hpet: 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;
    struct boo entry[];
};

size = sizeof(struct foo) + count * sizeof(struct boo);
instance = kzalloc(size, 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);

Notice that, in this case, variable siz is not necessary, hence
it is removed.

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Gustavo A. R. Silva 2019-02-19 16:10:54 -06:00 committed by Greg Kroah-Hartman
parent f2db7361cb
commit 401c9bd10b

View file

@ -842,7 +842,6 @@ int hpet_alloc(struct hpet_data *hdp)
struct hpet_dev *devp;
u32 i, ntimer;
struct hpets *hpetp;
size_t siz;
struct hpet __iomem *hpet;
static struct hpets *last;
unsigned long period;
@ -860,10 +859,8 @@ int hpet_alloc(struct hpet_data *hdp)
return 0;
}
siz = sizeof(struct hpets) + ((hdp->hd_nirqs - 1) *
sizeof(struct hpet_dev));
hpetp = kzalloc(siz, GFP_KERNEL);
hpetp = kzalloc(struct_size(hpetp, hp_dev, hdp->hd_nirqs - 1),
GFP_KERNEL);
if (!hpetp)
return -ENOMEM;