From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753511Ab3CATuz (ORCPT ); Fri, 1 Mar 2013 14:50:55 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:52037 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754544Ab3CATqr (ORCPT ); Fri, 1 Mar 2013 14:46:47 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Oleg Nesterov , Linus Torvalds , Michal Hocko Subject: [ 18/30] ptrace: introduce signal_wake_up_state() and ptrace_signal_wake_up() Date: Fri, 1 Mar 2013 11:45:39 -0800 Message-Id: <20130301194529.950634145@linuxfoundation.org> X-Mailer: git-send-email 1.8.1.rc1.5.g7e0651a In-Reply-To: <20130301194527.988540148@linuxfoundation.org> References: <20130301194527.988540148@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Oleg Nesterov Upstream commit 910ffdb18a6408e14febbb6e4b6840fd2c928c82. Cleanup and preparation for the next change. signal_wake_up(resume => true) is overused. None of ptrace/jctl callers actually want to wakeup a TASK_WAKEKILL task, but they can't specify the necessary mask. Turn signal_wake_up() into signal_wake_up_state(state), reintroduce signal_wake_up() as a trivial helper, and add ptrace_signal_wake_up() which adds __TASK_TRACED. This way ptrace_signal_wake_up() can work "inside" ptrace_request() even if the tracee doesn't have the TASK_WAKEKILL bit set. Signed-off-by: Oleg Nesterov Signed-off-by: Linus Torvalds Signed-off-by: Michal Hocko Signed-off-by: Greg Kroah-Hartman --- include/linux/sched.h | 11 ++++++++++- kernel/ptrace.c | 4 ++-- kernel/signal.c | 12 +++--------- 3 files changed, 15 insertions(+), 12 deletions(-) --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2564,7 +2564,16 @@ static inline void thread_group_cputime_ extern void recalc_sigpending_and_wake(struct task_struct *t); extern void recalc_sigpending(void); -extern void signal_wake_up(struct task_struct *t, int resume_stopped); +extern void signal_wake_up_state(struct task_struct *t, unsigned int state); + +static inline void signal_wake_up(struct task_struct *t, bool resume) +{ + signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0); +} +static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume) +{ + signal_wake_up_state(t, resume ? __TASK_TRACED : 0); +} /* * Wrappers for p->thread_info->cpu access. No-op on UP. --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -92,7 +92,7 @@ void __ptrace_unlink(struct task_struct * TASK_KILLABLE sleeps. */ if (child->group_stop & GROUP_STOP_PENDING || task_is_traced(child)) - signal_wake_up(child, task_is_traced(child)); + ptrace_signal_wake_up(child, true); spin_unlock(&child->sighand->siglock); } @@ -245,7 +245,7 @@ static int ptrace_attach(struct task_str */ if (task_is_stopped(task)) { task->group_stop |= GROUP_STOP_PENDING | GROUP_STOP_TRAPPING; - signal_wake_up(task, 1); + signal_wake_up_state(task, __TASK_STOPPED); wait_trap = true; } --- a/kernel/signal.c +++ b/kernel/signal.c @@ -631,23 +631,17 @@ int dequeue_signal(struct task_struct *t * No need to set need_resched since signal event passing * goes through ->blocked */ -void signal_wake_up(struct task_struct *t, int resume) +void signal_wake_up_state(struct task_struct *t, unsigned int state) { - unsigned int mask; - set_tsk_thread_flag(t, TIF_SIGPENDING); - /* - * For SIGKILL, we want to wake it up in the stopped/traced/killable + * TASK_WAKEKILL also means wake it up in the stopped/traced/killable * case. We don't check t->state here because there is a race with it * executing another processor and just now entering stopped state. * By using wake_up_state, we ensure the process will wake up and * handle its death signal. */ - mask = TASK_INTERRUPTIBLE; - if (resume) - mask |= TASK_WAKEKILL; - if (!wake_up_state(t, mask)) + if (!wake_up_state(t, state | TASK_INTERRUPTIBLE)) kick_process(t); }