clk: imx: imx7ulp: use struct_size() in kzalloc()

-----Original Message-----
From: Gustavo A. R. Silva [mailto:[email protected]]
Sent: Monday, December 24, 2018 2:40 PM

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 <[email protected]>

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 <[email protected]>

---
  drivers/clk/imx/clk-imx7ulp.c | 16 ++++++++--------
  1 file changed, 8 insertions(+), 8 deletions(-)

drivers/clk/imx/clk-imx7ulp.c +8 -8

index 4e18f629f823..ce306631e844 100644
@@ -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;
 

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 <[email protected]>

---

Quoting Gustavo A. R. Silva (2018-12-23 22:40:25)

Quoted 14 lines

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:

Quoted 6 lines

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 <[email protected]>

---

Applied to clk-next