From b1b4c6799fb59e710454bfe0ab477cb8523a8667 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Thu, 2 Apr 2009 16:58:13 -0700 Subject: 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 Cc: Jerome Marchand Cc: Roland McGrath Cc: Denys Vlasenko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 62 +++++++++++++++++++++++++++++++---------------------------- 1 file 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); - } } } -- cgit v1.2.3-70-g09d2