diff mbox series

drivers: qcom: rpmh: use struct_size() in kzalloc()

Message ID 20181224062235.GA27815@embeddedor.com (mailing list archive)
State New, archived
Headers show
Series drivers: qcom: rpmh: use struct_size() in kzalloc() | expand

Commit Message

Gustavo A. R. Silva Dec. 24, 2018, 6:22 a.m. UTC
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 <gustavo@embeddedor.com>
---
 drivers/soc/qcom/rpmh.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

Comments

Gustavo A. R. Silva Jan. 9, 2019, 5:38 p.m. UTC | #1
Hi,

Friendly ping:

Who can ack or review this patch, please?

Thanks
--
Gustavo


On 12/24/18 12:22 AM, 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 issue was detected with the help of Coccinelle.
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
>   drivers/soc/qcom/rpmh.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c
> index c7beb6841289..12c057a0b325 100644
> --- a/drivers/soc/qcom/rpmh.c
> +++ b/drivers/soc/qcom/rpmh.c
> @@ -362,8 +362,7 @@ int rpmh_write_batch(const struct device *dev, enum rpmh_state state,
>   	if (!count)
>   		return -EINVAL;
>   
> -	req = kzalloc(sizeof(*req) + count * sizeof(req->rpm_msgs[0]),
> -		      GFP_ATOMIC);
> +	req = kzalloc(struct_size(req, rpm_msgs, count), GFP_ATOMIC);
>   	if (!req)
>   		return -ENOMEM;
>   	req->count = count;
>
Gustavo A. R. Silva Jan. 29, 2019, 5:12 a.m. UTC | #2
Hi all,

Friendly ping:

Who can take this?

Thanks
--
Gustavo

On 1/9/19 11:38 AM, Gustavo A. R. Silva wrote:
> Hi,
> 
> Friendly ping:
> 
> Who can ack or review this patch, please?
> 
> Thanks
> -- 
> Gustavo
> 
> 
> On 12/24/18 12:22 AM, 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 issue was detected with the help of Coccinelle.
>>
>> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
>> ---
>>   drivers/soc/qcom/rpmh.c | 3 +--
>>   1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c
>> index c7beb6841289..12c057a0b325 100644
>> --- a/drivers/soc/qcom/rpmh.c
>> +++ b/drivers/soc/qcom/rpmh.c
>> @@ -362,8 +362,7 @@ int rpmh_write_batch(const struct device *dev, enum rpmh_state state,
>>       if (!count)
>>           return -EINVAL;
>>   -    req = kzalloc(sizeof(*req) + count * sizeof(req->rpm_msgs[0]),
>> -              GFP_ATOMIC);
>> +    req = kzalloc(struct_size(req, rpm_msgs, count), GFP_ATOMIC);
>>       if (!req)
>>           return -ENOMEM;
>>       req->count = count;
>>
Amit Kucheria Jan. 29, 2019, 5:26 a.m. UTC | #3
On Mon, Dec 24, 2018 at 11:52 AM Gustavo A. R. Silva
<gustavo@embeddedor.com> 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 issue was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>

> ---
>  drivers/soc/qcom/rpmh.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c
> index c7beb6841289..12c057a0b325 100644
> --- a/drivers/soc/qcom/rpmh.c
> +++ b/drivers/soc/qcom/rpmh.c
> @@ -362,8 +362,7 @@ int rpmh_write_batch(const struct device *dev, enum rpmh_state state,
>         if (!count)
>                 return -EINVAL;
>
> -       req = kzalloc(sizeof(*req) + count * sizeof(req->rpm_msgs[0]),
> -                     GFP_ATOMIC);
> +       req = kzalloc(struct_size(req, rpm_msgs, count), GFP_ATOMIC);
>         if (!req)
>                 return -ENOMEM;
>         req->count = count;
> --
> 2.17.0
>
Gustavo A. R. Silva Jan. 29, 2019, 6:57 a.m. UTC | #4
On 1/28/19 11:26 PM, Amit Kucheria wrote:
> On Mon, Dec 24, 2018 at 11:52 AM Gustavo A. R. Silva
> <gustavo@embeddedor.com> 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 issue was detected with the help of Coccinelle.
>>
>> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> 
> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
> 

Thanks, Amit.

--
Gustavo

>> ---
>>  drivers/soc/qcom/rpmh.c | 3 +--
>>  1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c
>> index c7beb6841289..12c057a0b325 100644
>> --- a/drivers/soc/qcom/rpmh.c
>> +++ b/drivers/soc/qcom/rpmh.c
>> @@ -362,8 +362,7 @@ int rpmh_write_batch(const struct device *dev, enum rpmh_state state,
>>         if (!count)
>>                 return -EINVAL;
>>
>> -       req = kzalloc(sizeof(*req) + count * sizeof(req->rpm_msgs[0]),
>> -                     GFP_ATOMIC);
>> +       req = kzalloc(struct_size(req, rpm_msgs, count), GFP_ATOMIC);
>>         if (!req)
>>                 return -ENOMEM;
>>         req->count = count;
>> --
>> 2.17.0
>>
diff mbox series

Patch

diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c
index c7beb6841289..12c057a0b325 100644
--- a/drivers/soc/qcom/rpmh.c
+++ b/drivers/soc/qcom/rpmh.c
@@ -362,8 +362,7 @@  int rpmh_write_batch(const struct device *dev, enum rpmh_state state,
 	if (!count)
 		return -EINVAL;
 
-	req = kzalloc(sizeof(*req) + count * sizeof(req->rpm_msgs[0]),
-		      GFP_ATOMIC);
+	req = kzalloc(struct_size(req, rpm_msgs, count), GFP_ATOMIC);
 	if (!req)
 		return -ENOMEM;
 	req->count = count;