Reviewed-by: Alex Hung <alex.hung@xxxxxxx>
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.chung@xxxxxxx>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx>
Cc: Roman Li <roman.li@xxxxxxx>
Cc: Alex Hung <alex.hung@xxxxxxx>
Cc: Aurabindo Pillai <aurabindo.pillai@xxxxxxx>
Cc: Harry Wentland <harry.wentland@xxxxxxx>
Cc: Hamza Mahfooz <hamza.mahfooz@xxxxxxx>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx>
---
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)
