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>

5 files changed, 6 insertions, 10 deletions

diff --git a/drivers/staging/fieldbus/anybuss/anybuss-client.h b/drivers/staging/fieldbus/anybuss/anybuss-client.h
index a219688006fe..c21c4bebfb84 100644
--- a/drivers/staging/fieldbus/anybuss/anybuss-client.h
+++ b/drivers/staging/fieldbus/anybuss/anybuss-client.h
@@ -44,11 +44,7 @@ static inline struct anybuss_client *to_anybuss_client(struct device *dev)
 	return container_of(dev, struct anybuss_client, dev);
 }
 
-static inline struct anybuss_client_driver *
-to_anybuss_client_driver(struct device_driver *drv)
-{
-	return container_of(drv, struct anybuss_client_driver, driver);
-}
+#define to_anybuss_client_driver(__drv) container_of_const(__drv, struct anybuss_client_driver, driver)
 
 static inline void *
 anybuss_get_drvdata(const struct anybuss_client *client)
diff --git a/drivers/staging/fieldbus/anybuss/host.c b/drivers/staging/fieldbus/anybuss/host.c
index 410e6f8073c0..4f2b2fce92ee 100644
--- a/drivers/staging/fieldbus/anybuss/host.c
+++ b/drivers/staging/fieldbus/anybuss/host.c
@@ -1166,9 +1166,9 @@ EXPORT_SYMBOL_GPL(anybuss_recv_msg);
 /* ------------------------ bus functions ------------------------ */
 
 static int anybus_bus_match(struct device *dev,
-			    struct device_driver *drv)
+			    const struct device_driver *drv)
 {
-	struct anybuss_client_driver *adrv =
+	const struct anybuss_client_driver *adrv =
 		to_anybuss_client_driver(drv);
 	struct anybuss_client *adev =
 		to_anybuss_client(dev);
diff --git a/drivers/staging/greybus/gbphy.c b/drivers/staging/greybus/gbphy.c
index d827f03f5253..fe4f76da7f9c 100644
--- a/drivers/staging/greybus/gbphy.c
+++ b/drivers/staging/greybus/gbphy.c
@@ -117,7 +117,7 @@ gbphy_dev_match_id(struct gbphy_device *gbphy_dev,
 	return NULL;
 }
 
-static int gbphy_dev_match(struct device *dev, struct device_driver *drv)
+static int gbphy_dev_match(struct device *dev, const struct device_driver *drv)
 {
 	struct gbphy_driver *gbphy_drv = to_gbphy_driver(drv);
 	struct gbphy_device *gbphy_dev = to_gbphy_dev(dev);
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_bus.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_bus.c
index 3f87b93c6537..41ece91ab88a 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_bus.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_bus.c
@@ -14,7 +14,7 @@
 #include "vchiq_arm.h"
 #include "vchiq_bus.h"
 
-static int vchiq_bus_type_match(struct device *dev, struct device_driver *drv)
+static int vchiq_bus_type_match(struct device *dev, const struct device_driver *drv)
 {
 	if (dev->bus == &vchiq_bus_type &&
 	    strcmp(dev_name(dev), drv->name) == 0)
diff --git a/drivers/staging/vme_user/vme.c b/drivers/staging/vme_user/vme.c
index 0cd370ab1008..9a091463656d 100644
--- a/drivers/staging/vme_user/vme.c
+++ b/drivers/staging/vme_user/vme.c
@@ -1931,7 +1931,7 @@ EXPORT_SYMBOL(vme_unregister_driver);
 
 /* - Bus Registration ------------------------------------------------------ */
 
-static int vme_bus_match(struct device *dev, struct device_driver *drv)
+static int vme_bus_match(struct device *dev, const struct device_driver *drv)
 {
 	struct vme_driver *vme_drv;