[PATCH 26/26] comedi: use array_size

Julia Lawall
2023-06-23T21:17:05Z

Use array_size to protect against multiplication overflows.

The changes were done using the following Coccinelle semantic patch:

// <smpl>
@@
size_t e1,e2;
expression COUNT;
identifier alloc = {vmalloc,vzalloc,kvmalloc,kvzalloc};
@@

(
alloc(
- (e1) * (e2)
+ array_size(e1, e2)
,...)
|
alloc(
- (e1) * (COUNT)
+ array_size(COUNT, e1)
,...)
)
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

---
drivers/comedi/comedi_buf.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/comedi/comedi_buf.c b/drivers/comedi/comedi_buf.c
index 393966c09740..32ad3e6e1ce8 100644
--- a/drivers/comedi/comedi_buf.c
+++ b/drivers/comedi/comedi_buf.c
@@ -89,7 +89,7 @@ comedi_buf_map_alloc(struct comedi_device *dev, enum dma_data_direction dma_dir,
bm->dma_hw_dev = get_device(dev->hw_dev);
}

- bm->page_list = vzalloc(sizeof(*buf) * n_pages);
+ bm->page_list = vzalloc(array_size(n_pages, sizeof(*buf)));
if (!bm->page_list)
goto err;

@@ -169,7 +169,7 @@ static void __comedi_buf_alloc(struct comedi_device *dev,
buf = &bm->page_list[0];
async->prealloc_buf = buf->virt_addr;
} else {
- pages = vmalloc(sizeof(struct page *) * n_pages);
+ pages = vmalloc(array_size(n_pages, sizeof(struct page *)));
if (!pages)
return;