From: Ville Syrjälä ville.syrjala@linux.intel.com
Add a variant of drm_mode_copy() that explicitly clears out the list head of the destination mode. Helpful to guarantee we don't have stack garbage left in there for on-stack modes.
Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com --- drivers/gpu/drm/drm_modes.c | 17 +++++++++++++++++ include/drm/drm_modes.h | 2 ++ 2 files changed, 19 insertions(+)
diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c index 96b13e36293c..40d4ce4a1da4 100644 --- a/drivers/gpu/drm/drm_modes.c +++ b/drivers/gpu/drm/drm_modes.c @@ -892,6 +892,23 @@ void drm_mode_copy(struct drm_display_mode *dst, const struct drm_display_mode * } EXPORT_SYMBOL(drm_mode_copy);
+/** + * drm_mode_init - initialize the mode from another mode + * @dst: mode to overwrite + * @src: mode to copy + * + * Copy an existing mode into another mode, zeroing the + * list head of the destination mode. Typically used + * to guarantee the list head is not left with stack + * garbage in on-stack modes. + */ +void drm_mode_init(struct drm_display_mode *dst, const struct drm_display_mode *src) +{ + memset(dst, 0, sizeof(*dst)); + drm_mode_copy(dst, src); +} +EXPORT_SYMBOL(drm_mode_init); + /** * drm_mode_duplicate - allocate and duplicate an existing mode * @dev: drm_device to allocate the duplicated mode for diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h index 29ba4adf0c53..e6e5a588fab1 100644 --- a/include/drm/drm_modes.h +++ b/include/drm/drm_modes.h @@ -484,6 +484,8 @@ void drm_mode_set_crtcinfo(struct drm_display_mode *p, int adjust_flags); void drm_mode_copy(struct drm_display_mode *dst, const struct drm_display_mode *src); +void drm_mode_init(struct drm_display_mode *dst, + const struct drm_display_mode *src); struct drm_display_mode *drm_mode_duplicate(struct drm_device *dev, const struct drm_display_mode *mode); bool drm_mode_match(const struct drm_display_mode *mode1,