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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 DC933C33CB3 for ; Thu, 16 Jan 2020 19:11:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B7ADD206E6 for ; Thu, 16 Jan 2020 19:11:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579201912; bh=HhTOEnfVPXjkdgMI5j2Rj7f81dghYJkTfY6kVie9fZE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=hFoVmSvmgSBwFQxoc9tFgEKHDioDOo+AYK8uznpNaQ/MiKphUrXiHnzWTkXq0LT+K nqNmpk/nOI4zUC7kkOPBVV0jmjRXsLsH6vPO79OpMahsvqqcNlp3V0BKWy1FS8ApXS 5tIcLByzCmQDtRauNgPfdIUE1mLkvtQu8zJTERtA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387683AbgAPRAK (ORCPT ); Thu, 16 Jan 2020 12:00:10 -0500 Received: from mail.kernel.org ([198.145.29.99]:49578 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387676AbgAPRAJ (ORCPT ); Thu, 16 Jan 2020 12:00:09 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7CD6624686; Thu, 16 Jan 2020 17:00:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579194008; bh=HhTOEnfVPXjkdgMI5j2Rj7f81dghYJkTfY6kVie9fZE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DhjDfcP4eTcGSP5jAbPvpQSQibbmMz/2JbyYcM2bXtWx598RB7tyL+NMkp2QC9LEH TQL53P+c/angnZ9Izpw3u5E4Po4euHD/PkV5FVffy34n6f6pCBxBT6pSAnM86TZMcn N+67QuqMHr5xKLtEQj0XjL5BrP72vym8Yq5EEniQ= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Moni Shoua , Leon Romanovsky , Saeed Mahameed , Sasha Levin , netdev@vger.kernel.org, linux-rdma@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 133/671] net/mlx5: Take lock with IRQs disabled to avoid deadlock Date: Thu, 16 Jan 2020 11:50:42 -0500 Message-Id: <20200116165940.10720-16-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116165940.10720-1-sashal@kernel.org> References: <20200116165940.10720-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: Moni Shoua [ Upstream commit 33814e5d127e21f53b52e17b0722c1b57d4f4d29 ] The lock in qp_table might be taken from process context or from interrupt context. This may lead to a deadlock unless it is taken with IRQs disabled. Discovered by lockdep ================================ WARNING: inconsistent lock state 4.20.0-rc6 -------------------------------- inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} python/12572 [HC1[1]:SC0[0]:HE0:SE1] takes: 00000000052a4df4 (&(&table->lock)->rlock#2){?.+.}, /0x50 [mlx5_core] {HARDIRQ-ON-W} state was registered at: _raw_spin_lock+0x33/0x70 mlx5_get_rsc+0x1a/0x50 [mlx5_core] mlx5_ib_eqe_pf_action+0x493/0x1be0 [mlx5_ib] process_one_work+0x90c/0x1820 worker_thread+0x87/0xbb0 kthread+0x320/0x3e0 ret_from_fork+0x24/0x30 irq event stamp: 103928 hardirqs last enabled at (103927): [] nk+0x1a/0x1c hardirqs last disabled at (103928): [] unk+0x1a/0x1c softirqs last enabled at (103924): [] tcp_sendmsg+0x31/0x40 softirqs last disabled at (103922): [] 80 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&table->lock)->rlock#2); lock(&(&table->lock)->rlock#2); *** DEADLOCK *** Fixes: 032080ab43ac ("IB/mlx5: Lock QP during page fault handling") Signed-off-by: Moni Shoua Reviewed-by: Leon Romanovsky Signed-off-by: Saeed Mahameed Signed-off-by: Sasha Levin --- drivers/net/ethernet/mellanox/mlx5/core/qp.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/qp.c b/drivers/net/ethernet/mellanox/mlx5/core/qp.c index f33707ce8b6b..479ac21cdbc6 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/qp.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/qp.c @@ -44,14 +44,15 @@ static struct mlx5_core_rsc_common *mlx5_get_rsc(struct mlx5_core_dev *dev, { struct mlx5_qp_table *table = &dev->priv.qp_table; struct mlx5_core_rsc_common *common; + unsigned long flags; - spin_lock(&table->lock); + spin_lock_irqsave(&table->lock, flags); common = radix_tree_lookup(&table->tree, rsn); if (common) atomic_inc(&common->refcount); - spin_unlock(&table->lock); + spin_unlock_irqrestore(&table->lock, flags); if (!common) { mlx5_core_warn(dev, "Async event for bogus resource 0x%x\n", -- 2.20.1