Commit 8e4ed3cf authored by Srinivasan Shanmugam's avatar Srinivasan Shanmugam Committed by Alex Deucher
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drm/amd/display: Add null check for pipe_ctx->plane_state in dcn20_program_pipe 



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 <chiahsuan.chung@amd.com>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Cc: Roman Li <roman.li@amd.com>
Cc: Alex Hung <alex.hung@amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: default avatarSrinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: default avatarTom Chung <chiahsuan.chung@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 25dd25f8

drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c

+19 −11
Original line number Diff line number Diff line
@@ -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) {

		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,