driver core: bus: constify bus_get()

It's funny to think about getting a reference count of a constant
structure pointer, but this locks into place the private data
"underneath" the struct bus_type() which is important to not go away
while we are working with the bus structure for some callbacks.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313182918.1312597-27-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 8fea26c22521a8756279d81061cc814c1a0f4871..84a21084d67d16ddfb73ede50715b3a881b5f96a 100644 (file)
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -84,7 +84,7 @@ done:
        return sp;
 }
 
-static struct bus_type *bus_get(struct bus_type *bus)
+static const struct bus_type *bus_get(const struct bus_type *bus)
 {
        struct subsys_private *sp = bus_to_subsys(bus);
 
@@ -233,7 +233,7 @@ static const struct kset_uevent_ops bus_uevent_ops = {
 static ssize_t unbind_store(struct device_driver *drv, const char *buf,
                            size_t count)
 {
-       struct bus_type *bus = bus_get(drv->bus);
+       const struct bus_type *bus = bus_get(drv->bus);
        struct device *dev;
        int err = -ENODEV;
 
@@ -256,7 +256,7 @@ static DRIVER_ATTR_IGNORE_LOCKDEP(unbind, 0200, NULL, unbind_store);
 static ssize_t bind_store(struct device_driver *drv, const char *buf,
                          size_t count)
 {
-       struct bus_type *bus = bus_get(drv->bus);
+       const struct bus_type *bus = bus_get(drv->bus);
        struct device *dev;
        int err = -ENODEV;