| Message ID | 20190108211556.GA5760@embeddedor (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | a73450036e3222ffd1cb20fc4a88832bb17921b8 |
| Headers | show |
| Series | Input: mcs_touchkey - use struct_size() in kzalloc() | expand |
On Tue, Jan 08, 2019 at 03:15:56PM -0600, Gustavo A. R. Silva 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@embeddedor.com> Applied, thank you. > --- > drivers/input/keyboard/mcs_touchkey.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/input/keyboard/mcs_touchkey.c b/drivers/input/keyboard/mcs_touchkey.c > index be56d4f262a7..b132662201a4 100644 > --- a/drivers/input/keyboard/mcs_touchkey.c > +++ b/drivers/input/keyboard/mcs_touchkey.c > @@ -113,9 +113,8 @@ static int mcs_touchkey_probe(struct i2c_client *client, > return -EINVAL; > } > > - data = kzalloc(sizeof(struct mcs_touchkey_data) + > - sizeof(data->keycodes[0]) * (pdata->key_maxval + 1), > - GFP_KERNEL); > + data = kzalloc(struct_size(data, keycodes, pdata->key_maxval + 1), > + GFP_KERNEL); > input_dev = input_allocate_device(); > if (!data || !input_dev) { > dev_err(&client->dev, "Failed to allocate memory\n"); > -- > 2.20.1 >
On 1/14/19 12:31 AM, Dmitry Torokhov wrote: >> >> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> > > Applied, thank you. > Thanks, Dmitry. -- Gustavo
diff --git a/drivers/input/keyboard/mcs_touchkey.c b/drivers/input/keyboard/mcs_touchkey.c index be56d4f262a7..b132662201a4 100644 --- a/drivers/input/keyboard/mcs_touchkey.c +++ b/drivers/input/keyboard/mcs_touchkey.c @@ -113,9 +113,8 @@ static int mcs_touchkey_probe(struct i2c_client *client, return -EINVAL; } - data = kzalloc(sizeof(struct mcs_touchkey_data) + - sizeof(data->keycodes[0]) * (pdata->key_maxval + 1), - GFP_KERNEL); + data = kzalloc(struct_size(data, keycodes, pdata->key_maxval + 1), + GFP_KERNEL); input_dev = input_allocate_device(); if (!data || !input_dev) { dev_err(&client->dev, "Failed to allocate memory\n");
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> --- drivers/input/keyboard/mcs_touchkey.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)