Re: [PATCH v3 3/4] drm/ingenic: Register devm action to cleanup encoders

2021-03-23 Thread Laurent Pinchart
Hi Paul,

Thank you for the patch.

On Sun, Jan 24, 2021 at 08:55:51AM +, Paul Cercueil wrote:
> Since the encoders have been devm-allocated, they will be freed way
> before drm_mode_config_cleanup() is called. To avoid use-after-free
> conditions, we then must ensure that drm_encoder_cleanup() is called
> before the encoders are freed.
> 
> v2: Use the new __drmm_simple_encoder_alloc() function
> 
> v3: Use the new drmm_plain_simple_encoder_alloc() macro
> 
> Fixes: c369cb27c267 ("drm/ingenic: Support multiple panels/bridges")
> Cc:  # 5.8+
> Signed-off-by: Paul Cercueil 

Reviewed-by: Laurent Pinchart 

> ---
> 
> Notes:
> Use the V1 of this patch to fix v5.11 and older kernels. This V3 only
> applies on the current drm-misc-next branch.
> 
>  drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 15 ++-
>  1 file changed, 6 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c 
> b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
> index 7bb31fbee29d..b23011c1c5d9 100644
> --- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
> +++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
> @@ -1014,20 +1014,17 @@ static int ingenic_drm_bind(struct device *dev, bool 
> has_components)
>   bridge = devm_drm_panel_bridge_add_typed(dev, panel,
>
> DRM_MODE_CONNECTOR_DPI);
>  
> - encoder = devm_kzalloc(dev, sizeof(*encoder), GFP_KERNEL);
> - if (!encoder)
> - return -ENOMEM;
> + encoder = drmm_plain_simple_encoder_alloc(drm, 
> DRM_MODE_ENCODER_DPI);
> + if (IS_ERR(encoder)) {
> + ret = PTR_ERR(encoder);
> + dev_err(dev, "Failed to init encoder: %d\n", ret);
> + return ret;
> + }
>  
>   encoder->possible_crtcs = 1;
>  
>   drm_encoder_helper_add(encoder, 
> _drm_encoder_helper_funcs);
>  
> - ret = drm_simple_encoder_init(drm, encoder, 
> DRM_MODE_ENCODER_DPI);
> - if (ret) {
> - dev_err(dev, "Failed to init encoder: %d\n", ret);
> - return ret;
> - }
> -
>   ret = drm_bridge_attach(encoder, bridge, NULL, 0);
>   if (ret) {
>   dev_err(dev, "Unable to attach bridge\n");

-- 
Regards,

Laurent Pinchart


[PATCH v3 3/4] drm/ingenic: Register devm action to cleanup encoders

2021-01-24 Thread Paul Cercueil
Since the encoders have been devm-allocated, they will be freed way
before drm_mode_config_cleanup() is called. To avoid use-after-free
conditions, we then must ensure that drm_encoder_cleanup() is called
before the encoders are freed.

v2: Use the new __drmm_simple_encoder_alloc() function

v3: Use the new drmm_plain_simple_encoder_alloc() macro

Fixes: c369cb27c267 ("drm/ingenic: Support multiple panels/bridges")
Cc:  # 5.8+
Signed-off-by: Paul Cercueil 
---

Notes:
Use the V1 of this patch to fix v5.11 and older kernels. This V3 only
applies on the current drm-misc-next branch.

 drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 15 ++-
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c 
b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
index 7bb31fbee29d..b23011c1c5d9 100644
--- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
+++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
@@ -1014,20 +1014,17 @@ static int ingenic_drm_bind(struct device *dev, bool 
has_components)
bridge = devm_drm_panel_bridge_add_typed(dev, panel,
 
DRM_MODE_CONNECTOR_DPI);
 
-   encoder = devm_kzalloc(dev, sizeof(*encoder), GFP_KERNEL);
-   if (!encoder)
-   return -ENOMEM;
+   encoder = drmm_plain_simple_encoder_alloc(drm, 
DRM_MODE_ENCODER_DPI);
+   if (IS_ERR(encoder)) {
+   ret = PTR_ERR(encoder);
+   dev_err(dev, "Failed to init encoder: %d\n", ret);
+   return ret;
+   }
 
encoder->possible_crtcs = 1;
 
drm_encoder_helper_add(encoder, 
_drm_encoder_helper_funcs);
 
-   ret = drm_simple_encoder_init(drm, encoder, 
DRM_MODE_ENCODER_DPI);
-   if (ret) {
-   dev_err(dev, "Failed to init encoder: %d\n", ret);
-   return ret;
-   }
-
ret = drm_bridge_attach(encoder, bridge, NULL, 0);
if (ret) {
dev_err(dev, "Unable to attach bridge\n");
-- 
2.29.2