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, 4 insertions, 4 deletions

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 12a707ab73f8..c857dc3975be 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -685,7 +685,7 @@ static const struct hv_vmbus_device_id vmbus_device_null;
  * Return a matching hv_vmbus_device_id pointer.
  * If there is no match, return NULL.
  */
-static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv,
+static const struct hv_vmbus_device_id *hv_vmbus_get_id(const struct hv_driver *drv,
 							struct hv_device *dev)
 {
 	const guid_t *guid = &dev->dev_type;
@@ -696,7 +696,7 @@ static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv,
 		return NULL;
 
 	/* Look at the dynamic ids first, before the static ones */
-	id = hv_vmbus_dynid_match(drv, guid);
+	id = hv_vmbus_dynid_match((struct hv_driver *)drv, guid);
 	if (!id)
 		id = hv_vmbus_dev_match(drv->id_table, guid);
 
@@ -809,9 +809,9 @@ ATTRIBUTE_GROUPS(vmbus_drv);
 /*
  * vmbus_match - Attempt to match the specified device to the specified driver
  */
-static int vmbus_match(struct device *device, struct device_driver *driver)
+static int vmbus_match(struct device *device, const struct device_driver *driver)
 {
-	struct hv_driver *drv = drv_to_hv_drv(driver);
+	const struct hv_driver *drv = drv_to_hv_drv(driver);
 	struct hv_device *hv_dev = device_to_hv_device(device);
 
 	/* The hv_sock driver handles all hv_sock offers. */