diff mbox series

backlight: pwm_bl: Avoid open coded arithmetic in memory allocation

Message ID bd3d74acfa58d59f6f5f81fc5a9fb409edb8d747.1644046817.git.christophe.jaillet@wanadoo.fr
State New
Headers show
Series backlight: pwm_bl: Avoid open coded arithmetic in memory allocation | expand

Commit Message

Christophe JAILLET Feb. 5, 2022, 7:40 a.m. UTC
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>
---
 drivers/video/backlight/pwm_bl.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

Comments

Daniel Thompson Feb. 7, 2022, 4:21 p.m. UTC | #1
On Sat, Feb 05, 2022 at 08:40:48AM +0100, Christophe JAILLET wrote:
> 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>

Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>


Daniel.
Lee Jones Feb. 8, 2022, 8:53 a.m. UTC | #2
On Sat, 05 Feb 2022, Christophe JAILLET wrote:

> 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>
> ---
>  drivers/video/backlight/pwm_bl.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)

Applied, thanks.
diff mbox series

Patch

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 8d8959a70e44..c0523a0269ee 100644
--- 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;
 			/*