Re: [PATCH] drm/bridge: Constify struct i2c_device_id

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Christophe,

Thank you for the patch.

On Tue, Nov 12, 2024 at 10:12:25PM +0100, Christophe JAILLET wrote:
> 'struct i2c_device_id' is not modified in these drivers.
> 
> Constifying this structure moves some data to a read-only section, so
> increase overall security.
> 
> On a x86_64, with allmodconfig, as an example:
> Before:
> ======
>    text	   data	    bss	    dec	    hex	filename
>   15566	    987	     32	  16585	   40c9	drivers/gpu/drm/bridge/chipone-icn6211.o
> 
> After:
> =====
>    text	   data	    bss	    dec	    hex	filename
>   15630	    923	     32	  16585	   40c9	drivers/gpu/drm/bridge/chipone-icn6211.o
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> Compile tested-only.
> ---
>  drivers/gpu/drm/bridge/chipone-icn6211.c   | 2 +-
>  drivers/gpu/drm/bridge/lontium-lt9211.c    | 2 +-
>  drivers/gpu/drm/bridge/lontium-lt9611.c    | 2 +-
>  drivers/gpu/drm/bridge/lontium-lt9611uxc.c | 2 +-
>  drivers/gpu/drm/bridge/ti-sn65dsi83.c      | 2 +-
>  drivers/gpu/drm/bridge/ti-sn65dsi86.c      | 2 +-

While at it, could you address drivers/gpu/drm/i2c/tda9950.c too ? If I
were to push a tad more, there are only two other drivers in the kernel
with the same issues outside of drivers/gpu/ according to

$ git grep '^static struct i2c_device_id'
drivers/gpu/drm/bridge/chipone-icn6211.c:static struct i2c_device_id chipone_i2c_id[] = {
drivers/gpu/drm/bridge/lontium-lt9211.c:static struct i2c_device_id lt9211_id[] = {
drivers/gpu/drm/bridge/lontium-lt9611.c:static struct i2c_device_id lt9611_id[] = {
drivers/gpu/drm/bridge/lontium-lt9611uxc.c:static struct i2c_device_id lt9611uxc_id[] = {
drivers/gpu/drm/bridge/ti-sn65dsi83.c:static struct i2c_device_id sn65dsi83_id[] = {
drivers/gpu/drm/bridge/ti-sn65dsi86.c:static struct i2c_device_id ti_sn65dsi86_id[] = {
drivers/gpu/drm/i2c/tda9950.c:static struct i2c_device_id tda9950_ids[] = {
drivers/input/keyboard/cypress-sf.c:static struct i2c_device_id cypress_sf_id_table[] = {
sound/soc/codecs/cs42l51-i2c.c:static struct i2c_device_id cs42l51_i2c_id[] = {

:-)

Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

>  6 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/chipone-icn6211.c b/drivers/gpu/drm/bridge/chipone-icn6211.c
> index 9eecac457dcf..d47703559b0d 100644
> --- a/drivers/gpu/drm/bridge/chipone-icn6211.c
> +++ b/drivers/gpu/drm/bridge/chipone-icn6211.c
> @@ -785,7 +785,7 @@ static struct mipi_dsi_driver chipone_dsi_driver = {
>  	},
>  };
>  
> -static struct i2c_device_id chipone_i2c_id[] = {
> +static const struct i2c_device_id chipone_i2c_id[] = {
>  	{ "chipone,icn6211" },
>  	{},
>  };
> diff --git a/drivers/gpu/drm/bridge/lontium-lt9211.c b/drivers/gpu/drm/bridge/lontium-lt9211.c
> index c8881796fba4..999ddebb832d 100644
> --- a/drivers/gpu/drm/bridge/lontium-lt9211.c
> +++ b/drivers/gpu/drm/bridge/lontium-lt9211.c
> @@ -773,7 +773,7 @@ static void lt9211_remove(struct i2c_client *client)
>  	drm_bridge_remove(&ctx->bridge);
>  }
>  
> -static struct i2c_device_id lt9211_id[] = {
> +static const struct i2c_device_id lt9211_id[] = {
>  	{ "lontium,lt9211" },
>  	{},
>  };
> diff --git a/drivers/gpu/drm/bridge/lontium-lt9611.c b/drivers/gpu/drm/bridge/lontium-lt9611.c
> index 1b31fdebe164..8f25b338a8d8 100644
> --- a/drivers/gpu/drm/bridge/lontium-lt9611.c
> +++ b/drivers/gpu/drm/bridge/lontium-lt9611.c
> @@ -1235,7 +1235,7 @@ static void lt9611_remove(struct i2c_client *client)
>  	of_node_put(lt9611->dsi0_node);
>  }
>  
> -static struct i2c_device_id lt9611_id[] = {
> +static const struct i2c_device_id lt9611_id[] = {
>  	{ "lontium,lt9611", 0 },
>  	{}
>  };
> diff --git a/drivers/gpu/drm/bridge/lontium-lt9611uxc.c b/drivers/gpu/drm/bridge/lontium-lt9611uxc.c
> index 4d1d40e1f1b4..f89af8203c9d 100644
> --- a/drivers/gpu/drm/bridge/lontium-lt9611uxc.c
> +++ b/drivers/gpu/drm/bridge/lontium-lt9611uxc.c
> @@ -913,7 +913,7 @@ static void lt9611uxc_remove(struct i2c_client *client)
>  	of_node_put(lt9611uxc->dsi0_node);
>  }
>  
> -static struct i2c_device_id lt9611uxc_id[] = {
> +static const struct i2c_device_id lt9611uxc_id[] = {
>  	{ "lontium,lt9611uxc", 0 },
>  	{ /* sentinel */ }
>  };
> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> index 57a7ed13f996..00d3bfa645f5 100644
> --- a/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> @@ -732,7 +732,7 @@ static void sn65dsi83_remove(struct i2c_client *client)
>  	drm_bridge_remove(&ctx->bridge);
>  }
>  
> -static struct i2c_device_id sn65dsi83_id[] = {
> +static const struct i2c_device_id sn65dsi83_id[] = {
>  	{ "ti,sn65dsi83", MODEL_SN65DSI83 },
>  	{ "ti,sn65dsi84", MODEL_SN65DSI84 },
>  	{},
> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> index 9e31f750fd88..ce4c026b064f 100644
> --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> @@ -1970,7 +1970,7 @@ static int ti_sn65dsi86_probe(struct i2c_client *client)
>  	return ti_sn65dsi86_add_aux_device(pdata, &pdata->aux_aux, "aux");
>  }
>  
> -static struct i2c_device_id ti_sn65dsi86_id[] = {
> +static const struct i2c_device_id ti_sn65dsi86_id[] = {
>  	{ "ti,sn65dsi86", 0},
>  	{},
>  };

-- 
Regards,

Laurent Pinchart