From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 917D9143C6B; Tue, 23 Apr 2024 21:44:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713908649; cv=none; b=FQ4iJtArolGJm1uGho/BkZKIG5yIy7K9n1YmQBg5bjbWOwxPtFjV06ybIJhkzkMlXKgeXG83Q2WEwNexayrSOTbfvVc953DZ1A1iCgVQtrf+IwLRdXR8mXVmMK7nnoF2s/RQeZfuwpd5XfixWnyuLZYbFZFgSYXLLiUAO5a6wzE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713908649; c=relaxed/simple; bh=YRxHusXoakFZBxlZH1Vc98M4cl46zjEhJFKr0ibbCfM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=o8PxKzvMWCmBwKtrlFQAYPrlXbBSHoHkoFX46Ql8gVPD1JrBmIZZKjLM3SdvkeeWrGq4fqSXiVsE/AAbTLlPfDEtSByoT5MTLbxHQwIFnYg6CCPLQ2iIohieo9ZbOmivT7npHw4o8pZnUdv6tkjXzAya66IKQ4eLah4n93zpmkg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=sn3sKbxs; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="sn3sKbxs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66591C3277B; Tue, 23 Apr 2024 21:44:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1713908649; bh=YRxHusXoakFZBxlZH1Vc98M4cl46zjEhJFKr0ibbCfM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sn3sKbxsUBaAORxxwp6ajwQNclUHHYtloUoEw8AmNu3BOy51dxNZtA/nYSxoOAeVk 3GxnMPWKdioxgAMR0a0hBKRXAVHEIAmK7vMuEdodpsmnrxnLaXoMgZOYTT+OKj3PDG mttYzBqWQfv4TxKuwus2LF3WeiEx7VaEQGzYSCXo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Frank Li , Emil Kronborg Subject: [PATCH 6.6 109/158] serial: mxs-auart: add spinlock around changing cts state Date: Tue, 23 Apr 2024 14:39:06 -0700 Message-ID: <20240423213859.289628970@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240423213855.696477232@linuxfoundation.org> References: <20240423213855.696477232@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Emil Kronborg commit 54c4ec5f8c471b7c1137a1f769648549c423c026 upstream. The uart_handle_cts_change() function in serial_core expects the caller to hold uport->lock. For example, I have seen the below kernel splat, when the Bluetooth driver is loaded on an i.MX28 board. [ 85.119255] ------------[ cut here ]------------ [ 85.124413] WARNING: CPU: 0 PID: 27 at /drivers/tty/serial/serial_core.c:3453 uart_handle_cts_change+0xb4/0xec [ 85.134694] Modules linked in: hci_uart bluetooth ecdh_generic ecc wlcore_sdio configfs [ 85.143314] CPU: 0 PID: 27 Comm: kworker/u3:0 Not tainted 6.6.3-00021-gd62a2f068f92 #1 [ 85.151396] Hardware name: Freescale MXS (Device Tree) [ 85.156679] Workqueue: hci0 hci_power_on [bluetooth] (...) [ 85.191765] uart_handle_cts_change from mxs_auart_irq_handle+0x380/0x3f4 [ 85.198787] mxs_auart_irq_handle from __handle_irq_event_percpu+0x88/0x210 (...) Cc: stable@vger.kernel.org Fixes: 4d90bb147ef6 ("serial: core: Document and assert lock requirements for irq helpers") Reviewed-by: Frank Li Signed-off-by: Emil Kronborg Link: https://lore.kernel.org/r/20240320121530.11348-1-emil.kronborg@protonmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/mxs-auart.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/drivers/tty/serial/mxs-auart.c +++ b/drivers/tty/serial/mxs-auart.c @@ -1080,11 +1080,13 @@ static void mxs_auart_set_ldisc(struct u static irqreturn_t mxs_auart_irq_handle(int irq, void *context) { - u32 istat; + u32 istat, stat; struct mxs_auart_port *s = context; u32 mctrl_temp = s->mctrl_prev; - u32 stat = mxs_read(s, REG_STAT); + uart_port_lock(&s->port); + + stat = mxs_read(s, REG_STAT); istat = mxs_read(s, REG_INTR); /* ack irq */ @@ -1120,6 +1122,8 @@ static irqreturn_t mxs_auart_irq_handle( istat &= ~AUART_INTR_TXIS; } + uart_port_unlock(&s->port); + return IRQ_HANDLED; }