masked_user_access_begin
uaddr = masked_user_access_begin(uaddr);
uaddr = masked_user_access_begin(uaddr);
src = masked_user_access_begin(src);
#ifdef masked_user_access_begin
# define masked_user_write_access_begin masked_user_access_begin
# define masked_user_read_access_begin masked_user_access_begin
#define masked_user_rw_access_begin(u) masked_user_access_begin(u)