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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0C48BC433EF for ; Tue, 17 May 2022 03:43:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233060AbiEQDnI (ORCPT ); Mon, 16 May 2022 23:43:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45560 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232341AbiEQDnG (ORCPT ); Mon, 16 May 2022 23:43:06 -0400 Received: from mail-pg1-x52e.google.com (mail-pg1-x52e.google.com [IPv6:2607:f8b0:4864:20::52e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A72BE27B04 for ; Mon, 16 May 2022 20:43:05 -0700 (PDT) Received: by mail-pg1-x52e.google.com with SMTP id h186so13220178pgc.3 for ; Mon, 16 May 2022 20:43:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=RZLhxx6MlZqNRCdcVJVHbSsteOlQC1pIs7RcktbmMu8=; b=NtawI9Ip81UQhVvPQo0Da4dcjHoRoVqAEAwk1UcuOPe1pwJBB/dTVSvYxp2mgjFkor gh7k0SHnk9impQHDo0O/5VTwLcMuS8fdbZfkoAIIrw5XQ5d3QsSdKeSW29216syzIlNu A5nM1taw+GbvScWxqChasirT4ZdVRL0bgwLRS0KKPzkr4PVxbkr/zQYlORP9I3jAncE0 0uDcz4UV23ZAcMWd5T86Si051sgG0vUx6XZhWIo7Va/09Vcm474+HeP+JemqcGXI/Rl1 2ebCtixQRhzUm7OPl7Ph1XIGKfi/49RM2/1l3e/mqBli1a+jK+3Li0Ois3kBsctSNTFA VN/g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=RZLhxx6MlZqNRCdcVJVHbSsteOlQC1pIs7RcktbmMu8=; b=6U8ABMF1EYd+gcTkPpmv7fzNjOvOwmOeRzQJzwB75E8YeVjtScsOKmfereypqq9jol l4CRTH3EHR7DXOHZc8Q08BAb3rpqp1UrSed99Dq35gndLejcvwCb5YJIWJGiaGGwRCXS v+lc8RSGGVzBiDnf0A4NzfUL0vwMJq9PaEzXcCus43a/GUlACyksM85PrgRuwAPxQNcM QFXzVkT2Ohz4/2sKTfvIQtFLrbRk2LvkGPn2UEPJb4lHOQRBqJnqmu+9vPBVPabPWvNo DyVz+yOoMnfvp1oI6S4ZQjm1/2qrv3h+tzApxpgoPexz4lFhXnwSz3IfUijdRakCZ39C YgQw== X-Gm-Message-State: AOAM5331zQ5GOT/pXQGxZO6Gl8DrGYK4mUpJiBmU14QA1e9Dsp4YezdN 9O/OKG2JYlRbaWH8H1rVYlo= X-Google-Smtp-Source: ABdhPJyS839djlzQlIBO8IF8MxH295znaIXa3/QzcR/aY3RCV5qS4H65coQj2QZFPkh/LYq7eXMIQg== X-Received: by 2002:a65:694a:0:b0:3db:141c:6db2 with SMTP id w10-20020a65694a000000b003db141c6db2mr17600608pgq.198.1652758985071; Mon, 16 May 2022 20:43:05 -0700 (PDT) Received: from Laptop-X1 ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id l1-20020a170903244100b0015ea4173bd6sm7953084pls.195.2022.05.16.20.42.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 16 May 2022 20:43:04 -0700 (PDT) Date: Tue, 17 May 2022 11:42:54 +0800 From: Hangbin Liu To: Jakub Kicinski Cc: netdev@vger.kernel.org, Jay Vosburgh , Veaceslav Falico , Andy Gospodarek , "David S . Miller" , David Ahern , Jonathan Toppins , Eric Dumazet , Paolo Abeni , syzbot+92beb3d46aab498710fa@syzkaller.appspotmail.com, Vladimir Oltean Subject: Re: [PATCH RESEND net] bonding: fix missed rcu protection Message-ID: References: <20220513103350.384771-1-liuhangbin@gmail.com> <20220516181028.7dbbf918@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220516181028.7dbbf918@kernel.org> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, May 16, 2022 at 06:10:28PM -0700, Jakub Kicinski wrote: > Can't ->get_ts_info sleep now? It'd be a little sad to force it > to be atomic just because of one upper dev trying to be fancy. > Maybe all we need to do is to take a ref on the real_dev? Do you mean diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 38e152548126..b60450211579 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -5591,16 +5591,20 @@ static int bond_ethtool_get_ts_info(struct net_device *bond_dev, const struct ethtool_ops *ops; struct net_device *real_dev; struct phy_device *phydev; + int ret = 0; real_dev = bond_option_active_slave_get_rcu(bond); if (real_dev) { + dev_hold(real_dev) ops = real_dev->ethtool_ops; phydev = real_dev->phydev; if (phy_has_tsinfo(phydev)) { - return phy_ts_info(phydev, info); + ret = phy_ts_info(phydev, info); + goto out; } else if (ops->get_ts_info) { - return ops->get_ts_info(real_dev, info); + ret = ops->get_ts_info(real_dev, info); + goto out; } } @@ -5608,7 +5612,10 @@ static int bond_ethtool_get_ts_info(struct net_device *bond_dev, SOF_TIMESTAMPING_SOFTWARE; info->phc_index = -1; - return 0; +out: + if (real_dev) + dev_put(real_dev); + return ret; } This look OK to me. Vladimir, Jay, WDYT? > > Also please add a Link: to the previous discussion, it'd have been > useful to get the context in which Vladimir suggested this. OK, I will. Thanks Hangbin