device_schedule_callback() needs a module reference

This patch (as896b) fixes an oversight in the design of
device_schedule_callback().  It is necessary to acquire a reference to the
module owning the callback routine, to prevent the module from being
unloaded before the callback can run.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Satyam Sharma <satyam.sharma@gmail.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 6 insertions, 2 deletions

diff --git a/include/linux/device.h b/include/linux/device.h
index af603a1..8511d14 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -367,8 +367,12 @@ extern int __must_check device_create_bin_file(struct device *dev,
 					       struct bin_attribute *attr);
 extern void device_remove_bin_file(struct device *dev,
 				   struct bin_attribute *attr);
-extern int device_schedule_callback(struct device *dev,
-		void (*func)(struct device *));
+extern int device_schedule_callback_owner(struct device *dev,
+		void (*func)(struct device *), struct module *owner);
+
+/* This is a macro to avoid include problems with THIS_MODULE */
+#define device_schedule_callback(dev, func)			\
+	device_schedule_callback_owner(dev, func, THIS_MODULE)
 
 /* device resource management */
 typedef void (*dr_release_t)(struct device *dev, void *res);