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Commit 9579f5bd authored by Akinobu Mita's avatar Akinobu Mita Committed by Linus Torvalds
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memory: memory notifier error injection module 



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

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

Example: Inject memory hotplug offline error (-12 == -ENOMEM)

	# cd /sys/kernel/debug/notifier-error-inject/memory
	# echo -12 > actions/MEM_GOING_OFFLINE/error
	# echo offline > /sys/devices/system/memory/memoryXXX/state
	bash: echo: write error: Cannot allocate memory

Signed-off-by: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
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 048b9c35

lib/Kconfig.debug

+23 −0
Original line number Original line Diff line number Diff line
@@ -1143,6 +1143,29 @@ config PM_NOTIFIER_ERROR_INJECT 




	  If unsure, say N.

	  If unsure, say N.





config MEMORY_NOTIFIER_ERROR_INJECT

	tristate "Memory hotplug notifier error injection module"

	depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION

	help

	  This option provides the ability to inject artifical errors to

	  memory hotplug notifier chain callbacks.  It is controlled through

	  debugfs interface under /sys/kernel/debug/notifier-error-inject/memory



	  If the notifier call chain should be failed with some events

	  notified, write the error code to "actions/<notifier event>/error".



	  Example: Inject memory hotplug offline error (-12 == -ENOMEM)



	  # cd /sys/kernel/debug/notifier-error-inject/memory

	  # echo -12 > actions/MEM_GOING_OFFLINE/error

	  # echo offline > /sys/devices/system/memory/memoryXXX/state

	  bash: echo: write error: Cannot allocate memory



	  To compile this code as a module, choose M here: the module will

	  be called pSeries-reconfig-notifier-error-inject.



	  If unsure, say N.



config FAULT_INJECTION

config FAULT_INJECTION

	bool "Fault-injection framework"

	bool "Fault-injection framework"

	depends on DEBUG_KERNEL

	depends on DEBUG_KERNEL

lib/Makefile

+1 −0
Original line number Original line Diff line number Diff line
@@ -93,6 +93,7 @@ obj-$(CONFIG_FAULT_INJECTION) += fault-inject.o 
obj-$(CONFIG_NOTIFIER_ERROR_INJECTION) += notifier-error-inject.o

obj-$(CONFIG_NOTIFIER_ERROR_INJECTION) += notifier-error-inject.o

obj-$(CONFIG_CPU_NOTIFIER_ERROR_INJECT) += cpu-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

obj-$(CONFIG_PM_NOTIFIER_ERROR_INJECT) += pm-notifier-error-inject.o

obj-$(CONFIG_MEMORY_NOTIFIER_ERROR_INJECT) += memory-notifier-error-inject.o





lib-$(CONFIG_GENERIC_BUG) += bug.o

lib-$(CONFIG_GENERIC_BUG) += bug.o

lib/memory-notifier-error-inject.c

0 → 100644
+48 −0
Original line number Original line Diff line number Diff line 
#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/memory.h>



#include "notifier-error-inject.h"



static int priority;

module_param(priority, int, 0);

MODULE_PARM_DESC(priority, "specify memory notifier priority");



static struct notifier_err_inject memory_notifier_err_inject = {

	.actions = {

		{ NOTIFIER_ERR_INJECT_ACTION(MEM_GOING_ONLINE) },

		{ NOTIFIER_ERR_INJECT_ACTION(MEM_GOING_OFFLINE) },

		{}

	}

};



static struct dentry *dir;



static int err_inject_init(void)

{

	int err;



	dir = notifier_err_inject_init("memory", notifier_err_inject_dir,

					&memory_notifier_err_inject, priority);

	if (IS_ERR(dir))

		return PTR_ERR(dir);



	err = register_memory_notifier(&memory_notifier_err_inject.nb);

	if (err)

		debugfs_remove_recursive(dir);



	return err;

}



static void err_inject_exit(void)

{

	unregister_memory_notifier(&memory_notifier_err_inject.nb);

	debugfs_remove_recursive(dir);

}



module_init(err_inject_init);

module_exit(err_inject_exit);



MODULE_DESCRIPTION("memory notifier error injection module");

MODULE_LICENSE("GPL");

MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");