The create/free mmap offset code must be synchronized. Yet only some
callers of omap_gem_mmap_offset() held struct_mutex. Leading to various
crashes around drm_mm_insert_helper_range(). (In the free-object path,
which is currently the only place we drm_gem_free_mmap_offset(),
struct_mutex is already held.)
Signed-off-by: Rob Clark <rob@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>