On 01/17, Eric W. Biederman wrote: > Kirill Tkhai <ktk...@virtuozzo.com> writes: > > > This reverts commit 20ac94378de5. > > > > send_sig() does not take tasklist_lock for a long time, > > so this commit and the problem it solves are not relevant > > anymore. > > > > Also, the problem of force_sig() is it clears SIGNAL_UNKILLABLE > > flag, thus even global init may be killed by __do_SAK(), > > which is definitely not the expected behavior. > > Actually it is. > > SAK should kill everything that has the tty open. If init opens the tty > I am so sorry, it can not operate correctly. init should not have your > tty open.
OK, but then we need "force" in other places too. __do_SAK() does send_sig(SIGKILL) in do_each_pid_task(PIDTYPE_SID) and if signal->tty == tty. Plus force_sig() is not rcu-friendly. So I personally agree with this change. Whether we want to kill the global init or not should be discussed, if we want to do this __do_SAK() should use SEND_SIG_FORCED and this is what Kirill is going to do (iiuc), but this needs another patch. Oleg.