| Message ID | bd3d74acfa58d59f6f5f81fc5a9fb409edb8d747.1644046817.git.christophe.jaillet@wanadoo.fr (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | backlight: pwm_bl: Avoid open coded arithmetic in memory allocation | expand |
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> LGTM Acked-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Thanks Uwe
On Mon, 07 Feb 2022, Uwe Kleine-König wrote: > 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> > > LGTM > > Acked-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> > > Thanks > Uwe I am totally confused!
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.
On Mon, Feb 07, 2022 at 09:31:00AM +0000, Lee Jones wrote: > On Mon, 07 Feb 2022, Uwe Kleine-König wrote: > > > 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> > > > > LGTM > > > > Acked-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> > > > > Thanks > > Uwe > > I am totally confused! An rightfully so. Copy-paste-fail, this was supposed to be Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Sorry! Uwe
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 --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; /*
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(-)