Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | Date | Thu, 29 Aug 2019 14:06:05 -0500 | From | "Gustavo A. R. Silva" <> | Subject | [PATCH] percpu: Use struct_size() helper |
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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 pcpu_alloc_info { ... struct pcpu_group_info groups[]; };
Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes.
So, replace the following form:
sizeof(*ai) + nr_groups * sizeof(ai->groups[0])
with:
struct_size(ai, groups, nr_groups)
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> --- mm/percpu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/percpu.c b/mm/percpu.c index 7e2aa0305c27..7e06a1e58720 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -2125,7 +2125,7 @@ struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, void *ptr; int unit; - base_size = ALIGN(sizeof(*ai) + nr_groups * sizeof(ai->groups[0]), + base_size = ALIGN(struct_size(ai, groups, nr_groups), __alignof__(ai->groups[0].cpu_map[0])); ai_size = base_size + nr_units * sizeof(ai->groups[0].cpu_map[0]); -- 2.23.0
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