Re: [PATCH] driver core: move uevent call to driver_register

[Sebastian Ott <sebott@linux.vnet.ibm.com>]

Hi,

On Tue, 17 Jul 2012, Ming Lei wrote:
> On Tue, Jul 3, 2012 at 1:08 AM, Sebastian Ott <sebott@linux.vnet.ibm.com> wrote:
> 
> > --- a/drivers/base/driver.c
> > +++ b/drivers/base/driver.c
> > @@ -187,6 +187,9 @@ int driver_register(struct device_driver
> >         ret = driver_add_groups(drv, drv->groups);
> >         if (ret)
> >                 bus_remove_driver(drv);
> > +
> > +       kobject_uevent(&drv->p->kobj, KOBJ_ADD);
> 
> You should just send the uevent if 'ret' equals to zero., otherwise
> OOPS may be triggered by kobject_uevent() after the 'drv' has been
> removed.

oh..sorry. Missed that. Thanks for catching it!
Updated Patch:

[PATCH] driver core: move uevent call to driver_register

Device driver attribute groups are created after userspace is notified
via an add event. Fix this by moving the kobject_uevent call to
driver_register after the attribute groups are added.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
---
 drivers/base/bus.c    |    1 -
 drivers/base/driver.c |    6 +++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -743,7 +743,6 @@ int bus_add_driver(struct device_driver 
 		}
 	}
 
-	kobject_uevent(&priv->kobj, KOBJ_ADD);
 	return 0;
 
 out_unregister:
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -185,8 +185,12 @@ int driver_register(struct device_driver
 	if (ret)
 		return ret;
 	ret = driver_add_groups(drv, drv->groups);
-	if (ret)
+	if (ret) {
 		bus_remove_driver(drv);
+		return ret;
+	}
+	kobject_uevent(&drv->p->kobj, KOBJ_ADD);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(driver_register);