Commit 9579f5bd authored by Akinobu Mita's avatar Akinobu Mita Committed by Linus Torvalds

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
......@@ -1143,6 +1143,29 @@ config PM_NOTIFIER_ERROR_INJECT
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
bool "Fault-injection framework"
depends on DEBUG_KERNEL
......
......@@ -93,6 +93,7 @@ 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
obj-$(CONFIG_MEMORY_NOTIFIER_ERROR_INJECT) += memory-notifier-error-inject.o
lib-$(CONFIG_GENERIC_BUG) += bug.o
......
#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>");
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