[PATCH v2] staging: greybus: power_supply: use struct_size() helper

From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Rui Miguel Silva <rmfrfs@gmail.com>,
	Johan Hovold <johan@kernel.org>, Alex Elder <elder@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: greybus-dev@lists.linaro.org, devel@driverdev.osuosl.org,
	linux-kernel@vger.kernel.org,
	"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [PATCH v2] staging: greybus: power_supply: use struct_size() helper
Date: Wed, 17 Apr 2019 13:44:40 -0500	[thread overview]
Message-ID: <20190417184440.GA6025@embeddedor> (raw)

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes, in particular in the
context in which this code is being used.

So, replace code of the following form:

sizeof(*resp) + props_count * sizeof(struct gb_power_supply_props_desc)

with:

struct_size(resp, props, props_count)

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
Changes in v2:
 - Rebase on top of 47830c1127ef ("staging: greybus: power_supply: fix prop-descriptor request size")

 drivers/staging/greybus/power_supply.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/greybus/power_supply.c b/drivers/staging/greybus/power_supply.c
index ae5c0285a942..34b40a409ea3 100644
--- a/drivers/staging/greybus/power_supply.c
+++ b/drivers/staging/greybus/power_supply.c
@@ -520,8 +520,8 @@ static int gb_power_supply_prop_descriptors_get(struct gb_power_supply *gbpsy)
 
 	op = gb_operation_create(connection,
 				 GB_POWER_SUPPLY_TYPE_GET_PROP_DESCRIPTORS,
-				 sizeof(*req), sizeof(*resp) + props_count *
-				 sizeof(struct gb_power_supply_props_desc),
+				 sizeof(*req),
+				 struct_size(resp, props, props_count),
 				 GFP_KERNEL);
 	if (!op)
 		return -ENOMEM;
-- 
2.21.0

