Hello Qingqing Zhuo,
The patch 7966f319c66d: "drm/amd/display: Introduce DML2" from Jul
28, 2023 (linux-next), leads to the following Smatch static checker
warning:
drivers/gpu/drm/amd/amdgpu/../display/dc/dml2/dml2_wrapper.c:77 map_hw_resources()
error: buffer overflow 'dml2->v20.scratch.dml_to_dc_pipe_mapping.disp_cfg_to_stream_id' 6 <= 7
drivers/gpu/drm/amd/amdgpu/../display/dc/dml2/dml2_wrapper.c:79 map_hw_resources()
error: buffer overflow 'dml2->v20.scratch.dml_to_dc_pipe_mapping.disp_cfg_to_plane_id' 6 <= 7
drivers/gpu/drm/amd/amdgpu/../display/dc/dml2/dml2_wrapper.c
59 static void map_hw_resources(struct dml2_context *dml2,
60 struct dml_display_cfg_st *in_out_display_cfg, struct dml_mode_support_info_st *mode_support_info)
61 {
62 unsigned int num_pipes = 0;
63 int i, j;
64
65 for (i = 0; i < __DML_NUM_PLANES__; i++) {
^^^^^^^^^^^^^^^^^^
__DML_NUM_PLANES__ is 8. This loops 0-7.
66 in_out_display_cfg->hw.ODMMode[i] = mode_support_info->ODMMode[i];
67 in_out_display_cfg->hw.DPPPerSurface[i] = mode_support_info->DPPPerSurface[i];
68 in_out_display_cfg->hw.DSCEnabled[i] = mode_support_info->DSCEnabled[i];
69 in_out_display_cfg->hw.NumberOfDSCSlices[i] = mode_support_info->NumberOfDSCSlices[i];
70 in_out_display_cfg->hw.DLGRefClkFreqMHz = 24;
71 if (dml2->v20.dml_core_ctx.project != dml_project_dcn35 &&
72 dml2->v20.dml_core_ctx.project != dml_project_dcn351) {
73 /*dGPU default as 50Mhz*/
74 in_out_display_cfg->hw.DLGRefClkFreqMHz = 50;
75 }
76 for (j = 0; j < mode_support_info->DPPPerSurface[i]; j++) {
--> 77 dml2->v20.scratch.dml_to_dc_pipe_mapping.dml_pipe_idx_to_stream_id[num_pipes] = dml2->v20.scratch.dml_to_dc_pipe_mapping.disp_cfg_to_stream_id[i];
Both of these arrays have 6 elements.
78 dml2->v20.scratch.dml_to_dc_pipe_mapping.dml_pipe_idx_to_stream_id_valid[num_pipes] = true;
79 dml2->v20.scratch.dml_to_dc_pipe_mapping.dml_pipe_idx_to_plane_id[num_pipes] = dml2->v20.scratch.dml_to_dc_pipe_mapping.disp_cfg_to_plane_id[i];
80 dml2->v20.scratch.dml_to_dc_pipe_mapping.dml_pipe_idx_to_plane_id_valid[num_pipes] = true;
81 num_pipes++;
82 }
83 }
84 }
regards,
dan carpenter
