The patch spi: dw: fix possible race condition has been applied to the spi tree at https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark >From 66b19d762378785d1568b5650935205edfeb0503 Mon Sep 17 00:00:00 2001 From: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> Date: Tue, 17 Jul 2018 16:23:10 +0200 Subject: [PATCH] spi: dw: fix possible race condition 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@xxxxxxxxxxx> Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> --- 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"); -- 2.18.0 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
