backlight: pwm_bl: Avoid open coded arithmetic in memory allocation

kmalloc_array()/kcalloc() should be used to avoid potential overflow when
a multiplication is needed to compute the size of the requested memory.

So turn a kzalloc()+explicit size computation into an equivalent kcalloc().

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/bd3d74acfa58d59f6f5f81fc5a9fb409edb8d747.1644046817.git.christophe.jaillet@wanadoo.fr

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 8d8959a..c0523a0 100644 (file)
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -263,9 +263,8 @@ static int pwm_backlight_parse_dt(struct device *dev,
 
        /* read brightness levels from DT property */
        if (num_levels > 0) {
-               size_t size = sizeof(*data->levels) * num_levels;
-
-               data->levels = devm_kzalloc(dev, size, GFP_KERNEL);
+               data->levels = devm_kcalloc(dev, num_levels,
+                                           sizeof(*data->levels), GFP_KERNEL);
                if (!data->levels)
                        return -ENOMEM;
 
@@ -320,8 +319,8 @@ static int pwm_backlight_parse_dt(struct device *dev,
                         * Create a new table of brightness levels with all the
                         * interpolated steps.
                         */
-                       size = sizeof(*table) * num_levels;
-                       table = devm_kzalloc(dev, size, GFP_KERNEL);
+                       table = devm_kcalloc(dev, num_levels, sizeof(*table),
+                                            GFP_KERNEL);
                        if (!table)
                                return -ENOMEM;
                        /*