Commit 2d3eec89 authored by Ville Syrjälä's avatar Ville Syrjälä
Browse files

drm: Add drm_mode_init() 



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: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220218100403.7028-2-ville.syrjala@linux.intel.com


Reviewed-by: default avatarAndrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: default avatarHarry Wentland <harry.wentland@amd.com>
parent b861de24

drivers/gpu/drm/drm_modes.c

+17 −0
Original line number Diff line number Diff line
@@ -941,6 +941,23 @@ 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

include/drm/drm_modes.h

+2 −0
Original line number Diff line number Diff line
@@ -492,6 +492,8 @@ 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,