Reviewed-by: Alex Hung <alex.h...@amd.com> On 2024-07-22 04:51, Srinivasan Shanmugam wrote:
This commit addresses a potential null pointer dereference issue in the `dcn30_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/dcn30/dcn30_hwseq.c:789 dcn30_init_hw() error: we previously assumed 'dc->clk_mgr' could be null (see line 628) Cc: Tom Chung <chiahsuan.ch...@amd.com> Cc: Rodrigo Siqueira <rodrigo.sique...@amd.com> Cc: Roman Li <roman...@amd.com> Cc: Alex Hung <alex.h...@amd.com> Cc: Aurabindo Pillai <aurabindo.pil...@amd.com> Cc: Harry Wentland <harry.wentl...@amd.com> Cc: Hamza Mahfooz <hamza.mahf...@amd.com> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmu...@amd.com> --- v2: Along with "dc->clk_mgr" add check for even dc->clk_mgr->funcs" (Tom) drivers/gpu/drm/amd/display/dc/hwss/dcn30/dcn30_hwseq.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/hwss/dcn30/dcn30_hwseq.c b/drivers/gpu/drm/amd/display/dc/hwss/dcn30/dcn30_hwseq.c index fc5936460ac2..98a40d46aaae 100644 --- a/drivers/gpu/drm/amd/display/dc/hwss/dcn30/dcn30_hwseq.c +++ b/drivers/gpu/drm/amd/display/dc/hwss/dcn30/dcn30_hwseq.c @@ -625,7 +625,7 @@ void dcn30_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);// Initialize the dccg@@ -786,11 +786,12 @@ void dcn30_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 softmax is enabled then hardmax will be set by a different call- if (dc->clk_mgr->funcs->set_hard_max_memclk && !dc->clk_mgr->dc_mode_softmax_enabled) + if (dc->clk_mgr && dc->clk_mgr->funcs && dc->clk_mgr->funcs->set_hard_max_memclk && + !dc->clk_mgr->dc_mode_softmax_enabled) dc->clk_mgr->funcs->set_hard_max_memclk(dc->clk_mgr);if (dc->res_pool->hubbub->funcs->force_pstate_change_control)
