Re: [Intel-gfx] [PATCH] drm/i915: Fix return type of mode_valid function hook

From: Andrzej Hajda
Date: Wed Sep 14 2022 - 09:47:34 EST


On 13.09.2022 22:55, Nathan Huckleberry wrote:
All of the functions used for intel_dvo_dev_ops.mode_valid have a return
type of enum drm_mode_status, but the mode_valid field in the struct
definition has a return type of int.

The mismatched return type breaks forward edge kCFI since the underlying
function definitions do not match the function hook definition.

The return type of the mode_valid field should be changed from int to
enum drm_mode_status.

Reported-by: Dan Carpenter <error27@xxxxxxxxx>
Link: https://github.com/ClangBuiltLinux/linux/issues/1703
Cc: llvm@xxxxxxxxxxxxxxx
Signed-off-by: Nathan Huckleberry <nhuck@xxxxxxxxxx>

Reviewed-by: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>

Regards
Andrzej

---
drivers/gpu/drm/i915/display/intel_dvo_dev.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dvo_dev.h b/drivers/gpu/drm/i915/display/intel_dvo_dev.h
index d96c3cc46e50..50205f064d93 100644
--- a/drivers/gpu/drm/i915/display/intel_dvo_dev.h
+++ b/drivers/gpu/drm/i915/display/intel_dvo_dev.h
@@ -75,8 +75,8 @@ struct intel_dvo_dev_ops {
*
* \return MODE_OK if the mode is valid, or another MODE_* otherwise.
*/
- int (*mode_valid)(struct intel_dvo_device *dvo,
- struct drm_display_mode *mode);
+ enum drm_mode_status (*mode_valid)(struct intel_dvo_device *dvo,
+ struct drm_display_mode *mode);
/*
* Callback for preparing mode changes on an output