clockevents: Sanitize min_delta_ns adjustment and prevent overflows
The current logic which handles clock events programming failures can
increase min_delta_ns unlimited and even can cause overflows.
Sanitize it by:
- prevent zero increase when min_delta_ns == 1
- limiting min_delta_ns to a jiffie
- bail out if the jiffie limit is hit
- add retries stats for /proc/timer_list so we can gather data
Reported-by: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h
index 0cf725b..fc53492 100644
--- a/include/linux/clockchips.h
+++ b/include/linux/clockchips.h
@@ -73,6 +73,7 @@
* @list: list head for the management code
* @mode: operating mode assigned by the management code
* @next_event: local storage for the next event in oneshot mode
+ * @retries: number of forced programming retries
*/
struct clock_event_device {
const char *name;
@@ -93,6 +94,7 @@
struct list_head list;
enum clock_event_mode mode;
ktime_t next_event;
+ unsigned long retries;
};
/*