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/thunderbolt/domain.c b/drivers/thunderbolt/domain.c
index 0023017299f7..144d0232a70c 100644
--- a/drivers/thunderbolt/domain.c
+++ b/drivers/thunderbolt/domain.c
@@ -45,9 +45,9 @@ static bool match_service_id(const struct tb_service_id *id,
 }
 
 static const struct tb_service_id *__tb_service_match(struct device *dev,
-						      struct device_driver *drv)
+						      const struct device_driver *drv)
 {
-	struct tb_service_driver *driver;
+	const struct tb_service_driver *driver;
 	const struct tb_service_id *ids;
 	struct tb_service *svc;
 
@@ -55,7 +55,7 @@ static const struct tb_service_id *__tb_service_match(struct device *dev,
 	if (!svc)
 		return NULL;
 
-	driver = container_of(drv, struct tb_service_driver, driver);
+	driver = container_of_const(drv, struct tb_service_driver, driver);
 	if (!driver->id_table)
 		return NULL;
 
@@ -67,7 +67,7 @@ static const struct tb_service_id *__tb_service_match(struct device *dev,
 	return NULL;
 }
 
-static int tb_service_match(struct device *dev, struct device_driver *drv)
+static int tb_service_match(struct device *dev, const struct device_driver *drv)
 {
 	return !!__tb_service_match(dev, drv);
 }