[PATCH] pinctrl: sirf: atlas7: use struct_size() in devm_kzalloc()

From: Gustavo A. R. Silva
Date: Fri Jan 04 2019 - 16:35:15 EST


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 = devm_kzalloc(dev, 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 = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL);

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
---
drivers/pinctrl/sirf/pinctrl-atlas7.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pinctrl/sirf/pinctrl-atlas7.c b/drivers/pinctrl/sirf/pinctrl-atlas7.c
index 4ba171827428..8a0eee044264 100644
--- a/drivers/pinctrl/sirf/pinctrl-atlas7.c
+++ b/drivers/pinctrl/sirf/pinctrl-atlas7.c
@@ -6007,8 +6007,8 @@ static int atlas7_gpio_probe(struct platform_device *pdev)
}

/* retrieve gpio descriptor data */
- a7gc = devm_kzalloc(&pdev->dev, sizeof(*a7gc) +
- sizeof(struct atlas7_gpio_bank) * nbank, GFP_KERNEL);
+ a7gc = devm_kzalloc(&pdev->dev, struct_size(a7gc, banks, nbank),
+ GFP_KERNEL);
if (!a7gc)
return -ENOMEM;

--
2.20.1