dm switch: use struct_size() in kzalloc()
authorGustavo A. R. Silva <gustavo@embeddedor.com>
Tue, 8 Jan 2019 16:02:33 +0000 (10:02 -0600)
committerMike Snitzer <snitzer@redhat.com>
Tue, 5 Mar 2019 19:48:51 +0000 (14:48 -0500)
commitd2832376b69e1e02cae0de660ab7c03223f09341
tree51572277eb740ea06883befe58fa939348a7bfe1
parente689fbab3ddd92557134ef92c40a780a33299d05
dm switch: 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 code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
drivers/md/dm-switch.c