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Kill some obsolete sub-thread-ptrace stuff

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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: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Oleg Nesterov 2007-08-04 01:04:41 +04:00 committed by Linus Torvalds
parent b6b1d87785
commit 247284481c
2 changed files with 2 additions and 10 deletions
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8
kernel/exit.c
View File

@ -813,7 +813,7 @@ static void exit_notify(struct task_struct *tsk)
__kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp);
}
/* Let father know we died
/* Let father know we died
*
* Thread signals are configurable, but you aren't going to use
* that to send signals to arbitary processes.
@ -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;

4
kernel/signal.c
View File

@ -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