backlight: Catch invalid input in sysfs attributes

Check input properly in backlight, echo > brightness should not turn off
the backlight.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix printk warning]
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index 0664fc032235d37903e14f607e0e798214e89abf..9593fdc042f731bccd0bed16f1cf730f0bfce8a9 100644 (file)
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -80,20 +80,18 @@ static ssize_t backlight_show_power(struct device *dev,
 static ssize_t backlight_store_power(struct device *dev,
                struct device_attribute *attr, const char *buf, size_t count)
 {
-       int rc = -ENXIO;
-       char *endp;
+       int rc;
        struct backlight_device *bd = to_backlight_device(dev);
-       int power = simple_strtoul(buf, &endp, 0);
-       size_t size = endp - buf;
+       unsigned long power;
 
-       if (*endp && isspace(*endp))
-               size++;
-       if (size != count)
-               return -EINVAL;
+       rc = strict_strtoul(buf, 0, &power);
+       if (rc)
+               return rc;
 
+       rc = -ENXIO;
        mutex_lock(&bd->ops_lock);
        if (bd->ops) {
-               pr_debug("backlight: set power to %d\n", power);
+               pr_debug("backlight: set power to %lu\n", power);
                if (bd->props.power != power) {
                        bd->props.power = power;
                        backlight_update_status(bd);
@@ -116,23 +114,22 @@ static ssize_t backlight_show_brightness(struct device *dev,
 static ssize_t backlight_store_brightness(struct device *dev,
                struct device_attribute *attr, const char *buf, size_t count)
 {
-       int rc = -ENXIO;
-       char *endp;
+       int rc;
        struct backlight_device *bd = to_backlight_device(dev);
-       int brightness = simple_strtoul(buf, &endp, 0);
-       size_t size = endp - buf;
+       unsigned long brightness;
+
+       rc = strict_strtoul(buf, 0, &brightness);
+       if (rc)
+               return rc;
 
-       if (*endp && isspace(*endp))
-               size++;
-       if (size != count)
-               return -EINVAL;
+       rc = -ENXIO;
 
        mutex_lock(&bd->ops_lock);
        if (bd->ops) {
                if (brightness > bd->props.max_brightness)
                        rc = -EINVAL;
                else {
-                       pr_debug("backlight: set brightness to %d\n",
+                       pr_debug("backlight: set brightness to %lu\n",
                                 brightness);
                        if (bd->props.brightness != brightness) {
                                bd->props.brightness = brightness;