Re: [PATCH][next] qtnfmac: replace qtnf_cmd_acl_data_size() with struct_size()

From: Kalle Valo
Date: Thu Apr 04 2019 - 12:40:14 EST


"Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx> writes:

> On 4/4/19 11:01 AM, Gustavo A. R. Silva wrote:
>>
>>
>> On 4/4/19 8:32 AM, Sergey Matyukevich 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[];
>>>> };
>>>>
>>>> size = sizeof(struct foo) + count * sizeof(struct boo);
>>>> instance = kzalloc(size, GFP_KERNEL)
>>>>
>>>> Instead of leaving these open-coded and prone to type mistakes, we can
>>>> now use the new struct_size() helper:
>>>>
>>>> size = struct_size(instance, entry, count);
>>>>
>>>> or
>>>>
>>>> instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL)
>>>>
>>>> Based on the above, replace qtnf_cmd_acl_data_size() with the
>>>> new struct_size() helper.
>>>>
>>>> This code was detected with the help of Coccinelle.
>>>>
>>>> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
>>>> ---
>>>> drivers/net/wireless/quantenna/qtnfmac/commands.c | 15 ++++-----------
>>>> 1 file changed, 4 insertions(+), 11 deletions(-)
>>>
>>> Hi Gustavo,
>>>
>>
>> Hey Sergey,
>>
>>> Thanks for the patch! By the way, it does not apply cleanly, so it needs
>>> to be rebased on top of the up-to-date wireless-drivers-next tree. Let
>>> me know if you would prefer me to care about rebase. Then I will
>>> add this patch to the upcoming series of qtnfmac fixes.
>>>
>>
>> Don't worry. I'll do it and send this again.
>>
>
> Hmm... I just applied it cleanly on top of wireless-drivers-next/master:
>
> 973a99be7943 (HEAD) qtnfmac: replace qtnf_cmd_acl_data_size() with struct_size()
> 38bb0baea310 (wireless-drivers-next/master) rtlwifi: move spin_lock_bh
> to spin_lock in tasklet
> 60209d482b97 rtlwifi: fix potential NULL pointer dereference
> 765976285a8c rtlwifi: fix a potential NULL pointer dereference
>
> Do you see any issues with this?

Yeah, I also was able to apply it without problems. So it's in w-d-next
now :)

--
Kalle Valo