Fix the following Wstringop-overflow warnings when building with GCC-11:
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dpia.c:493:17: warning: ‘dp_decide_lane_settings’ accessing 4 bytes in a region of size 1 [-Wstringop-overflow=] drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dpia.c:493:17: warning: ‘dp_decide_lane_settings’ accessing 4 bytes in a region of size 1 [-Wstringop-overflow=] drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dpia.c:493:17: warning: ‘dp_decide_lane_settings’ accessing 4 bytes in a region of size 1 [-Wstringop-overflow=] drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dpia.c:388:17: warning: ‘dp_decide_lane_settings’ accessing 4 bytes in a region of size 1 [-Wstringop-overflow=] drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dpia.c:388:17: warning: ‘dp_decide_lane_settings’ accessing 4 bytes in a region of size 1 [-Wstringop-overflow=] drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dpia.c:388:17: warning: ‘dp_decide_lane_settings’ accessing 4 bytes in a region of size 1 [-Wstringop-overflow=] drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dp.c:1491:17: warning: ‘dp_decide_lane_settings’ accessing 4 bytes in a region of size 1 [-Wstringop-overflow=] drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dp.c:2613:25: warning: ‘dp_decide_lane_settings’ accessing 4 bytes in a region of size 1 [-Wstringop-overflow=] drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dp.c:2613:25: warning: ‘dp_decide_lane_settings’ accessing 4 bytes in a region of size 1 [-Wstringop-overflow=]
by removing the over-specified array size from the argument declarations.
This helps with the ongoing efforts to globally enable -Wstringop-overflow.
Link: https://github.com/KSPP/linux/issues/181 Signed-off-by: Gustavo A. R. Silva gustavoars@kernel.org --- drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 4 ++-- drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c index f11a8d97fb60..81952e07acf6 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c @@ -823,7 +823,7 @@ bool dp_is_interlane_aligned(union lane_align_status_updated align_status) void dp_hw_to_dpcd_lane_settings( const struct link_training_settings *lt_settings, const struct dc_lane_settings hw_lane_settings[LANE_COUNT_DP_MAX], - union dpcd_training_lane dpcd_lane_settings[LANE_COUNT_DP_MAX]) + union dpcd_training_lane dpcd_lane_settings[]) { uint8_t lane = 0;
@@ -853,7 +853,7 @@ void dp_decide_lane_settings( const struct link_training_settings *lt_settings, const union lane_adjust ln_adjust[LANE_COUNT_DP_MAX], struct dc_lane_settings hw_lane_settings[LANE_COUNT_DP_MAX], - union dpcd_training_lane dpcd_lane_settings[LANE_COUNT_DP_MAX]) + union dpcd_training_lane dpcd_lane_settings[]) { uint32_t lane;
diff --git a/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h b/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h index ab9939db8cea..0d00da1640a7 100644 --- a/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h +++ b/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h @@ -147,12 +147,12 @@ bool dp_is_max_vs_reached( void dp_hw_to_dpcd_lane_settings( const struct link_training_settings *lt_settings, const struct dc_lane_settings hw_lane_settings[LANE_COUNT_DP_MAX], - union dpcd_training_lane dpcd_lane_settings[LANE_COUNT_DP_MAX]); + union dpcd_training_lane dpcd_lane_settings[]); void dp_decide_lane_settings( const struct link_training_settings *lt_settings, const union lane_adjust ln_adjust[LANE_COUNT_DP_MAX], struct dc_lane_settings hw_lane_settings[LANE_COUNT_DP_MAX], - union dpcd_training_lane dpcd_lane_settings[LANE_COUNT_DP_MAX]); + union dpcd_training_lane dpcd_lane_settings[]);
uint32_t dp_translate_training_aux_read_interval(uint32_t dpcd_aux_read_interval);
On Thu, Mar 03, 2022 at 11:25:03AM -0600, Gustavo A. R. Silva wrote:
Fix the following Wstringop-overflow warnings when building with GCC-11:
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dpia.c:493:17: warning: ‘dp_decide_lane_settings’ accessing 4 bytes in a region of size 1 [-Wstringop-overflow=]
Can you "show your work" a little more here? I don't actually see the what is getting fixed:
enum dc_lane_count { ... LANE_COUNT_FOUR = 4, ... LANE_COUNT_DP_MAX = LANE_COUNT_FOUR };
struct link_training_settings { ... union dpcd_training_lane dpcd_lane_settings[LANE_COUNT_DP_MAX]; };
void dp_hw_to_dpcd_lane_settings( ... union dpcd_training_lane dpcd_lane_settings[LANE_COUNT_DP_MAX]) { ... }
static enum link_training_result dpia_training_cr_transparent( ... struct link_training_settings *lt_settings) { ... dp_decide_lane_settings(lt_settings, dpcd_lane_adjust, lt_settings->hw_lane_settings, lt_settings->dpcd_lane_settings); ... }
Everything looks to be the correct size?
On Thu, Mar 03, 2022 at 09:43:28AM -0800, Kees Cook wrote:
Yep; this fix is similar to the one for intel_pm.c in this
commit e7c6e405e171fb33990a12ecfd14e6500d9e5cf2
where the array size of 8 seems to be fine for all the struct members related (pri_latency, spr_latency, cur_latency and skl_latency):
drivers/gpu/drm/i915/i915_drv.h:465:struct drm_i915_private { ...
drivers/gpu/drm/i915/i915_drv.h-739- struct {
... drivers/gpu/drm/i915/i915_drv.h-745- /* primary */ drivers/gpu/drm/i915/i915_drv.h-746- u16 pri_latency[5]; drivers/gpu/drm/i915/i915_drv.h-747- /* sprite */ drivers/gpu/drm/i915/i915_drv.h-748- u16 spr_latency[5]; drivers/gpu/drm/i915/i915_drv.h-749- /* cursor */ drivers/gpu/drm/i915/i915_drv.h-750- u16 cur_latency[5]; drivers/gpu/drm/i915/i915_drv.h-751- /* drivers/gpu/drm/i915/i915_drv.h-752- * Raw watermark memory latency values drivers/gpu/drm/i915/i915_drv.h-753- * for SKL for all 8 levels drivers/gpu/drm/i915/i915_drv.h-754- * in 1us units. drivers/gpu/drm/i915/i915_drv.h-755- */ drivers/gpu/drm/i915/i915_drv.h-756- u16 skl_latency[8];
... drivers/gpu/drm/i915/i915_drv.h-773- } wm; ... }
however GCC warns about accessing bytes beyond the limits, and turning the argument declarations into pointers (removing the over-specified array size from the argument declaration) silence the warnings.
-- Gustavo
On Thu, Mar 03, 2022 at 12:19:57PM -0600, Gustavo A. R. Silva wrote:
and in this case the ilk_wm_max_level() returns the right maximum size for the corresponding 'struct wm' member:
drivers/gpu/drm/i915/intel_pm.c:2993:int ilk_wm_max_level(const struct drm_i915_private *dev_priv) drivers/gpu/drm/i915/intel_pm.c-2994-{ drivers/gpu/drm/i915/intel_pm.c-2995- /* how many WM levels are we expecting */ drivers/gpu/drm/i915/intel_pm.c-2996- if (HAS_HW_SAGV_WM(dev_priv)) drivers/gpu/drm/i915/intel_pm.c-2997- return 5; drivers/gpu/drm/i915/intel_pm.c-2998- else if (DISPLAY_VER(dev_priv) >= 9) drivers/gpu/drm/i915/intel_pm.c-2999- return 7; drivers/gpu/drm/i915/intel_pm.c-3000- else if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) drivers/gpu/drm/i915/intel_pm.c-3001- return 4; drivers/gpu/drm/i915/intel_pm.c-3002- else if (DISPLAY_VER(dev_priv) >= 6) drivers/gpu/drm/i915/intel_pm.c-3003- return 3; drivers/gpu/drm/i915/intel_pm.c-3004- else drivers/gpu/drm/i915/intel_pm.c-3005- return 2; drivers/gpu/drm/i915/intel_pm.c-3006-}
drivers/gpu/drm/i915/intel_pm.c:3009:static void intel_print_wm_latency(struct drm_i915_private *dev_priv, drivers/gpu/drm/i915/intel_pm.c-3010- const char *name, drivers/gpu/drm/i915/intel_pm.c-3011- const u16 wm[]) drivers/gpu/drm/i915/intel_pm.c-3012-{ drivers/gpu/drm/i915/intel_pm.c-3013- int level, max_level = ilk_wm_max_level(dev_priv); drivers/gpu/drm/i915/intel_pm.c-3014- drivers/gpu/drm/i915/intel_pm.c-3015- for (level = 0; level <= max_level; level++) { drivers/gpu/drm/i915/intel_pm.c-3016- unsigned int latency = wm[level]; drivers/gpu/drm/i915/intel_pm.c-3017- ... }
still GCC warns about this with Wstringop-overread, as it is explained in commit e7c6e405e171.
-- Gustavo
On Thu, Mar 3, 2022 at 3:37 PM Gustavo A. R. Silva gustavoars@kernel.org wrote:
Did you want to respin with expanded explanation?
Alex
On 2022-03-03 12:25, Gustavo A. R. Silva wrote:
Acked-by: Harry Wentland harry.wentland@amd.com
Harry
dri-devel@lists.freedesktop.org
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Alex Deucher -
Gustavo A. R. Silva -
Harry Wentland -
Kees Cook