* [PATCH] serial: max310x: Use struct_size() in devm_kzalloc()
@ 2019-01-04 21:39 Gustavo A. R. Silva
2019-03-07 11:03 ` Jan Kundrát
0 siblings, 1 reply; 2+ messages in thread
From: Gustavo A. R. Silva @ 2019-01-04 21:39 UTC (permalink / raw)
To: Greg Kroah-Hartman, Jiri Slaby
Cc: linux-serial, linux-kernel, Gustavo A. R. Silva
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@embeddedor.com>
---
drivers/tty/serial/max310x.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index 4f479841769a..1d700a8ab517 100644
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -1197,8 +1197,7 @@ static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
return PTR_ERR(regmap);
/* Alloc port structure */
- s = devm_kzalloc(dev, sizeof(*s) +
- sizeof(struct max310x_one) * devtype->nr, GFP_KERNEL);
+ s = devm_kzalloc(dev, struct_size(s, p, devtype->nr), GFP_KERNEL);
if (!s) {
dev_err(dev, "Error allocating port structure\n");
return -ENOMEM;
--
2.20.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] serial: max310x: Use struct_size() in devm_kzalloc()
2019-01-04 21:39 [PATCH] serial: max310x: Use struct_size() in devm_kzalloc() Gustavo A. R. Silva
@ 2019-03-07 11:03 ` Jan Kundrát
0 siblings, 0 replies; 2+ messages in thread
From: Jan Kundrát @ 2019-03-07 11:03 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Greg Kroah-Hartman, Jiri Slaby, linux-serial, linux-kernel
On pátek 4. ledna 2019 22:39:13 CET, Gustavo A. R. Silva wrote:
> 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@embeddedor.com>
> ---
> drivers/tty/serial/max310x.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
> index 4f479841769a..1d700a8ab517 100644
> --- a/drivers/tty/serial/max310x.c
> +++ b/drivers/tty/serial/max310x.c
> @@ -1197,8 +1197,7 @@ static int max310x_probe(struct device
> *dev, struct max310x_devtype *devtype,
> return PTR_ERR(regmap);
>
> /* Alloc port structure */
> - s = devm_kzalloc(dev, sizeof(*s) +
> - sizeof(struct max310x_one) * devtype->nr, GFP_KERNEL);
> + s = devm_kzalloc(dev, struct_size(s, p, devtype->nr), GFP_KERNEL);
> if (!s) {
> dev_err(dev, "Error allocating port structure\n");
> return -ENOMEM;
Reviewed-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Tested-by: Jan Kundrát <jan.kundrat@cesnet.cz>
^ permalink raw reply [flat|nested] 2+ messages in thread
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