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

From: Lee Jones
Date: Mon Jul 03 2017 - 07:42:40 EST


On Tue, 27 Jun 2017, Kees Cook wrote:

> On Thu, May 4, 2017 at 1:10 PM, Julia Lawall <Julia.Lawall@xxxxxxx> 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@xxxxxxx>
> >
> > ---
> > 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@xxxxxxxxxxxx>
>
> Kernel janitors or Andrew, can you pick this up?

Same.

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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