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authorAkinobu Mita <akinobu.mita@gmail.com>2012-07-30 14:43:07 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-07-30 17:25:22 -0700
commit048b9c3549790af21eabd06a5ebdad305e75b1c5 (patch)
tree784e739face8b1ca4ff82cfe143c53b0eab1a1b6 /lib
parentf5a9f52e2c5654c3d212dbf7e7a169c60876691a (diff)
downloadlwn-048b9c3549790af21eabd06a5ebdad305e75b1c5.tar.gz
lwn-048b9c3549790af21eabd06a5ebdad305e75b1c5.zip
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>
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig.debug24
-rw-r--r--lib/Makefile1
-rw-r--r--lib/pm-notifier-error-inject.c49
3 files changed, 74 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 20341480bb54..c2024d86fb12 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -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
diff --git a/lib/Makefile b/lib/Makefile
index 71acfa4489f3..c32c66473ba1 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -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
diff --git a/lib/pm-notifier-error-inject.c b/lib/pm-notifier-error-inject.c
new file mode 100644
index 000000000000..c094b2dedc23
--- /dev/null
+++ b/lib/pm-notifier-error-inject.c
@@ -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>");