Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 24728448 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
Browse files

Kill some obsolete sub-thread-ptrace stuff 



There is a couple of subtle checks which were needed to handle ptracing from
the same thread group. This was deprecated a long ago, imho this code just
complicates the understanding.

And, the "->parent->signal->flags & SIGNAL_GROUP_EXIT" check in exit_notify()
is not right. SIGNAL_GROUP_EXIT can mean exec(), not exit_group(). This means
ptracer can lose a ptraced zombie on exec(). Minor problem, but still the bug.

Signed-off-by: default avatarOleg Nesterov <oleg@tv-sign.ru>
Acked-by: default avatarRoland McGrath <roland@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b6b1d877

kernel/exit.c

+2 −6
Original line number Diff line number Diff line
@@ -826,9 +826,7 @@ static void exit_notify(struct task_struct *tsk) 
	 * If our self_exec id doesn't match our parent_exec_id then

	 * we have changed execution domain as these two values started

	 * the same after a fork.

	 *	

	 */

	

	if (tsk->exit_signal != SIGCHLD && tsk->exit_signal != -1 &&

	    ( tsk->parent_exec_id != t->self_exec_id  ||

	      tsk->self_exec_id != tsk->parent_exec_id)
@@ -848,9 +846,7 @@ static void exit_notify(struct task_struct *tsk) 
	}



	state = EXIT_ZOMBIE;

	if (tsk->exit_signal == -1 &&

	    (likely(tsk->ptrace == 0) ||

	     unlikely(tsk->parent->signal->flags & SIGNAL_GROUP_EXIT)))

	if (tsk->exit_signal == -1 && likely(!tsk->ptrace))

		state = EXIT_DEAD;

	tsk->exit_state = state;

kernel/signal.c

+0 −4
Original line number Diff line number Diff line
@@ -1561,10 +1561,6 @@ static inline int may_ptrace_stop(void) 
		    (current->ptrace & PT_ATTACHED)))

		return 0;



	if (unlikely(current->signal == current->parent->signal) &&

	    unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))

		return 0;



	/*

	 * Are we in the middle of do_coredump?

	 * If so and our tracer is also part of the coredump stopping