Re: [PATCH 3/9] drbd: Drop unnecessary static

Kees Cook
2017-06-27T23:49:52Z

On Fri, May 5, 2017 at 12:19 AM, Roland Kammerer
<roland.kammerer@linbit.com> wrote:
> On Thu, May 04, 2017 at 10:10:48PM +0200, Julia Lawall wrote:
>> Drop static on a local variable, when the variable is initialized before
>> any use, on every possible execution path through the function. The static
>> has no benefit, and dropping it reduces the code size.
>>
>> The semantic patch that fixes this problem is as follows:
>> (http://coccinelle.lip6.fr/)
>>
>> // <smpl>
>> @bad exists@
>> position p;
>> identifier x;
>> type T;
>> @@
>>
>> static T x@p;
>> ...
>> x = <+...x...+>
>>
>> @@
>> identifier x;
>> expression e;
>> type T;
>> position p != bad.p;
>> @@
>>
>> -static
>> T x@p;
>> ... when != x
>> when strict
>> ?x = e;
>> // </smpl>
>>
>> The change in code size is indicates by the following output from the size
>> command.
>>
>> before:
>> text data bss dec hex filename
>> 67299 2291 1056 70646 113f6 drivers/block/drbd/drbd_nl.o
>>
>> after:
>> text data bss dec hex filename
>> 67283 2291 1056 70630 113e6 drivers/block/drbd/drbd_nl.o
>>
>> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
>>
>> ---
>> drivers/block/drbd/drbd_nl.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
>> index 02255a0..ad0fcb4 100644
>> --- a/drivers/block/drbd/drbd_nl.c
>> +++ b/drivers/block/drbd/drbd_nl.c
>> @@ -2294,7 +2294,7 @@ static bool conn_ov_running(struct drbd_connection *connection)
>> static enum drbd_ret_code
>> check_net_options(struct drbd_connection *connection, struct net_conf *new_net_conf)
>> {
>> - static enum drbd_ret_code rv;
>> + enum drbd_ret_code rv;
>> struct drbd_peer_device *peer_device;
>> int i;
>
> Yes, that already got dropped for drbd9 and is obviously correct for
> in-tree drbd8.
>
> Signed-off-by: Roland Kammerer <roland.kammerer@linbit.com>
>
> Regards, rck

Which tree should this go through? Jens, I think yours?

Thanks!

-Kees

--
Kees Cook
Pixel Security