| From | Sasha Levin <> | Subject | [PATCH AUTOSEL 4.18 08/92] spi: dw: fix possible race condition | Date | Sat, 15 Sep 2018 01:29:54 +0000 |
| |
From: Alexandre Belloni <alexandre.belloni@bootlin.com>
[ 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 <alexandre.belloni@bootlin.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> --- drivers/spi/spi-dw.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c index f693bfe95ab9..a087464efdd7 100644 --- a/drivers/spi/spi-dw.c +++ b/drivers/spi/spi-dw.c @@ -485,6 +485,8 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws) 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, struct dw_spi *dws) } } - spi_controller_set_devdata(master, dws); ret = devm_spi_register_controller(dev, master); if (ret) { dev_err(&master->dev, "problem registering spi master\n"); -- 2.17.1
|