Commit a3c286dc authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

drm/fb-helper: Fix clip rectangle height 



Computing the clip rectangle is prone to off-by-one errors when writes
happen near the end of a memory page. Point the end of the memory area
to the first trailing byte, so that (end - start) returns the area's
length.

Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209161617.3553-2-tzimmermann@suse.de
parent f5666d48

drivers/gpu/drm/drm_fb_helper.c

+1 −1
Original line number Diff line number Diff line
@@ -699,7 +699,7 @@ void drm_fb_helper_deferred_io(struct fb_info *info, 
	max = 0;

	list_for_each_entry(page, pagelist, lru) {

		start = page->index << PAGE_SHIFT;

		end = start + PAGE_SIZE - 1;

		end = start + PAGE_SIZE;

		min = min(min, start);

		max = max(max, end);

	}