Commit b1442b05 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds

reparent_thread: fix the "is it traced" check

reparent_thread() uses ptrace_reparented() to check whether this thread is
ptraced, in that case we should not notify the new parent.

But ptrace_reparented() is not exactly correct when the reparented thread
is traced by /sbin/init, because forget_original_parent() has already
changed ->real_parent.

Currently, the only problem is the false notification.  But with the next
patch the kernel crash in this (yes, pathological) case.
Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0a967a04
...@@ -832,7 +832,7 @@ static void reparent_thread(struct task_struct *p, struct task_struct *father) ...@@ -832,7 +832,7 @@ static void reparent_thread(struct task_struct *p, struct task_struct *father)
/* If we'd notified the old parent about this child's death, /* If we'd notified the old parent about this child's death,
* also notify the new parent. * also notify the new parent.
*/ */
if (!ptrace_reparented(p) && if (!p->ptrace &&
p->exit_state == EXIT_ZOMBIE && thread_group_empty(p)) p->exit_state == EXIT_ZOMBIE && thread_group_empty(p))
do_notify_parent(p, p->exit_signal); do_notify_parent(p, p->exit_signal);
......
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