[v2] drm/msm/dpu: check dpu_plane_atomic_print_state() for valid sspp

Commit Message

Abhinav Kumar Dec. 11, 2024, 7:50 p.m. UTC

Similar to the r_pipe sspp protect, add a check to protect
the pipe state prints to avoid NULL ptr dereference for cases when
the state is dumped without a corresponding atomic_check() where the
pipe->sspp is assigned.

Fixes: 31f7148fd370 ("drm/msm/dpu: move pstate->pipe initialization to dpu_plane_atomic_check")
Reported-by: Stephen Boyd <[e-mail]>
Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/67
Signed-off-by: Abhinav Kumar <[e-mail]>
---
To: Rob Clark <[e-mail]>
To: Dmitry Baryshkov <[e-mail]>
To: Sean Paul <[e-mail]>
To: Marijn Suijten <[e-mail]>
To: David Airlie <[e-mail]>
To: Simona Vetter <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: Stephen Boyd <[e-mail]>
---
Changes in v2:
- move pstate->stage out of the pipe->sspp check
- add reported-by credits for Stephen
- Link to v1: https://lore.kernel.org/r/[e-mail]
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)


---
base-commit: 9d6a414ad31e8eb296cd6f2c1834b2c6994960a0
change-id: 20241209-check-state-before-dump-2a015ace5f49

Best regards,

Comments

Dmitry Baryshkov Dec. 11, 2024, 9:09 p.m. UTC | #1

On Wed, Dec 11, 2024 at 11:50:26AM -0800, Abhinav Kumar wrote:
> Similar to the r_pipe sspp protect, add a check to protect
> the pipe state prints to avoid NULL ptr dereference for cases when
> the state is dumped without a corresponding atomic_check() where the
> pipe->sspp is assigned.
> 
> Fixes: 31f7148fd370 ("drm/msm/dpu: move pstate->pipe initialization to dpu_plane_atomic_check")
> Reported-by: Stephen Boyd <[e-mail]>
> Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/67
> Signed-off-by: Abhinav Kumar <[e-mail]>
> ---
> To: Rob Clark <[e-mail]>
> To: Dmitry Baryshkov <[e-mail]>
> To: Sean Paul <[e-mail]>
> To: Marijn Suijten <[e-mail]>
> To: David Airlie <[e-mail]>
> To: Simona Vetter <[e-mail]>
> Cc: [e-mail]
> Cc: [e-mail]
> Cc: [e-mail]
> Cc: [e-mail]
> Cc: Stephen Boyd <[e-mail]>
> ---
> Changes in v2:
> - move pstate->stage out of the pipe->sspp check
> - add reported-by credits for Stephen
> - Link to v1: https://lore.kernel.org/r/[e-mail]
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
> 

Reviewed-by: Dmitry Baryshkov <[e-mail]>

Douglas Anderson Dec. 11, 2024, 10:50 p.m. UTC | #2

Hi,

On Wed, Dec 11, 2024 at 11:51 AM Abhinav Kumar
<[e-mail]> wrote:
>
> Similar to the r_pipe sspp protect, add a check to protect
> the pipe state prints to avoid NULL ptr dereference for cases when
> the state is dumped without a corresponding atomic_check() where the
> pipe->sspp is assigned.
>
> Fixes: 31f7148fd370 ("drm/msm/dpu: move pstate->pipe initialization to dpu_plane_atomic_check")
> Reported-by: Stephen Boyd <[e-mail]>
> Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/67
> Signed-off-by: Abhinav Kumar <[e-mail]>
> ---
> To: Rob Clark <[e-mail]>
> To: Dmitry Baryshkov <[e-mail]>
> To: Sean Paul <[e-mail]>
> To: Marijn Suijten <[e-mail]>
> To: David Airlie <[e-mail]>
> To: Simona Vetter <[e-mail]>
> Cc: [e-mail]
> Cc: [e-mail]
> Cc: [e-mail]
> Cc: [e-mail]
> Cc: Stephen Boyd <[e-mail]>
> ---
> Changes in v2:
> - move pstate->stage out of the pipe->sspp check
> - add reported-by credits for Stephen
> - Link to v1: https://lore.kernel.org/r/[e-mail]
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)

Tested-by: Douglas Anderson <[e-mail]>

Stephen Boyd Dec. 12, 2024, 7:44 p.m. UTC | #3

Quoting Abhinav Kumar (2024-12-11 11:50:26)
> Similar to the r_pipe sspp protect, add a check to protect
> the pipe state prints to avoid NULL ptr dereference for cases when
> the state is dumped without a corresponding atomic_check() where the
> pipe->sspp is assigned.
>
> Fixes: 31f7148fd370 ("drm/msm/dpu: move pstate->pipe initialization to dpu_plane_atomic_check")
> Reported-by: Stephen Boyd <[e-mail]>
> Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/67
> Signed-off-by: Abhinav Kumar <[e-mail]>
> ---

Tested-by: Stephen Boyd <[e-mail]> # sc7180-trogdor

Patch

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
index 3ffac24333a2a5b01135d4ece418432d4a74dc04..703e58901d53f26eba69566c2784655015c6a584 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
@@ -1335,12 +1335,15 @@  static void dpu_plane_atomic_print_state(struct drm_printer *p,
 
 	drm_printf(p, "\tstage=%d\n", pstate->stage);
 
-	drm_printf(p, "\tsspp[0]=%s\n", pipe->sspp->cap->name);
-	drm_printf(p, "\tmultirect_mode[0]=%s\n", dpu_get_multirect_mode(pipe->multirect_mode));
-	drm_printf(p, "\tmultirect_index[0]=%s\n",
-		   dpu_get_multirect_index(pipe->multirect_index));
-	drm_printf(p, "\tsrc[0]=" DRM_RECT_FMT "\n", DRM_RECT_ARG(&pipe_cfg->src_rect));
-	drm_printf(p, "\tdst[0]=" DRM_RECT_FMT "\n", DRM_RECT_ARG(&pipe_cfg->dst_rect));
+	if (pipe->sspp) {
+		drm_printf(p, "\tsspp[0]=%s\n", pipe->sspp->cap->name);
+		drm_printf(p, "\tmultirect_mode[0]=%s\n",
+			   dpu_get_multirect_mode(pipe->multirect_mode));
+		drm_printf(p, "\tmultirect_index[0]=%s\n",
+			   dpu_get_multirect_index(pipe->multirect_index));
+		drm_printf(p, "\tsrc[0]=" DRM_RECT_FMT "\n", DRM_RECT_ARG(&pipe_cfg->src_rect));
+		drm_printf(p, "\tdst[0]=" DRM_RECT_FMT "\n", DRM_RECT_ARG(&pipe_cfg->dst_rect));
+	}
 
 	if (r_pipe->sspp) {
 		drm_printf(p, "\tsspp[1]=%s\n", r_pipe->sspp->cap->name);