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, 2 insertions, 2 deletions

diff --git a/arch/arm/common/locomo.c b/arch/arm/common/locomo.c
index 6d0c9f7268ba..06b0e5fd54a6 100644
--- a/arch/arm/common/locomo.c
+++ b/arch/arm/common/locomo.c
@@ -816,10 +816,10 @@ EXPORT_SYMBOL(locomo_frontlight_set);
  *	We model this as a regular bus type, and hang devices directly
  *	off this.
  */
-static int locomo_match(struct device *_dev, struct device_driver *_drv)
+static int locomo_match(struct device *_dev, const struct device_driver *_drv)
 {
 	struct locomo_dev *dev = LOCOMO_DEV(_dev);
-	struct locomo_driver *drv = LOCOMO_DRV(_drv);
+	const struct locomo_driver *drv = LOCOMO_DRV(_drv);
 
 	return dev->devid == drv->devid;
 }