2018-12-24 06:25:38

by Gustavo A. R. Silva

[permalink] [raw]
Subject: [PATCH] drivers: qcom: rpmh: use struct_size() in kzalloc()

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 <[email protected]>
---
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



2019-01-09 17:40:59

by Gustavo A. R. Silva

[permalink] [raw]
Subject: Re: [PATCH] drivers: qcom: rpmh: use struct_size() in kzalloc()

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 <[email protected]>
> ---
> 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;
>

2019-01-29 05:14:23

by Gustavo A. R. Silva

[permalink] [raw]
Subject: Re: [PATCH] drivers: qcom: rpmh: use struct_size() in kzalloc()

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 <[email protected]>
>> ---
>>   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;
>>

2019-01-29 05:27:02

by Amit Kucheria

[permalink] [raw]
Subject: Re: [PATCH] drivers: qcom: rpmh: use struct_size() in kzalloc()

On Mon, Dec 24, 2018 at 11:52 AM Gustavo A. R. Silva
<[email protected]> 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 <[email protected]>

Reviewed-by: Amit Kucheria <[email protected]>

> ---
> 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
>

2019-01-29 06:58:44

by Gustavo A. R. Silva

[permalink] [raw]
Subject: Re: [PATCH] drivers: qcom: rpmh: use struct_size() in kzalloc()



On 1/28/19 11:26 PM, Amit Kucheria wrote:
> On Mon, Dec 24, 2018 at 11:52 AM Gustavo A. R. Silva
> <[email protected]> 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 <[email protected]>
>
> Reviewed-by: Amit Kucheria <[email protected]>
>

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
>>