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>
This commit is contained in:
Thomas Gleixner
2010-03-12 17:34:14 +01:00
parent ad6759fbf3
commit 80a05b9ffa
3 changed files with 44 additions and 13 deletions

View File

@@ -73,6 +73,7 @@ enum clock_event_nofitiers {
* @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 clock_event_device {
struct list_head list;
enum clock_event_mode mode;
ktime_t next_event;
unsigned long retries;
};
/*