On Wed, Jan 20, 2021 at 2:21 PM Paul Cercueil paul@crapouillou.net wrote:
Le mer. 20 janv. 2021 à 14:01, Daniel Vetter daniel@ffwll.ch a écrit :
On Wed, Jan 20, 2021 at 1:36 PM Paul Cercueil paul@crapouillou.net 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
Fixes: c369cb27c267 ("drm/ingenic: Support multiple panels/bridges") Cc: stable@vger.kernel.org # 5.8+ Signed-off-by: Paul Cercueil paul@crapouillou.net
Notes: Use the V1 of this patch to fix v5.11 and older kernels. This V2 only applies on the current drm-misc-next branch.
drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 16 +++++++--------- 1 file changed, 7 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..158433b4c084 100644 --- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c +++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c @@ -1014,20 +1014,18 @@ 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_simple_encoder_alloc(drm,sizeof(*encoder), 0,
Please don't use the __ prefixed functions, those are the internal ones. The official one comes with type checking and all that included. Otherwise lgtm. -Daniel
The non-prefixed one assumes that I want to allocate a struct that contains the encoder, not just the drm_encoder itself.
Hm, but using the internal one is also a bit too ugly. A drm_plain_simple_enocder_alloc(drm, type) wrapper would be the right thing here I think? Setting the offsets and struct sizes directly in these in drivers really doesn't feel like a good idea. I think simple encoder is the only case where we really have a need for a non-embeddable struct. -Daniel
-Paul
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,&ingenic_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
-- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch