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 EB52EC32789 for ; Mon, 22 Aug 2022 13:03:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234611AbiHVNDT (ORCPT ); Mon, 22 Aug 2022 09:03:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40150 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234738AbiHVNC2 (ORCPT ); Mon, 22 Aug 2022 09:02:28 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 419D8356C9 for ; Mon, 22 Aug 2022 06:02:27 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id A8C78CE12B0 for ; Mon, 22 Aug 2022 13:02:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B40FC433C1; Mon, 22 Aug 2022 13:02:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661173344; bh=SRR+8Bo6nSdb+mSUfydpwECvjQpU2VUbRDFmJxIWnC0=; h=Subject:To:Cc:From:Date:From; b=QfPD0o+J87bRZNl3e0ZLQcefaihA4XUoQdP0abmMeirCSH/jq7kh6l/jIxIvPDs3m 26ccE6Q6vPl+dAGXKM/kckQpNy8C+d5UZ26KNeQzeMIoWpelTR18LnKHZ8bJ1qSVcq xCSENvN4/PUO3Ya6fN1jTZMONyTNeBGAKMMQ1Ug0= Subject: FAILED: patch "[PATCH] igb: Add lock to avoid data race" failed to apply to 4.9-stable tree To: linma@zju.edu.cn, anthony.l.nguyen@intel.com, konrad0.jankowski@intel.com, kuba@kernel.org Cc: From: Date: Mon, 22 Aug 2022 15:02:21 +0200 Message-ID: <166117334120467@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 6faee3d4ee8be0f0367d0c3d826afb3571b7a5e0 Mon Sep 17 00:00:00 2001 From: Lin Ma Date: Wed, 17 Aug 2022 11:49:21 -0700 Subject: [PATCH] igb: Add lock to avoid data race The commit c23d92b80e0b ("igb: Teardown SR-IOV before unregister_netdev()") places the unregister_netdev() call after the igb_disable_sriov() call to avoid functionality issue. However, it introduces several race conditions when detaching a device. For example, when .remove() is called, the below interleaving leads to use-after-free. (FREE from device detaching) | (USE from netdev core) igb_remove | igb_ndo_get_vf_config igb_disable_sriov | vf >= adapter->vfs_allocated_count? kfree(adapter->vf_data) | adapter->vfs_allocated_count = 0 | | memcpy(... adapter->vf_data[vf] Moreover, the igb_disable_sriov() also suffers from data race with the requests from VF driver. (FREE from device detaching) | (USE from requests) igb_remove | igb_msix_other igb_disable_sriov | igb_msg_task kfree(adapter->vf_data) | vf < adapter->vfs_allocated_count adapter->vfs_allocated_count = 0 | To this end, this commit first eliminates the data races from netdev core by using rtnl_lock (similar to commit 719479230893 ("dpaa2-eth: add MAC/PHY support through phylink")). And then adds a spinlock to eliminate races from driver requests. (similar to commit 1e53834ce541 ("ixgbe: Add locking to prevent panic when setting sriov_numvfs to zero") Fixes: c23d92b80e0b ("igb: Teardown SR-IOV before unregister_netdev()") Signed-off-by: Lin Ma Tested-by: Konrad Jankowski Signed-off-by: Tony Nguyen Link: https://lore.kernel.org/r/20220817184921.735244-1-anthony.l.nguyen@intel.com Signed-off-by: Jakub Kicinski diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h index 2d3daf022651..015b78144114 100644 --- a/drivers/net/ethernet/intel/igb/igb.h +++ b/drivers/net/ethernet/intel/igb/igb.h @@ -664,6 +664,8 @@ struct igb_adapter { struct igb_mac_addr *mac_table; struct vf_mac_filter vf_macs; struct vf_mac_filter *vf_mac_list; + /* lock for VF resources */ + spinlock_t vfs_lock; }; /* flags controlling PTP/1588 function */ diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index d8b836a85cc3..2796e81d2726 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -3637,6 +3637,7 @@ static int igb_disable_sriov(struct pci_dev *pdev) struct net_device *netdev = pci_get_drvdata(pdev); struct igb_adapter *adapter = netdev_priv(netdev); struct e1000_hw *hw = &adapter->hw; + unsigned long flags; /* reclaim resources allocated to VFs */ if (adapter->vf_data) { @@ -3649,12 +3650,13 @@ static int igb_disable_sriov(struct pci_dev *pdev) pci_disable_sriov(pdev); msleep(500); } - + spin_lock_irqsave(&adapter->vfs_lock, flags); kfree(adapter->vf_mac_list); adapter->vf_mac_list = NULL; kfree(adapter->vf_data); adapter->vf_data = NULL; adapter->vfs_allocated_count = 0; + spin_unlock_irqrestore(&adapter->vfs_lock, flags); wr32(E1000_IOVCTL, E1000_IOVCTL_REUSE_VFQ); wrfl(); msleep(100); @@ -3814,7 +3816,9 @@ static void igb_remove(struct pci_dev *pdev) igb_release_hw_control(adapter); #ifdef CONFIG_PCI_IOV + rtnl_lock(); igb_disable_sriov(pdev); + rtnl_unlock(); #endif unregister_netdev(netdev); @@ -3974,6 +3978,9 @@ static int igb_sw_init(struct igb_adapter *adapter) spin_lock_init(&adapter->nfc_lock); spin_lock_init(&adapter->stats64_lock); + + /* init spinlock to avoid concurrency of VF resources */ + spin_lock_init(&adapter->vfs_lock); #ifdef CONFIG_PCI_IOV switch (hw->mac.type) { case e1000_82576: @@ -7958,8 +7965,10 @@ static void igb_rcv_msg_from_vf(struct igb_adapter *adapter, u32 vf) static void igb_msg_task(struct igb_adapter *adapter) { struct e1000_hw *hw = &adapter->hw; + unsigned long flags; u32 vf; + spin_lock_irqsave(&adapter->vfs_lock, flags); for (vf = 0; vf < adapter->vfs_allocated_count; vf++) { /* process any reset requests */ if (!igb_check_for_rst(hw, vf)) @@ -7973,6 +7982,7 @@ static void igb_msg_task(struct igb_adapter *adapter) if (!igb_check_for_ack(hw, vf)) igb_rcv_ack_from_vf(adapter, vf); } + spin_unlock_irqrestore(&adapter->vfs_lock, flags); } /**