Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753676AbdFOR7m (ORCPT ); Thu, 15 Jun 2017 13:59:42 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:54876 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753653AbdFOR7j (ORCPT ); Thu, 15 Jun 2017 13:59:39 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Chan , "David S. Miller" , Sasha Levin Subject: [PATCH 4.9 076/108] bnxt_en: Fix RTNL lock usage on bnxt_update_link(). Date: Thu, 15 Jun 2017 19:53:22 +0200 Message-Id: <20170615175340.778411130@linuxfoundation.org> X-Mailer: git-send-email 2.13.1 In-Reply-To: <20170615175337.190782107@linuxfoundation.org> References: <20170615175337.190782107@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3674 Lines: 99 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michael Chan [ Upstream commit 0eaa24b971ae251ae9d3be23f77662a655532063 ] bnxt_update_link() is called from multiple code paths. Most callers, such as open, ethtool, already hold RTNL. Only the caller bnxt_sp_task() does not. So it is a bug to take RTNL inside bnxt_update_link(). Fix it by removing the RTNL inside bnxt_update_link(). The function now expects the caller to always hold RTNL. In bnxt_sp_task(), call bnxt_rtnl_lock_sp() before calling bnxt_update_link(). We also need to move the call to the end of bnxt_sp_task() since it will be clearing the BNXT_STATE_IN_SP_TASK bit. Signed-off-by: Michael Chan Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/broadcom/bnxt/bnxt.c | 37 ++++++++++++++---------------- 1 file changed, 18 insertions(+), 19 deletions(-) --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -5204,17 +5204,12 @@ static int bnxt_update_link(struct bnxt if ((link_info->support_auto_speeds | diff) != link_info->support_auto_speeds) { /* An advertised speed is no longer supported, so we need to - * update the advertisement settings. See bnxt_reset() for - * comments about the rtnl_lock() sequence below. + * update the advertisement settings. Caller holds RTNL + * so we can modify link settings. */ - clear_bit(BNXT_STATE_IN_SP_TASK, &bp->state); - rtnl_lock(); link_info->advertising = link_info->support_auto_speeds; - if (test_bit(BNXT_STATE_OPEN, &bp->state) && - (link_info->autoneg & BNXT_AUTONEG_SPEED)) + if (link_info->autoneg & BNXT_AUTONEG_SPEED) bnxt_hwrm_set_link_setting(bp, true, false); - set_bit(BNXT_STATE_IN_SP_TASK, &bp->state); - rtnl_unlock(); } return 0; } @@ -6130,7 +6125,6 @@ static void bnxt_cfg_ntp_filters(struct static void bnxt_sp_task(struct work_struct *work) { struct bnxt *bp = container_of(work, struct bnxt, sp_task); - int rc; set_bit(BNXT_STATE_IN_SP_TASK, &bp->state); smp_mb__after_atomic(); @@ -6144,16 +6138,6 @@ static void bnxt_sp_task(struct work_str if (test_and_clear_bit(BNXT_RX_NTP_FLTR_SP_EVENT, &bp->sp_event)) bnxt_cfg_ntp_filters(bp); - if (test_and_clear_bit(BNXT_LINK_CHNG_SP_EVENT, &bp->sp_event)) { - if (test_and_clear_bit(BNXT_LINK_SPEED_CHNG_SP_EVENT, - &bp->sp_event)) - bnxt_hwrm_phy_qcaps(bp); - - rc = bnxt_update_link(bp, true); - if (rc) - netdev_err(bp->dev, "SP task can't update link (rc: %x)\n", - rc); - } if (test_and_clear_bit(BNXT_HWRM_EXEC_FWD_REQ_SP_EVENT, &bp->sp_event)) bnxt_hwrm_exec_fwd_req(bp); if (test_and_clear_bit(BNXT_VXLAN_ADD_PORT_SP_EVENT, &bp->sp_event)) { @@ -6183,6 +6167,21 @@ static void bnxt_sp_task(struct work_str /* These functions below will clear BNXT_STATE_IN_SP_TASK. They * must be the last functions to be called before exiting. */ + if (test_and_clear_bit(BNXT_LINK_CHNG_SP_EVENT, &bp->sp_event)) { + int rc = 0; + + if (test_and_clear_bit(BNXT_LINK_SPEED_CHNG_SP_EVENT, + &bp->sp_event)) + bnxt_hwrm_phy_qcaps(bp); + + bnxt_rtnl_lock_sp(bp); + if (test_bit(BNXT_STATE_OPEN, &bp->state)) + rc = bnxt_update_link(bp, true); + bnxt_rtnl_unlock_sp(bp); + if (rc) + netdev_err(bp->dev, "SP task can't update link (rc: %x)\n", + rc); + } if (test_and_clear_bit(BNXT_RESET_TASK_SP_EVENT, &bp->sp_event)) bnxt_reset(bp, false);