[PATCH] pinctrl: tb10x: Use flexible-array member and struct_size() helper

From: Gustavo A. R. Silva
Date: Thu Jun 06 2019 - 11:16:53 EST


Update the code to use a flexible array member instead of a pointer in
structure i2c_mux_pinctrl and use the struct_size() helper:

struct tb10x_pinctrl {
...
struct tb10x_of_pinfunc pinfuncs[];
};

Also, 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 the following form:

sizeof(struct tb10x_pinctrl) + of_get_child_count(of_node) * sizeof(struct tb10x_of_pinfunc)

with:

struct_size(state, pinfuncs, of_get_child_count(of_node))

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
---
drivers/pinctrl/pinctrl-tb10x.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-tb10x.c b/drivers/pinctrl/pinctrl-tb10x.c
index 2e90a6d8fb3b..a32badf3f118 100644
--- a/drivers/pinctrl/pinctrl-tb10x.c
+++ b/drivers/pinctrl/pinctrl-tb10x.c
@@ -483,22 +483,22 @@ struct tb10x_port {
* @base: register set base address.
* @pingroups: pointer to an array of the pin groups this driver manages.
* @pinfuncgrpcnt: number of pingroups in @pingroups.
- * @pinfuncs: pointer to an array of pin functions this driver manages.
* @pinfuncnt: number of pin functions in @pinfuncs.
* @mutex: mutex for exclusive access to a pin controller's state.
* @ports: current state of each port.
* @gpios: Indicates if a given pin is currently used as GPIO (1) or not (0).
+ * @pinfuncs: flexible array of pin functions this driver manages.
*/
struct tb10x_pinctrl {
struct pinctrl_dev *pctl;
void *base;
const struct tb10x_pinfuncgrp *pingroups;
unsigned int pinfuncgrpcnt;
- struct tb10x_of_pinfunc *pinfuncs;
unsigned int pinfuncnt;
struct mutex mutex;
struct tb10x_port ports[TB10X_PORTS];
DECLARE_BITMAP(gpios, MAX_PIN + 1);
+ struct tb10x_of_pinfunc pinfuncs[];
};

static inline void tb10x_pinctrl_set_config(struct tb10x_pinctrl *state,
@@ -771,15 +771,13 @@ static int tb10x_pinctrl_probe(struct platform_device *pdev)
return -EINVAL;
}

- state = devm_kzalloc(dev, sizeof(struct tb10x_pinctrl) +
- of_get_child_count(of_node)
- * sizeof(struct tb10x_of_pinfunc),
- GFP_KERNEL);
+ state = devm_kzalloc(dev, struct_size(state, pinfuncs,
+ of_get_child_count(of_node)),
+ GFP_KERNEL);
if (!state)
return -ENOMEM;

platform_set_drvdata(pdev, state);
- state->pinfuncs = (struct tb10x_of_pinfunc *)(state + 1);
mutex_init(&state->mutex);

mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
--
2.21.0