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, 1 insertions, 5 deletions

diff --git a/arch/sparc/include/asm/vio.h b/arch/sparc/include/asm/vio.h
index 587fb7841096..0ca8c3463166 100644
--- a/arch/sparc/include/asm/vio.h
+++ b/arch/sparc/include/asm/vio.h
@@ -483,11 +483,7 @@ int __vio_register_driver(struct vio_driver *drv, struct module *owner,
 	__vio_register_driver(driver, THIS_MODULE, KBUILD_MODNAME)
 void vio_unregister_driver(struct vio_driver *drv);
 
-static inline struct vio_driver *to_vio_driver(struct device_driver *drv)
-{
-	return container_of(drv, struct vio_driver, driver);
-}
-
+#define to_vio_driver(__drv)	container_of_const(__drv, struct vio_driver, driver)
 #define to_vio_dev(__dev)	container_of_const(__dev, struct vio_dev, dev)
 
 int vio_ldc_send(struct vio_driver_state *vio, void *data, int len);