From patchwork Tue Feb 5 22:07:09 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Herton Ronaldo Krzesinski X-Patchwork-Id: 218440 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from chlorine.canonical.com (chlorine.canonical.com [91.189.94.204]) by ozlabs.org (Postfix) with ESMTP id 7DB762C02B1 for ; Wed, 6 Feb 2013 09:12:51 +1100 (EST) Received: from localhost ([127.0.0.1] helo=chlorine.canonical.com) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1U2qkr-0003nB-PX; Tue, 05 Feb 2013 22:12:41 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1U2qkp-0003m2-7I for kernel-team@lists.ubuntu.com; Tue, 05 Feb 2013 22:12:39 +0000 Received: from 189.58.24.194.dynamic.adsl.gvt.net.br ([189.58.24.194] helo=canonical.com) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1U2qko-0003nz-8I; Tue, 05 Feb 2013 22:12:39 +0000 From: Herton Ronaldo Krzesinski To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 80/93] ptrace: introduce signal_wake_up_state() and ptrace_signal_wake_up() Date: Tue, 5 Feb 2013 20:07:09 -0200 Message-Id: <1360102042-10732-81-git-send-email-herton.krzesinski@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1360102042-10732-1-git-send-email-herton.krzesinski@canonical.com> References: <1360102042-10732-1-git-send-email-herton.krzesinski@canonical.com> X-Extended-Stable: 3.5 Cc: Linus Torvalds , Oleg Nesterov X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.13 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: kernel-team-bounces@lists.ubuntu.com Errors-To: kernel-team-bounces@lists.ubuntu.com 3.5.7.5 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Oleg Nesterov commit 910ffdb18a6408e14febbb6e4b6840fd2c928c82 upstream. 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: Herton Ronaldo Krzesinski --- 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 e63650f..3a9e314 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2674,7 +2674,16 @@ 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 a232bb5..901df1e 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, true); spin_unlock(&child->sighand->siglock); } @@ -310,7 +310,7 @@ 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); @@ -727,7 +727,7 @@ 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; @@ -753,7 +753,7 @@ 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 e9d3270..47c8e05 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -678,23 +678,17 @@ 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); } @@ -842,7 +836,7 @@ 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); } /*