From: Oleg Nesterov Date: Fri, 3 Aug 2007 21:04:41 +0000 (+0400) Subject: Kill some obsolete sub-thread-ptrace stuff X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=247284481ca40288bd120cf0707681c3bdbee78f;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git Kill some obsolete sub-thread-ptrace stuff There is a couple of subtle checks which were needed to handle ptracing from the same thread group. This was deprecated a long ago, imho this code just complicates the understanding. And, the "->parent->signal->flags & SIGNAL_GROUP_EXIT" check in exit_notify() is not right. SIGNAL_GROUP_EXIT can mean exec(), not exit_group(). This means ptracer can lose a ptraced zombie on exec(). Minor problem, but still the bug. Signed-off-by: Oleg Nesterov Acked-by: Roland McGrath Signed-off-by: Linus Torvalds --- diff --git a/kernel/exit.c b/kernel/exit.c index 464c2b172f0..9578c1ae19c 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -813,7 +813,7 @@ static void exit_notify(struct task_struct *tsk) __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp); } - /* Let father know we died + /* Let father know we died * * Thread signals are configurable, but you aren't going to use * that to send signals to arbitary processes. @@ -826,9 +826,7 @@ static void exit_notify(struct task_struct *tsk) * If our self_exec id doesn't match our parent_exec_id then * we have changed execution domain as these two values started * the same after a fork. - * */ - if (tsk->exit_signal != SIGCHLD && tsk->exit_signal != -1 && ( tsk->parent_exec_id != t->self_exec_id || tsk->self_exec_id != tsk->parent_exec_id) @@ -848,9 +846,7 @@ static void exit_notify(struct task_struct *tsk) } state = EXIT_ZOMBIE; - if (tsk->exit_signal == -1 && - (likely(tsk->ptrace == 0) || - unlikely(tsk->parent->signal->flags & SIGNAL_GROUP_EXIT))) + if (tsk->exit_signal == -1 && likely(!tsk->ptrace)) state = EXIT_DEAD; tsk->exit_state = state; diff --git a/kernel/signal.c b/kernel/signal.c index ef8156a6aad..b27c01a6644 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1561,10 +1561,6 @@ static inline int may_ptrace_stop(void) (current->ptrace & PT_ATTACHED))) return 0; - if (unlikely(current->signal == current->parent->signal) && - unlikely(current->signal->flags & SIGNAL_GROUP_EXIT)) - return 0; - /* * Are we in the middle of do_coredump? * If so and our tracer is also part of the coredump stopping