driver core: have match() callback in struct bus_type take a const *

In the match() callback, the struct device_driver * should not be
changed, so change the function callback to be a const *.  This is one
step of many towards making the driver core safe to have struct
device_driver in read-only memory.

Because the match() callback is in all busses, all busses are modified
to handle this properly.  This does entail switching some container_of()
calls to container_of_const() to properly handle the constant *.

For some busses, like PCI and USB and HV, the const * is cast away in
the match callback as those busses do want to modify those structures at
this point in time (they have a local lock in the driver structure.)
That will have to be changed in the future if they wish to have their
struct device * in read-only-memory.

Cc: Rafael J. Wysocki <rafael@kernel.org>
Reviewed-by: Alex Elder <elder@kernel.org>
Acked-by: Sumit Garg <sumit.garg@linaro.org>
Link: https://lore.kernel.org/r/2024070136-wrongdoer-busily-01e8@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/bcma/main.c b/drivers/bcma/main.c
index 6b5d34919c72..6ecfc821cf83 100644
--- a/drivers/bcma/main.c
+++ b/drivers/bcma/main.c
@@ -26,7 +26,7 @@ static unsigned int bcma_bus_next_num;
 /* bcma_buses_mutex locks the bcma_bus_next_num */
 static DEFINE_MUTEX(bcma_buses_mutex);
 
-static int bcma_bus_match(struct device *dev, struct device_driver *drv);
+static int bcma_bus_match(struct device *dev, const struct device_driver *drv);
 static int bcma_device_probe(struct device *dev);
 static void bcma_device_remove(struct device *dev);
 static int bcma_device_uevent(const struct device *dev, struct kobj_uevent_env *env);
@@ -584,10 +584,10 @@ void bcma_driver_unregister(struct bcma_driver *drv)
 }
 EXPORT_SYMBOL_GPL(bcma_driver_unregister);
 
-static int bcma_bus_match(struct device *dev, struct device_driver *drv)
+static int bcma_bus_match(struct device *dev, const struct device_driver *drv)
 {
 	struct bcma_device *core = container_of(dev, struct bcma_device, dev);
-	struct bcma_driver *adrv = container_of(drv, struct bcma_driver, drv);
+	const struct bcma_driver *adrv = container_of_const(drv, struct bcma_driver, drv);
 	const struct bcma_device_id *cid = &core->id;
 	const struct bcma_device_id *did;