[PATCH] watchdog/iTCO_wdt: fix bug related to gcc uninit warning

From: Jeff Garzik
Date: Tue Oct 10 2006 - 03:41:00 EST



gcc emits the following warning:

drivers/char/watchdog/iTCO_wdt.c: In function âiTCO_wdt_ioctlâ:
drivers/char/watchdog/iTCO_wdt.c:429: warning: âtime_leftâ may be used uninitialized in this function

This indicates a condition near enough to a bug, to want to fix.
iTCO_wdt_get_timeleft() stores a value in 'time_left' iff
iTCO_version==(1 or 2). This driver only supports versions
1 or 2, so this is ok. However, since (a) the return value of
iTCO_wdt_get_timeleft() is handled anyway, (b) it fixes the warning,
and (c) it future-proofs the driver, we go ahead and add the obvious
return value.

Signed-off-by: Jeff Garzik <jeff@xxxxxxxxxx>

---

drivers/char/watchdog/iTCO_wdt.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/char/watchdog/iTCO_wdt.c b/drivers/char/watchdog/iTCO_wdt.c
index aaac94d..bf5cd55 100644
--- a/drivers/char/watchdog/iTCO_wdt.c
+++ b/drivers/char/watchdog/iTCO_wdt.c
@@ -355,7 +355,8 @@ static int iTCO_wdt_get_timeleft (int *t
spin_unlock(&iTCO_wdt_private.io_lock);

*time_left = (val8 * 6) / 10;
- }
+ } else
+ return -EINVAL;
return 0;
}

@@ -426,7 +427,6 @@ static int iTCO_wdt_ioctl (struct inode
{
int new_options, retval = -EINVAL;
int new_heartbeat;
- int time_left;
void __user *argp = (void __user *)arg;
int __user *p = argp;
static struct watchdog_info ident = {
@@ -486,6 +486,8 @@ static int iTCO_wdt_ioctl (struct inode

case WDIOC_GETTIMELEFT:
{
+ int time_left;
+
if (iTCO_wdt_get_timeleft(&time_left))
return -EINVAL;

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/