[PATCH][next] iwlwifi: lib: Use struct_size() helper

From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Johannes Berg <johannes.berg@intel.com>,
	Emmanuel Grumbach <emmanuel.grumbach@intel.com>,
	Luca Coelho <luciano.coelho@intel.com>,
	Intel Linux Wireless <linuxwifi@intel.com>,
	Kalle Valo <kvalo@codeaurora.org>,
	"David S. Miller" <davem@davemloft.net>
Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [PATCH][next] iwlwifi: lib: Use struct_size() helper
Date: Wed, 3 Apr 2019 10:59:01 -0500	[thread overview]
Message-ID: <20190403155901.GA22686@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, change the following form:

sizeof(*pattern_cmd) +
               wowlan->n_patterns * sizeof(struct iwlagn_wowlan_pattern)

 to :

struct_size(pattern_cmd, patterns, wowlan->n_patterns)

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 drivers/net/wireless/intel/iwlwifi/dvm/lib.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/dvm/lib.c b/drivers/net/wireless/intel/iwlwifi/dvm/lib.c
index b2f172d4f78a..cae9cd438697 100644
--- a/drivers/net/wireless/intel/iwlwifi/dvm/lib.c
+++ b/drivers/net/wireless/intel/iwlwifi/dvm/lib.c
@@ -1022,8 +1022,7 @@ int iwlagn_send_patterns(struct iwl_priv *priv,
 	if (!wowlan->n_patterns)
 		return 0;
 
-	cmd.len[0] = sizeof(*pattern_cmd) +
-		wowlan->n_patterns * sizeof(struct iwlagn_wowlan_pattern);
+	cmd.len[0] = struct_size(pattern_cmd, patterns, wowlan->n_patterns);
 
 	pattern_cmd = kmalloc(cmd.len[0], GFP_KERNEL);
 	if (!pattern_cmd)
-- 
2.21.0

