* [PATCH] Input: mcs_touchkey - use struct_size() in kzalloc()
@ 2019-01-08 21:15 Gustavo A. R. Silva
2019-01-14 6:31 ` Dmitry Torokhov
0 siblings, 1 reply; 3+ messages in thread
From: Gustavo A. R. Silva @ 2019-01-08 21:15 UTC (permalink / raw)
To: Dmitry Torokhov; +Cc: linux-input, 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 = 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 code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
drivers/input/keyboard/mcs_touchkey.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/input/keyboard/mcs_touchkey.c b/drivers/input/keyboard/mcs_touchkey.c
index be56d4f262a7..b132662201a4 100644
--- a/drivers/input/keyboard/mcs_touchkey.c
+++ b/drivers/input/keyboard/mcs_touchkey.c
@@ -113,9 +113,8 @@ static int mcs_touchkey_probe(struct i2c_client *client,
return -EINVAL;
}
- data = kzalloc(sizeof(struct mcs_touchkey_data) +
- sizeof(data->keycodes[0]) * (pdata->key_maxval + 1),
- GFP_KERNEL);
+ data = kzalloc(struct_size(data, keycodes, pdata->key_maxval + 1),
+ GFP_KERNEL);
input_dev = input_allocate_device();
if (!data || !input_dev) {
dev_err(&client->dev, "Failed to allocate memory\n");
--
2.20.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] Input: mcs_touchkey - use struct_size() in kzalloc()
2019-01-08 21:15 [PATCH] Input: mcs_touchkey - use struct_size() in kzalloc() Gustavo A. R. Silva
@ 2019-01-14 6:31 ` Dmitry Torokhov
2019-01-14 17:27 ` Gustavo A. R. Silva
0 siblings, 1 reply; 3+ messages in thread
From: Dmitry Torokhov @ 2019-01-14 6:31 UTC (permalink / raw)
To: Gustavo A. R. Silva; +Cc: linux-input, linux-kernel
On Tue, Jan 08, 2019 at 03:15:56PM -0600, 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 = 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 code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Applied, thank you.
> ---
> drivers/input/keyboard/mcs_touchkey.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/input/keyboard/mcs_touchkey.c b/drivers/input/keyboard/mcs_touchkey.c
> index be56d4f262a7..b132662201a4 100644
> --- a/drivers/input/keyboard/mcs_touchkey.c
> +++ b/drivers/input/keyboard/mcs_touchkey.c
> @@ -113,9 +113,8 @@ static int mcs_touchkey_probe(struct i2c_client *client,
> return -EINVAL;
> }
>
> - data = kzalloc(sizeof(struct mcs_touchkey_data) +
> - sizeof(data->keycodes[0]) * (pdata->key_maxval + 1),
> - GFP_KERNEL);
> + data = kzalloc(struct_size(data, keycodes, pdata->key_maxval + 1),
> + GFP_KERNEL);
> input_dev = input_allocate_device();
> if (!data || !input_dev) {
> dev_err(&client->dev, "Failed to allocate memory\n");
> --
> 2.20.1
>
--
Dmitry
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] Input: mcs_touchkey - use struct_size() in kzalloc()
2019-01-14 6:31 ` Dmitry Torokhov
@ 2019-01-14 17:27 ` Gustavo A. R. Silva
0 siblings, 0 replies; 3+ messages in thread
From: Gustavo A. R. Silva @ 2019-01-14 17:27 UTC (permalink / raw)
To: Dmitry Torokhov; +Cc: linux-input, linux-kernel
On 1/14/19 12:31 AM, Dmitry Torokhov wrote:
>>
>> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
>
> Applied, thank you.
>
Thanks, Dmitry.
--
Gustavo
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-01-08 21:15 [PATCH] Input: mcs_touchkey - use struct_size() in kzalloc() Gustavo A. R. Silva
2019-01-14 6:31 ` Dmitry Torokhov
2019-01-14 17:27 ` Gustavo A. R. Silva
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