| Message ID | 20210924092859.3057562-1-sudeep.holla@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] firmware: arm_ffa: Add missing remove callback to ffa_bus_type | expand |
On Fri, Sep 24, 2021 at 11:29 AM Sudeep Holla <sudeep.holla@arm.com> wrote: > > Currently the arm_ffa firmware driver can be built as module and hence > all the users of FFA driver. If any driver on the ffa bus is removed or > unregistered, the remove callback on all the device bound to the driver > being removed should be callback. For that to happen, we must register > a remove callback on the ffa_bus which is currently missing. This results > in the probe getting called again without the previous remove callback > on a device which may result in kernel crash. > > Fix the issue by registering the remove callback on the FFA bus. > > Fixes: e781858488b9 ("firmware: arm_ffa: Add initial FFA bus support for device enumeration") > Reported-by: Jens Wiklander <jens.wiklander@linaro.org> > Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> > --- > drivers/firmware/arm_ffa/bus.c | 8 ++++++++ > 1 file changed, 8 insertions(+) Tested-by: Jens Wiklander <jens.wiklander@linaro.org>
On Fri, 24 Sep 2021 10:28:58 +0100, Sudeep Holla wrote: > Currently the arm_ffa firmware driver can be built as module and hence > all the users of FFA driver. If any driver on the ffa bus is removed or > unregistered, the remove callback on all the device bound to the driver > being removed should be callback. For that to happen, we must register > a remove callback on the ffa_bus which is currently missing. This results > in the probe getting called again without the previous remove callback > on a device which may result in kernel crash. > > [...] Applied to sudeep.holla/linux (for-next/ffa), thanks! [1/2] firmware: arm_ffa: Add missing remove callback to ffa_bus_type https://git.kernel.org/sudeep.holla/c/244f5d597e [2/2] firmware: arm_ffa: Fix __ffa_devices_unregister https://git.kernel.org/sudeep.holla/c/eb7b52e6db -- Regards, Sudeep
diff --git a/drivers/firmware/arm_ffa/bus.c b/drivers/firmware/arm_ffa/bus.c index 00fe595a5bc8..f01348e6cf1c 100644 --- a/drivers/firmware/arm_ffa/bus.c +++ b/drivers/firmware/arm_ffa/bus.c @@ -49,6 +49,13 @@ static int ffa_device_probe(struct device *dev) return ffa_drv->probe(ffa_dev); } +static void ffa_device_remove(struct device *dev) +{ + struct ffa_driver *ffa_drv = to_ffa_driver(dev->driver); + + ffa_drv->remove(to_ffa_dev(dev)); +} + static int ffa_device_uevent(struct device *dev, struct kobj_uevent_env *env) { struct ffa_device *ffa_dev = to_ffa_dev(dev); @@ -86,6 +93,7 @@ struct bus_type ffa_bus_type = { .name = "arm_ffa", .match = ffa_device_match, .probe = ffa_device_probe, + .remove = ffa_device_remove, .uevent = ffa_device_uevent, .dev_groups = ffa_device_attributes_groups, };
Currently the arm_ffa firmware driver can be built as module and hence all the users of FFA driver. If any driver on the ffa bus is removed or unregistered, the remove callback on all the device bound to the driver being removed should be callback. For that to happen, we must register a remove callback on the ffa_bus which is currently missing. This results in the probe getting called again without the previous remove callback on a device which may result in kernel crash. Fix the issue by registering the remove callback on the FFA bus. Fixes: e781858488b9 ("firmware: arm_ffa: Add initial FFA bus support for device enumeration") Reported-by: Jens Wiklander <jens.wiklander@linaro.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> --- drivers/firmware/arm_ffa/bus.c | 8 ++++++++ 1 file changed, 8 insertions(+) -- 2.25.1