This is a note to let you know that I've just added the patch titled
drm/amd/display: fix shift-out-of-bounds in CalculateVMAndRowBytes
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-amd-display-fix-shift-out-of-bounds-in-calculate.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ea0d24fdcbc505856e1eff19b53b1a7184407442
Author: Alex Hung <alex.hung@xxxxxxx>
Date: Wed Jan 11 09:54:11 2023 -0700
drm/amd/display: fix shift-out-of-bounds in CalculateVMAndRowBytes
[ Upstream commit 031f196d1b1b6d5dfcb0533b431e3ab1750e6189 ]
[WHY]
When PTEBufferSizeInRequests is zero, UBSAN reports the following
warning because dml_log2 returns an unexpected negative value:
shift exponent 4294966273 is too large for 32-bit type 'int'
[HOW]
In the case PTEBufferSizeInRequests is zero, skip the dml_log2() and
assign the result directly.
Reviewed-by: Jun Lei <Jun.Lei@xxxxxxx>
Acked-by: Qingqing Zhuo <qingqing.zhuo@xxxxxxx>
Signed-off-by: Alex Hung <alex.hung@xxxxxxx>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c b/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c
index e427f4ffa0807..e5b1002d7f3f0 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dcn30/display_mode_vba_30.c
@@ -1868,7 +1868,10 @@ static unsigned int CalculateVMAndRowBytes(
}
if (SurfaceTiling == dm_sw_linear) {
- *dpte_row_height = dml_min(128, 1 << (unsigned int) dml_floor(dml_log2(PTEBufferSizeInRequests * *PixelPTEReqWidth / Pitch), 1));
+ if (PTEBufferSizeInRequests == 0)
+ *dpte_row_height = 1;
+ else
+ *dpte_row_height = dml_min(128, 1 << (unsigned int) dml_floor(dml_log2(PTEBufferSizeInRequests * *PixelPTEReqWidth / Pitch), 1));
*dpte_row_width_ub = (dml_ceil(((double) SwathWidth - 1) / *PixelPTEReqWidth, 1) + 1) * *PixelPTEReqWidth;
*PixelPTEBytesPerRow = *dpte_row_width_ub / *PixelPTEReqWidth * *PTERequestSize;
} else if (ScanDirection != dm_vert) {
