2015-11-28 21:45 GMT+09:00 Nikolay Aleksandrov [off-list ref]:

From: Nikolay Aleksandrov <redacted>

This module allows to insert errors in some of netdevice's notifier
events. All network drivers use these notifiers to signal various events
and to check if they are allowed, e.g. PRECHANGEMTU and CHANGEMTU
afterwards. Until recently I had to run failure tests by injecting
a custom module, but now this infrastructure makes it trivial to test
these failure paths. Some of the recent bugs I fixed were found using
this module.
Here's an example:
 $ cd /sys/kernel/debug/notifier-error-inject/netdev
 $ echo -22 > actions/NETDEV_CHANGEMTU/error
 $ ip link set eth0 mtu 1024
 RTNETLINK answers: Invalid argument

This patch looks good to me.  It would be nice if you add tools like
tools/testing/selftests/cpu-hotplug/cpu-on-off-test.sh for this feature.