This commit addresses a potential null pointer dereference issue in the `dcn401_init_hw` function. The issue could occur when `dc->clk_mgr` or `dc->clk_mgr->funcs` is null.
The fix adds a check to ensure `dc->clk_mgr` and `dc->clk_mgr->funcs` is not null before accessing its functions. This prevents a potential null pointer dereference. Reported by smatch: drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn401/dcn401_hwseq.c:416 dcn401_init_hw() error: we previously assumed 'dc->clk_mgr' could be null (see line 225) 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]> --- v2: Along with "dc->clk_mgr" add check for even dc->clk_mgr->funcs" (Tom) drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c b/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c index 87c5ef579ecb..0fa610590245 100644 --- a/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c +++ b/drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c @@ -222,7 +222,7 @@ void dcn401_init_hw(struct dc *dc) uint32_t backlight = MAX_BACKLIGHT_LEVEL; uint32_t user_level = MAX_BACKLIGHT_LEVEL; - if (dc->clk_mgr && dc->clk_mgr->funcs->init_clocks) { + if (dc->clk_mgr && dc->clk_mgr->funcs && dc->clk_mgr->funcs->init_clocks) { dc->clk_mgr->funcs->init_clocks(dc->clk_mgr); // mark dcmode limits present if any clock has distinct AC and DC values from SMU @@ -413,7 +413,7 @@ void dcn401_init_hw(struct dc *dc) if (!dcb->funcs->is_accelerated_mode(dcb) && dc->res_pool->hubbub->funcs->init_watermarks) dc->res_pool->hubbub->funcs->init_watermarks(dc->res_pool->hubbub); - if (dc->clk_mgr->funcs->notify_wm_ranges) + if (dc->clk_mgr && dc->clk_mgr->funcs && dc->clk_mgr->funcs->notify_wm_ranges) dc->clk_mgr->funcs->notify_wm_ranges(dc->clk_mgr); if (dc->res_pool->hubbub->funcs->force_pstate_change_control) @@ -435,7 +435,9 @@ void dcn401_init_hw(struct dc *dc) dc->debug.fams2_config.bits.enable &= dc->ctx->dmub_srv->dmub->feature_caps.fw_assisted_mclk_switch_ver == 2; if (!dc->debug.fams2_config.bits.enable && dc->res_pool->funcs->update_bw_bounding_box) { /* update bounding box if FAMS2 disabled */ - dc->res_pool->funcs->update_bw_bounding_box(dc, dc->clk_mgr->bw_params); + if (dc->clk_mgr) + dc->res_pool->funcs->update_bw_bounding_box(dc, + dc->clk_mgr->bw_params); } } } -- 2.34.1
