From: Ville Syrjälä Date: Fri, 18 Feb 2022 10:03:42 +0000 (+0200) Subject: drm: Add drm_mode_init() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=2d3eec8970335148278a6e350bc4840374f06471;p=linux.git 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: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20220218100403.7028-2-ville.syrjala@linux.intel.com Reviewed-by: Andrzej Hajda Reviewed-by: Harry Wentland --- diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c index 3f819c7a021b0..6e7e10f16ec03 100644 --- a/drivers/gpu/drm/drm_modes.c +++ b/drivers/gpu/drm/drm_modes.c @@ -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 diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h index 2fa6b2c33b3ff..a80ae9639e969 100644 --- a/include/drm/drm_modes.h +++ b/include/drm/drm_modes.h @@ -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,