* [PATCH] IB/core: Use struct_size() in kzalloc()
@ 2019-01-04 18:15 Gustavo A. R. Silva
2019-01-07 19:00 ` Jason Gunthorpe
0 siblings, 1 reply; 2+ messages in thread
From: Gustavo A. R. Silva @ 2019-01-04 18:15 UTC (permalink / raw)
To: Doug Ledford, Jason Gunthorpe
Cc: linux-rdma, linux-kernel, Gustavo A. R. Silva
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@embeddedor.com>
---
drivers/infiniband/core/sa_query.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c
index 97e6d7b69abf..7925e45ea88a 100644
--- a/drivers/infiniband/core/sa_query.c
+++ b/drivers/infiniband/core/sa_query.c
@@ -2342,9 +2342,7 @@ static void ib_sa_add_one(struct ib_device *device)
s = rdma_start_port(device);
e = rdma_end_port(device);
- sa_dev = kzalloc(sizeof *sa_dev +
- (e - s + 1) * sizeof (struct ib_sa_port),
- GFP_KERNEL);
+ sa_dev = kzalloc(struct_size(sa_dev, port, e - s + 1), GFP_KERNEL);
if (!sa_dev)
return;
--
2.20.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] IB/core: Use struct_size() in kzalloc()
2019-01-04 18:15 [PATCH] IB/core: Use struct_size() in kzalloc() Gustavo A. R. Silva
@ 2019-01-07 19:00 ` Jason Gunthorpe
0 siblings, 0 replies; 2+ messages in thread
From: Jason Gunthorpe @ 2019-01-07 19:00 UTC (permalink / raw)
To: Gustavo A. R. Silva; +Cc: Doug Ledford, linux-rdma, linux-kernel
On Fri, Jan 04, 2019 at 12:15:58PM -0600, Gustavo A. R. Silva wrote:
> 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@embeddedor.com>
> ---
> drivers/infiniband/core/sa_query.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
Applied to for-next, thanks
Jason
^ permalink raw reply [flat|nested] 2+ messages in thread
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2019-01-07 19:00 ` Jason Gunthorpe
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