Re: [PATCH] md-linear: use struct_size() in kzalloc()

[Song Liu]

I will take it, and send pull request.

Thanks,
Song

On Tue, Jan 29, 2019 at 9:22 AM Gustavo A. R. Silva
<gustavo@xxxxxxxxxxxxxx> 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
> > <gustavo@xxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxx>
> >
> > Acked-by: Song Liu <songliubraving@xxxxxx>
> >
> >> ---
> >>  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
> >>