| Message ID | 20220505015528.344-1-quic_jesszhan@quicinc.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] drm/msm/mdp5: Return error code in mdp5_pipe_release when deadlock is detected | expand |
On Wed, May 4, 2022 at 6:55 PM Jessica Zhang <quic_jesszhan@quicinc.com> wrote: > > mdp5_get_global_state runs the risk of hitting a -EDEADLK when acquiring > the modeset lock, but currently mdp5_pipe_release doesn't check for if > an error is returned. Because of this, there is a possibility of > mdp5_pipe_release hitting a NULL dereference error. > > To avoid this, let's have mdp5_pipe_release check if > mdp5_get_global_state returns an error and propogate that error. > > Changes since v1: > - Separated declaration and initialization of *new_state to avoid > compiler warning > - Fixed some spelling mistakes in commit message > Note that mdp5_mixer_release() needs the same treatment.. one more comment below > Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com> > --- > drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c | 15 +++++++++++---- > drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h | 2 +- > drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c | 20 ++++++++++++++++---- > 3 files changed, 28 insertions(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c > index ba6695963aa6..97887a2be082 100644 > --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c > +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c > @@ -119,18 +119,23 @@ int mdp5_pipe_assign(struct drm_atomic_state *s, struct drm_plane *plane, > return 0; > } > > -void mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe) > +int mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe) > { > struct msm_drm_private *priv = s->dev->dev_private; > struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms)); > struct mdp5_global_state *state = mdp5_get_global_state(s); > - struct mdp5_hw_pipe_state *new_state = &state->hwpipe; > + struct mdp5_hw_pipe_state *new_state; > > if (!hwpipe) > - return; > + return -EINVAL; At least per the current code, !hwpipe is "normal".. I think that fits the model of things like kfree(NULL), so lets make this just return 0 > + > + if (IS_ERR(state)) > + return PTR_ERR(state); > + > + new_state = &state->hwpipe; > > if (WARN_ON(!new_state->hwpipe_to_plane[hwpipe->idx])) > - return; > + return -EINVAL; > > DBG("%s: release from plane %s", hwpipe->name, > new_state->hwpipe_to_plane[hwpipe->idx]->name); > @@ -141,6 +146,8 @@ void mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe) > } > > new_state->hwpipe_to_plane[hwpipe->idx] = NULL; > + > + return 0; > } > > void mdp5_pipe_destroy(struct mdp5_hw_pipe *hwpipe) > diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h > index 9b26d0761bd4..cca67938cab2 100644 > --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h > +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h > @@ -37,7 +37,7 @@ int mdp5_pipe_assign(struct drm_atomic_state *s, struct drm_plane *plane, > uint32_t caps, uint32_t blkcfg, > struct mdp5_hw_pipe **hwpipe, > struct mdp5_hw_pipe **r_hwpipe); > -void mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe); > +int mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe); > > struct mdp5_hw_pipe *mdp5_pipe_init(enum mdp5_pipe pipe, > uint32_t reg_offset, uint32_t caps); > diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c > index 228b22830970..979458482841 100644 > --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c > +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c > @@ -311,12 +311,24 @@ static int mdp5_plane_atomic_check_with_state(struct drm_crtc_state *crtc_state, > mdp5_state->r_hwpipe = NULL; > > > - mdp5_pipe_release(state->state, old_hwpipe); > - mdp5_pipe_release(state->state, old_right_hwpipe); > + ret = mdp5_pipe_release(state->state, old_hwpipe); > + if (ret) > + return ret; > + > + ret = mdp5_pipe_release(state->state, old_right_hwpipe); > + if (ret) > + return ret; > + > } > } else { > - mdp5_pipe_release(state->state, mdp5_state->hwpipe); > - mdp5_pipe_release(state->state, mdp5_state->r_hwpipe); > + ret = mdp5_pipe_release(state->state, mdp5_state->hwpipe); > + if (ret) > + return ret; > + > + ret = mdp5_pipe_release(state->state, mdp5_state->r_hwpipe); > + if (ret) > + return ret; > + > mdp5_state->hwpipe = mdp5_state->r_hwpipe = NULL; > } > > -- > 2.35.1 >
On Thu, 5 May 2022 at 05:06, Rob Clark <robdclark@gmail.com> wrote: > > On Wed, May 4, 2022 at 6:55 PM Jessica Zhang <quic_jesszhan@quicinc.com> wrote: > > > > mdp5_get_global_state runs the risk of hitting a -EDEADLK when acquiring > > the modeset lock, but currently mdp5_pipe_release doesn't check for if > > an error is returned. Because of this, there is a possibility of > > mdp5_pipe_release hitting a NULL dereference error. > > > > To avoid this, let's have mdp5_pipe_release check if > > mdp5_get_global_state returns an error and propogate that error. > > > > Changes since v1: > > - Separated declaration and initialization of *new_state to avoid > > compiler warning > > - Fixed some spelling mistakes in commit message > > > > Note that mdp5_mixer_release() needs the same treatment.. one more comment below > > > Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com> > > --- > > drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c | 15 +++++++++++---- > > drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h | 2 +- > > drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c | 20 ++++++++++++++++---- > > 3 files changed, 28 insertions(+), 9 deletions(-) > > > > diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c > > index ba6695963aa6..97887a2be082 100644 > > --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c > > +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c > > @@ -119,18 +119,23 @@ int mdp5_pipe_assign(struct drm_atomic_state *s, struct drm_plane *plane, > > return 0; > > } > > > > -void mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe) > > +int mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe) > > { > > struct msm_drm_private *priv = s->dev->dev_private; > > struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms)); > > struct mdp5_global_state *state = mdp5_get_global_state(s); > > - struct mdp5_hw_pipe_state *new_state = &state->hwpipe; > > + struct mdp5_hw_pipe_state *new_state; > > > > if (!hwpipe) > > - return; > > + return -EINVAL; > > At least per the current code, !hwpipe is "normal".. I think that fits > the model of things like kfree(NULL), so lets make this just return 0 Especially since we release the r_hwpipe w/o additional check. And r_hwpipe frequently is NULL. > > > + > > + if (IS_ERR(state)) > > + return PTR_ERR(state); > > + > > + new_state = &state->hwpipe; > > > > if (WARN_ON(!new_state->hwpipe_to_plane[hwpipe->idx])) > > - return; > > + return -EINVAL; > > > > DBG("%s: release from plane %s", hwpipe->name, > > new_state->hwpipe_to_plane[hwpipe->idx]->name); > > @@ -141,6 +146,8 @@ void mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe) > > } > > > > new_state->hwpipe_to_plane[hwpipe->idx] = NULL; > > + > > + return 0; > > } > > > > void mdp5_pipe_destroy(struct mdp5_hw_pipe *hwpipe) > > diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h > > index 9b26d0761bd4..cca67938cab2 100644 > > --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h > > +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h > > @@ -37,7 +37,7 @@ int mdp5_pipe_assign(struct drm_atomic_state *s, struct drm_plane *plane, > > uint32_t caps, uint32_t blkcfg, > > struct mdp5_hw_pipe **hwpipe, > > struct mdp5_hw_pipe **r_hwpipe); > > -void mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe); > > +int mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe); > > > > struct mdp5_hw_pipe *mdp5_pipe_init(enum mdp5_pipe pipe, > > uint32_t reg_offset, uint32_t caps); > > diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c > > index 228b22830970..979458482841 100644 > > --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c > > +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c > > @@ -311,12 +311,24 @@ static int mdp5_plane_atomic_check_with_state(struct drm_crtc_state *crtc_state, > > mdp5_state->r_hwpipe = NULL; > > > > > > - mdp5_pipe_release(state->state, old_hwpipe); > > - mdp5_pipe_release(state->state, old_right_hwpipe); > > + ret = mdp5_pipe_release(state->state, old_hwpipe); > > + if (ret) > > + return ret; > > + > > + ret = mdp5_pipe_release(state->state, old_right_hwpipe); > > + if (ret) > > + return ret; > > + > > } > > } else { > > - mdp5_pipe_release(state->state, mdp5_state->hwpipe); > > - mdp5_pipe_release(state->state, mdp5_state->r_hwpipe); > > + ret = mdp5_pipe_release(state->state, mdp5_state->hwpipe); > > + if (ret) > > + return ret; > > + > > + ret = mdp5_pipe_release(state->state, mdp5_state->r_hwpipe); > > + if (ret) > > + return ret; > > + > > mdp5_state->hwpipe = mdp5_state->r_hwpipe = NULL; > > } > > > > -- > > 2.35.1 > >
On 5/5/2022 1:48 AM, Dmitry Baryshkov wrote: > On Thu, 5 May 2022 at 05:06, Rob Clark <robdclark@gmail.com> wrote: >> >> On Wed, May 4, 2022 at 6:55 PM Jessica Zhang <quic_jesszhan@quicinc.com> wrote: >>> >>> mdp5_get_global_state runs the risk of hitting a -EDEADLK when acquiring >>> the modeset lock, but currently mdp5_pipe_release doesn't check for if >>> an error is returned. Because of this, there is a possibility of >>> mdp5_pipe_release hitting a NULL dereference error. >>> >>> To avoid this, let's have mdp5_pipe_release check if >>> mdp5_get_global_state returns an error and propogate that error. >>> >>> Changes since v1: >>> - Separated declaration and initialization of *new_state to avoid >>> compiler warning >>> - Fixed some spelling mistakes in commit message >>> >> >> Note that mdp5_mixer_release() needs the same treatment.. one more comment below Got it, will submit a fix for that. >> >>> Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com> >>> --- >>> drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c | 15 +++++++++++---- >>> drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h | 2 +- >>> drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c | 20 ++++++++++++++++---- >>> 3 files changed, 28 insertions(+), 9 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c >>> index ba6695963aa6..97887a2be082 100644 >>> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c >>> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c >>> @@ -119,18 +119,23 @@ int mdp5_pipe_assign(struct drm_atomic_state *s, struct drm_plane *plane, >>> return 0; >>> } >>> >>> -void mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe) >>> +int mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe) >>> { >>> struct msm_drm_private *priv = s->dev->dev_private; >>> struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms)); >>> struct mdp5_global_state *state = mdp5_get_global_state(s); >>> - struct mdp5_hw_pipe_state *new_state = &state->hwpipe; >>> + struct mdp5_hw_pipe_state *new_state; >>> >>> if (!hwpipe) >>> - return; >>> + return -EINVAL; >> >> At least per the current code, !hwpipe is "normal".. I think that fits >> the model of things like kfree(NULL), so lets make this just return 0 > > Especially since we release the r_hwpipe w/o additional check. And > r_hwpipe frequently is NULL. Noted. Thanks, Jessica Zhang > >> >>> + >>> + if (IS_ERR(state)) >>> + return PTR_ERR(state); >>> + >>> + new_state = &state->hwpipe; >>> >>> if (WARN_ON(!new_state->hwpipe_to_plane[hwpipe->idx])) >>> - return; >>> + return -EINVAL; >>> >>> DBG("%s: release from plane %s", hwpipe->name, >>> new_state->hwpipe_to_plane[hwpipe->idx]->name); >>> @@ -141,6 +146,8 @@ void mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe) >>> } >>> >>> new_state->hwpipe_to_plane[hwpipe->idx] = NULL; >>> + >>> + return 0; >>> } >>> >>> void mdp5_pipe_destroy(struct mdp5_hw_pipe *hwpipe) >>> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h >>> index 9b26d0761bd4..cca67938cab2 100644 >>> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h >>> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h >>> @@ -37,7 +37,7 @@ int mdp5_pipe_assign(struct drm_atomic_state *s, struct drm_plane *plane, >>> uint32_t caps, uint32_t blkcfg, >>> struct mdp5_hw_pipe **hwpipe, >>> struct mdp5_hw_pipe **r_hwpipe); >>> -void mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe); >>> +int mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe); >>> >>> struct mdp5_hw_pipe *mdp5_pipe_init(enum mdp5_pipe pipe, >>> uint32_t reg_offset, uint32_t caps); >>> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c >>> index 228b22830970..979458482841 100644 >>> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c >>> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c >>> @@ -311,12 +311,24 @@ static int mdp5_plane_atomic_check_with_state(struct drm_crtc_state *crtc_state, >>> mdp5_state->r_hwpipe = NULL; >>> >>> >>> - mdp5_pipe_release(state->state, old_hwpipe); >>> - mdp5_pipe_release(state->state, old_right_hwpipe); >>> + ret = mdp5_pipe_release(state->state, old_hwpipe); >>> + if (ret) >>> + return ret; >>> + >>> + ret = mdp5_pipe_release(state->state, old_right_hwpipe); >>> + if (ret) >>> + return ret; >>> + >>> } >>> } else { >>> - mdp5_pipe_release(state->state, mdp5_state->hwpipe); >>> - mdp5_pipe_release(state->state, mdp5_state->r_hwpipe); >>> + ret = mdp5_pipe_release(state->state, mdp5_state->hwpipe); >>> + if (ret) >>> + return ret; >>> + >>> + ret = mdp5_pipe_release(state->state, mdp5_state->r_hwpipe); >>> + if (ret) >>> + return ret; >>> + >>> mdp5_state->hwpipe = mdp5_state->r_hwpipe = NULL; >>> } >>> >>> -- >>> 2.35.1 >>> > > > > -- > With best wishes > Dmitry
diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c index ba6695963aa6..97887a2be082 100644 --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c @@ -119,18 +119,23 @@ int mdp5_pipe_assign(struct drm_atomic_state *s, struct drm_plane *plane, return 0; } -void mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe) +int mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe) { struct msm_drm_private *priv = s->dev->dev_private; struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms)); struct mdp5_global_state *state = mdp5_get_global_state(s); - struct mdp5_hw_pipe_state *new_state = &state->hwpipe; + struct mdp5_hw_pipe_state *new_state; if (!hwpipe) - return; + return -EINVAL; + + if (IS_ERR(state)) + return PTR_ERR(state); + + new_state = &state->hwpipe; if (WARN_ON(!new_state->hwpipe_to_plane[hwpipe->idx])) - return; + return -EINVAL; DBG("%s: release from plane %s", hwpipe->name, new_state->hwpipe_to_plane[hwpipe->idx]->name); @@ -141,6 +146,8 @@ void mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe) } new_state->hwpipe_to_plane[hwpipe->idx] = NULL; + + return 0; } void mdp5_pipe_destroy(struct mdp5_hw_pipe *hwpipe) diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h index 9b26d0761bd4..cca67938cab2 100644 --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h @@ -37,7 +37,7 @@ int mdp5_pipe_assign(struct drm_atomic_state *s, struct drm_plane *plane, uint32_t caps, uint32_t blkcfg, struct mdp5_hw_pipe **hwpipe, struct mdp5_hw_pipe **r_hwpipe); -void mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe); +int mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe); struct mdp5_hw_pipe *mdp5_pipe_init(enum mdp5_pipe pipe, uint32_t reg_offset, uint32_t caps); diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c index 228b22830970..979458482841 100644 --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c @@ -311,12 +311,24 @@ static int mdp5_plane_atomic_check_with_state(struct drm_crtc_state *crtc_state, mdp5_state->r_hwpipe = NULL; - mdp5_pipe_release(state->state, old_hwpipe); - mdp5_pipe_release(state->state, old_right_hwpipe); + ret = mdp5_pipe_release(state->state, old_hwpipe); + if (ret) + return ret; + + ret = mdp5_pipe_release(state->state, old_right_hwpipe); + if (ret) + return ret; + } } else { - mdp5_pipe_release(state->state, mdp5_state->hwpipe); - mdp5_pipe_release(state->state, mdp5_state->r_hwpipe); + ret = mdp5_pipe_release(state->state, mdp5_state->hwpipe); + if (ret) + return ret; + + ret = mdp5_pipe_release(state->state, mdp5_state->r_hwpipe); + if (ret) + return ret; + mdp5_state->hwpipe = mdp5_state->r_hwpipe = NULL; }
mdp5_get_global_state runs the risk of hitting a -EDEADLK when acquiring the modeset lock, but currently mdp5_pipe_release doesn't check for if an error is returned. Because of this, there is a possibility of mdp5_pipe_release hitting a NULL dereference error. To avoid this, let's have mdp5_pipe_release check if mdp5_get_global_state returns an error and propogate that error. Changes since v1: - Separated declaration and initialization of *new_state to avoid compiler warning - Fixed some spelling mistakes in commit message Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com> --- drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c | 15 +++++++++++---- drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.h | 2 +- drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c | 20 ++++++++++++++++---- 3 files changed, 28 insertions(+), 9 deletions(-)