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=-19.1 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, URIBL_BLOCKED,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 6C7BEC433DB for ; Fri, 5 Feb 2021 21:35:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 13D8264E33 for ; Fri, 5 Feb 2021 21:35:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229988AbhBEVe7 (ORCPT ); Fri, 5 Feb 2021 16:34:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:45592 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233019AbhBEPAA (ORCPT ); Fri, 5 Feb 2021 10:00:00 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4024F65052; Fri, 5 Feb 2021 14:12:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1612534338; bh=OCMQnjJPCi1dx8063Pqa+B+Pdskt7p/0dDR+1YtO/bk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1eayAgjLpRfth3mB8RHOikfw9Qr+X0QUHQklUgw5m8ewqqXpPE0SKZQ2AmouTpysF 8tdZMvYlaquY7OVGFUwm9d7JA+4dfvekuHo/xM16wE3JTfv0xhGLYygAE3wAakkSro MEJO3eBzb3mz3/a8laE17FpFVgu+3fxuutv7oXLA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Petr Machata , Rasmus Villemoes , Jakub Kicinski Subject: [PATCH 5.4 02/32] net: switchdev: dont set port_obj_info->handled true when -EOPNOTSUPP Date: Fri, 5 Feb 2021 15:07:17 +0100 Message-Id: <20210205140652.456963490@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210205140652.348864025@linuxfoundation.org> References: <20210205140652.348864025@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rasmus Villemoes commit 20776b465c0c249f5e5b5b4fe077cd24ef1cda86 upstream. It's not true that switchdev_port_obj_notify() only inspects the ->handled field of "struct switchdev_notifier_port_obj_info" if call_switchdev_blocking_notifiers() returns 0 - there's a WARN_ON() triggering for a non-zero return combined with ->handled not being true. But the real problem here is that -EOPNOTSUPP is not being properly handled. The wrapper functions switchdev_handle_port_obj_add() et al change a return value of -EOPNOTSUPP to 0, and the treatment of ->handled in switchdev_port_obj_notify() seems to be designed to change that back to -EOPNOTSUPP in case nobody actually acted on the notifier (i.e., everybody returned -EOPNOTSUPP). Currently, as soon as some device down the stack passes the check_cb() check, ->handled gets set to true, which means that switchdev_port_obj_notify() cannot actually ever return -EOPNOTSUPP. This, for example, means that the detection of hardware offload support in the MRP code is broken: switchdev_port_obj_add() used by br_mrp_switchdev_send_ring_test() always returns 0, so since the MRP code thinks the generation of MRP test frames has been offloaded, no such frames are actually put on the wire. Similarly, br_mrp_switchdev_set_ring_role() also always returns 0, causing mrp->ring_role_offloaded to be set to 1. To fix this, continue to set ->handled true if any callback returns success or any error distinct from -EOPNOTSUPP. But if all the callbacks return -EOPNOTSUPP, make sure that ->handled stays false, so the logic in switchdev_port_obj_notify() can propagate that information. Fixes: 9a9f26e8f7ea ("bridge: mrp: Connect MRP API with the switchdev API") Fixes: f30f0601eb93 ("switchdev: Add helpers to aid traversal through lower devices") Reviewed-by: Petr Machata Signed-off-by: Rasmus Villemoes Link: https://lore.kernel.org/r/20210125124116.102928-1-rasmus.villemoes@prevas.dk Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/switchdev/switchdev.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) --- a/net/switchdev/switchdev.c +++ b/net/switchdev/switchdev.c @@ -461,10 +461,11 @@ static int __switchdev_handle_port_obj_a extack = switchdev_notifier_info_to_extack(&port_obj_info->info); if (check_cb(dev)) { - /* This flag is only checked if the return value is success. */ - port_obj_info->handled = true; - return add_cb(dev, port_obj_info->obj, port_obj_info->trans, - extack); + err = add_cb(dev, port_obj_info->obj, port_obj_info->trans, + extack); + if (err != -EOPNOTSUPP) + port_obj_info->handled = true; + return err; } /* Switch ports might be stacked under e.g. a LAG. Ignore the @@ -513,9 +514,10 @@ static int __switchdev_handle_port_obj_d int err = -EOPNOTSUPP; if (check_cb(dev)) { - /* This flag is only checked if the return value is success. */ - port_obj_info->handled = true; - return del_cb(dev, port_obj_info->obj); + err = del_cb(dev, port_obj_info->obj); + if (err != -EOPNOTSUPP) + port_obj_info->handled = true; + return err; } /* Switch ports might be stacked under e.g. a LAG. Ignore the @@ -563,9 +565,10 @@ static int __switchdev_handle_port_attr_ int err = -EOPNOTSUPP; if (check_cb(dev)) { - port_attr_info->handled = true; - return set_cb(dev, port_attr_info->attr, - port_attr_info->trans); + err = set_cb(dev, port_attr_info->attr, port_attr_info->trans); + if (err != -EOPNOTSUPP) + port_attr_info->handled = true; + return err; } /* Switch ports might be stacked under e.g. a LAG. Ignore the