From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:58928 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387876AbeIXSmH (ORCPT ); Mon, 24 Sep 2018 14:42:07 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexandre Belloni , Andy Shevchenko , Mark Brown , Sasha Levin Subject: [PATCH 4.18 153/235] spi: dw: fix possible race condition Date: Mon, 24 Sep 2018 13:52:19 +0200 Message-Id: <20180924113120.644318048@linuxfoundation.org> In-Reply-To: <20180924113103.999624566@linuxfoundation.org> References: <20180924113103.999624566@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexandre Belloni [ Upstream commit 66b19d762378785d1568b5650935205edfeb0503 ] It is possible to get an interrupt as soon as it is requested. dw_spi_irq does spi_controller_get_devdata(master) and expects it to be different than NULL. However, spi_controller_set_devdata() is called after request_irq(), resulting in the following crash: CPU 0 Unable to handle kernel paging request at virtual address 00000030, epc == 8058e09c, ra == 8018ff90 [...] Call Trace: [<8058e09c>] dw_spi_irq+0x8/0x64 [<8018ff90>] __handle_irq_event_percpu+0x70/0x1d4 [<80190128>] handle_irq_event_percpu+0x34/0x8c [<801901c4>] handle_irq_event+0x44/0x80 [<801951a8>] handle_level_irq+0xdc/0x194 [<8018f580>] generic_handle_irq+0x38/0x50 [<804c6924>] ocelot_irq_handler+0x104/0x1c0 Signed-off-by: Alexandre Belloni Reviewed-by: Andy Shevchenko Signed-off-by: Mark Brown Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/spi/spi-dw.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/spi/spi-dw.c +++ b/drivers/spi/spi-dw.c @@ -485,6 +485,8 @@ int dw_spi_add_host(struct device *dev, dws->dma_inited = 0; dws->dma_addr = (dma_addr_t)(dws->paddr + DW_SPI_DR); + spi_controller_set_devdata(master, dws); + ret = request_irq(dws->irq, dw_spi_irq, IRQF_SHARED, dev_name(dev), master); if (ret < 0) { @@ -518,7 +520,6 @@ int dw_spi_add_host(struct device *dev, } } - spi_controller_set_devdata(master, dws); ret = devm_spi_register_controller(dev, master); if (ret) { dev_err(&master->dev, "problem registering spi master\n");