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/pnp/driver.c b/drivers/pnp/driver.c
index 3483e52e3a81..7de7aabb275e 100644
--- a/drivers/pnp/driver.c
+++ b/drivers/pnp/driver.c
@@ -41,7 +41,7 @@ int compare_pnp_id(struct pnp_id *pos, const char *id)
 	return 0;
 }
 
-static const struct pnp_device_id *match_device(struct pnp_driver *drv,
+static const struct pnp_device_id *match_device(const struct pnp_driver *drv,
 						struct pnp_dev *dev)
 {
 	const struct pnp_device_id *drv_id = drv->id_table;
@@ -150,10 +150,10 @@ static void pnp_device_shutdown(struct device *dev)
 		drv->shutdown(pnp_dev);
 }
 
-static int pnp_bus_match(struct device *dev, struct device_driver *drv)
+static int pnp_bus_match(struct device *dev, const struct device_driver *drv)
 {
 	struct pnp_dev *pnp_dev = to_pnp_dev(dev);
-	struct pnp_driver *pnp_drv = to_pnp_driver(drv);
+	const struct pnp_driver *pnp_drv = to_pnp_driver(drv);
 
 	if (match_device(pnp_drv, pnp_dev) == NULL)
 		return 0;