[PATCH][next] fpga: dfl: Use struct_size() in kzalloc()

[PATCH][next] fpga: dfl: Use struct_size() in kzalloc()

[Gustavo A. R. Silva]

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes. Also, remove unnecessary
function dfl_feature_platform_data_size().

This code was detected with the help of Coccinelle and, audited and
fixed manually.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/fpga/dfl.c | 3 +--
 drivers/fpga/dfl.h | 6 ------
 2 files changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
index 990994874bf1..2dd13e036d45 100644
--- a/drivers/fpga/dfl.c
+++ b/drivers/fpga/dfl.c
@@ -487,8 +487,7 @@ static int build_info_commit_dev(struct build_feature_devs_info *binfo)
 	 * it will be automatically freed by device's release() callback,
 	 * platform_device_release().
 	 */
-	pdata = kzalloc(dfl_feature_platform_data_size(binfo->feature_num),
-			GFP_KERNEL);
+	pdata = kzalloc(struct_size(pdata, features, binfo->feature_num), GFP_KERNEL);
 	if (!pdata)
 		return -ENOMEM;
 
diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
index 2f5d3052e36e..044b0e88e5a8 100644
--- a/drivers/fpga/dfl.h
+++ b/drivers/fpga/dfl.h
@@ -299,12 +299,6 @@ struct dfl_feature_ops {
 #define DFL_FPGA_FEATURE_DEV_FME		"dfl-fme"
 #define DFL_FPGA_FEATURE_DEV_PORT		"dfl-port"
 
-static inline int dfl_feature_platform_data_size(const int num)
-{
-	return sizeof(struct dfl_feature_platform_data) +
-		num * sizeof(struct dfl_feature);
-}
-
 void dfl_fpga_dev_feature_uinit(struct platform_device *pdev);
 int dfl_fpga_dev_feature_init(struct platform_device *pdev,
 			      struct dfl_feature_driver *feature_drvs);
-- 
2.27.0

Re: [PATCH][next] fpga: dfl: Use struct_size() in kzalloc()

[Moritz Fischer]

On Wed, Jun 17, 2020 at 05:10:39PM -0500, Gustavo A. R. Silva wrote:
> Make use of the struct_size() helper instead of an open-coded version
> in order to avoid any potential type mistakes. Also, remove unnecessary
> function dfl_feature_platform_data_size().
> 
> This code was detected with the help of Coccinelle and, audited and
> fixed manually.
> 
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
>  drivers/fpga/dfl.c | 3 +--
>  drivers/fpga/dfl.h | 6 ------
>  2 files changed, 1 insertion(+), 8 deletions(-)
> 
> diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
> index 990994874bf1..2dd13e036d45 100644
> --- a/drivers/fpga/dfl.c
> +++ b/drivers/fpga/dfl.c
> @@ -487,8 +487,7 @@ static int build_info_commit_dev(struct build_feature_devs_info *binfo)
>  	 * it will be automatically freed by device's release() callback,
>  	 * platform_device_release().
>  	 */
> -	pdata = kzalloc(dfl_feature_platform_data_size(binfo->feature_num),
> -			GFP_KERNEL);
> +	pdata = kzalloc(struct_size(pdata, features, binfo->feature_num), GFP_KERNEL);
>  	if (!pdata)
>  		return -ENOMEM;
>  
> diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
> index 2f5d3052e36e..044b0e88e5a8 100644
> --- a/drivers/fpga/dfl.h
> +++ b/drivers/fpga/dfl.h
> @@ -299,12 +299,6 @@ struct dfl_feature_ops {
>  #define DFL_FPGA_FEATURE_DEV_FME		"dfl-fme"
>  #define DFL_FPGA_FEATURE_DEV_PORT		"dfl-port"
>  
> -static inline int dfl_feature_platform_data_size(const int num)
> -{
> -	return sizeof(struct dfl_feature_platform_data) +
> -		num * sizeof(struct dfl_feature);
> -}
> -
>  void dfl_fpga_dev_feature_uinit(struct platform_device *pdev);
>  int dfl_fpga_dev_feature_init(struct platform_device *pdev,
>  			      struct dfl_feature_driver *feature_drvs);
> -- 
> 2.27.0
> 
Applied to for-next,

Thanks!