On Saturday, June 23, 2012, Akinobu Mita wrote:
> 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@xxxxxxxxx>
> Cc: Pavel Machek <pavel@xxxxxx>
> Cc: "Rafael J. Wysocki" <rjw@xxxxxxx>
> Cc: linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx
OK, I have no objections.
Thanks,
Rafael
> ---
> * v4
> - update modules to follow new interface
>
> lib/Kconfig.debug | 24 ++++++++++++++++++++
> lib/Makefile | 1 +
> lib/pm-notifier-error-inject.c | 49 ++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 74 insertions(+)
> create mode 100644 lib/pm-notifier-error-inject.c
>
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index be0c197..246cea6 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 23fba9e..230a949 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 0000000..c094b2d
> --- /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@xxxxxxxxx>");
>
