drm/radeon: forbid mapping of userptr bo through radeon device file

Allowing userptr bo which are basicly a list of page from some vma
(so either anonymous page or file backed page) would lead to serious
corruption of kernel structures and counters (because we overwrite
the page->mapping field when mapping buffer).

This will already block if the buffer was populated before anyone does
try to mmap it because then TTM_PAGE_FLAG_SG would be set in in the
ttm_tt flags. But that flag is check before ttm_tt_populate in the ttm
vm fault handler.

So to be safe just add a check to verify_access() callback.

Reviewed-by: Christian König <[email protected]>
Signed-off-by: Jérôme Glisse <[email protected]>
Cc: <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

0 files changed, 0 insertions, 0 deletions