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Commit 048b9c35 authored by Akinobu Mita's avatar Akinobu Mita Committed by Linus Torvalds
Browse files

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: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Acked-by: default avatar"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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f5a9f52e

lib/Kconfig.debug

+24 −0
Original line number Diff line number Diff line
@@ -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

lib/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -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

lib/pm-notifier-error-inject.c

0 → 100644
+49 −0
Original line number Diff line number Diff line 
#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>");