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>

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;
 }

arch/arm/include/asm/hardware/locomo.h

@@ -189,7 +189,7 @@ struct locomo_driver {
 	void (*remove)(struct locomo_dev *);
 };
 
-#define LOCOMO_DRV(_d)	container_of((_d), struct locomo_driver, drv)
+#define LOCOMO_DRV(_d)	container_of_const((_d), struct locomo_driver, drv)
 
 #define LOCOMO_DRIVER_NAME(_ldev) ((_ldev)->dev.driver->name)
 

arch/parisc/include/asm/parisc-device.h

@@ -41,7 +41,7 @@ struct parisc_driver {
 
 
 #define to_parisc_device(d)	container_of(d, struct parisc_device, dev)
-#define to_parisc_driver(d)	container_of(d, struct parisc_driver, drv)
+#define to_parisc_driver(d)	container_of_const(d, struct parisc_driver, drv)
 #define parisc_parent(d)	to_parisc_device(d->dev.parent)
 
 static inline const char *parisc_pathname(struct parisc_device *d)

arch/parisc/kernel/drivers.c

@@ -97,7 +97,7 @@ static int for_each_padev(int (*fn)(struct device *, void *), void * data)
  * @driver: the PA-RISC driver to try
  * @dev: the PA-RISC device to try
  */
-static int match_device(struct parisc_driver *driver, struct parisc_device *dev)
+static int match_device(const struct parisc_driver *driver, struct parisc_device *dev)
 {
 	const struct parisc_device_id *ids;
 
@@ -548,7 +548,7 @@ alloc_pa_dev(unsigned long hpa, struct hardware_path *mod_path)
 	return dev;
 }
 
-static int parisc_generic_match(struct device *dev, struct device_driver *drv)
+static int parisc_generic_match(struct device *dev, const struct device_driver *drv)
 {
 	return match_device(to_parisc_driver(drv), to_parisc_device(dev));
 }

arch/powerpc/include/asm/ps3.h

@@ -390,11 +390,7 @@ int ps3_system_bus_device_register(struct ps3_system_bus_device *dev);
 int ps3_system_bus_driver_register(struct ps3_system_bus_driver *drv);
 void ps3_system_bus_driver_unregister(struct ps3_system_bus_driver *drv);
 
-static inline struct ps3_system_bus_driver *ps3_drv_to_system_bus_drv(
-	struct device_driver *_drv)
-{
-	return container_of(_drv, struct ps3_system_bus_driver, core);
-}
+#define ps3_drv_to_system_bus_drv(_drv) container_of_const(_drv, struct ps3_system_bus_driver, core)
 static inline struct ps3_system_bus_device *ps3_dev_to_system_bus_dev(
 	const struct device *_dev)
 {

arch/powerpc/include/asm/vio.h

@@ -156,11 +156,7 @@ static inline int vio_enable_interrupts(struct vio_dev *dev)
 }
 #endif
 
-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)
 
 #endif /* __KERNEL__ */

arch/powerpc/platforms/ps3/system-bus.c

@@ -333,10 +333,10 @@ int ps3_mmio_region_init(struct ps3_system_bus_device *dev,
 EXPORT_SYMBOL_GPL(ps3_mmio_region_init);
 
 static int ps3_system_bus_match(struct device *_dev,
-	struct device_driver *_drv)
+	const struct device_driver *_drv)
 {
 	int result;
-	struct ps3_system_bus_driver *drv = ps3_drv_to_system_bus_drv(_drv);
+	const struct ps3_system_bus_driver *drv = ps3_drv_to_system_bus_drv(_drv);
 	struct ps3_system_bus_device *dev = ps3_dev_to_system_bus_dev(_dev);
 
 	if (!dev->match_sub_id)

arch/powerpc/platforms/pseries/ibmebus.c

@@ -339,7 +339,7 @@ static struct attribute *ibmbus_bus_attrs[] = {
 };
 ATTRIBUTE_GROUPS(ibmbus_bus);
 
-static int ibmebus_bus_bus_match(struct device *dev, struct device_driver *drv)
+static int ibmebus_bus_bus_match(struct device *dev, const struct device_driver *drv)
 {
 	const struct of_device_id *matches = drv->of_match_table;
 

arch/powerpc/platforms/pseries/vio.c

@@ -1576,10 +1576,10 @@ void vio_unregister_device(struct vio_dev *viodev)
 }
 EXPORT_SYMBOL(vio_unregister_device);
 
-static int vio_bus_match(struct device *dev, struct device_driver *drv)
+static int vio_bus_match(struct device *dev, const struct device_driver *drv)
 {
 	const struct vio_dev *vio_dev = to_vio_dev(dev);
-	struct vio_driver *vio_drv = to_vio_driver(drv);
+	const struct vio_driver *vio_drv = to_vio_driver(drv);
 	const struct vio_device_id *ids = vio_drv->id_table;
 
 	return (ids != NULL) && (vio_match_device(ids, vio_dev) != NULL);
@@ -1689,7 +1689,7 @@ struct vio_dev *vio_find_node(struct device_node *vnode)
 	/* construct the kobject name from the device node */
 	if (of_node_is_type(vnode_parent, "vdevice")) {
 		const __be32 *prop;
-		
+
 		prop = of_get_property(vnode, "reg", NULL);
 		if (!prop)
 			goto out;

arch/s390/include/asm/ccwdev.h

@@ -210,7 +210,7 @@ extern void ccw_device_get_id(struct ccw_device *, struct ccw_dev_id *);
 #define get_ccwdev_lock(x) (x)->ccwlock
 
 #define to_ccwdev(n) container_of(n, struct ccw_device, dev)
-#define to_ccwdrv(n) container_of(n, struct ccw_driver, driver)
+#define to_ccwdrv(n) container_of_const(n, struct ccw_driver, driver)
 
 extern struct ccw_device *ccw_device_create_console(struct ccw_driver *);
 extern void ccw_device_destroy_console(struct ccw_device *);

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);

arch/sparc/kernel/vio.c

@@ -54,10 +54,10 @@ static int vio_hotplug(const struct device *dev, struct kobj_uevent_env *env)
 	return 0;
 }
 
-static int vio_bus_match(struct device *dev, struct device_driver *drv)
+static int vio_bus_match(struct device *dev, const struct device_driver *drv)
 {
 	struct vio_dev *vio_dev = to_vio_dev(dev);
-	struct vio_driver *vio_drv = to_vio_driver(drv);
+	const struct vio_driver *vio_drv = to_vio_driver(drv);
 	const struct vio_device_id *matches = vio_drv->id_table;
 
 	if (!matches)

drivers/acpi/bus.c

@@ -1045,10 +1045,10 @@ EXPORT_SYMBOL(acpi_bus_unregister_driver);
                               ACPI Bus operations
    -------------------------------------------------------------------------- */
 
-static int acpi_bus_match(struct device *dev, struct device_driver *drv)
+static int acpi_bus_match(struct device *dev, const struct device_driver *drv)
 {
 	struct acpi_device *acpi_dev = to_acpi_device(dev);
-	struct acpi_driver *acpi_drv = to_acpi_driver(drv);
+	const struct acpi_driver *acpi_drv = to_acpi_driver(drv);
 
 	return acpi_dev->flags.match_driver
 		&& !acpi_match_device_ids(acpi_dev, acpi_drv->ids);

drivers/amba/bus.c

@@ -26,7 +26,7 @@
 #include <linux/iommu.h>
 #include <linux/dma-map-ops.h>
 
-#define to_amba_driver(d)	container_of(d, struct amba_driver, drv)
+#define to_amba_driver(d)	container_of_const(d, struct amba_driver, drv)
 
 /* called on periphid match and class 0x9 coresight device. */
 static int
@@ -205,10 +205,10 @@ err_out:
 	return ret;
 }
 
-static int amba_match(struct device *dev, struct device_driver *drv)
+static int amba_match(struct device *dev, const struct device_driver *drv)
 {
 	struct amba_device *pcdev = to_amba_device(dev);
-	struct amba_driver *pcdrv = to_amba_driver(drv);
+	const struct amba_driver *pcdrv = to_amba_driver(drv);
 
 	mutex_lock(&pcdev->periphid_lock);
 	if (!pcdev->periphid) {

drivers/base/auxiliary.c

@@ -177,7 +177,7 @@ static const struct auxiliary_device_id *auxiliary_match_id(const struct auxilia
 	return NULL;
 }
 
-static int auxiliary_match(struct device *dev, struct device_driver *drv)
+static int auxiliary_match(struct device *dev, const struct device_driver *drv)
 {
 	struct auxiliary_device *auxdev = to_auxiliary_dev(dev);
 	const struct auxiliary_driver *auxdrv = to_auxiliary_drv(drv);

drivers/base/base.h

@@ -164,8 +164,7 @@ void device_set_deferred_probe_reason(const struct device *dev, struct va_format
 static inline int driver_match_device(const struct device_driver *drv,
 				      struct device *dev)
 {
-	/* cast will be removed in the future when match can handle a const pointer properly. */
-	return drv->bus->match ? drv->bus->match(dev, (struct device_driver *)drv) : 1;
+	return drv->bus->match ? drv->bus->match(dev, drv) : 1;
 }
 
 static inline void dev_sync_state(struct device *dev)

drivers/base/cpu.c

@@ -26,7 +26,7 @@
 
 static DEFINE_PER_CPU(struct device *, cpu_sys_devices);
 
-static int cpu_subsys_match(struct device *dev, struct device_driver *drv)
+static int cpu_subsys_match(struct device *dev, const struct device_driver *drv)
 {
 	/* ACPI style match is the only one that may succeed. */
 	if (acpi_driver_match_device(dev, drv))

drivers/base/isa.c

@@ -23,7 +23,7 @@ struct isa_dev {
 
 #define to_isa_dev(x) container_of((x), struct isa_dev, dev)
 
-static int isa_bus_match(struct device *dev, struct device_driver *driver)
+static int isa_bus_match(struct device *dev, const struct device_driver *driver)
 {
 	struct isa_driver *isa_driver = to_isa_driver(driver);
 

drivers/base/platform.c

@@ -1332,7 +1332,7 @@ __ATTRIBUTE_GROUPS(platform_dev);
  * and compare it against the name of the driver. Return whether they match
  * or not.
  */
-static int platform_match(struct device *dev, struct device_driver *drv)
+static int platform_match(struct device *dev, const struct device_driver *drv)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct platform_driver *pdrv = to_platform_driver(drv);

drivers/bcma/main.c

@@ -26,7 +26,7 @@ static unsigned int bcma_bus_next_num;
 /* bcma_buses_mutex locks the bcma_bus_next_num */
 static DEFINE_MUTEX(bcma_buses_mutex);
 
-static int bcma_bus_match(struct device *dev, struct device_driver *drv);
+static int bcma_bus_match(struct device *dev, const struct device_driver *drv);
 static int bcma_device_probe(struct device *dev);
 static void bcma_device_remove(struct device *dev);
 static int bcma_device_uevent(const struct device *dev, struct kobj_uevent_env *env);
@@ -584,10 +584,10 @@ void bcma_driver_unregister(struct bcma_driver *drv)
 }
 EXPORT_SYMBOL_GPL(bcma_driver_unregister);
 
-static int bcma_bus_match(struct device *dev, struct device_driver *drv)
+static int bcma_bus_match(struct device *dev, const struct device_driver *drv)
 {
 	struct bcma_device *core = container_of(dev, struct bcma_device, dev);
-	struct bcma_driver *adrv = container_of(drv, struct bcma_driver, drv);
+	const struct bcma_driver *adrv = container_of_const(drv, struct bcma_driver, drv);
 	const struct bcma_device_id *cid = &core->id;
 	const struct bcma_device_id *did;