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authorOleg Nesterov <oleg@redhat.com>2009-04-02 16:58:13 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-04-02 19:04:59 -0700
commitb1b4c6799fb59e710454bfe0ab477cb8523a8667 (patch)
tree1cdd19f00c584a8800ce0d3a5530b78d1cbd6e56
parent6d69cb87f05eef3b02370b2f7bae608ad2301a00 (diff)
ptrace: reintroduce __ptrace_detach() as a callee of ptrace_exit()
No functional changes, preparation for the next patch. Move the "should we release this child" logic into the separate handler, __ptrace_detach(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Roland McGrath <roland@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--kernel/exit.c62
1 files changed, 33 insertions, 29 deletions
diff --git a/kernel/exit.c b/kernel/exit.c
index 7a831142293..576eae233b5 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -744,6 +744,38 @@ static int ignoring_children(struct sighand_struct *sigh)
return ret;
}
+/* Returns nonzero if the tracee should be released. */
+int __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
+{
+ __ptrace_unlink(p);
+
+ if (p->exit_state != EXIT_ZOMBIE)
+ return 0;
+ /*
+ * If it's a zombie, our attachedness prevented normal
+ * parent notification or self-reaping. Do notification
+ * now if it would have happened earlier. If it should
+ * reap itself we return true.
+ *
+ * If it's our own child, there is no notification to do.
+ * But if our normal children self-reap, then this child
+ * was prevented by ptrace and we must reap it now.
+ */
+ if (!task_detached(p) && thread_group_empty(p)) {
+ if (!same_thread_group(p->real_parent, tracer))
+ do_notify_parent(p, p->exit_signal);
+ else if (ignoring_children(tracer->sighand))
+ p->exit_signal = -1;
+ }
+
+ if (!task_detached(p))
+ return 0;
+
+ /* Mark it as in the process of being reaped. */
+ p->exit_state = EXIT_DEAD;
+ return 1;
+}
+
/*
* Detach all tasks we were using ptrace on.
* Any that need to be release_task'd are put on the @dead list.
@@ -755,36 +787,8 @@ static void ptrace_exit(struct task_struct *parent, struct list_head *dead)
struct task_struct *p, *n;
list_for_each_entry_safe(p, n, &parent->ptraced, ptrace_entry) {
- __ptrace_unlink(p);
-
- if (p->exit_state != EXIT_ZOMBIE)
- continue;
-
- /*
- * If it's a zombie, our attachedness prevented normal
- * parent notification or self-reaping. Do notification
- * now if it would have happened earlier. If it should
- * reap itself, add it to the @dead list. We can't call
- * release_task() here because we already hold tasklist_lock.
- *
- * If it's our own child, there is no notification to do.
- * But if our normal children self-reap, then this child
- * was prevented by ptrace and we must reap it now.
- */
- if (!task_detached(p) && thread_group_empty(p)) {
- if (!same_thread_group(p->real_parent, parent))
- do_notify_parent(p, p->exit_signal);
- else if (ignoring_children(parent->sighand))
- p->exit_signal = -1;
- }
-
- if (task_detached(p)) {
- /*
- * Mark it as in the process of being reaped.
- */
- p->exit_state = EXIT_DEAD;
+ if (__ptrace_detach(parent, p))
list_add(&p->ptrace_entry, dead);
- }
}
}