From: Jessica Zhang quic_jesszhan@quicinc.com
[ Upstream commit ca75f6f7c6f89365e40f10f641b15981b1f07c31 ]
There is a possibility for mdp5_get_global_state to return -EDEADLK when acquiring the modeset lock, but currently global_state in mdp5_mixer_release doesn't check for if an error is returned.
To avoid a NULL dereference error, let's have mdp5_mixer_release check if an error is returned and propagate that error.
Reported-by: Tomeu Vizoso tomeu.vizoso@collabora.com Signed-off-by: Jessica Zhang quic_jesszhan@quicinc.com Fixes: 7907a0d77cb4 ("drm/msm/mdp5: Use the new private_obj state") Reviewed-by: Rob Clark robdclark@gmail.com Reviewed-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Patchwork: https://patchwork.freedesktop.org/patch/485181/ Link: https://lore.kernel.org/r/20220505214051.155-2-quic_jesszhan@quicinc.com Signed-off-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c | 10 ++++++++-- drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.c | 15 +++++++++++---- drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.h | 4 ++-- 3 files changed, 21 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c index aa28a43ff842..76639a108ff5 100644 --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c @@ -537,9 +537,15 @@ int mdp5_crtc_setup_pipeline(struct drm_crtc *crtc, if (ret) return ret;
- mdp5_mixer_release(new_crtc_state->state, old_mixer); + ret = mdp5_mixer_release(new_crtc_state->state, old_mixer); + if (ret) + return ret; + if (old_r_mixer) { - mdp5_mixer_release(new_crtc_state->state, old_r_mixer); + ret = mdp5_mixer_release(new_crtc_state->state, old_r_mixer); + if (ret) + return ret; + if (!need_right_mixer) pipeline->r_mixer = NULL; } diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.c index 113e6b569562..9c8275300b55 100644 --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.c +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.c @@ -127,21 +127,28 @@ int mdp5_mixer_assign(struct drm_atomic_state *s, struct drm_crtc *crtc, return 0; }
-void mdp5_mixer_release(struct drm_atomic_state *s, struct mdp5_hw_mixer *mixer) +int mdp5_mixer_release(struct drm_atomic_state *s, struct mdp5_hw_mixer *mixer) { struct mdp5_global_state *global_state = mdp5_get_global_state(s); - struct mdp5_hw_mixer_state *new_state = &global_state->hwmixer; + struct mdp5_hw_mixer_state *new_state;
if (!mixer) - return; + return 0; + + if (IS_ERR(global_state)) + return PTR_ERR(global_state); + + new_state = &global_state->hwmixer;
if (WARN_ON(!new_state->hwmixer_to_crtc[mixer->idx])) - return; + return -EINVAL;
DBG("%s: release from crtc %s", mixer->name, new_state->hwmixer_to_crtc[mixer->idx]->name);
new_state->hwmixer_to_crtc[mixer->idx] = NULL; + + return 0; }
void mdp5_mixer_destroy(struct mdp5_hw_mixer *mixer) diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.h b/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.h index 9be94f567fbd..6bcb0b544665 100644 --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.h +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.h @@ -41,7 +41,7 @@ void mdp5_mixer_destroy(struct mdp5_hw_mixer *lm); int mdp5_mixer_assign(struct drm_atomic_state *s, struct drm_crtc *crtc, uint32_t caps, struct mdp5_hw_mixer **mixer, struct mdp5_hw_mixer **r_mixer); -void mdp5_mixer_release(struct drm_atomic_state *s, - struct mdp5_hw_mixer *mixer); +int mdp5_mixer_release(struct drm_atomic_state *s, + struct mdp5_hw_mixer *mixer);
#endif /* __MDP5_LM_H__ */