This is a note to let you know that I've just added the patch titled
drm/i915/selftests: fix subtraction overflow bug
to the 5.18-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-i915-selftests-fix-subtraction-overflow-bug.patch
and it can be found in the queue-5.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 879831dc95c2fc056a1a27a29150d30fa4f343c4
Author: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
Date: Fri Jun 24 13:35:28 2022 +0200
drm/i915/selftests: fix subtraction overflow bug
[ Upstream commit 333991c4e66b3d4b5613315f18016da80344f659 ]
On some machines hole_end can be small enough to cause subtraction
overflow. On the other side (addr + 2 * min_alignment) can overflow
in case of mock tests. This patch should handle both cases.
Fixes: e1c5f754067b59 ("drm/i915: Avoid overflow in computing pot_hole loop termination")
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/3674
Signed-off-by: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
Reviewed-by: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>
Signed-off-by: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20220624113528.2159210-1-andrzej.hajda@xxxxxxxxx
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
(cherry picked from commit ab3edc679c552a466e4bf0b11af3666008bd65a2)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
index ab751192eb3b..34d1ef015233 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
@@ -742,7 +742,7 @@ static int pot_hole(struct i915_address_space *vm,
u64 addr;
for (addr = round_up(hole_start + min_alignment, step) - min_alignment;
- addr <= round_down(hole_end - (2 * min_alignment), step) - min_alignment;
+ hole_end > addr && hole_end - addr >= 2 * min_alignment;
addr += step) {
err = i915_vma_pin(vma, 0, 0, addr | flags);
if (err) {
