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/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 101c425f3e8b..2237715e42eb 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -272,7 +272,7 @@ long nvdimm_clear_poison(struct device *dev, phys_addr_t phys,
 }
 EXPORT_SYMBOL_GPL(nvdimm_clear_poison);
 
-static int nvdimm_bus_match(struct device *dev, struct device_driver *drv);
+static int nvdimm_bus_match(struct device *dev, const struct device_driver *drv);
 
 static const struct bus_type nvdimm_bus_type = {
 	.name = "nd",
@@ -468,9 +468,9 @@ static struct nd_device_driver nd_bus_driver = {
 	},
 };
 
-static int nvdimm_bus_match(struct device *dev, struct device_driver *drv)
+static int nvdimm_bus_match(struct device *dev, const struct device_driver *drv)
 {
-	struct nd_device_driver *nd_drv = to_nd_device_driver(drv);
+	const struct nd_device_driver *nd_drv = to_nd_device_driver(drv);
 
 	if (is_nvdimm_bus(dev) && nd_drv == &nd_bus_driver)
 		return true;