fault-injection: add CPU notifier error injection module
I used this module to test the series of modification to the cpu notifiers
code.
Example1: inject CPU offline error (-1 == -EPERM)
# modprobe cpu-notifier-error-inject cpu_down_prepare_error=-1
# echo 0 > /sys/devices/system/cpu/cpu1/online
bash: echo: write error: Operation not permitted
Example2: inject CPU online error (-2 == -ENOENT)
# modprobe cpu-notifier-error-inject cpu_up_prepare_error=-2
# echo 1 > /sys/devices/system/cpu/cpu1/online
bash: echo: write error: No such file or directory
[akpm@linux-foundation.org: fix Kconfig help text]
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 2312089..e722e9d 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -898,6 +898,18 @@
Documentation on how to use the module can be found in
Documentation/fault-injection/provoke-crashes.txt
+config CPU_NOTIFIER_ERROR_INJECT
+ tristate "CPU notifier error injection module"
+ depends on HOTPLUG_CPU && DEBUG_KERNEL
+ help
+ This option provides a kernel module that can be used to test
+ the error handling of the cpu notifiers
+
+ To compile this code as a module, choose M here: the module will
+ be called cpu-notifier-error-inject.
+
+ If unsure, say N.
+
config FAULT_INJECTION
bool "Fault-injection framework"
depends on DEBUG_KERNEL