Re: [PATCH] drm: do not use device name as a format string

[Boris Brezillon]

On Wed, 18 Nov 2015 18:58:18 +0100
Nicolas Iooss <nicolas.iooss_linux@xxxxxxx> wrote:

> drm_dev_set_unique() formats its parameter using kvasprintf() but many
> of its callers directly pass dev_name(dev) as printf format string,
> without any format parameter.  This can cause some issues when the
> device name contains '%' characters.
> 
> To avoid any potential issue, always use "%s" when using
> drm_dev_set_unique() with dev_name().
> 
> Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@xxxxxxx>

I'll let Daniel decide whether it's relevant or not to add a new
function/macro to hide this, but I'm fine with the current patch.

[for the atmel-hlcdc driver]
Acked-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>

> ---
>  drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c | 2 +-
>  drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c    | 2 +-
>  drivers/gpu/drm/tegra/drm.c                  | 2 +-
>  drivers/gpu/drm/vc4/vc4_drv.c                | 2 +-
>  include/drm/drmP.h                           | 1 +
>  5 files changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
> index 244df0a440b7..0d720d3a7ee0 100644
> --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
> +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
> @@ -733,7 +733,7 @@ static int atmel_hlcdc_dc_drm_probe(struct platform_device *pdev)
>  	if (!ddev)
>  		return -ENOMEM;
>  
> -	ret = drm_dev_set_unique(ddev, dev_name(ddev->dev));
> +	ret = drm_dev_set_unique(ddev, "%s", dev_name(ddev->dev));
>  	if (ret)
>  		goto err_unref;
>  
> diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> index 1930234ba5f1..947d75f59881 100644
> --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> @@ -363,7 +363,7 @@ static int fsl_dcu_drm_probe(struct platform_device *pdev)
>  	fsl_dev->np = dev->of_node;
>  	drm->dev_private = fsl_dev;
>  	dev_set_drvdata(dev, fsl_dev);
> -	drm_dev_set_unique(drm, dev_name(dev));
> +	drm_dev_set_unique(drm, "%s", dev_name(dev));
>  
>  	ret = drm_dev_register(drm, 0);
>  	if (ret < 0)
> diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
> index 159ef515cab1..b278f60f4376 100644
> --- a/drivers/gpu/drm/tegra/drm.c
> +++ b/drivers/gpu/drm/tegra/drm.c
> @@ -991,7 +991,7 @@ static int host1x_drm_probe(struct host1x_device *dev)
>  	if (!drm)
>  		return -ENOMEM;
>  
> -	drm_dev_set_unique(drm, dev_name(&dev->dev));
> +	drm_dev_set_unique(drm, "%s", dev_name(&dev->dev));
>  	dev_set_drvdata(&dev->dev, drm);
>  
>  	err = drm_dev_register(drm, 0);
> diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c
> index 6e730605edcc..c90a451aaa79 100644
> --- a/drivers/gpu/drm/vc4/vc4_drv.c
> +++ b/drivers/gpu/drm/vc4/vc4_drv.c
> @@ -168,7 +168,7 @@ static int vc4_drm_bind(struct device *dev)
>  	vc4->dev = drm;
>  	drm->dev_private = vc4;
>  
> -	drm_dev_set_unique(drm, dev_name(dev));
> +	drm_dev_set_unique(drm, "%s", dev_name(dev));
>  
>  	drm_mode_config_init(drm);
>  	if (ret)
> diff --git a/include/drm/drmP.h b/include/drm/drmP.h
> index 0b921ae06cd8..995fb96cb740 100644
> --- a/include/drm/drmP.h
> +++ b/include/drm/drmP.h
> @@ -1049,6 +1049,7 @@ void drm_dev_ref(struct drm_device *dev);
>  void drm_dev_unref(struct drm_device *dev);
>  int drm_dev_register(struct drm_device *dev, unsigned long flags);
>  void drm_dev_unregister(struct drm_device *dev);
> +__printf(2, 3)
>  int drm_dev_set_unique(struct drm_device *dev, const char *fmt, ...);
>  
>  struct drm_minor *drm_minor_acquire(unsigned int minor_id);



-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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