[PATCH] clk: imx: imx7ulp: use struct_size() in kzalloc()

From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Shawn Guo <shawnguo@kernel.org>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Fabio Estevam <fabio.estevam@nxp.com>,
	NXP Linux Team <linux-imx@nxp.com>,
	Michael Turquette <mturquette@baylibre.com>,
	Stephen Boyd <sboyd@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org, linux-clk@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [PATCH] clk: imx: imx7ulp: use struct_size() in kzalloc()
Date: Mon, 24 Dec 2018 00:40:25 -0600	[thread overview]
Message-ID: <20181224064025.GA9588@embeddedor.com> (raw)

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;
    void *entry[];
};

instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

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

instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);

This issue was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 drivers/clk/imx/clk-imx7ulp.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/clk/imx/clk-imx7ulp.c b/drivers/clk/imx/clk-imx7ulp.c
index 4e18f629f823..ce306631e844 100644
--- a/drivers/clk/imx/clk-imx7ulp.c
+++ b/drivers/clk/imx/clk-imx7ulp.c
@@ -48,8 +48,8 @@ static void __init imx7ulp_clk_scg1_init(struct device_node *np)
 	struct clk_hw **clks;
 	void __iomem *base;
 
-	clk_data = kzalloc(sizeof(*clk_data) + sizeof(*clk_data->hws) *
-			   IMX7ULP_CLK_SCG1_END, GFP_KERNEL);
+	clk_data = kzalloc(struct_size(clk_data, hws, IMX7ULP_CLK_SCG1_END),
+			   GFP_KERNEL);
 	if (!clk_data)
 		return;
 
@@ -136,8 +136,8 @@ static void __init imx7ulp_clk_pcc2_init(struct device_node *np)
 	struct clk_hw **clks;
 	void __iomem *base;
 
-	clk_data = kzalloc(sizeof(*clk_data) + sizeof(*clk_data->hws) *
-			   IMX7ULP_CLK_PCC2_END, GFP_KERNEL);
+	clk_data = kzalloc(struct_size(clk_data, hws, IMX7ULP_CLK_PCC2_END),
+			   GFP_KERNEL);
 	if (!clk_data)
 		return;
 
@@ -183,8 +183,8 @@ static void __init imx7ulp_clk_pcc3_init(struct device_node *np)
 	struct clk_hw **clks;
 	void __iomem *base;
 
-	clk_data = kzalloc(sizeof(*clk_data) + sizeof(*clk_data->hws) *
-			   IMX7ULP_CLK_PCC3_END, GFP_KERNEL);
+	clk_data = kzalloc(struct_size(clk_data, hws, IMX7ULP_CLK_PCC3_END),
+			   GFP_KERNEL);
 	if (!clk_data)
 		return;
 
@@ -228,8 +228,8 @@ static void __init imx7ulp_clk_smc1_init(struct device_node *np)
 	struct clk_hw **clks;
 	void __iomem *base;
 
-	clk_data = kzalloc(sizeof(*clk_data) + sizeof(*clk_data->hws) *
-			   IMX7ULP_CLK_SMC1_END, GFP_KERNEL);
+	clk_data = kzalloc(struct_size(clk_data, hws, IMX7ULP_CLK_SMC1_END),
+			   GFP_KERNEL);
 	if (!clk_data)
 		return;
 
-- 
2.20.1

