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Input: evdev - use struct_size() in kzalloc() and vzalloc() 

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 size 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: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Gustavo A. R. Silva 2019-04-03 10:51:10 -07:00 committed by Dmitry Torokhov
parent 6d3a41ab0c
commit ecdf3a9658
1 changed files with 3 additions and 4 deletions
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7
drivers/input/evdev.c
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@ -503,14 +503,13 @@ static int evdev_open(struct inode *inode, struct file *file)
{
struct evdev *evdev = container_of(inode->i_cdev, struct evdev, cdev);
unsigned int bufsize = evdev_compute_buffer_size(evdev->handle.dev);
unsigned int size = sizeof(struct evdev_client) +
bufsize * sizeof(struct input_event);
struct evdev_client *client;
int error;
client = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
client = kzalloc(struct_size(client, buffer, bufsize),
GFP_KERNEL | __GFP_NOWARN);
if (!client)
client = vzalloc(size);
client = vzalloc(struct_size(client, buffer, bufsize));
if (!client)
return -ENOMEM;