Re: [PATCH net-next] xprtrdma: Use struct_size() in kzalloc()

From: Gustavo A. R. Silva
Date: Thu Mar 28 2019 - 16:41:56 EST


Hi all,

Friendly ping:

Who can take this?

Thanks
--
Gustavo

On 1/31/19 8:11 AM, Chuck Lever wrote:
>
>
>> On Jan 30, 2019, at 7:46 PM, Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx> 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;
>> struct boo entry[];
>> };
>>
>> instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), 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>
>
> Reviewed-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
>
>
>> ---
>> net/sunrpc/xprtrdma/verbs.c | 3 +--
>> 1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
>> index 4994e75945b8..9e8cf7456840 100644
>> --- a/net/sunrpc/xprtrdma/verbs.c
>> +++ b/net/sunrpc/xprtrdma/verbs.c
>> @@ -811,8 +811,7 @@ static struct rpcrdma_sendctx *rpcrdma_sendctx_create(struct rpcrdma_ia *ia)
>> {
>> struct rpcrdma_sendctx *sc;
>>
>> - sc = kzalloc(sizeof(*sc) +
>> - ia->ri_max_send_sges * sizeof(struct ib_sge),
>> + sc = kzalloc(struct_size(sc, sc_sges, ia->ri_max_send_sges),
>> GFP_KERNEL);
>> if (!sc)
>> return NULL;
>> --
>> 2.20.1
>>
>
> --
> Chuck Lever
>
>
>