[10/80] drm/ttm: request zeroed system memory pages for new TT buffer objects

Greg KH
2011-12-07T16:16:47Z

From: Ben Skeggs <bskeggs@redhat.com>

commit ff02b13f6867af72682d7a9bb9bd705f9af2bab0 upstream.

Fixes an information leak to userspace, we were handing out un-zeroed pages
for any newly created TTM_PL_TT buffer.

Reported-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Tested-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/gpu/drm/ttm/ttm_bo.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -394,7 +394,8 @@ static int ttm_bo_handle_move_mem(struct

if (!(new_man->flags & TTM_MEMTYPE_FLAG_FIXED)) {
if (bo->ttm == NULL) {
- ret = ttm_bo_add_ttm(bo, false);
+ bool zero = !(old_man->flags & TTM_MEMTYPE_FLAG_FIXED);
+ ret = ttm_bo_add_ttm(bo, zero);
if (ret)
goto out_err;
}