[PATCH] drm: pre-fill getfb2 modifier array with INVALID

Simon Ser contact at emersion.fr
Thu Nov 11 10:10:54 UTC 2021


User-space shouldn't look up the modifier array when the modifier
flag is missing, but at the moment no docs make this clear (working
on it). Right now the modifier array is pre-filled with zeroes, aka.
LINEAR. Instead, pre-fill with INVALID to avoid footguns.

This is a uAPI change, but OTOH any user-space which looks up the
modifier array without checking the flag is broken already, so
should be fine.

Signed-off-by: Simon Ser <contact at emersion.fr>
Cc: Daniel Vetter <daniel at ffwll.ch>
Cc: Pekka Paalanen <ppaalanen at gmail.com>
Cc: Daniel Stone <daniels at collabora.com>
---
 drivers/gpu/drm/drm_framebuffer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
index 07f5abc875e9..f7041c0a0407 100644
--- a/drivers/gpu/drm/drm_framebuffer.c
+++ b/drivers/gpu/drm/drm_framebuffer.c
@@ -601,7 +601,7 @@ int drm_mode_getfb2_ioctl(struct drm_device *dev,
 		r->handles[i] = 0;
 		r->pitches[i] = 0;
 		r->offsets[i] = 0;
-		r->modifier[i] = 0;
+		r->modifier[i] = DRM_FORMAT_MOD_INVALID;
 	}
 
 	for (i = 0; i < fb->format->num_planes; i++) {
-- 
2.33.1




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