From d2832376b69e1e02cae0de660ab7c03223f09341 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Tue, 8 Jan 2019 10:02:33 -0600 Subject: [PATCH] dm switch: use struct_size() in kzalloc() 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 Signed-off-by: Mike Snitzer --- drivers/md/dm-switch.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/md/dm-switch.c b/drivers/md/dm-switch.c index fae35caf3672..8a0f057b8122 100644 --- a/drivers/md/dm-switch.c +++ b/drivers/md/dm-switch.c @@ -61,8 +61,7 @@ static struct switch_ctx *alloc_switch_ctx(struct dm_target *ti, unsigned nr_pat { struct switch_ctx *sctx; - sctx = kzalloc(sizeof(struct switch_ctx) + nr_paths * sizeof(struct switch_path), - GFP_KERNEL); + sctx = kzalloc(struct_size(sctx, path_list, nr_paths), GFP_KERNEL); if (!sctx) return NULL;