[PATCH AUTOSEL 6.11 155/244] drm/amd/display: fix a UBSAN warning in DML2.1

Sasha Levin
2024-09-25T11:46:58Z

From: Aurabindo Pillai <aurabindo.pillai@amd.com>

[ Upstream commit eaf3adb8faab611ba57594fa915893fc93a7788c ]

When programming phantom pipe, since cursor_width is explicity set to 0,
this causes calculation logic to trigger overflow for an unsigned int
triggering the kernel's UBSAN check as below:

[ 40.962845] UBSAN: shift-out-of-bounds in /tmp/amd.EfpumTkO/amd/amdgpu/../display/dc/dml2/dml21/src/dml2_core/dml2_core_dcn4_calcs.c:3312:34
[ 40.962849] shift exponent 4294967170 is too large for 32-bit type 'unsigned int'
[ 40.962852] CPU: 1 PID: 1670 Comm: gnome-shell Tainted: G W OE 6.5.0-41-generic #41~22.04.2-Ubuntu
[ 40.962854] Hardware name: Gigabyte Technology Co., Ltd. X670E AORUS PRO X/X670E AORUS PRO X, BIOS F21 01/10/2024
[ 40.962856] Call Trace:
[ 40.962857] <TASK>
[ 40.962860] dump_stack_lvl+0x48/0x70
[ 40.962870] dump_stack+0x10/0x20
[ 40.962872] __ubsan_handle_shift_out_of_bounds+0x1ac/0x360
[ 40.962878] calculate_cursor_req_attributes.cold+0x1b/0x28 [amdgpu]
[ 40.963099] dml_core_mode_support+0x6b91/0x16bc0 [amdgpu]
[ 40.963327] ? srso_alias_return_thunk+0x5/0x7f
[ 40.963331] ? CalculateWatermarksMALLUseAndDRAMSpeedChangeSupport+0x18b8/0x2790 [amdgpu]
[ 40.963534] ? srso_alias_return_thunk+0x5/0x7f
[ 40.963536] ? dml_core_mode_support+0xb3db/0x16bc0 [amdgpu]
[ 40.963730] dml2_core_calcs_mode_support_ex+0x2c/0x90 [amdgpu]
[ 40.963906] ? srso_alias_return_thunk+0x5/0x7f
[ 40.963909] ? dml2_core_calcs_mode_support_ex+0x2c/0x90 [amdgpu]
[ 40.964078] core_dcn4_mode_support+0x72/0xbf0 [amdgpu]
[ 40.964247] dml2_top_optimization_perform_optimization_phase+0x1d3/0x2a0 [amdgpu]
[ 40.964420] dml2_build_mode_programming+0x23d/0x750 [amdgpu]
[ 40.964587] dml21_validate+0x274/0x770 [amdgpu]
[ 40.964761] ? srso_alias_return_thunk+0x5/0x7f
[ 40.964763] ? resource_append_dpp_pipes_for_plane_composition+0x27c/0x3b0 [amdgpu]
[ 40.964942] dml2_validate+0x504/0x750 [amdgpu]
[ 40.965117] ? dml21_copy+0x95/0xb0 [amdgpu]
[ 40.965291] ? srso_alias_return_thunk+0x5/0x7f
[ 40.965295] dcn401_validate_bandwidth+0x4e/0x70 [amdgpu]
[ 40.965491] update_planes_and_stream_state+0x38d/0x5c0 [amdgpu]
[ 40.965672] update_planes_and_stream_v3+0x52/0x1e0 [amdgpu]
[ 40.965845] ? srso_alias_return_thunk+0x5/0x7f
[ 40.965849] dc_update_planes_and_stream+0x71/0xb0 [amdgpu]

Fix this by adding a guard for checking cursor width before triggering
the size calculation.

Reviewed-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../src/dml2_core/dml2_core_dcn4_calcs.c | 93 ++++++++++---------
1 file changed, 49 insertions(+), 44 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_core/dml2_core_dcn4_calcs.c b/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_core/dml2_core_dcn4_calcs.c
index 6f4026e396e09..c40cd5d634568 100644
--- a/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_core/dml2_core_dcn4_calcs.c
+++ b/drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_core/dml2_core_dcn4_calcs.c
@@ -7231,10 +7231,9 @@ static bool dml_core_mode_support(struct dml2_core_calcs_mode_support_ex *in_out
/* Cursor Support Check */
mode_lib->ms.support.CursorSupport = true;
for (k = 0; k < mode_lib->ms.num_active_planes; k++) {
- if (display_cfg->plane_descriptors[k].cursor.cursor_width > 0.0) {
- if (display_cfg->plane_descriptors[k].cursor.cursor_bpp == 64 && mode_lib->ip.cursor_64bpp_support == false) {
+ if (display_cfg->plane_descriptors[k].cursor.num_cursors > 0) {
+ if (display_cfg->plane_descriptors[k].cursor.cursor_bpp == 64 && mode_lib->ip.cursor_64bpp_support == false)
mode_lib->ms.support.CursorSupport = false;
- }
}
}

@@ -8091,27 +8090,31 @@ static bool dml_core_mode_support(struct dml2_core_calcs_mode_support_ex *in_out
for (k = 0; k < mode_lib->ms.num_active_planes; ++k) {
double line_time_us = (double)display_cfg->stream_descriptors[display_cfg->plane_descriptors[k].stream_index].timing.h_total / ((double)display_cfg->stream_descriptors[display_cfg->plane_descriptors[k].stream_index].timing.pixel_clock_khz / 1000);
bool cursor_not_enough_urgent_latency_hiding = 0;
- calculate_cursor_req_attributes(
- display_cfg->plane_descriptors[k].cursor.cursor_width,
- display_cfg->plane_descriptors[k].cursor.cursor_bpp,

- // output
- &s->cursor_lines_per_chunk[k],
- &s->cursor_bytes_per_line[k],
- &s->cursor_bytes_per_chunk[k],
- &s->cursor_bytes[k]);
-
- calculate_cursor_urgent_burst_factor(
- mode_lib->ip.cursor_buffer_size,
- display_cfg->plane_descriptors[k].cursor.cursor_width,
- s->cursor_bytes_per_chunk[k],
- s->cursor_lines_per_chunk[k],
- line_time_us,
- mode_lib->ms.UrgLatency,
+ if (display_cfg->plane_descriptors[k].cursor.num_cursors > 0) {
+ calculate_cursor_req_attributes(
+ display_cfg->plane_descriptors[k].cursor.cursor_width,
+ display_cfg->plane_descriptors[k].cursor.cursor_bpp,
+
+ // output
+ &s->cursor_lines_per_chunk[k],
+ &s->cursor_bytes_per_line[k],
+ &s->cursor_bytes_per_chunk[k],
+ &s->cursor_bytes[k]);
+
+ calculate_cursor_urgent_burst_factor(
+ mode_lib->ip.cursor_buffer_size,
+ display_cfg->plane_descriptors[k].cursor.cursor_width,
+ s->cursor_bytes_per_chunk[k],
+ s->cursor_lines_per_chunk[k],
+ line_time_us,
+ mode_lib->ms.UrgLatency,
+
+ // output
+ &mode_lib->ms.UrgentBurstFactorCursor[k],
+ &cursor_not_enough_urgent_latency_hiding);
+ }

- // output
- &mode_lib->ms.UrgentBurstFactorCursor[k],
- &cursor_not_enough_urgent_latency_hiding);
mode_lib->ms.UrgentBurstFactorCursorPre[k] = mode_lib->ms.UrgentBurstFactorCursor[k];

#ifdef __DML_VBA_DEBUG__
@@ -10592,31 +10595,33 @@ static bool dml_core_mode_programming(struct dml2_core_calcs_mode_programming_ex

for (k = 0; k < s->num_active_planes; ++k) {
bool cursor_not_enough_urgent_latency_hiding = 0;
- double line_time_us;
+ double line_time_us = 0.0;

- calculate_cursor_req_attributes(
- display_cfg->plane_descriptors[k].cursor.cursor_width,
- display_cfg->plane_descriptors[k].cursor.cursor_bpp,
+ line_time_us = display_cfg->stream_descriptors[display_cfg->plane_descriptors[k].stream_index].timing.h_total /
+ ((double)display_cfg->stream_descriptors[display_cfg->plane_descriptors[k].stream_index].timing.pixel_clock_khz / 1000);
+ if (display_cfg->plane_descriptors[k].cursor.num_cursors > 0) {
+ calculate_cursor_req_attributes(
+ display_cfg->plane_descriptors[k].cursor.cursor_width,
+ display_cfg->plane_descriptors[k].cursor.cursor_bpp,

- // output
- &s->cursor_lines_per_chunk[k],
- &s->cursor_bytes_per_line[k],
- &s->cursor_bytes_per_chunk[k],
- &s->cursor_bytes[k]);
-
- line_time_us = display_cfg->stream_descriptors[display_cfg->plane_descriptors[k].stream_index].timing.h_total / ((double)display_cfg->stream_descriptors[display_cfg->plane_descriptors[k].stream_index].timing.pixel_clock_khz / 1000);
-
- calculate_cursor_urgent_burst_factor(
- mode_lib->ip.cursor_buffer_size,
- display_cfg->plane_descriptors[k].cursor.cursor_width,
- s->cursor_bytes_per_chunk[k],
- s->cursor_lines_per_chunk[k],
- line_time_us,
- mode_lib->mp.UrgentLatency,
+ // output
+ &s->cursor_lines_per_chunk[k],
+ &s->cursor_bytes_per_line[k],
+ &s->cursor_bytes_per_chunk[k],
+ &s->cursor_bytes[k]);
+
+ calculate_cursor_urgent_burst_factor(
+ mode_lib->ip.cursor_buffer_size,
+ display_cfg->plane_descriptors[k].cursor.cursor_width,
+ s->cursor_bytes_per_chunk[k],
+ s->cursor_lines_per_chunk[k],
+ line_time_us,
+ mode_lib->mp.UrgentLatency,

- // output
- &mode_lib->mp.UrgentBurstFactorCursor[k],
- &cursor_not_enough_urgent_latency_hiding);
+ // output
+ &mode_lib->mp.UrgentBurstFactorCursor[k],
+ &cursor_not_enough_urgent_latency_hiding);
+ }
mode_lib->mp.UrgentBurstFactorCursorPre[k] = mode_lib->mp.UrgentBurstFactorCursor[k];

CalculateUrgentBurstFactor(
--
2.43.0