From a2e20e7f8e57cb0c2f016ae8bcfa01204a9142b4 Mon Sep 17 00:00:00 2001 From: Sudeep Holla Date: Fri, 24 Sep 2021 10:28:58 +0100 Subject: [PATCH] BACKPORT: firmware: arm_ffa: Add missing remove callback to ffa_bus_type 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. Link: https://lore.kernel.org/r/20210924092859.3057562-1-sudeep.holla@arm.com Fixes: e781858488b9 ("firmware: arm_ffa: Add initial FFA bus support for device enumeration") Reported-by: Jens Wiklander Tested-by: Jens Wiklander Signed-off-by: Sudeep Holla (cherry picked from commit 244f5d597e1ea519c2085fbd9819458688775e42) (backported void->int return value for remove callback) Change-Id: Ifc076ec9af4d60d5b7111dbc8ec4c2ad5b441b6f Bug: 168585974 Signed-off-by: Will Deacon --- drivers/firmware/arm_ffa/bus.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/firmware/arm_ffa/bus.c b/drivers/firmware/arm_ffa/bus.c index 00fe595a5bc8..b544c7198111 100644 --- a/drivers/firmware/arm_ffa/bus.c +++ b/drivers/firmware/arm_ffa/bus.c @@ -49,6 +49,15 @@ static int ffa_device_probe(struct device *dev) return ffa_drv->probe(ffa_dev); } +static int ffa_device_remove(struct device *dev) +{ + struct ffa_driver *ffa_drv = to_ffa_driver(dev->driver); + + ffa_drv->remove(to_ffa_dev(dev)); + + return 0; +} + static int ffa_device_uevent(struct device *dev, struct kobj_uevent_env *env) { struct ffa_device *ffa_dev = to_ffa_dev(dev); @@ -86,6 +95,7 @@ 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, };