Le mer. 20 janv. 2021 à 15:04, Daniel Vetter <daniel@xxxxxxxx> a
écrit :
On Wed, Jan 20, 2021 at 2:21 PM Paul Cercueil <paul@xxxxxxxxxxxxxxx>
wrote:
Le mer. 20 janv. 2021 à 14:01, Daniel Vetter <daniel@xxxxxxxx> a
écrit :
> On Wed, Jan 20, 2021 at 1:36 PM Paul Cercueil
<paul@xxxxxxxxxxxxxxx>
> 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@xxxxxxxxxxxxxxx> # 5.8+
>> Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
>> ---
>>
>> 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
Alright, I will add a wrapper.
Cheers,
-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
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
