[PATCH] drm/amd/display: Check pipe_ctx before it is used

[PATCH] drm/amd/display: Check pipe_ctx before it is used

[Ma Ke]

resource_get_otg_master_for_stream() could return NULL, we
should check the return value of 'otg_master' before it is
used in resource_log_pipe_for_stream().

Signed-off-by: Ma Ke <make24@iscas.ac.cn>
---
 drivers/gpu/drm/amd/display/dc/core/dc_resource.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index 15819416a2f3..597ca9f369c6 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -2279,6 +2279,8 @@ void resource_log_pipe_topology_update(struct dc *dc, struct dc_state *state)
 					state->stream_status[stream_idx].mall_stream_config.paired_stream);
 			otg_master = resource_get_otg_master_for_stream(
 					&state->res_ctx, state->streams[phantom_stream_idx]);
+			if (!otg_master)
+				continue;
 			resource_log_pipe_for_stream(dc, state, otg_master, stream_idx);
 		}
 	}
-- 
2.25.1

Re: [PATCH] drm/amd/display: Check pipe_ctx before it is used

[Markus Elfring]

> resource_get_otg_master_for_stream() could return NULL, we
> should check the return value of 'otg_master' before it is
> used in resource_log_pipe_for_stream().

A similar fix was integrated already according to a contribution
by Natanel Roizenman.
From which Linux version did you take source files for your static code analyses?

Please take another look at the corresponding software update.
[PATCH 16/37] drm/amd/display: Add null check in resource_log_pipe_topology_update
https://lore.kernel.org/amd-gfx/20240422152817.2765349-17-aurabindo.pillai@amd.com/

Regards,
Markus

Re: [PATCH] drm/amd/display: Check pipe_ctx before it is used

[Markus Elfring]

>> resource_get_otg_master_for_stream() could return NULL, we
>> should check the return value of 'otg_master' before it is
>> used in resource_log_pipe_for_stream().
>
> A similar fix was integrated already according to a contribution
> by Natanel Roizenman.
> From which Linux version did you take source files for your static code analyses?
>
> Please take another look at the corresponding software update.
> [PATCH 16/37] drm/amd/display: Add null check in resource_log_pipe_topology_update
> https://lore.kernel.org/amd-gfx/20240422152817.2765349-17-aurabindo.pillai@amd.com/

How “interesting” is it that a similar source code correction needed
to be repeated by Hersen Wu?

drm/amd/display: Add otg_master NULL check within resource_log_pipe_topology_update
https://lore.kernel.org/amd-gfx/20240501071651.3541919-31-chiahsuan.chung@amd.com/

Regards,
Markus