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=-8.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 CAD5BC33CB8 for ; Thu, 23 Jan 2020 17:18:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A2E642467E for ; Thu, 23 Jan 2020 17:18:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UDgwVBzZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729152AbgAWRSK (ORCPT ); Thu, 23 Jan 2020 12:18:10 -0500 Received: from mail-pf1-f193.google.com ([209.85.210.193]:38293 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727296AbgAWRSK (ORCPT ); Thu, 23 Jan 2020 12:18:10 -0500 Received: by mail-pf1-f193.google.com with SMTP id x185so1837218pfc.5; Thu, 23 Jan 2020 09:18:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=J1JTF63Y6CzMxj8f1LiDzyUrvtnW4rRNEJCmiTqTTc0=; b=UDgwVBzZnhcvQaZx0mH//TdPlf3Gt4jyCzwd+rkzyX903/m4za7IhsqXAAQsQI3EBE THeC36+wxa5si4l/zbzlCngfI1/v/lXgk45ujsDWmJ3e9D2V+Y7mnHJ3YDEDWal64BF8 Uk0folij7LXBqGQ//PcYaX7bVLorg82w9p5jXg4+xi7ykcDAH089kK/vBzB5oys/KdCY 9Sp9iZByzaGLsfLlOROKHuM7lfcHaFzuh4SRY+O3hPYvE3IYjMfzoQkO5F6XMN7y4S8C CCZuAp6yS/bc3hM7Qq1oNI/aN2fn079sAhVOcRzOrIAeIYYW2Dp5tq8Mh8bdR8srVQr9 NodQ== 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:references :mime-version:content-disposition:in-reply-to:user-agent; bh=J1JTF63Y6CzMxj8f1LiDzyUrvtnW4rRNEJCmiTqTTc0=; b=cGkCIFwOaV+waL8H5SuUO08heyP+qU0y8lThtcwf0r+4ZRqIu7ePhNy/ruA1/Wvktf kCgf8MijngkIoKyhwqhMMWYWCtg5CPMgQ3893h0B3rHpJ5PFkO8ukxdrxVfhBwR+4vHz C8ipAi5ujxuvgYN9PwT+GQ0dvSVbH4esxIm3FMZ4/tw3m7n/cGcHKdom0ejcgH4jK6Nb kAQIt56GM3nK3DvmRZixlM2ZSEuQ2k6PBG1ehg+pmcB0DKu2CgXZYOj4dPM7e0rTMjIA X1GOY7OWmdWSkzwdPJLoXPhDOyDUXwqajDTCtGgxHw9HMs0j6vKPZuIUuRapuM90lmSa Oi5Q== X-Gm-Message-State: APjAAAUHMbzcvjFL+lIWhNGAgxAhe960wASFY7Ni37pABPlqszwxEmcq b3zw7sRdL2jM4ZLi3m9e3Tc= X-Google-Smtp-Source: APXvYqz7qTAcmw9UEgNAfy3malI6VgsOZj09ScBH7BYVJLdSqEWfjSTC8UICf4Yfm6wS7weR9FOztg== X-Received: by 2002:a63:950c:: with SMTP id p12mr5161358pgd.85.1579799889566; Thu, 23 Jan 2020 09:18:09 -0800 (PST) Received: from workstation-portable ([103.211.17.138]) by smtp.gmail.com with ESMTPSA id j9sm3338554pfn.152.2020.01.23.09.18.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Jan 2020 09:18:09 -0800 (PST) Date: Thu, 23 Jan 2020 22:48:00 +0530 From: Amol Grover To: Alexei Starovoitov , Daniel Borkmann , "David S . Miller" , Jesper Dangaard Brouer , John Fastabend , Martin KaFai Lau , Song Liu , Yonghong Song , Andrii Nakryiko , brouer@redhat.com, toke@redhat.com Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org, Joel Fernandes , Madhuparna Bhowmik , "Paul E . McKenney" Subject: Re: [PATCH] bpf: devmap: Pass lockdep expression to RCU lists Message-ID: <20200123171800.GC4484@workstation-portable> References: <20200123120437.26506-1-frextrite@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200123120437.26506-1-frextrite@gmail.com> User-Agent: Mutt/1.12.2 (2019-09-21) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Jan 23, 2020 at 05:34:38PM +0530, Amol Grover wrote: > head is traversed using hlist_for_each_entry_rcu outside an > RCU read-side critical section but under the protection > of dtab->index_lock. > > Hence, add corresponding lockdep expression to silence false-positive > lockdep warnings, and harden RCU lists. > Fixes: 6f9d451ab1a3 ("xdp: Add devmap_hash map type for looking up devices by hashed index") > Signed-off-by: Amol Grover > --- > kernel/bpf/devmap.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c > index 3d3d61b5985b..b4b6b77f309c 100644 > --- a/kernel/bpf/devmap.c > +++ b/kernel/bpf/devmap.c > @@ -293,7 +293,8 @@ struct bpf_dtab_netdev *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key) > struct hlist_head *head = dev_map_index_hash(dtab, key); > struct bpf_dtab_netdev *dev; > > - hlist_for_each_entry_rcu(dev, head, index_hlist) > + hlist_for_each_entry_rcu(dev, head, index_hlist, > + lockdep_is_held(&dtab->index_lock)) > if (dev->idx == key) > return dev; > > -- > 2.24.1 >