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 8AC79C27C76 for ; Sun, 22 Jan 2023 15:22:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231280AbjAVPWN (ORCPT ); Sun, 22 Jan 2023 10:22:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49694 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231283AbjAVPWM (ORCPT ); Sun, 22 Jan 2023 10:22:12 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B51F22791 for ; Sun, 22 Jan 2023 07:21:51 -0800 (PST) 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 ams.source.kernel.org (Postfix) with ESMTPS id 1B6BEB80B22 for ; Sun, 22 Jan 2023 15:21:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 765DAC433AC; Sun, 22 Jan 2023 15:21:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1674400909; bh=D6s/yyyaUWdS5aQRr0KLWg1UG3ODLc97Z3aGGYAuOFQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZTpQN1vk7j6V+Rpics61wnhQ7lXS47f7Pbeurm7XcTItyFVO5auFV8PrRVzMJ4R0I o62blBNXE+CqvWheiGnxgvive7/w1terpilGY8lTLOJGDoXT+cFyIK8AB3olgLyVZ3 SoDp7TphiPOIAsjWIrB8yZaTh2LJYm2h/lh3Vpes= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eli Cohen , "Michael S. Tsirkin" , Sasha Levin Subject: [PATCH 6.1 009/193] vdpa/mlx5: Avoid using reslock in event_handler Date: Sun, 22 Jan 2023 16:02:18 +0100 Message-Id: <20230122150246.800880121@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230122150246.321043584@linuxfoundation.org> References: <20230122150246.321043584@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eli Cohen [ Upstream commit 0dbc1b4ae07d003b2e88ba9d4142846320f8e349 ] event_handler runs under atomic context and may not acquire reslock. We can still guarantee that the handler won't be called after suspend by clearing nb_registered, unregistering the handler and flushing the workqueue. Signed-off-by: Eli Cohen Message-Id: <20221114131759.57883-5-elic@nvidia.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin --- drivers/vdpa/mlx5/net/mlx5_vnet.c | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-) diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c index b06260a37680..98dd8ce8af26 100644 --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c @@ -2845,8 +2845,8 @@ static int mlx5_vdpa_suspend(struct vdpa_device *vdev) int i; down_write(&ndev->reslock); - mlx5_notifier_unregister(mvdev->mdev, &ndev->nb); ndev->nb_registered = false; + mlx5_notifier_unregister(mvdev->mdev, &ndev->nb); flush_workqueue(ndev->mvdev.wq); for (i = 0; i < ndev->cur_num_vqs; i++) { mvq = &ndev->vqs[i]; @@ -3024,7 +3024,7 @@ static void update_carrier(struct work_struct *work) else ndev->config.status &= cpu_to_mlx5vdpa16(mvdev, ~VIRTIO_NET_S_LINK_UP); - if (ndev->config_cb.callback) + if (ndev->nb_registered && ndev->config_cb.callback) ndev->config_cb.callback(ndev->config_cb.private); kfree(wqent); @@ -3041,21 +3041,13 @@ static int event_handler(struct notifier_block *nb, unsigned long event, void *p switch (eqe->sub_type) { case MLX5_PORT_CHANGE_SUBTYPE_DOWN: case MLX5_PORT_CHANGE_SUBTYPE_ACTIVE: - down_read(&ndev->reslock); - if (!ndev->nb_registered) { - up_read(&ndev->reslock); - return NOTIFY_DONE; - } wqent = kzalloc(sizeof(*wqent), GFP_ATOMIC); - if (!wqent) { - up_read(&ndev->reslock); + if (!wqent) return NOTIFY_DONE; - } wqent->mvdev = &ndev->mvdev; INIT_WORK(&wqent->work, update_carrier); queue_work(ndev->mvdev.wq, &wqent->work); - up_read(&ndev->reslock); ret = NOTIFY_OK; break; default: @@ -3242,8 +3234,8 @@ static void mlx5_vdpa_dev_del(struct vdpa_mgmt_dev *v_mdev, struct vdpa_device * struct workqueue_struct *wq; if (ndev->nb_registered) { - mlx5_notifier_unregister(mvdev->mdev, &ndev->nb); ndev->nb_registered = false; + mlx5_notifier_unregister(mvdev->mdev, &ndev->nb); } wq = mvdev->wq; mvdev->wq = NULL; -- 2.35.1