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authorAlexandre Belloni <alexandre.belloni@bootlin.com>2018-07-17 16:23:10 +0200
committerMark Brown <broonie@kernel.org>2018-07-18 13:21:33 +0100
commit66b19d762378785d1568b5650935205edfeb0503 (patch)
tree397e6a3f84beb9f367dba8f2705ac8cf63f86893 /drivers/spi
parent2ba87a9bcc7a10aa28af9fbf5b4354b3168366e2 (diff)
downloadlinux-66b19d762378785d1568b5650935205edfeb0503.tar.bz2
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@bootlin.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-dw.c3
1 files changed, 2 insertions, 1 deletions
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");