PM: PM notifier error injection module

This provides the ability to inject artifical errors to PM notifier chain
callbacks.  It is controlled through debugfs interface under
/sys/kernel/debug/notifier-error-inject/pm

Each of the files in "error" directory represents an event which can be
failed and contains the error code.  If the notifier call chain should be
failed with some events notified, write the error code to the files.

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

Example: Inject PM suspend error (-12 = -ENOMEM)

	# cd /sys/kernel/debug/notifier-error-inject/pm
	# echo -12 > actions/PM_SUSPEND_PREPARE/error
	# echo mem > /sys/power/state
	bash: echo: write error: Cannot allocate memory

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Greg KH <greg@kroah.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Dave Jones <davej@redhat.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 2012-07-30 14:43:07 -07:00 committed by Linus Torvalds
parent f5a9f52e2c
commit 048b9c3549
3 changed files with 74 additions and 0 deletions

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@ -1119,6 +1119,30 @@ config CPU_NOTIFIER_ERROR_INJECT
If unsure, say N.
config PM_NOTIFIER_ERROR_INJECT
tristate "PM notifier error injection module"
depends on PM && NOTIFIER_ERROR_INJECTION
default m if PM_DEBUG
help
This option provides the ability to inject artifical errors to
PM notifier chain callbacks. It is controlled through debugfs
interface /sys/kernel/debug/notifier-error-inject/pm
If the notifier call chain should be failed with some events
notified, write the error code to "actions/<notifier event>/error".
Example: Inject PM suspend error (-12 = -ENOMEM)
# cd /sys/kernel/debug/notifier-error-inject/pm/
# echo -12 > actions/PM_SUSPEND_PREPARE/error
# echo mem > /sys/power/state
bash: echo: write error: Cannot allocate memory
To compile this code as a module, choose M here: the module will
be called pm-notifier-error-inject.
If unsure, say N.
config FAULT_INJECTION
bool "Fault-injection framework"
depends on DEBUG_KERNEL

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@ -92,6 +92,7 @@ obj-$(CONFIG_IOMMU_HELPER) += iommu-helper.o
obj-$(CONFIG_FAULT_INJECTION) += fault-inject.o
obj-$(CONFIG_NOTIFIER_ERROR_INJECTION) += notifier-error-inject.o
obj-$(CONFIG_CPU_NOTIFIER_ERROR_INJECT) += cpu-notifier-error-inject.o
obj-$(CONFIG_PM_NOTIFIER_ERROR_INJECT) += pm-notifier-error-inject.o
lib-$(CONFIG_GENERIC_BUG) += bug.o

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@ -0,0 +1,49 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/suspend.h>
#include "notifier-error-inject.h"
static int priority;
module_param(priority, int, 0);
MODULE_PARM_DESC(priority, "specify PM notifier priority");
static struct notifier_err_inject pm_notifier_err_inject = {
.actions = {
{ NOTIFIER_ERR_INJECT_ACTION(PM_HIBERNATION_PREPARE) },
{ NOTIFIER_ERR_INJECT_ACTION(PM_SUSPEND_PREPARE) },
{ NOTIFIER_ERR_INJECT_ACTION(PM_RESTORE_PREPARE) },
{}
}
};
static struct dentry *dir;
static int err_inject_init(void)
{
int err;
dir = notifier_err_inject_init("pm", notifier_err_inject_dir,
&pm_notifier_err_inject, priority);
if (IS_ERR(dir))
return PTR_ERR(dir);
err = register_pm_notifier(&pm_notifier_err_inject.nb);
if (err)
debugfs_remove_recursive(dir);
return err;
}
static void err_inject_exit(void)
{
unregister_pm_notifier(&pm_notifier_err_inject.nb);
debugfs_remove_recursive(dir);
}
module_init(err_inject_init);
module_exit(err_inject_exit);
MODULE_DESCRIPTION("PM notifier error injection module");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");