Messages in this thread Patch in this message | | | Date | Thu, 21 Feb 2019 09:46:22 -0600 | From | "Gustavo A. R. Silva" <> | Subject | [PATCH] mm/swapfile.c: use struct_size() in kvzalloc() |
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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 = kvzalloc(size, GFP_KERNEL);
Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper:
instance = kvzalloc(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> --- mm/swapfile.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/mm/swapfile.c b/mm/swapfile.c index cca8420b12db..fd9b0025ad00 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -2713,9 +2713,8 @@ static struct swap_info_struct *alloc_swap_info(void) struct swap_info_struct *p; unsigned int type; int i; - unsigned int size = sizeof(*p) + nr_node_ids * sizeof(struct plist_node); - p = kvzalloc(size, GFP_KERNEL); + p = kvzalloc(struct_size(p, avail_lists, nr_node_ids), GFP_KERNEL); if (!p) return ERR_PTR(-ENOMEM); -- 2.20.1
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