linux-hardened/lib/cpu-notifier-error-inject.c
Akinobu Mita c9d221f86e 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>
2010-05-27 09:12:48 -07:00

63 lines
1.5 KiB
C

#include <linux/kernel.h>
#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/notifier.h>
static int priority;
static int cpu_up_prepare_error;
static int cpu_down_prepare_error;
module_param(priority, int, 0);
MODULE_PARM_DESC(priority, "specify cpu notifier priority");
module_param(cpu_up_prepare_error, int, 0644);
MODULE_PARM_DESC(cpu_up_prepare_error,
"specify error code to inject CPU_UP_PREPARE action");
module_param(cpu_down_prepare_error, int, 0644);
MODULE_PARM_DESC(cpu_down_prepare_error,
"specify error code to inject CPU_DOWN_PREPARE action");
static int err_inject_cpu_callback(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
int err = 0;
switch (action) {
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
err = cpu_up_prepare_error;
break;
case CPU_DOWN_PREPARE:
case CPU_DOWN_PREPARE_FROZEN:
err = cpu_down_prepare_error;
break;
}
if (err)
printk(KERN_INFO "Injecting error (%d) at cpu notifier\n", err);
return notifier_from_errno(err);
}
static struct notifier_block err_inject_cpu_notifier = {
.notifier_call = err_inject_cpu_callback,
};
static int err_inject_init(void)
{
err_inject_cpu_notifier.priority = priority;
return register_hotcpu_notifier(&err_inject_cpu_notifier);
}
static void err_inject_exit(void)
{
unregister_hotcpu_notifier(&err_inject_cpu_notifier);
}
module_init(err_inject_init);
module_exit(err_inject_exit);
MODULE_DESCRIPTION("CPU notifier error injection module");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");