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authorSasha Levin <sashal@kernel.org>2020-06-15 17:28:08 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-06-20 10:23:17 +0200
commitefc093e63fa85b1863d900642123f5b84a78a115 (patch)
treeb0eada103b4f2a7ffaadc43cbe228df50b45d711 /drivers/spi
parent7a5764e8990096fd08e8566b87df3c111bf5a736 (diff)
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 <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 <sashal@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 5688591e9cd3..61a951549eba 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -501,6 +501,8 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
snprintf(dws->name, sizeof(dws->name), "dw_spi%d", dws->bus_num);
spin_lock_init(&dws->buf_lock);
+ spi_master_set_devdata(master, dws);
+
ret = request_irq(dws->irq, dw_spi_irq, IRQF_SHARED, dws->name, master);
if (ret < 0) {
dev_err(dev, "can not get IRQ\n");
@@ -532,7 +534,6 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
}
}
- spi_master_set_devdata(master, dws);
ret = devm_spi_register_master(dev, master);
if (ret) {
dev_err(&master->dev, "problem registering spi master\n");