From david-b@pacbell.net Wed Aug 6 21:25:59 2008 From: David Brownell Date: Wed, 6 Aug 2008 18:52:44 -0700 Subject: driver model: anti-oopsing medicine To: Greg KH Cc: linux-usb@vger.kernel.org Message-ID: <200808061852.44765.david-b@pacbell.net> Content-Disposition: inline From: David Brownell Anti-oops medicine for the class iterators ... the oops was observed when a class was implicitly referenced before it was initialized. [Modified by Greg to spit a warning back so someone knows to fix their code] Signed-off-by: David Brownell Signed-off-by: Greg Kroah-Hartman --- drivers/base/class.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/drivers/base/class.c +++ b/drivers/base/class.c @@ -295,6 +295,12 @@ int class_for_each_device(struct class * if (!class) return -EINVAL; + if (!class->p) { + WARN(1, "%s called for class '%s' before it was initialized", + __func__, class->name); + return -EINVAL; + } + mutex_lock(&class->p->class_mutex); list_for_each_entry(dev, &class->p->class_devices, node) { if (start) { @@ -344,6 +350,11 @@ struct device *class_find_device(struct if (!class) return NULL; + if (!class->p) { + WARN(1, "%s called for class '%s' before it was initialized", + __func__, class->name); + return NULL; + } mutex_lock(&class->p->class_mutex); list_for_each_entry(dev, &class->p->class_devices, node) {