From: "Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx>
Subject: kernel/gcov/gcc_3_4.c: 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.
Link: http://lkml.kernel.org/r/20190109172445.GA15908@embeddedor
Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
Reviewed-by: Peter Oberparleiter <oberpar@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/kernel/gcov/gcc_3_4.c~gcov-use-struct_size-in-kzalloc
+++ a/kernel/gcov/gcc_3_4.c
@@ -245,8 +245,7 @@ struct gcov_info *gcov_info_dup(struct g
/* Duplicate gcov_info. */
active = num_counter_active(info);
- dup = kzalloc(sizeof(struct gcov_info) +
- sizeof(struct gcov_ctr_info) * active, GFP_KERNEL);
+ dup = kzalloc(struct_size(dup, counts, active), GFP_KERNEL);
if (!dup)
return NULL;
dup->version = info->version;
@@ -364,8 +363,7 @@ struct gcov_iterator *gcov_iter_new(stru
{
struct gcov_iterator *iter;
- iter = kzalloc(sizeof(struct gcov_iterator) +
- num_counter_active(info) * sizeof(struct type_info),
+ iter = kzalloc(struct_size(iter, type_info, num_counter_active(info)),
GFP_KERNEL);
if (iter)
iter->info = info;
_
