Panic watchdog pretimeout governor, on watchdog pretimeout event the
kernel shall panic.
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@xxxxxxxxxx>
---
Changes from v1 to v2:
* removed #ifdef CONFIG_WATCHDOG_PRETIMEOUT_DEFAULT_GOV_PANIC,
now this selection is done in a centralized manner,
* added module owner reference to count users of the governor,
* slightly improved description of the governors in Kconfig.
drivers/watchdog/Kconfig | 29 +++++++++++++++++++++
drivers/watchdog/Makefile | 2 ++
drivers/watchdog/pretimeout_panic.c | 47 ++++++++++++++++++++++++++++++++++
drivers/watchdog/watchdog_pretimeout.h | 7 +++++
4 files changed, 85 insertions(+)
create mode 100644 drivers/watchdog/pretimeout_panic.c
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 8613639..8eccc93 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1633,4 +1633,33 @@ config WATCHDOG_PRETIMEOUT_GOV
help
The option allows to select watchdog pretimeout governors.
+if WATCHDOG_PRETIMEOUT_GOV
+
+choice
+ prompt "Default Watchdog Pretimeout Governor"
+ default WATCHDOG_PRETIMEOUT_DEFAULT_GOV_PANIC
+ help
+ This option selects a default watchdog pretimeout governor.
+ The governor takes its action, if a watchdog is capable
+ to report a pretimeout event.
+
+config WATCHDOG_PRETIMEOUT_DEFAULT_GOV_PANIC
+ bool "panic"
+ select WATCHDOG_PRETIMEOUT_GOV_PANIC
+ help
+ Use panic watchdog pretimeout governor by default, if
+ a watchdog pretimeout event happens, consider that
+ a watchdog feeder is dead and reboot is unavoidable.
+
+endchoice
+
+config WATCHDOG_PRETIMEOUT_GOV_PANIC
+ tristate "Panic watchdog pretimeout governor"
+ help
+ Select this option to enable panic watchdog pretimeout
+ governor, on a watchdog pretimeout event the kernel shall
+ panic before an expected system reboot.
+
+endif # WATCHDOG_PRETIMEOUT_GOV
+
endif # WATCHDOG
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 6749cac..127f342 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -9,6 +9,8 @@ watchdog-objs += watchdog_core.o watchdog_dev.o
watchdog-$(CONFIG_WATCHDOG_PRETIMEOUT_GOV) += watchdog_pretimeout.o
+obj-$(CONFIG_WATCHDOG_PRETIMEOUT_GOV_PANIC) += pretimeout_panic.o
+
# Only one watchdog can succeed. We probe the ISA/PCI/USB based
# watchdog-cards first, then the architecture specific watchdog
# drivers and then the architecture independent "softdog" driver.
diff --git a/drivers/watchdog/pretimeout_panic.c b/drivers/watchdog/pretimeout_panic.c
new file mode 100644
index 0000000..1d439f4
--- /dev/null
+++ b/drivers/watchdog/pretimeout_panic.c
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2015 Mentor Graphics
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/watchdog.h>
+
+#include <watchdog_pretimeout.h>
+
+/**
+ * pretimeout_panic - Panic on watchdog pretimeout event
+ * @wdd - watchdog_device
+ *
+ * Panic, watchdog has not been fed till pretimeout event.
+ */
+static void pretimeout_panic(struct watchdog_device *wdd)
+{
+ panic("panic on watchdog pretimeout event\n");
+}
+
+static struct watchdog_governor watchdog_gov_panic = {
+ .name = "panic",
+ .pretimeout = pretimeout_panic,
+ .owner = THIS_MODULE,
+};
+
+static int __init watchdog_gov_panic_register(void)
+{
+ return watchdog_register_governor(&watchdog_gov_panic);
+}
+
+static void __exit watchdog_gov_panic_unregister(void)
+{
+ watchdog_unregister_governor(&watchdog_gov_panic);
+}
+module_init(watchdog_gov_panic_register);
+module_exit(watchdog_gov_panic_unregister);
+
+MODULE_AUTHOR("Vladimir Zapolskiy <vladimir_zapolskiy@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Panic watchdog pretimeout governor");
+MODULE_LICENSE("GPL");
diff --git a/drivers/watchdog/watchdog_pretimeout.h b/drivers/watchdog/watchdog_pretimeout.h
index e888424f..cf28267 100644
--- a/drivers/watchdog/watchdog_pretimeout.h
+++ b/drivers/watchdog/watchdog_pretimeout.h
@@ -19,6 +19,13 @@ void watchdog_unregister_governor(struct watchdog_governor *gov);
/* Interfaces to watchdog_core.c */
#ifdef CONFIG_WATCHDOG_PRETIMEOUT_GOV
+
+#if IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_DEFAULT_GOV_PANIC)
+#define WATCHDOG_PRETIMEOUT_DEFAULT_GOV "panic"
+#else
+#error "Default watchdog pretimeout governor is not set."
+#endif
+
int watchdog_register_pretimeout(struct watchdog_device *wdd);
void watchdog_unregister_pretimeout(struct watchdog_device *wdd);
#else
--
2.5.0
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