• David Herrmann's avatar
    drm: verify vma access in TTM+GEM drivers · acb46527
    David Herrmann authored
    GEM does already a good job in tracking access to gem buffers via handles
    and drm_vma access management. However, TTM drivers currently do not
    verify this during mmap().
    
    TTM provides the verify_access() callback to test this. So fix all drivers
    to actually call into gem+vma to verify access instead of always returning
    0.
    
    All drivers assume that user-space can only get access to TTM buffers via
    GEM handles. So whenever the verify_access() callback is called from
    ttm_bo_mmap(), the buffer must have a valid embedded gem object. This is
    true for all TTM+GEM drivers. But that's why this patch doesn't touch pure
    TTM drivers (ie, vmwgfx).
    
    v2: Switch to drm_vma_node_verify_access() to correctly return -EACCES if
        access was denied.
    
    Cc: Dave Airlie <airlied@redhat.com>
    Cc: Alex Deucher <alexander.deucher@amd.com>
    Cc: Ben Skeggs <bskeggs@redhat.com>
    Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
    Cc: Jerome Glisse <jglisse@redhat.com>
    Signed-off-by: default avatarDavid Herrmann <dh.herrmann@gmail.com>
    Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
    acb46527
qxl_ttm.c 15 KB