[igt-dev] [PATCH i-g-t v2] tests/kms_concurrent: check if second primary plane is valid

[Abhinav Kumar]

prepare_planes() in kms_concurrent loops through the list
of planes and assigns them to the data->plane array.

During this assignment, it skips planes which are of type
DRM_PLANE_TYPE_PRIMARY as they are assigned separately.

However, only one primary plane is assigned and prepared for
the test.

This causes an issue later on in the test when there are
multiple primary planes as the second one is not added
to the data->plane list causing a segmentation fault
when trying to access the second primary plane.

Check if the data->plane is valid before accessing its
members to fix this crash.

This fixes the crash and makes kms_concurrent pass on devices
having multiple primary planes.

localhost /usr/local/libexec/igt-gpu-tools # ./kms_concurrent
IGT-Version: 1.26-NO-GIT (arm) (Linux: 5.17.0-rc2-lockdep-75821-g6200d34d858f aarch64)
Starting subtest: pipe-A
Testing resolution with connector eDP-1 using pipe A with seed 1648151339
Subtest pipe-A: SUCCESS (0.429s)
Starting subtest: pipe-B
Testing resolution with connector eDP-1 using pipe B with seed 1648151340
Subtest pipe-B: SUCCESS (0.592s)
Test requirement not met in function igt_require_pipe, file ../igt-gpu-tools-9999/lib/igt_kms.c:2135:
Test requirement: !(pipe >= display->n_pipes || !display->pipes[pipe].enabled)
Pipe C does not exist or not enabled
Subtest pipe-C: SKIP
Test requirement not met in function igt_require_pipe, file ../igt-gpu-tools-9999/lib/igt_kms.c:2135:
Test requirement: !(pipe >= display->n_pipes || !display->pipes[pipe].enabled)
Pipe D does not exist or not enabled
Subtest pipe-D: SKIP
Test requirement not met in function igt_require_pipe, file ../igt-gpu-tools-9999/lib/igt_kms.c:2135:
Test requirement: !(pipe >= display->n_pipes || !display->pipes[pipe].enabled)
Pipe E does not exist or not enabled
Subtest pipe-E: SKIP
Test requirement not met in function igt_require_pipe, file ../igt-gpu-tools-9999/lib/igt_kms.c:2135:
Test requirement: !(pipe >= display->n_pipes || !display->pipes[pipe].enabled)
Pipe F does not exist or not enabled
Subtest pipe-F: SKIP

changes in v2:
		- add a comment on to explain the NULL check

Reviewed-by: Mark Yacoub <markyacoub at chromium.org>
Signed-off-by: Abhinav Kumar <quic_abhinavk at quicinc.com>
---
 tests/kms_concurrent.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/tests/kms_concurrent.c b/tests/kms_concurrent.c
index 1b8f4b0..dc1e36f 100644
--- a/tests/kms_concurrent.c
+++ b/tests/kms_concurrent.c
@@ -116,7 +116,18 @@ create_fb_for_mode_position(data_t *data, drmModeModeInfo *mode,
 			0.0f, 0.0f, 1.0f);
 
 	for (int i = 0; i < max_planes; i++) {
-		if (data->plane[i]->type == DRM_PLANE_TYPE_PRIMARY)
+		/*
+		 * prepare_planes() skips the assignment of data->plane
+		 * for primary planes as they are handled separately.
+		 *
+		 * Only one primary plane is assigned and prepared for
+		 * the test. If there are multiple primary planes, the
+		 * remaining are unassigned.
+		 *
+		 * Check if the data->plane is valid before accessing its
+		 * members to fix this crash
+		 */
+		if (data->plane[i] && data->plane[i]->type == DRM_PLANE_TYPE_PRIMARY)
 			continue;
 
 		igt_paint_color(cr, rect_x[i], rect_y[i],
-- 
2.7.4