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Re: [PATCH 9/9] mfd: max8925-i2c: Drop unnecessary static

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  Re: [PATCH 9/9] mfd: max8925-i2c: Drop unnecessary static Kees Cook <keescook@chromium.org> - 2017-06-28 01:50 +0200
    Re: [PATCH 9/9] mfd: max8925-i2c: Drop unnecessary static Lee Jones <lee.jones@linaro.org> - 2017-07-03 13:50 +0200

#1676273 — Re: [PATCH 9/9] mfd: max8925-i2c: Drop unnecessary static

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 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
>    2579     240      16    2835     b13 drivers/mfd/max8925-i2c.o
>
> after:
>    text    data     bss     dec     hex filename
>    2531     240       8    2779     adb drivers/mfd/max8925-i2c.o
>
> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
>
> ---
>  drivers/mfd/max8925-i2c.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mfd/max8925-i2c.c b/drivers/mfd/max8925-i2c.c
> index 5c80aea..1006323 100644
> --- a/drivers/mfd/max8925-i2c.c
> +++ b/drivers/mfd/max8925-i2c.c
> @@ -151,7 +151,7 @@ static int max8925_probe(struct i2c_client *client,
>                                    const struct i2c_device_id *id)
>  {
>         struct max8925_platform_data *pdata = dev_get_platdata(&client->dev);
> -       static struct max8925_chip *chip;
> +       struct max8925_chip *chip;
>         struct device_node *node = client->dev.of_node;
>
>         if (node && !pdata) {
>

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

Kernel janitors or Andrew, can you pick this up?

Thanks!

-Kees

-- 
Kees Cook
Pixel Security

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#1679929

On Tue, 27 Jun 2017, Kees Cook wrote:

> 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 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
> >    2579     240      16    2835     b13 drivers/mfd/max8925-i2c.o
> >
> > after:
> >    text    data     bss     dec     hex filename
> >    2531     240       8    2779     adb drivers/mfd/max8925-i2c.o
> >
> > Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
> >
> > ---
> >  drivers/mfd/max8925-i2c.c |    2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/mfd/max8925-i2c.c b/drivers/mfd/max8925-i2c.c
> > index 5c80aea..1006323 100644
> > --- a/drivers/mfd/max8925-i2c.c
> > +++ b/drivers/mfd/max8925-i2c.c
> > @@ -151,7 +151,7 @@ static int max8925_probe(struct i2c_client *client,
> >                                    const struct i2c_device_id *id)
> >  {
> >         struct max8925_platform_data *pdata = dev_get_platdata(&client->dev);
> > -       static struct max8925_chip *chip;
> > +       struct max8925_chip *chip;
> >         struct device_node *node = client->dev.of_node;
> >
> >         if (node && !pdata) {
> >
> 
> Acked-by: Kees Cook <keescook@chromium.org>
> 
> Kernel janitors or Andrew, can you pick this up?

Didn't see this before.

Thanks for the poke Kees, I will pick this up in due course.

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

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