From: Nathan Huckleberry <nhuck@xxxxxxxxxx>
The mode_valid field in drm_bridge_helper_funcs is expected to be of
type
enum drm_mode_status (* mode_valid) (struct drm_bridge *bridge,
struct drm_display_mode *mode);
The mismatched return type breaks forward edge kCFI since the underlying
function definition does not match the function hook definition. A new
warning in clang will catch this at compile time:
drivers/gpu/drm/xlnx/zynqmp_dp.c:1573:16: error: incompatible function pointer types initializing 'enum drm_mode_status (*)(struct drm_bridge *, const struct drm_display_info *, const struct drm_display_mode *)' with an expression of type 'int (struct drm_bridge *, const struct drm_display_info *, const struct drm_display_mode *)' [-Werror,-Wincompatible-function-pointer-types-strict]
.mode_valid = zynqmp_dp_bridge_mode_valid,
^~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
The return type of zynqmp_dp_bridge_mode_valid should be changed from
int to enum drm_mode_status.
Reported-by: Dan Carpenter <error27@xxxxxxxxx>
Link: https://github.com/ClangBuiltLinux/linux/issues/1703
Link: https://github.com/ClangBuiltLinux/linux/issues/1750
Signed-off-by: Nathan Huckleberry <nhuck@xxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
[nathan: Rebase on drm-misc-next and fix conflicts
Add note about new clang warning]
Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
---
Please consider picking this up so that it makes 6.2.
v2:
- Take over for Nathan, as he is busy with other matters.
- Rebase on drm-misc-next and resolve conflicts.
- Add a note about new clang warning that will catch this issue at
compile time.
v1: https://lore.kernel.org/20220913205600.155172-1-nhuck@xxxxxxxxxx/
drivers/gpu/drm/xlnx/zynqmp_dp.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c
index 7c9ae167eac7..0a7b466446fb 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_dp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c
@@ -1362,9 +1362,10 @@ static void zynqmp_dp_bridge_detach(struct drm_bridge *bridge)
zynqmp_dp_aux_cleanup(dp);
}
-static int zynqmp_dp_bridge_mode_valid(struct drm_bridge *bridge,
- const struct drm_display_info *info,
- const struct drm_display_mode *mode)
+static enum drm_mode_status
+zynqmp_dp_bridge_mode_valid(struct drm_bridge *bridge,
+ const struct drm_display_info *info,
+ const struct drm_display_mode *mode)
{
struct zynqmp_dp *dp = bridge_to_dp(bridge);
int rate;
base-commit: 1a0257c352638916fdaffaac2ddedb8e049312f3
--
2.38.1
