* the system call. That must prevent normal entry so no system call is
* made. If @task ever returns to user mode after this, its register state
* is unspecified, but should be something harmless like an %ENOSYS error
- * return.
+ * return. It should preserve enough information so that syscall_rollback()
+ * can work (see asm-generic/syscall.h).
*
* Called without locks, just after entering kernel mode.
*/