpf_prog_put(attached); -out: + return 0; +} + +int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr, + struct bpf_prog *prog) +{ + int ret; + + mutex_lock(&flow_dissector_mutex); + ret = flow_dissector_bpf_prog_attach(current->nsproxy->net_ns, prog); mutex_unlock(&flow_dissector_mutex); + return ret; } -- 2.25.4