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 <[email protected]>
---
drivers/md/md-linear.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/md/md-linear.c b/drivers/md/md-linear.c
index d45c697c0ebe..5998d78aa189 100644
--- a/drivers/md/md-linear.c
+++ b/drivers/md/md-linear.c
@@ -96,8 +96,7 @@ static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks)
int i, cnt;
bool discard_supported = false;
- conf = kzalloc (sizeof (*conf) + raid_disks*sizeof(struct dev_info),
- GFP_KERNEL);
+ conf = kzalloc(struct_size(conf, disks, raid_disks), GFP_KERNEL);
if (!conf)
return NULL;
--
2.20.1
On Mon, Jan 7, 2019 at 10:35 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 code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
Acked-by: Song Liu <[email protected]>
> ---
> drivers/md/md-linear.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/md/md-linear.c b/drivers/md/md-linear.c
> index d45c697c0ebe..5998d78aa189 100644
> --- a/drivers/md/md-linear.c
> +++ b/drivers/md/md-linear.c
> @@ -96,8 +96,7 @@ static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks)
> int i, cnt;
> bool discard_supported = false;
>
> - conf = kzalloc (sizeof (*conf) + raid_disks*sizeof(struct dev_info),
> - GFP_KERNEL);
> + conf = kzalloc(struct_size(conf, disks, raid_disks), GFP_KERNEL);
> if (!conf)
> return NULL;
>
> --
> 2.20.1
>
Hi all,
Friendly ping:
Who can take this?
Thanks
--
Gustavo
On 1/7/19 5:01 PM, Song Liu wrote:
> On Mon, Jan 7, 2019 at 10:35 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 code was detected with the help of Coccinelle.
>>
>> Signed-off-by: Gustavo A. R. Silva <[email protected]>
>
> Acked-by: Song Liu <[email protected]>
>
>> ---
>> drivers/md/md-linear.c | 3 +--
>> 1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/drivers/md/md-linear.c b/drivers/md/md-linear.c
>> index d45c697c0ebe..5998d78aa189 100644
>> --- a/drivers/md/md-linear.c
>> +++ b/drivers/md/md-linear.c
>> @@ -96,8 +96,7 @@ static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks)
>> int i, cnt;
>> bool discard_supported = false;
>>
>> - conf = kzalloc (sizeof (*conf) + raid_disks*sizeof(struct dev_info),
>> - GFP_KERNEL);
>> + conf = kzalloc(struct_size(conf, disks, raid_disks), GFP_KERNEL);
>> if (!conf)
>> return NULL;
>>
>> --
>> 2.20.1
>>
I will take it, and send pull request.
Thanks,
Song
On Tue, Jan 29, 2019 at 9:22 AM Gustavo A. R. Silva
<[email protected]> wrote:
>
> Hi all,
>
> Friendly ping:
>
> Who can take this?
>
> Thanks
> --
> Gustavo
>
> On 1/7/19 5:01 PM, Song Liu wrote:
> > On Mon, Jan 7, 2019 at 10:35 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 code was detected with the help of Coccinelle.
> >>
> >> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> >
> > Acked-by: Song Liu <[email protected]>
> >
> >> ---
> >> drivers/md/md-linear.c | 3 +--
> >> 1 file changed, 1 insertion(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/md/md-linear.c b/drivers/md/md-linear.c
> >> index d45c697c0ebe..5998d78aa189 100644
> >> --- a/drivers/md/md-linear.c
> >> +++ b/drivers/md/md-linear.c
> >> @@ -96,8 +96,7 @@ static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks)
> >> int i, cnt;
> >> bool discard_supported = false;
> >>
> >> - conf = kzalloc (sizeof (*conf) + raid_disks*sizeof(struct dev_info),
> >> - GFP_KERNEL);
> >> + conf = kzalloc(struct_size(conf, disks, raid_disks), GFP_KERNEL);
> >> if (!conf)
> >> return NULL;
> >>
> >> --
> >> 2.20.1
> >>
On 1/29/19 4:10 PM, Song Liu wrote:
> I will take it, and send pull request.
>
Thank you, Song.
--
Gustavo