[PATCH] memory: samsung: exynos5422-dmc: Avoid some over memory allocation

[PATCH] memory: samsung: exynos5422-dmc: Avoid some over memory allocation

[Christophe JAILLET]

'dmc->counter' is a 'struct devfreq_event_dev **', so there is some
over memory allocation. 'counters_size' should be computed with
'sizeof(struct devfreq_event_dev *)'.

Use 'sizeof(*dmc->counter)' instead to fix it.

While at it, use devm_kcalloc() instead of devm_kzalloc()+open coded
multiplication.

Fixes: 6e7674c3c6df ("memory: Add DMC driver for Exynos5422")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
devm_kmalloc_array() could also be used to save a few cycles because the
array is fully initialized a few lines below.
---
 drivers/memory/samsung/exynos5422-dmc.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/memory/samsung/exynos5422-dmc.c b/drivers/memory/samsung/exynos5422-dmc.c
index 9c8318923ed0..4733e7898ffe 100644
--- a/drivers/memory/samsung/exynos5422-dmc.c
+++ b/drivers/memory/samsung/exynos5422-dmc.c
@@ -1322,7 +1322,6 @@ static int exynos5_dmc_init_clks(struct exynos5_dmc *dmc)
  */
 static int exynos5_performance_counters_init(struct exynos5_dmc *dmc)
 {
-	int counters_size;
 	int ret, i;
 
 	dmc->num_counters = devfreq_event_get_edev_count(dmc->dev,
@@ -1332,8 +1331,8 @@ static int exynos5_performance_counters_init(struct exynos5_dmc *dmc)
 		return dmc->num_counters;
 	}
 
-	counters_size = sizeof(struct devfreq_event_dev) * dmc->num_counters;
-	dmc->counter = devm_kzalloc(dmc->dev, counters_size, GFP_KERNEL);
+	dmc->counter = devm_kcalloc(dmc->dev, dmc->num_counters,
+				    sizeof(*dmc->counter), GFP_KERNEL);
 	if (!dmc->counter)
 		return -ENOMEM;
 
-- 
2.32.0

Re: [PATCH] memory: samsung: exynos5422-dmc: Avoid some over memory allocation

[Krzysztof Kozlowski]

On 20/03/2022 08:10, Christophe JAILLET wrote:
> 'dmc->counter' is a 'struct devfreq_event_dev **', so there is some
> over memory allocation. 'counters_size' should be computed with
> 'sizeof(struct devfreq_event_dev *)'.
> 
> Use 'sizeof(*dmc->counter)' instead to fix it.
> 
> While at it, use devm_kcalloc() instead of devm_kzalloc()+open coded
> multiplication.
> 
> Fixes: 6e7674c3c6df ("memory: Add DMC driver for Exynos5422")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> devm_kmalloc_array() could also be used to save a few cycles because the
> array is fully initialized a few lines below.
> ---
>  drivers/memory/samsung/exynos5422-dmc.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 

Thanks, looks good. I'll take it after merge window.


Best regards,
Krzysztof

Re: [PATCH] memory: samsung: exynos5422-dmc: Avoid some over memory allocation

[Krzysztof Kozlowski]

On Sun, 20 Mar 2022 08:10:30 +0100, Christophe JAILLET wrote:
> 'dmc->counter' is a 'struct devfreq_event_dev **', so there is some
> over memory allocation. 'counters_size' should be computed with
> 'sizeof(struct devfreq_event_dev *)'.
> 
> Use 'sizeof(*dmc->counter)' instead to fix it.
> 
> While at it, use devm_kcalloc() instead of devm_kzalloc()+open coded
> multiplication.
> 
> [...]

Applied, thanks!

[1/1] memory: samsung: exynos5422-dmc: Avoid some over memory allocation
      commit: 56653827f0d7bc7c2d8bac0e119fd1521fa9990a

Best regards,
-- 
Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>