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path: root/drivers/base/sys.c
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Diffstat (limited to 'drivers/base/sys.c')
-rw-r--r--drivers/base/sys.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/base/sys.c b/drivers/base/sys.c
index 8e13fd94216..1a06c239371 100644
--- a/drivers/base/sys.c
+++ b/drivers/base/sys.c
@@ -167,6 +167,22 @@ int sysdev_driver_register(struct sysdev_class *cls, struct sysdev_driver *drv)
{
int err = 0;
+ if (!cls) {
+ printk(KERN_WARNING "sysdev: invalid class passed to "
+ "sysdev_driver_register!\n");
+ WARN_ON(1);
+ return -EINVAL;
+ }
+
+ /* Check whether this driver has already been added to a class. */
+ if ((drv->entry.next != drv->entry.prev) ||
+ (drv->entry.next != NULL)) {
+ printk(KERN_WARNING "sysdev: class %s: driver (%p) has already"
+ " been registered to a class, something is wrong, but "
+ "will forge on!\n", cls->name, drv);
+ WARN_ON(1);
+ }
+
mutex_lock(&sysdev_drivers_lock);
if (cls && kset_get(&cls->kset)) {
list_add_tail(&drv->entry, &cls->drivers);