| Message ID | 20190108162152.GA25361@embeddedor (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | qxl: Use struct_size() in kzalloc() | expand |
On Tue, Jan 08, 2019 at 10:21:52AM -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. Patch queued up. thanks, Gerd
diff --git a/drivers/gpu/drm/qxl/qxl_display.c b/drivers/gpu/drm/qxl/qxl_display.c index ce0b9c40fc21..c8642712412e 100644 --- a/drivers/gpu/drm/qxl/qxl_display.c +++ b/drivers/gpu/drm/qxl/qxl_display.c @@ -48,8 +48,8 @@ static int qxl_alloc_client_monitors_config(struct qxl_device *qdev, } if (!qdev->client_monitors_config) { qdev->client_monitors_config = kzalloc( - sizeof(struct qxl_monitors_config) + - sizeof(struct qxl_head) * count, GFP_KERNEL); + struct_size(qdev->client_monitors_config, + heads, count), GFP_KERNEL); if (!qdev->client_monitors_config) return -ENOMEM; }
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/gpu/drm/qxl/qxl_display.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)