watchdog: WatchDog Timer Driver Core - Add minimum and max timeout
Add min_timeout (minimum timeout) and max_timeout
values so that the framework can check if the new
timeout value is between the minimum and maximum
timeout values. If both values are 0, then the
framework will leave the check for the watchdog
device driver itself.
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
index 47fc126..cfa1a15 100644
--- a/drivers/watchdog/watchdog_core.c
+++ b/drivers/watchdog/watchdog_core.c
@@ -59,6 +59,16 @@
return -EINVAL;
/*
+ * Check that we have valid min and max timeout values, if
+ * not reset them both to 0 (=not used or unknown)
+ */
+ if (wdd->min_timeout > wdd->max_timeout) {
+ pr_info("Invalid min and max timeout values, resetting to 0!\n");
+ wdd->min_timeout = 0;
+ wdd->max_timeout = 0;
+ }
+
+ /*
* Note: now that all watchdog_device data has been verified, we
* will not check this anymore in other functions. If data gets
* corrupted in a later stage then we expect a kernel panic!
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index e7134a5..d33520d 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -220,6 +220,9 @@
return -EOPNOTSUPP;
if (get_user(val, p))
return -EFAULT;
+ if ((wdd->max_timeout != 0) &&
+ (val < wdd->min_timeout || val > wdd->max_timeout))
+ return -EINVAL;
err = wdd->ops->set_timeout(wdd, val);
if (err < 0)
return err;