drm/vc4: 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) + count * sizeof(struct boo), 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: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20190131010015.GA32272@embeddedor
This commit is contained in:
Gustavo A. R. Silva 2019-01-30 19:00:15 -06:00 committed by Eric Anholt
parent 8c77b22243
commit 1eb6ea4a82

View File

@ -117,7 +117,7 @@ int vc4_perfmon_create_ioctl(struct drm_device *dev, void *data,
return -EINVAL;
}
perfmon = kzalloc(sizeof(*perfmon) + (req->ncounters * sizeof(u64)),
perfmon = kzalloc(struct_size(perfmon, counters, req->ncounters),
GFP_KERNEL);
if (!perfmon)
return -ENOMEM;