From: Alexandre Belloni Date: Tue, 17 Jul 2018 14:23:10 +0000 (+0200) Subject: spi: dw: fix possible race condition X-Git-Tag: v4.18.10~78 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=b4a9422266f2e81b59c1baad11acb4f0c6c581e7;p=users%2Fdwmw2%2Flinux.git spi: dw: fix possible race condition [ 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 --- diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c index f693bfe95ab9a..a087464efdd75 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");