drm/sti: Use drm_mode_copy()

[ Upstream commit 442cf8e22ba25a77cb9092d78733fdbac9844e50 ]

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: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221107192545.9896-8-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/sti/sti_dvo.c b/drivers/gpu/drm/sti/sti_dvo.c
index e8c1ed08a9f7eea0726347082a8f35c9e21c762e..4be5b567059954a622bfe9e8a0fc1173f3538df6 100644 (file)
--- a/drivers/gpu/drm/sti/sti_dvo.c
+++ b/drivers/gpu/drm/sti/sti_dvo.c
@@ -296,7 +296,7 @@ static void sti_dvo_set_mode(struct drm_bridge *bridge,
 
        DRM_DEBUG_DRIVER("\n");
 
-       memcpy(&dvo->mode, mode, sizeof(struct drm_display_mode));
+       drm_mode_copy(&dvo->mode, mode);
 
        /* According to the path used (main or aux), the dvo clocks should
         * have a different parent clock. */

diff --git a/drivers/gpu/drm/sti/sti_hda.c b/drivers/gpu/drm/sti/sti_hda.c
index 08808e3701de96783f76b2a124636adf56908b92..cbceea7d4f87fc02b0672e7d6d3854e9a26640c1 100644 (file)
--- a/drivers/gpu/drm/sti/sti_hda.c
+++ b/drivers/gpu/drm/sti/sti_hda.c
@@ -528,7 +528,7 @@ static void sti_hda_set_mode(struct drm_bridge *bridge,
 
        DRM_DEBUG_DRIVER("\n");
 
-       memcpy(&hda->mode, mode, sizeof(struct drm_display_mode));
+       drm_mode_copy(&hda->mode, mode);
 
        if (!hda_get_mode_idx(hda->mode, &mode_idx)) {
                DRM_ERROR("Undefined mode\n");

diff --git a/drivers/gpu/drm/sti/sti_hdmi.c b/drivers/gpu/drm/sti/sti_hdmi.c
index a5412a6fbeca2a9c1a3ded6d97323bc6ae16c5d7..c450668883b5979aadb396489471165c6e700e3b 100644 (file)
--- a/drivers/gpu/drm/sti/sti_hdmi.c
+++ b/drivers/gpu/drm/sti/sti_hdmi.c
@@ -848,7 +848,7 @@ static void sti_hdmi_set_mode(struct drm_bridge *bridge,
        DRM_DEBUG_DRIVER("\n");
 
        /* Copy the drm display mode in the connector local structure */
-       memcpy(&hdmi->mode, mode, sizeof(struct drm_display_mode));
+       drm_mode_copy(&hdmi->mode, mode);
 
        /* Update clock framerate according to the selected mode */
        ret = clk_set_rate(hdmi->clk_pix, mode->clock * 1000);