[i2c] class_for_each_device() oops

[David Brownell]

On Wednesday 23 July 2008, Greg KH wrote:
> > In this case adding 
> > 
> >       if (!class->p)
> >               return -EINVAL;
> > 
> > at the top of class_for_each_device() would prevent such
> > oopses from ever happening.
> 
> Makes sense, care to send a real patch for this?

Here you go ... I noticed another place with the same
type of oops-affinity, and fixed that too.

===== CUT HERE
From: David Brownell <dbrownell at users.sourceforge.net>

Anti-oops medicine for the class iterators ... the oops was
observed when a class was implicitly referenced before it
was initialized.

Signed-off-by: David Brownell <dbrownell at users.sourceforge.net>
---
 drivers/base/class.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/base/class.c	2008-07-22 15:27:52.000000000 -0700
+++ b/drivers/base/class.c	2008-07-23 16:39:58.000000000 -0700
@@ -292,7 +292,7 @@ int class_for_each_device(struct class *
 	struct device *dev;
 	int error = 0;
 
-	if (!class)
+	if (!class || !class->p)
 		return -EINVAL;
 	mutex_lock(&class->p->class_mutex);
 	list_for_each_entry(dev, &class->p->class_devices, node) {
@@ -341,7 +341,7 @@ struct device *class_find_device(struct 
 	struct device *dev;
 	int found = 0;
 
-	if (!class)
+	if (!class || !class->p)
 		return NULL;
 
 	mutex_lock(&class->p->class_mutex);