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=-2.5 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 2F2BDC282E1 for ; Wed, 24 Apr 2019 00:12:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F0F37218FC for ; Wed, 24 Apr 2019 00:12:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=fomichev-me.20150623.gappssmtp.com header.i=@fomichev-me.20150623.gappssmtp.com header.b="s6nhwvfR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728559AbfDXAMJ (ORCPT ); Tue, 23 Apr 2019 20:12:09 -0400 Received: from mail-pf1-f193.google.com ([209.85.210.193]:37151 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727831AbfDXAMJ (ORCPT ); Tue, 23 Apr 2019 20:12:09 -0400 Received: by mail-pf1-f193.google.com with SMTP id 8so8319828pfr.4 for ; Tue, 23 Apr 2019 17:12:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fomichev-me.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=NAqZicel5yW3F1h3BQXm8xfCpsAdHRvGDjuMUeIa3RA=; b=s6nhwvfR1xYwja2NUT13GQfQIpffFA9UCtdCCpvrGfviUioABQacpr3ZXODwp+aHaP 2PbFoLvkubk1caDkmNQsQ1VzOvNOraDKUOjTNMYt2xnsu0pLgtJE8OyinnDx1ya6YJsR ObSOA/gGbtyE2q1kF4zJc5hmk+MXATM0kbgShYwQfxoi6XeLfTrncFGo01ZuZCWntVLY sAbwew0ZCqH6DIEMOetdPfZcdb0h21wjiqttdmMTYcBxA28ndtDCL8aQVfvilUiJMH48 4Dc6SSZ3iS40d5K7VhGbuB1UndzYWMnnkYEmoj7oY+d85exLgZUMnLlszHhWjwBu9TKv nHbA== 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=NAqZicel5yW3F1h3BQXm8xfCpsAdHRvGDjuMUeIa3RA=; b=LGcAVDYz0YS1CvVljanxWNSsCVvwSR21IKaQMlyJ+kJRj/q2y6YQeBo/V13neZarTM O6b9lGi+drTxh8jXAJohtIiHSKuPSqYNgj1ed8LsEdfee5w3E8+23YJXmoyAgNm/D/Ni hc/NzYqAnkDQzHvc6iursYPfKVIBd1g0eAO4GhqRLjUSVhdS9AO46sJK++0RNEffcLSO uLUwPPKgXOMhHZTWKsRwYwEAnRfEEevlpEtqVFLcaiQp2gt2RoS5AJ0ffewdD4mGE+/j Xt6mHi/geA0287TaQzFYojond139VJeTwE0zLJL8+H5rIUwtxtfgd+RkWA6f7BO5iVjo u2ew== X-Gm-Message-State: APjAAAUQfQb2UIbFGcZocjQ4z9sAgWv+UfyCtEQMBxG+GN+i0n8+tRMX 2XMD2xjlA1JASiXivCH4X9wZtQ== X-Google-Smtp-Source: APXvYqz0sxphtushKPN/M2VLvo0tabEIwWlQgfSHC9xxk67xxOGnXKTNeczv42u/E3RwM8s+tkPBJA== X-Received: by 2002:a65:43c8:: with SMTP id n8mr26616337pgp.365.1556064728342; Tue, 23 Apr 2019 17:12:08 -0700 (PDT) Received: from localhost ([2601:646:8f00:18d9:d0fa:7a4b:764f:de48]) by smtp.gmail.com with ESMTPSA id h20sm46077872pfj.40.2019.04.23.17.12.07 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 23 Apr 2019 17:12:07 -0700 (PDT) Date: Tue, 23 Apr 2019 17:12:06 -0700 From: Stanislav Fomichev To: Jakub Kicinski Cc: Stanislav Fomichev , netdev@vger.kernel.org, bpf@vger.kernel.org, davem@davemloft.net, ast@kernel.org, daniel@iogearbox.net, quentin.monnet@netronome.com Subject: Re: [PATCH bpf-next 1/2] bpf: support BPF_PROG_QUERY for BPF_FLOW_DISSECTOR attach_type Message-ID: <20190424001206.GA1247@mini-arch> References: <20190423232200.101627-1-sdf@google.com> <20190423162855.4580667d@cakuba.netronome.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190423162855.4580667d@cakuba.netronome.com> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 04/23, Jakub Kicinski wrote: > On Tue, 23 Apr 2019 16:21:59 -0700, Stanislav Fomichev wrote: > > + rcu_read_lock(); > > + attached = rcu_dereference(net->flow_dissector_prog); > > + if (attached) { > > + cnt = 1; > > + if (prog_ids && > > + copy_to_user(prog_ids, &attached->aux->id, sizeof(u32))) { > > Not sure you can do copy_to_user inside an RCU section, doesn't it > sleep? Good point, I need to copy that aux->id somewhere and exit rcu section. > > + rcu_read_unlock(); > > + return -EFAULT; > > + } > > + } > > + rcu_read_unlock(); >