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@xxxxxxxxxxxxxx>
---
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;
--
2.20.1
--
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