Netdev notifier error injection module

modulename: netdev-notifier-error-inject.ko

configname: CONFIG_NETDEV_NOTIFIER_ERROR_INJECT

Linux Kernel Configuration
└─>Kernel hacking
└─>Kernel Testing and Coverage
└─>Netdev notifier error injection module
In linux kernel since version 3.10 (release Date: 2013-06-30)  
This option provides the ability to inject artificial errors to
netdevice notifier chain callbacks. It is controlled through debugfs
interface /sys/kernel/debug/notifier-error-inject/netdev

If the notifier call chain should be failed with some events
notified, write the error code to "actions/<notifier event>/error".

Example: Inject netdevice mtu change error (-22 = -EINVAL)

# cd /sys/kernel/debug/notifier-error-inject/netdev
# echo -22 > actions/NETDEV_CHANGEMTU/error
# ip link set eth0 mtu 1024
RTNETLINK answers: Invalid argument

To compile this code as a module, choose M here: the module will
be called netdev-notifier-error-inject.

If unsure, say N.

source code: