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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>
This commit is contained in:
Akinobu Mita 2010-05-26 14:43:36 -07:00 committed by Linus Torvalds
parent 55af6bb509
commit c9d221f86e
3 changed files with 76 additions and 0 deletions
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12
lib/Kconfig.debug
View File

@ -898,6 +898,18 @@ config LKDTM
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

1
lib/Makefile
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@ -85,6 +85,7 @@ obj-$(CONFIG_AUDIT_GENERIC) += audit.o
obj-$(CONFIG_SWIOTLB) += swiotlb.o
obj-$(CONFIG_IOMMU_HELPER) += iommu-helper.o
obj-$(CONFIG_FAULT_INJECTION) += fault-inject.o
obj-$(CONFIG_CPU_NOTIFIER_ERROR_INJECT) += cpu-notifier-error-inject.o
lib-$(CONFIG_GENERIC_BUG) += bug.o

63
lib/cpu-notifier-error-inject.c Normal file
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@ -0,0 +1,63 @@
#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>");