[PATCH] drivers/thermal/thermal_sys.c: fix strncmp tests

[PATCH] drivers/thermal/thermal_sys.c: fix strncmp tests

[Joe Perches]

Use strncmp(var, "foo", sizeof("foo") - 1)
not strncmp(var, "foo", sizeof("foo"))

Signed-off-by: Joe Perches <joe@perches.com>

diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c
index 4e83c29..c35d538 100644
--- a/drivers/thermal/thermal_sys.c
+++ b/drivers/thermal/thermal_sys.c
@@ -147,9 +147,9 @@ mode_store(struct device *dev, struct device_attribute *attr,
 	if (!tz->ops->set_mode)
 		return -EPERM;
 
-	if (!strncmp(buf, "enabled", sizeof("enabled")))
+	if (!strncmp(buf, "enabled", sizeof("enabled") - 1))
 		result = tz->ops->set_mode(tz, THERMAL_DEVICE_ENABLED);
-	else if (!strncmp(buf, "disabled", sizeof("disabled")))
+	else if (!strncmp(buf, "disabled", sizeof("disabled") - 1))
 		result = tz->ops->set_mode(tz, THERMAL_DEVICE_DISABLED);
 	else
 		result = -EINVAL;
@@ -228,8 +228,8 @@ passive_store(struct device *dev, struct device_attribute *attr,
 	if (state && !tz->forced_passive) {
 		mutex_lock(&thermal_list_lock);
 		list_for_each_entry(cdev, &thermal_cdev_list, node) {
-			if (!strncmp("Processor", cdev->type,
-				     sizeof("Processor")))
+			if (!strncmp(cdev->type, "Processor",
+				     sizeof("Processor") - 1))
 				thermal_zone_bind_cooling_device(tz,
 								 THERMAL_TRIPS_NONE,
 								 cdev);
@@ -238,8 +238,8 @@ passive_store(struct device *dev, struct device_attribute *attr,
 	} else if (!state && tz->forced_passive) {
 		mutex_lock(&thermal_list_lock);
 		list_for_each_entry(cdev, &thermal_cdev_list, node) {
-			if (!strncmp("Processor", cdev->type,
-				     sizeof("Processor")))
+			if (!strncmp(cdev->type, "Processor",
+				     sizeof("Processor") - 1))
 				thermal_zone_unbind_cooling_device(tz,
 								   THERMAL_TRIPS_NONE,
 								   cdev);
@@ -796,7 +796,7 @@ static void thermal_release(struct device *dev)
 	struct thermal_zone_device *tz;
 	struct thermal_cooling_device *cdev;
 
-	if (!strncmp(dev_name(dev), "thermal_zone", sizeof "thermal_zone" - 1)) {
+	if (!strncmp(dev_name(dev), "thermal_zone", sizeof("thermal_zone") - 1)) {
 		tz = to_thermal_zone(dev);
 		kfree(tz);
 	} else {

Re: [PATCH] drivers/thermal/thermal_sys.c: fix strncmp tests

[Andrew Morton]

On Mon, 09 Nov 2009 14:12:49 -0800
Joe Perches <joe@perches.com> wrote:

> Use strncmp(var, "foo", sizeof("foo") - 1)
> not strncmp(var, "foo", sizeof("foo"))
> 
> Signed-off-by: Joe Perches <joe@perches.com>
> 
> diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c
> index 4e83c29..c35d538 100644
> --- a/drivers/thermal/thermal_sys.c
> +++ b/drivers/thermal/thermal_sys.c
> @@ -147,9 +147,9 @@ mode_store(struct device *dev, struct device_attribute *attr,
>  	if (!tz->ops->set_mode)
>  		return -EPERM;
>  
> -	if (!strncmp(buf, "enabled", sizeof("enabled")))
> +	if (!strncmp(buf, "enabled", sizeof("enabled") - 1))

How about

	if (!strcmp(buf, "enabled"))

?

Re: [PATCH] drivers/thermal/thermal_sys.c: fix strncmp tests

[Joe Perches]

On Fri, 2009-11-13 at 14:22 -0800, Andrew Morton wrote:
> On Mon, 09 Nov 2009 14:12:49 -0800
> Joe Perches <joe@perches.com> wrote:
> 
> > Use strncmp(var, "foo", sizeof("foo") - 1)
> > not strncmp(var, "foo", sizeof("foo"))
> > 
> > Signed-off-by: Joe Perches <joe@perches.com>
> > 
> > diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c
> > index 4e83c29..c35d538 100644
> > --- a/drivers/thermal/thermal_sys.c
> > +++ b/drivers/thermal/thermal_sys.c
> > @@ -147,9 +147,9 @@ mode_store(struct device *dev, struct device_attribute *attr,
> >  	if (!tz->ops->set_mode)
> >  		return -EPERM;
> >  
> > -	if (!strncmp(buf, "enabled", sizeof("enabled")))
> > +	if (!strncmp(buf, "enabled", sizeof("enabled") - 1))
> 
> How about
> 
> 	if (!strcmp(buf, "enabled"))

Fine with me.

I think strncmp(foo, "bar", sizeof("bar"))
where foo has a trailing 0 should be
converted to strcmp(foo, "bar");