diff options
| -rw-r--r-- | kernel/exit.c | 45 |
1 files changed, 21 insertions, 24 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 9d6e0897a447..b4d569675d4b 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1158,8 +1158,7 @@ static int wait_task_zombie(struct task_struct *p, int noreap, int __user *stat_addr, struct rusage __user *ru) { unsigned long state; - int retval; - int status; + int retval, status, traced; if (unlikely(noreap)) { pid_t pid = p->pid; @@ -1201,7 +1200,10 @@ static int wait_task_zombie(struct task_struct *p, int noreap, return 0; } - if (likely(p->real_parent == p->parent)) { + /* traced means p->ptrace, but not vice versa */ + traced = (p->real_parent != p->parent); + + if (likely(!traced)) { struct signal_struct *psig; struct signal_struct *sig; @@ -1288,35 +1290,30 @@ static int wait_task_zombie(struct task_struct *p, int noreap, retval = put_user(p->pid, &infop->si_pid); if (!retval && infop) retval = put_user(p->uid, &infop->si_uid); - if (retval) { - // TODO: is this safe? - p->exit_state = EXIT_ZOMBIE; - return retval; - } - retval = p->pid; - if (p->real_parent != p->parent) { + if (!retval) + retval = p->pid; + + if (traced) { write_lock_irq(&tasklist_lock); - /* Double-check with lock held. */ - if (p->real_parent != p->parent) { - __ptrace_unlink(p); - // TODO: is this safe? - p->exit_state = EXIT_ZOMBIE; - /* - * If this is not a detached task, notify the parent. - * If it's still not detached after that, don't release - * it now. - */ + /* We dropped tasklist, ptracer could die and untrace */ + ptrace_unlink(p); + /* + * If this is not a detached task, notify the parent. + * If it's still not detached after that, don't release + * it now. + */ + if (p->exit_signal != -1) { + do_notify_parent(p, p->exit_signal); if (p->exit_signal != -1) { - do_notify_parent(p, p->exit_signal); - if (p->exit_signal != -1) - p = NULL; + p->exit_state = EXIT_ZOMBIE; + p = NULL; } } write_unlock_irq(&tasklist_lock); } if (p != NULL) release_task(p); - BUG_ON(!retval); + return retval; } |