[PATCH][next] ice: Use struct_size() helper

[PATCH][next] ice: Use struct_size() helper

[Gustavo A. R. Silva]

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    struct boo entry[];
};

size = sizeof(struct foo) + count * sizeof(struct boo);
instance = alloc(size, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

size = struct_size(instance, entry, count);

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 drivers/net/ethernet/intel/ice/ice_sched.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_sched.c b/drivers/net/ethernet/intel/ice/ice_sched.c
index e0218f4c8f0b..a2dd7c74bba3 100644
--- a/drivers/net/ethernet/intel/ice/ice_sched.c
+++ b/drivers/net/ethernet/intel/ice/ice_sched.c
@@ -664,10 +664,10 @@ ice_sched_add_elems(struct ice_port_info *pi, struct ice_sched_node *tc_node,
 	u16 i, num_groups_added = 0;
 	enum ice_status status = 0;
 	struct ice_hw *hw = pi->hw;
-	u16 buf_size;
+	size_t buf_size;
 	u32 teid;
 
-	buf_size = sizeof(*buf) + sizeof(*buf->generic) * (num_nodes - 1);
+	buf_size = struct_size(buf, generic, num_nodes - 1);
 	buf = devm_kzalloc(ice_hw_to_dev(hw), buf_size, GFP_KERNEL);
 	if (!buf)
 		return ICE_ERR_NO_MEMORY;
-- 
2.21.0

[Intel-wired-lan] [PATCH][next] ice: Use struct_size() helper

[Jeff Kirsher]

On Thu, 2019-03-28 at 11:34 -0500, Gustavo A. R. Silva wrote:
> One of the more common cases of allocation size calculations is finding
> the size of a structure that has a zero-sized array at the end, along
> with memory for some number of elements for that array. For example:
> 
> struct foo {
>     int stuff;
>     struct boo entry[];
> };
> 
> size = sizeof(struct foo) + count * sizeof(struct boo);
> instance = alloc(size, GFP_KERNEL);
> 
> Instead of leaving these open-coded and prone to type mistakes, we can
> now use the new struct_size() helper:
> 
> size = struct_size(instance, entry, count);
> 
> This code was detected with the help of Coccinelle.
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
>  drivers/net/ethernet/intel/ice/ice_sched.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Thanks Gustavo, I will queue this up.
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Re: [PATCH][next] ice: Use struct_size() helper

[Jeff Kirsher]

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On Thu, 2019-03-28 at 11:34 -0500, Gustavo A. R. Silva wrote:
> One of the more common cases of allocation size calculations is finding
> the size of a structure that has a zero-sized array at the end, along
> with memory for some number of elements for that array. For example:
> 
> struct foo {
>     int stuff;
>     struct boo entry[];
> };
> 
> size = sizeof(struct foo) + count * sizeof(struct boo);
> instance = alloc(size, GFP_KERNEL);
> 
> Instead of leaving these open-coded and prone to type mistakes, we can
> now use the new struct_size() helper:
> 
> size = struct_size(instance, entry, count);
> 
> This code was detected with the help of Coccinelle.
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
>  drivers/net/ethernet/intel/ice/ice_sched.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Thanks Gustavo, I will queue this up.

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[PATCH][next] ice: Use struct_size() helper

[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.

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

Addresses-KSPP-ID: https://github.com/KSPP/linux/issues/83
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/net/ethernet/intel/ice/ice_flex_pipe.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_flex_pipe.c b/drivers/net/ethernet/intel/ice/ice_flex_pipe.c
index 4420fc02f7e7..d92c4d70dbcd 100644
--- a/drivers/net/ethernet/intel/ice/ice_flex_pipe.c
+++ b/drivers/net/ethernet/intel/ice/ice_flex_pipe.c
@@ -1121,8 +1121,7 @@ static enum ice_status ice_get_pkg_info(struct ice_hw *hw)
 	u16 size;
 	u32 i;
 
-	size = sizeof(*pkg_info) + (sizeof(pkg_info->pkg_info[0]) *
-				    (ICE_PKG_CNT - 1));
+	size = struct_size(pkg_info, pkg_info, ICE_PKG_CNT - 1);
 	pkg_info = kzalloc(size, GFP_KERNEL);
 	if (!pkg_info)
 		return ICE_ERR_NO_MEMORY;
-- 
2.27.0