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| author |   Oleg Nesterov <oleg@tv-sign.ru> | 2008-04-30 00:53:13 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-30 08:29:38 -0700 |
| commit | 53b6f9fbd3b63af14b4f6268e8b5b80d178d05bc (patch) | |
| tree | 93a5bd26974e07a3d7fa20dc17c8b70daacc1d85 | |
| parent | document de_thread() with exit_notify() connection (diff) | |
| download | linux-dev-53b6f9fbd3b63af14b4f6268e8b5b80d178d05bc.tar.xz linux-dev-53b6f9fbd3b63af14b4f6268e8b5b80d178d05bc.zip | |
ptrace: introduce ptrace_reparented() helper
Add another trivial helper for the sake of grep. It also auto-documents the
fact that ->parent != real_parent implies ->ptrace.
No functional changes.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/ptrace.h | 4 | ||||
| -rw-r--r-- | kernel/exit.c | 9 |
2 files changed, 8 insertions, 5 deletions
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index ebe0c17039cf..f98501ba557e 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -98,6 +98,10 @@ extern void ptrace_untrace(struct task_struct *child); extern int ptrace_may_attach(struct task_struct *task); extern int __ptrace_may_attach(struct task_struct *task); +static inline int ptrace_reparented(struct task_struct *child) +{ + return child->real_parent != child->parent; +} static inline void ptrace_link(struct task_struct *child, struct task_struct *new_parent) { diff --git a/kernel/exit.c b/kernel/exit.c index 879ed6e1c883..0da2921b1e7f 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -698,7 +698,7 @@ reparent_thread(struct task_struct *p, struct task_struct *father, int traced) if (unlikely(traced)) { /* Preserve ptrace links if someone else is tracing this child. */ list_del_init(&p->ptrace_list); - if (p->parent != p->real_parent) + if (ptrace_reparented(p)) list_add(&p->ptrace_list, &p->real_parent->ptrace_children); } else { /* If this child is being traced, then we're the one tracing it @@ -865,8 +865,8 @@ static void exit_notify(struct task_struct *tsk, int group_dead) * only has special meaning to our real parent. */ if (!task_detached(tsk) && thread_group_empty(tsk)) { - int signal = (tsk->parent == tsk->real_parent) - ? tsk->exit_signal : SIGCHLD; + int signal = ptrace_reparented(tsk) ? + SIGCHLD : tsk->exit_signal; do_notify_parent(tsk, signal); } else if (tsk->ptrace) { do_notify_parent(tsk, SIGCHLD); @@ -1269,8 +1269,7 @@ static int wait_task_zombie(struct task_struct *p, int noreap, return 0; } - /* traced means p->ptrace, but not vice versa */ - traced = (p->real_parent != p->parent); + traced = ptrace_reparented(p); if (likely(!traced)) { struct signal_struct *psig; |