[PATCH 1/2] firmware: arm_ffa: Ensure drivers provide a probe function

[PATCH 1/2] firmware: arm_ffa: Ensure drivers provide a probe function

[Uwe Kleine-König]

The bus probe callback calls the driver callback without further
checking. Better be safe than sorry and refuse registration of a driver
without a probe function to prevent a NULL pointer exception.

Fixes: e781858488b9 ("firmware: arm_ffa: Add initial FFA bus support for device enumeration")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/firmware/arm_ffa/bus.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/firmware/arm_ffa/bus.c b/drivers/firmware/arm_ffa/bus.c
index 83166e02b191..d2cc24319626 100644
--- a/drivers/firmware/arm_ffa/bus.c
+++ b/drivers/firmware/arm_ffa/bus.c
@@ -99,6 +99,9 @@ int ffa_driver_register(struct ffa_driver *driver, struct module *owner,
 {
 	int ret;
 
+	if (!driver->probe)
+		return -EINVAL;
+
 	driver->driver.bus = &ffa_bus_type;
 	driver->driver.name = driver->name;
 	driver->driver.owner = owner;
-- 
2.30.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 2/2] firmware: arm_ffa: Simplify probe function

[Uwe Kleine-König]

When the driver core calls the probe callback it already checked that
the devices match, so there is no need to call the match callback again.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/firmware/arm_ffa/bus.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/firmware/arm_ffa/bus.c b/drivers/firmware/arm_ffa/bus.c
index d2cc24319626..00fe595a5bc8 100644
--- a/drivers/firmware/arm_ffa/bus.c
+++ b/drivers/firmware/arm_ffa/bus.c
@@ -46,9 +46,6 @@ static int ffa_device_probe(struct device *dev)
 	struct ffa_driver *ffa_drv = to_ffa_driver(dev->driver);
 	struct ffa_device *ffa_dev = to_ffa_dev(dev);
 
-	if (!ffa_device_match(dev, dev->driver))
-		return -ENODEV;
-
 	return ffa_drv->probe(ffa_dev);
 }
 
-- 
2.30.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 1/2] firmware: arm_ffa: Ensure drivers provide a probe function

[Sudeep Holla]

On Mon, 21 Jun 2021 22:16:51 +0200, Uwe Kleine-König wrote:
> The bus probe callback calls the driver callback without further
> checking. Better be safe than sorry and refuse registration of a driver
> without a probe function to prevent a NULL pointer exception.


Applied to sudeep.holla/linux (for-next/ffa), thanks!

[1/2] firmware: arm_ffa: Ensure drivers provide a probe function
      https://git.kernel.org/sudeep.holla/c/80421ba63f
[2/2] firmware: arm_ffa: Simplify probe function
      https://git.kernel.org/sudeep.holla/c/bc5ea7449a

--
Regards,
Sudeep


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel