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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 D6AE1C35250 for ; Sun, 9 Feb 2020 13:02:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AB5CC20733 for ; Sun, 9 Feb 2020 13:02:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581253350; bh=BUivcDV2LVBIkC7rFeUNgi6D41Jri7KRmfGnlnlxg+c=; h=Subject:To:Cc:From:Date:List-ID:From; b=M/9G5A96z71SqEd0WJ6118svHNN6tIBWsKxBFb6Q+taUOonJAk73EfyFzhshXONm7 b7XfI6sggHvTHUy8QrWft42cnUIRFpn6UnylhpRu24h4vGoxeqbyps1Si0MT2KGnVq HdgLLEzN6hEh7Nc0NIeYtEHGF33y+HVHTz32g2js= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727698AbgBINCa (ORCPT ); Sun, 9 Feb 2020 08:02:30 -0500 Received: from out5-smtp.messagingengine.com ([66.111.4.29]:58323 "EHLO out5-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727473AbgBINCa (ORCPT ); Sun, 9 Feb 2020 08:02:30 -0500 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailout.nyi.internal (Postfix) with ESMTP id 0F06621B2C; Sun, 9 Feb 2020 08:02:29 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute6.internal (MEProxy); Sun, 09 Feb 2020 08:02:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=HihXDd H3KCGqJ7/dsJpZkXckx4P5a+qjzV+D5c8rhWE=; b=cfDrpunkxbSAU4A2X5AgOw z0Vn9gww4vzfkHU6qeZFv36da3PgyLN8JQBBc7Z7Pl/asaLFF+CNrJ0rkqWG0De8 /ZLp3gvnkY0q2kRqcPAu6bICaCpqc6jteQY8vj17B440HGYzMNcBCGNUrjKrmvQd snuMluQ7r5TY19SA+PM5tAfZYPj9Yddkhb1OmmuspQ2H+yg8v3JOs1Zhl1SiwJNF BZT90EfPKZHFUsb1HWKjrY0RBntstCe8BjiH2JJyEiU8OtLlbc9egJZjV8xJbfRE Nb2NXcXhoWk3WBg9y+XFIEHQ6ZL9C/JTMnQ1PktzMt1QD2/avWO/jmWfcCl1VrVA == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedugedrheelgddvgecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecunecujfgurhepuffvhfffkfggtgfgsehtkeertddttd flnecuhfhrohhmpeeoghhrvghgkhhhsehlihhnuhigfhhouhhnuggrthhiohhnrdhorhhg qeenucfkphepfeekrdelkedrfeejrddufeehnecuvehluhhsthgvrhfuihiivgepuddvne curfgrrhgrmhepmhgrihhlfhhrohhmpehgrhgvgheskhhrohgrhhdrtghomh X-ME-Proxy: Received: from localhost (unknown [38.98.37.135]) by mail.messagingengine.com (Postfix) with ESMTPA id AB88A30600DC; Sun, 9 Feb 2020 08:02:27 -0500 (EST) Subject: FAILED: patch "[PATCH] platform/mellanox: fix potential deadlock in the tmfifo" failed to apply to 5.5-stable tree To: lsun@mellanox.com, andriy.shevchenko@linux.intel.com, dwoods@mellanox.com, stable@vger.kernel.org Cc: From: Date: Sun, 09 Feb 2020 12:39:11 +0100 Message-ID: <1581248351144103@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.5-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 3454eeeebd115891f34aa2e76eccf08c9b0882bb Mon Sep 17 00:00:00 2001 From: Liming Sun Date: Fri, 20 Dec 2019 12:04:33 -0500 Subject: [PATCH] platform/mellanox: fix potential deadlock in the tmfifo driver This commit fixes the potential deadlock caused by the console Rx and Tx processing at the same time. Rx and Tx both take the console and tmfifo spinlock but in different order which causes potential deadlock. The fix is to use different tmfifo spinlock for Rx and Tx since they protect different resources and it's safe to split the lock. Below is the reported call trace when copying/pasting large string in the console. Rx: _raw_spin_lock_irqsave (hvc lock) __hvc_poll hvc_poll in_intr vring_interrupt mlxbf_tmfifo_rxtx_one_desc (tmfifo lock) mlxbf_tmfifo_rxtx mlxbf_tmfifo_work_rxtx Tx: _raw_spin_lock_irqsave (tmfifo lock) mlxbf_tmfifo_virtio_notify virtqueue_notify virtqueue_kick put_chars hvc_push hvc_write (hvc lock) ... do_tty_write tty_write Fixes: 1357dfd7261f ("platform/mellanox: Add TmFifo driver for Mellanox BlueField Soc") Cc: # 5.4+ Reviewed-by: David Woods Signed-off-by: Liming Sun Signed-off-by: Andy Shevchenko diff --git a/drivers/platform/mellanox/mlxbf-tmfifo.c b/drivers/platform/mellanox/mlxbf-tmfifo.c index 9a5c9fd2dbc6..5739a9669b29 100644 --- a/drivers/platform/mellanox/mlxbf-tmfifo.c +++ b/drivers/platform/mellanox/mlxbf-tmfifo.c @@ -149,7 +149,7 @@ struct mlxbf_tmfifo_irq_info { * @work: work struct for deferred process * @timer: background timer * @vring: Tx/Rx ring - * @spin_lock: spin lock + * @spin_lock: Tx/Rx spin lock * @is_ready: ready flag */ struct mlxbf_tmfifo { @@ -164,7 +164,7 @@ struct mlxbf_tmfifo { struct work_struct work; struct timer_list timer; struct mlxbf_tmfifo_vring *vring[2]; - spinlock_t spin_lock; /* spin lock */ + spinlock_t spin_lock[2]; /* spin lock */ bool is_ready; }; @@ -525,7 +525,7 @@ static void mlxbf_tmfifo_console_tx(struct mlxbf_tmfifo *fifo, int avail) writeq(*(u64 *)&hdr, fifo->tx_base + MLXBF_TMFIFO_TX_DATA); /* Use spin-lock to protect the 'cons->tx_buf'. */ - spin_lock_irqsave(&fifo->spin_lock, flags); + spin_lock_irqsave(&fifo->spin_lock[0], flags); while (size > 0) { addr = cons->tx_buf.buf + cons->tx_buf.tail; @@ -552,7 +552,7 @@ static void mlxbf_tmfifo_console_tx(struct mlxbf_tmfifo *fifo, int avail) } } - spin_unlock_irqrestore(&fifo->spin_lock, flags); + spin_unlock_irqrestore(&fifo->spin_lock[0], flags); } /* Rx/Tx one word in the descriptor buffer. */ @@ -731,9 +731,9 @@ static bool mlxbf_tmfifo_rxtx_one_desc(struct mlxbf_tmfifo_vring *vring, fifo->vring[is_rx] = NULL; /* Notify upper layer that packet is done. */ - spin_lock_irqsave(&fifo->spin_lock, flags); + spin_lock_irqsave(&fifo->spin_lock[is_rx], flags); vring_interrupt(0, vring->vq); - spin_unlock_irqrestore(&fifo->spin_lock, flags); + spin_unlock_irqrestore(&fifo->spin_lock[is_rx], flags); } mlxbf_tmfifo_desc_done: @@ -852,10 +852,10 @@ static bool mlxbf_tmfifo_virtio_notify(struct virtqueue *vq) * worker handler. */ if (vring->vdev_id == VIRTIO_ID_CONSOLE) { - spin_lock_irqsave(&fifo->spin_lock, flags); + spin_lock_irqsave(&fifo->spin_lock[0], flags); tm_vdev = fifo->vdev[VIRTIO_ID_CONSOLE]; mlxbf_tmfifo_console_output(tm_vdev, vring); - spin_unlock_irqrestore(&fifo->spin_lock, flags); + spin_unlock_irqrestore(&fifo->spin_lock[0], flags); } else if (test_and_set_bit(MLXBF_TM_TX_LWM_IRQ, &fifo->pend_events)) { return true; @@ -1189,7 +1189,8 @@ static int mlxbf_tmfifo_probe(struct platform_device *pdev) if (!fifo) return -ENOMEM; - spin_lock_init(&fifo->spin_lock); + spin_lock_init(&fifo->spin_lock[0]); + spin_lock_init(&fifo->spin_lock[1]); INIT_WORK(&fifo->work, mlxbf_tmfifo_work_handler); mutex_init(&fifo->lock);