This commit addresses a null pointer dereference issue in the `dcn20_program_pipe` function. The issue could occur when `pipe_ctx->plane_state` is null.
The fix adds a check to ensure `pipe_ctx->plane_state` is not null before accessing. This prevents a null pointer dereference. Reported by smatch: drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn20/dcn20_hwseq.c:1925 dcn20_program_pipe() error: we previously assumed 'pipe_ctx->plane_state' could be null (see line 1877) Cc: Tom Chung <[email protected]> Cc: Rodrigo Siqueira <[email protected]> Cc: Roman Li <[email protected]> Cc: Alex Hung <[email protected]> Cc: Aurabindo Pillai <[email protected]> Cc: Harry Wentland <[email protected]> Cc: Hamza Mahfooz <[email protected]> Signed-off-by: Srinivasan Shanmugam <[email protected]> --- .../amd/display/dc/hwss/dcn20/dcn20_hwseq.c | 30 ++++++++++++------- 1 file changed, 19 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c b/drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c index 270e337ae27b..5a6064999033 100644 --- a/drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c +++ b/drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c @@ -1922,22 +1922,29 @@ static void dcn20_program_pipe( dc->res_pool->hubbub, pipe_ctx->plane_res.hubp->inst, pipe_ctx->hubp_regs.det_size); } - if (pipe_ctx->update_flags.raw || pipe_ctx->plane_state->update_flags.raw || pipe_ctx->stream->update_flags.raw) + if (pipe_ctx->update_flags.raw || + (pipe_ctx->plane_state && pipe_ctx->plane_state->update_flags.raw) || + pipe_ctx->stream->update_flags.raw) dcn20_update_dchubp_dpp(dc, pipe_ctx, context); - if (pipe_ctx->update_flags.bits.enable - || pipe_ctx->plane_state->update_flags.bits.hdr_mult) + if (pipe_ctx->update_flags.bits.enable || + (pipe_ctx->plane_state && pipe_ctx->plane_state->update_flags.bits.hdr_mult)) hws->funcs.set_hdr_multiplier(pipe_ctx); if (hws->funcs.populate_mcm_luts) { - hws->funcs.populate_mcm_luts(dc, pipe_ctx, pipe_ctx->plane_state->mcm_luts, - pipe_ctx->plane_state->lut_bank_a); - pipe_ctx->plane_state->lut_bank_a = !pipe_ctx->plane_state->lut_bank_a; + if (pipe_ctx->plane_state) { + hws->funcs.populate_mcm_luts(dc, pipe_ctx, pipe_ctx->plane_state->mcm_luts, + pipe_ctx->plane_state->lut_bank_a); + pipe_ctx->plane_state->lut_bank_a = !pipe_ctx->plane_state->lut_bank_a; + } } if (pipe_ctx->update_flags.bits.enable || - pipe_ctx->plane_state->update_flags.bits.in_transfer_func_change || - pipe_ctx->plane_state->update_flags.bits.gamma_change || - pipe_ctx->plane_state->update_flags.bits.lut_3d) + (pipe_ctx->plane_state && + pipe_ctx->plane_state->update_flags.bits.in_transfer_func_change) || + (pipe_ctx->plane_state && + pipe_ctx->plane_state->update_flags.bits.gamma_change) || + (pipe_ctx->plane_state && + pipe_ctx->plane_state->update_flags.bits.lut_3d)) hws->funcs.set_input_transfer_func(dc, pipe_ctx, pipe_ctx->plane_state); /* dcn10_translate_regamma_to_hw_format takes 750us to finish @@ -1947,7 +1954,8 @@ static void dcn20_program_pipe( if (pipe_ctx->update_flags.bits.enable || pipe_ctx->update_flags.bits.plane_changed || pipe_ctx->stream->update_flags.bits.out_tf || - pipe_ctx->plane_state->update_flags.bits.output_tf_change) + (pipe_ctx->plane_state && + pipe_ctx->plane_state->update_flags.bits.output_tf_change)) hws->funcs.set_output_transfer_func(dc, pipe_ctx, pipe_ctx->stream); /* If the pipe has been enabled or has a different opp, we @@ -1971,7 +1979,7 @@ static void dcn20_program_pipe( } /* Set ABM pipe after other pipe configurations done */ - if (pipe_ctx->plane_state->visible) { + if ((pipe_ctx->plane_state && pipe_ctx->plane_state->visible)) { if (pipe_ctx->stream_res.abm) { dc->hwss.set_pipe(pipe_ctx); pipe_ctx->stream_res.abm->funcs->set_abm_level(pipe_ctx->stream_res.abm, -- 2.34.1
