Messages in this thread Patch in this message | | | From | Nathan Chancellor <> | Subject | [PATCH v2] drm: xlnx: Fix return type of zynqmp_dp_bridge_mode_valid | Date | Tue, 8 Nov 2022 17:14:25 -0700 |
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From: Nathan Huckleberry <nhuck@google.com>
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@gmail.com> Link: https://github.com/ClangBuiltLinux/linux/issues/1703 Link: https://github.com/ClangBuiltLinux/linux/issues/1750 Signed-off-by: Nathan Huckleberry <nhuck@google.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> [nathan: Rebase on drm-misc-next and fix conflicts Add note about new clang warning] Signed-off-by: Nathan Chancellor <nathan@kernel.org> ---
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@google.com/
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
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