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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 9A67EC48BD1 for ; Wed, 9 Jun 2021 10:33:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 821DB613AD for ; Wed, 9 Jun 2021 10:33:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238844AbhFIKfe (ORCPT ); Wed, 9 Jun 2021 06:35:34 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:43239 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238903AbhFIKfb (ORCPT ); Wed, 9 Jun 2021 06:35:31 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623234817; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=c/SrqPGFLKHkMSppfFjGdsFHhz75MKKcU6rUhA3fuUE=; b=B0mbVZl/WIpapdiEQ3DlRw6F6/ADNABUPTca/tt0eBYVaITHe+9b8re4k5jgB4J9trOYEq fTgn+Z89Xi9A4zZdPhVkT5PZaNltgHbsBKzHzlHLsgndu8SToTJg1EiDKM3cjVVe67ubeW yuD5S8SV6bmArHxx4EKSEBIx/0k/dV8= Received: from mail-ej1-f69.google.com (mail-ej1-f69.google.com [209.85.218.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-350-nZKnQVf3Mzuix2C7w8fJRw-1; Wed, 09 Jun 2021 06:33:33 -0400 X-MC-Unique: nZKnQVf3Mzuix2C7w8fJRw-1 Received: by mail-ej1-f69.google.com with SMTP id w13-20020a170906384db02903d9ad6b26d8so7865976ejc.0 for ; Wed, 09 Jun 2021 03:33:33 -0700 (PDT) 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=c/SrqPGFLKHkMSppfFjGdsFHhz75MKKcU6rUhA3fuUE=; b=DS6ns9gvJ/sMouuV5Ggb3DyahKxJEj7X1XUpXfU55GIybC0rXSPOX//sYSW37HIV+l C0ROtB0I+ZlVEI5mser8nBj06xN13Qo+DtnKyvb3+jRmvKpUK2BxMrtDRX3WBZnLzjEe NxzOM2W5F8qPXjL6AtenSKmpH03d0TtekSKG/CymnRNiXUcWVFZJnx/NE4UNavksK8xm I8w0yTbfUuPyUTPc5wExMLj9optDsDnh0pt+IKbPVzm+jBCfnI4qvlgbEzZYQ7Bd3P6t SBGuLWK1X2T2YV2oO5+QVzUG3xw0/3CcE0GkDDL5OGm0EFgOz+zekhdzkAzMPfe/ZQw5 TSew== X-Gm-Message-State: AOAM533EkF5RNG4IVWl1O8wK7ImfsFL67N0I+c4LCRtZfn+88JTig8Qq qYxTYomveZr51FFh5Znd+Lst+GC6eZGnT7ndIqCGS/3gIzSYOe4FaQvbTMxHBofRO6fZsUU6QOy LFJLXqm15a5Cl X-Received: by 2002:a17:906:7052:: with SMTP id r18mr27442490ejj.449.1623234812601; Wed, 09 Jun 2021 03:33:32 -0700 (PDT) X-Google-Smtp-Source: ABdhPJy4/qlqfnwcNgWwFsRkkZlUJhNrhFNB6oEw7PGNWLub37Dm+YNrF8XK6GjyP+L1HoY7Bz9mQQ== X-Received: by 2002:a17:906:7052:: with SMTP id r18mr27442470ejj.449.1623234812401; Wed, 09 Jun 2021 03:33:32 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk ([45.145.92.2]) by smtp.gmail.com with ESMTPSA id n26sm930539ejc.27.2021.06.09.03.33.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Jun 2021 03:33:32 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 6E3F3180727; Wed, 9 Jun 2021 12:33:30 +0200 (CEST) From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= To: bpf@vger.kernel.org, netdev@vger.kernel.org Cc: Martin KaFai Lau , Hangbin Liu , Jesper Dangaard Brouer , Magnus Karlsson , "Paul E . McKenney" , =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Subject: [PATCH bpf-next 03/17] dev: add rcu_read_lock_bh_held() as a valid check when getting a RCU dev ref Date: Wed, 9 Jun 2021 12:33:12 +0200 Message-Id: <20210609103326.278782-4-toke@redhat.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210609103326.278782-1-toke@redhat.com> References: <20210609103326.278782-1-toke@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Some of the XDP helpers (in particular, xdp_do_redirect()) will get a struct net_device reference using dev_get_by_index_rcu(). These are called from a NAPI poll context, which means the RCU reference liveness is ensured by local_bh_disable(). Add rcu_read_lock_bh_held() as a condition to the RCU list traversal in dev_get_by_index_rcu() so lockdep understands that the dereferences are safe from *both* an rcu_read_lock() *and* with local_bh_disable(). Signed-off-by: Toke Høiland-Jørgensen --- net/core/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/dev.c b/net/core/dev.c index febb23708184..a499c5ffe4a5 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1002,7 +1002,7 @@ struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex) struct net_device *dev; struct hlist_head *head = dev_index_hash(net, ifindex); - hlist_for_each_entry_rcu(dev, head, index_hlist) + hlist_for_each_entry_rcu(dev, head, index_hlist, rcu_read_lock_bh_held()) if (dev->ifindex == ifindex) return dev; -- 2.31.1