stack_access_ok
if (!stack_access_ok(state, (unsigned long)p, sizeof(unsigned long)))
if (!stack_access_ok(state, (unsigned long)p, sizeof(unsigned long)))
if (!stack_access_ok(state, (unsigned long)regs, sizeof(*regs)))
if (!stack_access_ok(state, addr, sizeof(long)))
if (!stack_access_ok(state, addr, sizeof(struct pt_regs)))
if (!stack_access_ok(state, addr, IRET_FRAME_SIZE))