[PATCH] backlight: pwm_bl: Avoid open coded arithmetic in memory allocation

From: Christophe JAILLET
Date: Sat Feb 05 2022 - 02:42:28 EST


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

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;
/*
--
2.32.0