Re: [PATCH 5/9] mfd: Drop unnecessary static

Kees Cook
2017-06-27T23:46:19Z

On Thu, May 4, 2017 at 1:10 PM, Julia Lawall <Julia.Lawall@lip6.fr> wrote:
> Drop static on a local variable, when the variable is initialized before
> any use, on every possible execution path through the function.
>
> 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 increases the code size but decreases the size of the bss segment.
>
> before:
> text data bss dec hex filename
> 3369 272 300 3941 f65 drivers/mfd/twl4030-irq.o
>
> after:
> text data bss dec hex filename
> 3401 272 28 3701 e75 drivers/mfd/twl4030-irq.o
>
> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
>
> ---
> drivers/mfd/twl4030-irq.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mfd/twl4030-irq.c b/drivers/mfd/twl4030-irq.c
> index b46c0cf..c775f27 100644
> --- a/drivers/mfd/twl4030-irq.c
> +++ b/drivers/mfd/twl4030-irq.c
> @@ -683,7 +683,7 @@ int twl4030_sih_setup(struct device *dev, int module, int irq_base)
>
> int twl4030_init_irq(struct device *dev, int irq_num)
> {
> - static struct irq_chip twl4030_irq_chip;
> + struct irq_chip twl4030_irq_chip;
> int status, i;
> int irq_base, irq_end, nr_irqs;
> struct device_node *node = dev->of_node;
>

Acked-by: Kees Cook <keescook@chromium.org>

Kernel janitors or Andrew, can you pick this up?

Thanks!

--
Kees Cook
Pixel Security