This is a note to let you know that I've just added the patch titled
drm/msm: Use drm_mode_copy()
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-msm-use-drm_mode_copy.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 382a733c7dce26e0aa2e26717b55159069e6b578
Author: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Date: Mon Nov 7 21:25:42 2022 +0200
drm/msm: Use drm_mode_copy()
[ Upstream commit b2a1c5ca50db22b3677676dd5bad5f6092429acf ]
struct drm_display_mode embeds a list head, so overwriting
the full struct with another one will corrupt the list
(if the destination mode is on a list). Use drm_mode_copy()
instead which explicitly preserves the list head of
the destination mode.
Even if we know the destination mode is not on any list
using drm_mode_copy() seems decent as it sets a good
example. Bad examples of not using it might eventually
get copied into code where preserving the list head
actually matters.
Obviously one case not covered here is when the mode
itself is embedded in a larger structure and the whole
structure is copied. But if we are careful when copying
into modes embedded in structures I think we can be a
little more reassured that bogus list heads haven't been
propagated in.
@is_mode_copy@
@@
drm_mode_copy(...)
{
...
}
@depends on !is_mode_copy@
struct drm_display_mode *mode;
expression E, S;
@@
(
- *mode = E
+ drm_mode_copy(mode, &E)
|
- memcpy(mode, E, S)
+ drm_mode_copy(mode, E)
)
@depends on !is_mode_copy@
struct drm_display_mode mode;
expression E;
@@
(
- mode = E
+ drm_mode_copy(&mode, &E)
|
- memcpy(&mode, E, S)
+ drm_mode_copy(&mode, E)
)
@@
struct drm_display_mode *mode;
@@
- &*mode
+ mode
Cc: Rob Clark <robdclark@xxxxxxxxx>
Cc: Sean Paul <sean@xxxxxxxxxx>
Cc: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
Cc: linux-arm-msm@xxxxxxxxxxxxxxx
Cc: freedreno@xxxxxxxxxxxxxxxxxxxxx
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Reviewed-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20221107192545.9896-5-ville.syrjala@xxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 5a152d505dfb..1c3dcbc6cce8 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -848,7 +848,7 @@ static int dp_display_set_mode(struct msm_dp *dp_display,
dp = container_of(dp_display, struct dp_display_private, dp_display);
- dp->panel->dp_mode.drm_mode = mode->drm_mode;
+ drm_mode_copy(&dp->panel->dp_mode.drm_mode, &mode->drm_mode);
dp->panel->dp_mode.bpp = mode->bpp;
dp->panel->dp_mode.capabilities = mode->capabilities;
dp_panel_init_panel_info(dp->panel);
