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=-4.0 required=3.0 tests=BAYES_00,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 307A3C433E0 for ; Sun, 9 Aug 2020 15:32:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ECE942068F for ; Sun, 9 Aug 2020 15:32:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=networkplumber-org.20150623.gappssmtp.com header.i=@networkplumber-org.20150623.gappssmtp.com header.b="iOpaCFmG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726234AbgHIPcr (ORCPT ); Sun, 9 Aug 2020 11:32:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43238 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726175AbgHIPcq (ORCPT ); Sun, 9 Aug 2020 11:32:46 -0400 Received: from mail-pj1-x102e.google.com (mail-pj1-x102e.google.com [IPv6:2607:f8b0:4864:20::102e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A7E07C061756 for ; Sun, 9 Aug 2020 08:32:44 -0700 (PDT) Received: by mail-pj1-x102e.google.com with SMTP id kr4so3436912pjb.2 for ; Sun, 09 Aug 2020 08:32:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=rPxyoRq/TgJI7TmnhLluclJ2I+ZFZughTp/LX9Coaw4=; b=iOpaCFmGyC92qRmorEb34NeTPlHMbjBYO+tqhodBUh/xg5tGr1y0Gwq1qRnVIcpDaB KkCzJ+Sd3kqCa2NwxwVNxY/D2a8Yt6fU6Ov2rz6MgFQGzD+dKzrIaPVMpYXTZoPnsU2l 3U9GXq9p37TajqA2ZZ8Lf/oNTj3w/zajUpk625ISL6/60pDy2J4YNsHfWxQQxTLWSeUM wfb4ukCc/HLOmvLcgb9qekBzMEzJEMUK0mZXLMMDnm2CAEt+ZlqylDEqQVD2eR1Pr0mh WZDuDXRORfEPp3phUwrfjGuiR1343qPt4UGXpEHlx/f5fwGMxn3rY3TZk8yqmSA5h9L+ dA5g== 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:mime-version:content-transfer-encoding; bh=rPxyoRq/TgJI7TmnhLluclJ2I+ZFZughTp/LX9Coaw4=; b=Nr4CtX+5cxKSb3WR2n7ykfzYP55rx7ZVG8p37jGPNd5ghiQsej1/SK2OUWLLXqbAJI 8AWYELZV4aMU0js5/9txKnd78bR8l3bp/Wv4p/xsw0w065zV8ZqmaNbAthGckcKalYYx WB1JJjmWJqZyCtxCZdJY01MEuBaNW9KNWf61KbiaIotM5tVhE6BhWXWL5yzvrOKuTC+7 Kw6LefGMfbPnGvwjpvbARY/JKvdVKikZRiUwBBo2qgaEjh8M6mWhNAc2kM+k4pyKtRYn J73+d11paBJlwwwFssuc85C44NpMHIGL3Pm/XrwLdDrnS6z/UA/iEEW3msxdHrhKZCy0 zvUQ== X-Gm-Message-State: AOAM533EBPRvI/PXCOcus1zsRRWDXlqdChGNjJwh8PmNyLx/ZFQ3XX0g uE/TwQ1r5N8ngZf9lXmI1A3m11oSrFw= X-Google-Smtp-Source: ABdhPJwqk9PUEwC3ca7WjB9rPPo3HAr7ihKiqA9SI3OSR7Ww/ZgiK1N768wophtGobV7i5vY8Wylkw== X-Received: by 2002:a17:90a:414d:: with SMTP id m13mr22309053pjg.163.1596987162218; Sun, 09 Aug 2020 08:32:42 -0700 (PDT) Received: from hermes.lan (204-195-22-127.wavecable.com. [204.195.22.127]) by smtp.gmail.com with ESMTPSA id q25sm15995539pfn.181.2020.08.09.08.32.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 09 Aug 2020 08:32:41 -0700 (PDT) Date: Sun, 9 Aug 2020 08:32:33 -0700 From: Stephen Hemminger To: Hillf Danton Cc: Rasmus Villemoes , Nikolay Aleksandrov , Network Development , Markus Elfring Subject: Re: rtnl_trylock() versus SCHED_FIFO lockup Message-ID: <20200809083233.00822e44@hermes.lan> In-Reply-To: <20200809134924.12056-1-hdanton@sina.com> References: <20200805163425.6c13ef11@hermes.lan> <191e0da8-178f-5f91-3d37-9b7cefb61352@prevas.dk> <2a6edf25-b12b-c500-ad33-c0ec9e60cde9@cumulusnetworks.com> <20200806203922.3d687bf2@hermes.lan> <29a82363-411c-6f2b-9f55-97482504e453@prevas.dk> <20200809134924.12056-1-hdanton@sina.com> 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 Sun, 9 Aug 2020 21:49:24 +0800 Hillf Danton wrote: > + > +static void br_workfn(struct work_struct *w) > +{ > + struct br_work *brw = container_of(w, struct br_work, work); > + > + rtnl_lock(); > + brw->err = brw->set(brw->br, brw->val); > + if (!brw->err) > + netdev_state_change(brw->br->dev); > + rtnl_unlock(); > + > + brw->done = true; > + wake_up(&brw->waitq); > +} Sorry, this is unsafe. This has the potential of running when bridge itself has been deleted.