From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752479Ab3ATTZz (ORCPT ); Sun, 20 Jan 2013 14:25:55 -0500 Received: from mx1.redhat.com ([209.132.183.28]:29857 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752433Ab3ATTZx (ORCPT ); Sun, 20 Jan 2013 14:25:53 -0500 Date: Sun, 20 Jan 2013 20:25:09 +0100 From: Oleg Nesterov To: Linus Torvalds Cc: Dan Carpenter , Kernel Security , Michael Davidson , Suleiman Souhlal , Julien Tinnes , Aaron Durbin , Andrew Morton , linux-kernel@vger.kernel.org, Tejun Heo , Roland McGrath , Tony Luck , Fenghua Yu , Greg Kroah-Hartman Subject: [PATCH 1/4] ptrace: introduce signal_wake_up_state() and ptrace_signal_wake_up() Message-ID: <20130120192509.GB6771@redhat.com> References: <20130116181830.GA6469@redhat.com> <20130118153700.GA27915@redhat.com> <20130118172854.GA29753@redhat.com> <20130118175224.GA520@redhat.com> <20130118185559.GA3773@redhat.com> <20130120192448.GA6771@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130120192448.GA6771@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- include/linux/sched.h | 11 ++++++++++- kernel/ptrace.c | 8 ++++---- kernel/signal.c | 14 ++++---------- 3 files changed, 18 insertions(+), 15 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 206bb08..48b4151 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2713,7 +2713,16 @@ static inline void thread_group_cputime_init(struct signal_struct *sig) 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. diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 1599157..74ebdec 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -117,7 +117,7 @@ void __ptrace_unlink(struct task_struct *child) * TASK_KILLABLE sleeps. */ if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child)) - signal_wake_up(child, task_is_traced(child)); + ptrace_signal_wake_up(child, task_is_traced(child)); spin_unlock(&child->sighand->siglock); } @@ -317,7 +317,7 @@ static int ptrace_attach(struct task_struct *task, long request, */ if (task_is_stopped(task) && task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) - signal_wake_up(task, 1); + signal_wake_up_state(task, __TASK_STOPPED); spin_unlock(&task->sighand->siglock); @@ -737,7 +737,7 @@ int ptrace_request(struct task_struct *child, long request, * tracee into STOP. */ if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP))) - signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); + ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING); unlock_task_sighand(child, &flags); ret = 0; @@ -763,7 +763,7 @@ int ptrace_request(struct task_struct *child, long request, * start of this trap and now. Trigger re-trap. */ if (child->jobctl & JOBCTL_TRAP_NOTIFY) - signal_wake_up(child, true); + ptrace_signal_wake_up(child, true); ret = 0; } unlock_task_sighand(child, &flags); diff --git a/kernel/signal.c b/kernel/signal.c index 372771e..2bf2731 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -680,23 +680,17 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info) * 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); } @@ -844,7 +838,7 @@ static void ptrace_trap_notify(struct task_struct *t) assert_spin_locked(&t->sighand->siglock); task_set_jobctl_pending(t, JOBCTL_TRAP_NOTIFY); - signal_wake_up(t, t->jobctl & JOBCTL_LISTENING); + ptrace_signal_wake_up(t, t->jobctl & JOBCTL_LISTENING); } /* -- 1.5.5.1