2024-01-28 09:04:50

by Lenko Donchev

Subject: [PATCH] drm/amd/display: Use kcalloc() instead of kzalloc()

We are trying to get rid of all multiplications from allocation
functions to prevent integer overflows. Here the multiplication is
obviously safe, but using kcalloc() is more appropriate and improves
readability. This patch has no effect on runtime behavior.

Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
Link: https://github.com/KSPP/linux/issues/162

Signed-off-by: Lenko Donchev <[email protected]>
---
drivers/gpu/drm/amd/display/dc/link/protocols/link_dpcd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dpcd.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dpcd.c
index 5c9a30211c10..b67cd78e7c58 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dpcd.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dpcd.c
@@ -164,7 +164,7 @@ static void dpcd_extend_address_range(
if (new_addr_range.start != in_address || new_addr_range.end != end_address) {
*out_address = new_addr_range.start;
*out_size = ADDRESS_RANGE_SIZE(new_addr_range.start, new_addr_range.end);
- *out_data = kzalloc(*out_size * sizeof(**out_data), GFP_KERNEL);
+ *out_data = kcalloc(*out_size, sizeof(**out_data), GFP_KERNEL);
}
}

--
2.43.0

2024-02-21 23:04:35

by Rodrigo Siqueira Jordao

Subject: Re: [PATCH] drm/amd/display: Use kcalloc() instead of kzalloc()

On 1/28/24 02:04, Lenko Donchev wrote:
> We are trying to get rid of all multiplications from allocation
> functions to prevent integer overflows. Here the multiplication is
> obviously safe, but using kcalloc() is more appropriate and improves
> readability. This patch has no effect on runtime behavior.
>
> Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments
> Link: https://github.com/KSPP/linux/issues/162
>
> Signed-off-by: Lenko Donchev <[email protected]>
> ---
> drivers/gpu/drm/amd/display/dc/link/protocols/link_dpcd.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dpcd.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dpcd.c
> index 5c9a30211c10..b67cd78e7c58 100644
> --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dpcd.c
> +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dpcd.c
> @@ -164,7 +164,7 @@ static void dpcd_extend_address_range(
> if (new_addr_range.start != in_address || new_addr_range.end != end_address) {
> *out_address = new_addr_range.start;
> *out_size = ADDRESS_RANGE_SIZE(new_addr_range.start, new_addr_range.end);
> - *out_data = kzalloc(*out_size * sizeof(**out_data), GFP_KERNEL);
> + *out_data = kcalloc(*out_size, sizeof(**out_data), GFP_KERNEL);
> }
> }
>

lgtm,

Reviewed-by: Rodrigo Siqueira <[email protected]>