1 files changed, 648 insertions, 307 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index 7165af5f1b1..291c9700be7 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -87,7 +87,7 @@ static int sig_ignored(struct task_struct *t, int sig, int from_ancestor_ns)
 	/*
 	 * Tracers may want to know about even ignored signals.
 	 */
-	return !tracehook_consider_ignored_signal(t, sig);
+	return !t->ptrace;
 }
 
 /*
@@ -124,7 +124,7 @@ static inline int has_pending_signals(sigset_t *signal, sigset_t *blocked)
 
 static int recalc_sigpending_tsk(struct task_struct *t)
 {
-	if (t->signal->group_stop_count > 0 ||
+	if ((t->jobctl & JOBCTL_PENDING_MASK) ||
 	    PENDING(&t->pending, &t->blocked) ||
 	    PENDING(&t->signal->shared_pending, &t->blocked)) {
 		set_tsk_thread_flag(t, TIF_SIGPENDING);
@@ -150,9 +150,7 @@ void recalc_sigpending_and_wake(struct task_struct *t)
 
 void recalc_sigpending(void)
 {
-	if (unlikely(tracehook_force_sigpending()))
-		set_thread_flag(TIF_SIGPENDING);
-	else if (!recalc_sigpending_tsk(current) && !freezing(current))
+	if (!recalc_sigpending_tsk(current) && !freezing(current))
 		clear_thread_flag(TIF_SIGPENDING);
 
 }
@@ -223,6 +221,129 @@ static inline void print_dropped_signal(int sig)
 				current->comm, current->pid, sig);
 }
 
+/**
+ * task_set_jobctl_pending - set jobctl pending bits
+ * @task: target task
+ * @mask: pending bits to set
+ *
+ * Clear @mask from @task->jobctl.  @mask must be subset of
+ * %JOBCTL_PENDING_MASK | %JOBCTL_STOP_CONSUME | %JOBCTL_STOP_SIGMASK |
+ * %JOBCTL_TRAPPING.  If stop signo is being set, the existing signo is
+ * cleared.  If @task is already being killed or exiting, this function
+ * becomes noop.
+ *
+ * CONTEXT:
+ * Must be called with @task->sighand->siglock held.
+ *
+ * RETURNS:
+ * %true if @mask is set, %false if made noop because @task was dying.
+ */
+bool task_set_jobctl_pending(struct task_struct *task, unsigned int mask)
+{
+	BUG_ON(mask & ~(JOBCTL_PENDING_MASK | JOBCTL_STOP_CONSUME |
+			JOBCTL_STOP_SIGMASK | JOBCTL_TRAPPING));
+	BUG_ON((mask & JOBCTL_TRAPPING) && !(mask & JOBCTL_PENDING_MASK));
+
+	if (unlikely(fatal_signal_pending(task) || (task->flags & PF_EXITING)))
+		return false;
+
+	if (mask & JOBCTL_STOP_SIGMASK)
+		task->jobctl &= ~JOBCTL_STOP_SIGMASK;
+
+	task->jobctl |= mask;
+	return true;
+}
+
+/**
+ * task_clear_jobctl_trapping - clear jobctl trapping bit
+ * @task: target task
+ *
+ * If JOBCTL_TRAPPING is set, a ptracer is waiting for us to enter TRACED.
+ * Clear it and wake up the ptracer.  Note that we don't need any further
+ * locking.  @task->siglock guarantees that @task->parent points to the
+ * ptracer.
+ *
+ * CONTEXT:
+ * Must be called with @task->sighand->siglock held.
+ */
+void task_clear_jobctl_trapping(struct task_struct *task)
+{
+	if (unlikely(task->jobctl & JOBCTL_TRAPPING)) {
+		task->jobctl &= ~JOBCTL_TRAPPING;
+		wake_up_bit(&task->jobctl, JOBCTL_TRAPPING_BIT);
+	}
+}
+
+/**
+ * task_clear_jobctl_pending - clear jobctl pending bits
+ * @task: target task
+ * @mask: pending bits to clear
+ *
+ * Clear @mask from @task->jobctl.  @mask must be subset of
+ * %JOBCTL_PENDING_MASK.  If %JOBCTL_STOP_PENDING is being cleared, other
+ * STOP bits are cleared together.
+ *
+ * If clearing of @mask leaves no stop or trap pending, this function calls
+ * task_clear_jobctl_trapping().
+ *
+ * CONTEXT:
+ * Must be called with @task->sighand->siglock held.
+ */
+void task_clear_jobctl_pending(struct task_struct *task, unsigned int mask)
+{
+	BUG_ON(mask & ~JOBCTL_PENDING_MASK);
+
+	if (mask & JOBCTL_STOP_PENDING)
+		mask |= JOBCTL_STOP_CONSUME | JOBCTL_STOP_DEQUEUED;
+
+	task->jobctl &= ~mask;
+
+	if (!(task->jobctl & JOBCTL_PENDING_MASK))
+		task_clear_jobctl_trapping(task);
+}
+
+/**
+ * task_participate_group_stop - participate in a group stop
+ * @task: task participating in a group stop
+ *
+ * @task has %JOBCTL_STOP_PENDING set and is participating in a group stop.
+ * Group stop states are cleared and the group stop count is consumed if
+ * %JOBCTL_STOP_CONSUME was set.  If the consumption completes the group
+ * stop, the appropriate %SIGNAL_* flags are set.
+ *
+ * CONTEXT:
+ * Must be called with @task->sighand->siglock held.
+ *
+ * RETURNS:
+ * %true if group stop completion should be notified to the parent, %false
+ * otherwise.
+ */
+static bool task_participate_group_stop(struct task_struct *task)
+{
+	struct signal_struct *sig = task->signal;
+	bool consume = task->jobctl & JOBCTL_STOP_CONSUME;
+
+	WARN_ON_ONCE(!(task->jobctl & JOBCTL_STOP_PENDING));
+
+	task_clear_jobctl_pending(task, JOBCTL_STOP_PENDING);
+
+	if (!consume)
+		return false;
+
+	if (!WARN_ON_ONCE(sig->group_stop_count == 0))
+		sig->group_stop_count--;
+
+	/*
+	 * Tell the caller to notify completion iff we are entering into a
+	 * fresh group stop.  Read comment in do_signal_stop() for details.
+	 */
+	if (!sig->group_stop_count && !(sig->flags & SIGNAL_STOP_STOPPED)) {
+		sig->flags = SIGNAL_STOP_STOPPED;
+		return true;
+	}
+	return false;
+}
+
 /*
  * allocate a new signal queue record
  * - this may be called without locks if and only if t == current, otherwise an
@@ -372,7 +493,8 @@ int unhandled_signal(struct task_struct *tsk, int sig)
 		return 1;
 	if (handler != SIG_IGN && handler != SIG_DFL)
 		return 0;
-	return !tracehook_consider_fatal_signal(tsk, sig);
+	/* if ptraced, let the tracer determine */
+	return !tsk->ptrace;
 }
 
 /*
@@ -527,7 +649,7 @@ int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info)
 		 * is to alert stop-signal processing code when another
 		 * processor has come along and cleared the flag.
 		 */
-		tsk->signal->flags |= SIGNAL_STOP_DEQUEUED;
+		current->jobctl |= JOBCTL_STOP_DEQUEUED;
 	}
 	if ((info->si_code & __SI_MASK) == __SI_TIMER && info->si_sys_private) {
 		/*
@@ -592,7 +714,7 @@ static int rm_from_queue_full(sigset_t *mask, struct sigpending *s)
 	if (sigisemptyset(&m))
 		return 0;
 
-	signandsets(&s->signal, &s->signal, mask);
+	sigandnsets(&s->signal, &s->signal, mask);
 	list_for_each_entry_safe(q, n, &s->list, list) {
 		if (sigismember(mask, q->info.si_signo)) {
 			list_del_init(&q->list);
@@ -696,6 +818,32 @@ static int check_kill_permission(int sig, struct siginfo *info,
 	return security_task_kill(t, info, sig, 0);
 }
 
+/**
+ * ptrace_trap_notify - schedule trap to notify ptracer
+ * @t: tracee wanting to notify tracer
+ *
+ * This function schedules sticky ptrace trap which is cleared on the next
+ * TRAP_STOP to notify ptracer of an event.  @t must have been seized by
+ * ptracer.
+ *
+ * If @t is running, STOP trap will be taken.  If trapped for STOP and
+ * ptracer is listening for events, tracee is woken up so that it can
+ * re-trap for the new event.  If trapped otherwise, STOP trap will be
+ * eventually taken without returning to userland after the existing traps
+ * are finished by PTRACE_CONT.
+ *
+ * CONTEXT:
+ * Must be called with @task->sighand->siglock held.
+ */
+static void ptrace_trap_notify(struct task_struct *t)
+{
+	WARN_ON_ONCE(!(t->ptrace & PT_SEIZED));
+	assert_spin_locked(&t->sighand->siglock);
+
+	task_set_jobctl_pending(t, JOBCTL_TRAP_NOTIFY);
+	signal_wake_up(t, t->jobctl & JOBCTL_LISTENING);
+}
+
 /*
  * Handle magic process-wide effects of stop/continue signals. Unlike
  * the signal actions, these happen immediately at signal-generation
@@ -727,34 +875,17 @@ static int prepare_signal(int sig, struct task_struct *p, int from_ancestor_ns)
 	} else if (sig == SIGCONT) {
 		unsigned int why;
 		/*
-		 * Remove all stop signals from all queues,
-		 * and wake all threads.
+		 * Remove all stop signals from all queues, wake all threads.
 		 */
 		rm_from_queue(SIG_KERNEL_STOP_MASK, &signal->shared_pending);
 		t = p;
 		do {
-			unsigned int state;
+			task_clear_jobctl_pending(t, JOBCTL_STOP_PENDING);
 			rm_from_queue(SIG_KERNEL_STOP_MASK, &t->pending);
-			/*
-			 * If there is a handler for SIGCONT, we must make
-			 * sure that no thread returns to user mode before
-			 * we post the signal, in case it was the only
-			 * thread eligible to run the signal handler--then
-			 * it must not do anything between resuming and
-			 * running the handler.  With the TIF_SIGPENDING
-			 * flag set, the thread will pause and acquire the
-			 * siglock that we hold now and until we've queued
-			 * the pending signal.
-			 *
-			 * Wake up the stopped thread _after_ setting
-			 * TIF_SIGPENDING
-			 */
-			state = __TASK_STOPPED;
-			if (sig_user_defined(t, SIGCONT) && !sigismember(&t->blocked, SIGCONT)) {
-				set_tsk_thread_flag(t, TIF_SIGPENDING);
-				state |= TASK_INTERRUPTIBLE;
-			}
-			wake_up_state(t, state);
+			if (likely(!(t->ptrace & PT_SEIZED)))
+				wake_up_state(t, __TASK_STOPPED);
+			else
+				ptrace_trap_notify(t);
 		} while_each_thread(p, t);
 
 		/*
@@ -780,13 +911,6 @@ static int prepare_signal(int sig, struct task_struct *p, int from_ancestor_ns)
 			signal->flags = why | SIGNAL_STOP_CONTINUED;
 			signal->group_stop_count = 0;
 			signal->group_exit_code = 0;
-		} else {
-			/*
-			 * We are not stopped, but there could be a stop
-			 * signal in the middle of being processed after
-			 * being removed from the queue.  Clear that too.
-			 */
-			signal->flags &= ~SIGNAL_STOP_DEQUEUED;
 		}
 	}
 
@@ -858,8 +982,7 @@ static void complete_signal(int sig, struct task_struct *p, int group)
 	if (sig_fatal(p, sig) &&
 	    !(signal->flags & (SIGNAL_UNKILLABLE | SIGNAL_GROUP_EXIT)) &&
 	    !sigismember(&t->real_blocked, sig) &&
-	    (sig == SIGKILL ||
-	     !tracehook_consider_fatal_signal(t, sig))) {
+	    (sig == SIGKILL || !t->ptrace)) {
 		/*
 		 * This signal will be fatal to the whole group.
 		 */
@@ -875,6 +998,7 @@ static void complete_signal(int sig, struct task_struct *p, int group)
 			signal->group_stop_count = 0;
 			t = p;
 			do {
+				task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK);
 				sigaddset(&t->pending.signal, SIGKILL);
 				signal_wake_up(t, 1);
 			} while_each_thread(p, t);
@@ -1109,6 +1233,7 @@ int zap_other_threads(struct task_struct *p)
 	p->signal->group_stop_count = 0;
 
 	while_each_thread(p, t) {
+		task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK);
 		count++;
 
 		/* Don't bother with already dead threads */
@@ -1126,18 +1251,25 @@ struct sighand_struct *__lock_task_sighand(struct task_struct *tsk,
 {
 	struct sighand_struct *sighand;
 
-	rcu_read_lock();
 	for (;;) {
+		local_irq_save(*flags);
+		rcu_read_lock();
 		sighand = rcu_dereference(tsk->sighand);
-		if (unlikely(sighand == NULL))
+		if (unlikely(sighand == NULL)) {
+			rcu_read_unlock();
+			local_irq_restore(*flags);
 			break;
+		}
 
-		spin_lock_irqsave(&sighand->siglock, *flags);
-		if (likely(sighand == tsk->sighand))
+		spin_lock(&sighand->siglock);
+		if (likely(sighand == tsk->sighand)) {
+			rcu_read_unlock();
 			break;
-		spin_unlock_irqrestore(&sighand->siglock, *flags);
+		}
+		spin_unlock(&sighand->siglock);
+		rcu_read_unlock();
+		local_irq_restore(*flags);
 	}
-	rcu_read_unlock();
 
 	return sighand;
 }
@@ -1452,22 +1584,22 @@ ret:
  * Let a parent know about the death of a child.
  * For a stopped/continued status change, use do_notify_parent_cldstop instead.
  *
- * Returns -1 if our parent ignored us and so we've switched to
- * self-reaping, or else @sig.
+ * Returns true if our parent ignored us and so we've switched to
+ * self-reaping.
  */
-int do_notify_parent(struct task_struct *tsk, int sig)
+bool do_notify_parent(struct task_struct *tsk, int sig)
 {
 	struct siginfo info;
 	unsigned long flags;
 	struct sighand_struct *psig;
-	int ret = sig;
+	bool autoreap = false;
 
 	BUG_ON(sig == -1);
 
  	/* do_notify_parent_cldstop should have been called instead.  */
  	BUG_ON(task_is_stopped_or_traced(tsk));
 
-	BUG_ON(!task_ptrace(tsk) &&
+	BUG_ON(!tsk->ptrace &&
 	       (tsk->group_leader != tsk || !thread_group_empty(tsk)));
 
 	info.si_signo = sig;
@@ -1506,7 +1638,7 @@ int do_notify_parent(struct task_struct *tsk, int sig)
 
 	psig = tsk->parent->sighand;
 	spin_lock_irqsave(&psig->siglock, flags);
-	if (!task_ptrace(tsk) && sig == SIGCHLD &&
+	if (!tsk->ptrace && sig == SIGCHLD &&
 	    (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN ||
 	     (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))) {
 		/*
@@ -1524,28 +1656,42 @@ int do_notify_parent(struct task_struct *tsk, int sig)
 		 * is implementation-defined: we do (if you don't want
 		 * it, just use SIG_IGN instead).
 		 */
-		ret = tsk->exit_signal = -1;
+		autoreap = true;
 		if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN)
-			sig = -1;
+			sig = 0;
 	}
-	if (valid_signal(sig) && sig > 0)
+	if (valid_signal(sig) && sig)
 		__group_send_sig_info(sig, &info, tsk->parent);
 	__wake_up_parent(tsk, tsk->parent);
 	spin_unlock_irqrestore(&psig->siglock, flags);
 
-	return ret;
+	return autoreap;
 }
 
-static void do_notify_parent_cldstop(struct task_struct *tsk, int why)
+/**
+ * do_notify_parent_cldstop - notify parent of stopped/continued state change
+ * @tsk: task reporting the state change
+ * @for_ptracer: the notification is for ptracer
+ * @why: CLD_{CONTINUED|STOPPED|TRAPPED} to report
+ *
+ * Notify @tsk's parent that the stopped/continued state has changed.  If
+ * @for_ptracer is %false, @tsk's group leader notifies to its real parent.
+ * If %true, @tsk reports to @tsk->parent which should be the ptracer.
+ *
+ * CONTEXT:
+ * Must be called with tasklist_lock at least read locked.
+ */
+static void do_notify_parent_cldstop(struct task_struct *tsk,
+				     bool for_ptracer, int why)
 {
 	struct siginfo info;
 	unsigned long flags;
 	struct task_struct *parent;
 	struct sighand_struct *sighand;
 
-	if (task_ptrace(tsk))
+	if (for_ptracer) {
 		parent = tsk->parent;
-	else {
+	} else {
 		tsk = tsk->group_leader;
 		parent = tsk->real_parent;
 	}
@@ -1592,7 +1738,7 @@ static void do_notify_parent_cldstop(struct task_struct *tsk, int why)
 
 static inline int may_ptrace_stop(void)
 {
-	if (!likely(task_ptrace(current)))
+	if (!likely(current->ptrace))
 		return 0;
 	/*
 	 * Are we in the middle of do_coredump?
@@ -1631,10 +1777,12 @@ static int sigkill_pending(struct task_struct *tsk)
  * If we actually decide not to stop at all because the tracer
  * is gone, we keep current->exit_code unless clear_code.
  */
-static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info)
+static void ptrace_stop(int exit_code, int why, int clear_code, siginfo_t *info)
 	__releases(&current->sighand->siglock)
 	__acquires(&current->sighand->siglock)
 {
+	bool gstop_done = false;
+
 	if (arch_ptrace_stop_needed(exit_code, info)) {
 		/*
 		 * The arch code has something special to do before a
@@ -1655,21 +1803,52 @@ static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info)
 	}
 
 	/*
-	 * If there is a group stop in progress,
-	 * we must participate in the bookkeeping.
+	 * We're committing to trapping.  TRACED should be visible before
+	 * TRAPPING is cleared; otherwise, the tracer might fail do_wait().
+	 * Also, transition to TRACED and updates to ->jobctl should be
+	 * atomic with respect to siglock and should be done after the arch
+	 * hook as siglock is released and regrabbed across it.
 	 */
-	if (current->signal->group_stop_count > 0)
-		--current->signal->group_stop_count;
+	set_current_state(TASK_TRACED);
 
 	current->last_siginfo = info;
 	current->exit_code = exit_code;
 
-	/* Let the debugger run.  */
-	__set_current_state(TASK_TRACED);
+	/*
+	 * If @why is CLD_STOPPED, we're trapping to participate in a group
+	 * stop.  Do the bookkeeping.  Note that if SIGCONT was delievered
+	 * across siglock relocks since INTERRUPT was scheduled, PENDING
+	 * could be clear now.  We act as if SIGCONT is received after
+	 * TASK_TRACED is entered - ignore it.
+	 */
+	if (why == CLD_STOPPED && (current->jobctl & JOBCTL_STOP_PENDING))
+		gstop_done = task_participate_group_stop(current);
+
+	/* any trap clears pending STOP trap, STOP trap clears NOTIFY */
+	task_clear_jobctl_pending(current, JOBCTL_TRAP_STOP);
+	if (info && info->si_code >> 8 == PTRACE_EVENT_STOP)
+		task_clear_jobctl_pending(current, JOBCTL_TRAP_NOTIFY);
+
+	/* entering a trap, clear TRAPPING */
+	task_clear_jobctl_trapping(current);
+
 	spin_unlock_irq(&current->sighand->siglock);
 	read_lock(&tasklist_lock);
 	if (may_ptrace_stop()) {
-		do_notify_parent_cldstop(current, CLD_TRAPPED);
+		/*
+		 * Notify parents of the stop.
+		 *
+		 * While ptraced, there are two parents - the ptracer and
+		 * the real_parent of the group_leader.  The ptracer should
+		 * know about every stop while the real parent is only
+		 * interested in the completion of group stop.  The states
+		 * for the two don't interact with each other.  Notify
+		 * separately unless they're gonna be duplicates.
+		 */
+		do_notify_parent_cldstop(current, true, why);
+		if (gstop_done && ptrace_reparented(current))
+			do_notify_parent_cldstop(current, false, why);
+
 		/*
 		 * Don't want to allow preemption here, because
 		 * sys_ptrace() needs this task to be inactive.
@@ -1684,7 +1863,16 @@ static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info)
 		/*
 		 * By the time we got the lock, our tracer went away.
 		 * Don't drop the lock yet, another tracer may come.
+		 *
+		 * If @gstop_done, the ptracer went away between group stop
+		 * completion and here.  During detach, it would have set
+		 * JOBCTL_STOP_PENDING on us and we'll re-enter
+		 * TASK_STOPPED in do_signal_stop() on return, so notifying
+		 * the real parent of the group stop completion is enough.
 		 */
+		if (gstop_done)
+			do_notify_parent_cldstop(current, false, why);
+
 		__set_current_state(TASK_RUNNING);
 		if (clear_code)
 			current->exit_code = 0;
@@ -1706,6 +1894,9 @@ static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info)
 	spin_lock_irq(&current->sighand->siglock);
 	current->last_siginfo = NULL;
 
+	/* LISTENING can be set only during STOP traps, clear it */
+	current->jobctl &= ~JOBCTL_LISTENING;
+
 	/*
 	 * Queued signals ignored us while we were stopped for tracing.
 	 * So check for any that we should take before resuming user mode.
@@ -1714,107 +1905,204 @@ static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info)
 	recalc_sigpending_tsk(current);
 }
 
-void ptrace_notify(int exit_code)
+static void ptrace_do_notify(int signr, int exit_code, int why)
 {
 	siginfo_t info;
 
-	BUG_ON((exit_code & (0x7f | ~0xffff)) != SIGTRAP);
-
 	memset(&info, 0, sizeof info);
-	info.si_signo = SIGTRAP;
+	info.si_signo = signr;
 	info.si_code = exit_code;
 	info.si_pid = task_pid_vnr(current);
 	info.si_uid = current_uid();
 
 	/* Let the debugger run.  */
+	ptrace_stop(exit_code, why, 1, &info);
+}
+
+void ptrace_notify(int exit_code)
+{
+	BUG_ON((exit_code & (0x7f | ~0xffff)) != SIGTRAP);
+
 	spin_lock_irq(&current->sighand->siglock);
-	ptrace_stop(exit_code, 1, &info);
+	ptrace_do_notify(SIGTRAP, exit_code, CLD_TRAPPED);
 	spin_unlock_irq(&current->sighand->siglock);
 }
 
-/*
- * This performs the stopping for SIGSTOP and other stop signals.
- * We have to stop all threads in the thread group.
- * Returns non-zero if we've actually stopped and released the siglock.
- * Returns zero if we didn't stop and still hold the siglock.
+/**
+ * do_signal_stop - handle group stop for SIGSTOP and other stop signals
+ * @signr: signr causing group stop if initiating
+ *
+ * If %JOBCTL_STOP_PENDING is not set yet, initiate group stop with @signr
+ * and participate in it.  If already set, participate in the existing
+ * group stop.  If participated in a group stop (and thus slept), %true is
+ * returned with siglock released.
+ *
+ * If ptraced, this function doesn't handle stop itself.  Instead,
+ * %JOBCTL_TRAP_STOP is scheduled and %false is returned with siglock
+ * untouched.  The caller must ensure that INTERRUPT trap handling takes
+ * places afterwards.
+ *
+ * CONTEXT:
+ * Must be called with @current->sighand->siglock held, which is released
+ * on %true return.
+ *
+ * RETURNS:
+ * %false if group stop is already cancelled or ptrace trap is scheduled.
+ * %true if participated in group stop.
  */
-static int do_signal_stop(int signr)
+static bool do_signal_stop(int signr)
+	__releases(&current->sighand->siglock)
 {
 	struct signal_struct *sig = current->signal;
-	int notify;
 
-	if (!sig->group_stop_count) {
+	if (!(current->jobctl & JOBCTL_STOP_PENDING)) {
+		unsigned int gstop = JOBCTL_STOP_PENDING | JOBCTL_STOP_CONSUME;
 		struct task_struct *t;
 
-		if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED) ||
+		/* signr will be recorded in task->jobctl for retries */
+		WARN_ON_ONCE(signr & ~JOBCTL_STOP_SIGMASK);
+
+		if (!likely(current->jobctl & JOBCTL_STOP_DEQUEUED) ||
 		    unlikely(signal_group_exit(sig)))
-			return 0;
+			return false;
 		/*
-		 * There is no group stop already in progress.
-		 * We must initiate one now.
+		 * There is no group stop already in progress.  We must
+		 * initiate one now.
+		 *
+		 * While ptraced, a task may be resumed while group stop is
+		 * still in effect and then receive a stop signal and
+		 * initiate another group stop.  This deviates from the
+		 * usual behavior as two consecutive stop signals can't
+		 * cause two group stops when !ptraced.  That is why we
+		 * also check !task_is_stopped(t) below.
+		 *
+		 * The condition can be distinguished by testing whether
+		 * SIGNAL_STOP_STOPPED is already set.  Don't generate
+		 * group_exit_code in such case.
+		 *
+		 * This is not necessary for SIGNAL_STOP_CONTINUED because
+		 * an intervening stop signal is required to cause two
+		 * continued events regardless of ptrace.
 		 */
-		sig->group_exit_code = signr;
+		if (!(sig->flags & SIGNAL_STOP_STOPPED))
+			sig->group_exit_code = signr;
+		else
+			WARN_ON_ONCE(!current->ptrace);
+
+		sig->group_stop_count = 0;
 
-		sig->group_stop_count = 1;
-		for (t = next_thread(current); t != current; t = next_thread(t))
+		if (task_set_jobctl_pending(current, signr | gstop))
+			sig->group_stop_count++;
+
+		for (t = next_thread(current); t != current;
+		     t = next_thread(t)) {
 			/*
 			 * Setting state to TASK_STOPPED for a group
 			 * stop is always done with the siglock held,
 			 * so this check has no races.
 			 */
-			if (!(t->flags & PF_EXITING) &&
-			    !task_is_stopped_or_traced(t)) {
+			if (!task_is_stopped(t) &&
+			    task_set_jobctl_pending(t, signr | gstop)) {
 				sig->group_stop_count++;
-				signal_wake_up(t, 0);
+				if (likely(!(t->ptrace & PT_SEIZED)))
+					signal_wake_up(t, 0);
+				else
+					ptrace_trap_notify(t);
 			}
+		}
 	}
-	/*
-	 * If there are no other threads in the group, or if there is
-	 * a group stop in progress and we are the last to stop, report
-	 * to the parent.  When ptraced, every thread reports itself.
-	 */
-	notify = sig->group_stop_count == 1 ? CLD_STOPPED : 0;
-	notify = tracehook_notify_jctl(notify, CLD_STOPPED);
-	/*
-	 * tracehook_notify_jctl() can drop and reacquire siglock, so
-	 * we keep ->group_stop_count != 0 before the call. If SIGCONT
-	 * or SIGKILL comes in between ->group_stop_count == 0.
-	 */
-	if (sig->group_stop_count) {
-		if (!--sig->group_stop_count)
-			sig->flags = SIGNAL_STOP_STOPPED;
-		current->exit_code = sig->group_exit_code;
+
+	if (likely(!current->ptrace)) {
+		int notify = 0;
+
+		/*
+		 * If there are no other threads in the group, or if there
+		 * is a group stop in progress and we are the last to stop,
+		 * report to the parent.
+		 */
+		if (task_participate_group_stop(current))
+			notify = CLD_STOPPED;
+
 		__set_current_state(TASK_STOPPED);
-	}
-	spin_unlock_irq(&current->sighand->siglock);
+		spin_unlock_irq(&current->sighand->siglock);
 
-	if (notify) {
-		read_lock(&tasklist_lock);
-		do_notify_parent_cldstop(current, notify);
-		read_unlock(&tasklist_lock);
-	}
+		/*
+		 * Notify the parent of the group stop completion.  Because
+		 * we're not holding either the siglock or tasklist_lock
+		 * here, ptracer may attach inbetween; however, this is for
+		 * group stop and should always be delivered to the real
+		 * parent of the group leader.  The new ptracer will get
+		 * its notification when this task transitions into
+		 * TASK_TRACED.
+		 */
+		if (notify) {
+			read_lock(&tasklist_lock);
+			do_notify_parent_cldstop(current, false, notify);
+			read_unlock(&tasklist_lock);
+		}
 
-	/* Now we don't run again until woken by SIGCONT or SIGKILL */
-	do {
+		/* Now we don't run again until woken by SIGCONT or SIGKILL */
 		schedule();
-	} while (try_to_freeze());
-
-	tracehook_finish_jctl();
-	current->exit_code = 0;
+		return true;
+	} else {
+		/*
+		 * While ptraced, group stop is handled by STOP trap.
+		 * Schedule it and let the caller deal with it.
+		 */
+		task_set_jobctl_pending(current, JOBCTL_TRAP_STOP);
+		return false;
+	}
+}
 
-	return 1;
+/**
+ * do_jobctl_trap - take care of ptrace jobctl traps
+ *
+ * When PT_SEIZED, it's used for both group stop and explicit
+ * SEIZE/INTERRUPT traps.  Both generate PTRACE_EVENT_STOP trap with
+ * accompanying siginfo.  If stopped, lower eight bits of exit_code contain
+ * the stop signal; otherwise, %SIGTRAP.
+ *
+ * When !PT_SEIZED, it's used only for group stop trap with stop signal
+ * number as exit_code and no siginfo.
+ *
+ * CONTEXT:
+ * Must be called with @current->sighand->siglock held, which may be
+ * released and re-acquired before returning with intervening sleep.
+ */
+static void do_jobctl_trap(void)
+{
+	struct signal_struct *signal = current->signal;
+	int signr = current->jobctl & JOBCTL_STOP_SIGMASK;
+
+	if (current->ptrace & PT_SEIZED) {
+		if (!signal->group_stop_count &&
+		    !(signal->flags & SIGNAL_STOP_STOPPED))
+			signr = SIGTRAP;
+		WARN_ON_ONCE(!signr);
+		ptrace_do_notify(signr, signr | (PTRACE_EVENT_STOP << 8),
+				 CLD_STOPPED);
+	} else {
+		WARN_ON_ONCE(!signr);
+		ptrace_stop(signr, CLD_STOPPED, 0, NULL);
+		current->exit_code = 0;
+	}
 }
 
 static int ptrace_signal(int signr, siginfo_t *info,
 			 struct pt_regs *regs, void *cookie)
 {
-	if (!task_ptrace(current))
-		return signr;
-
 	ptrace_signal_deliver(regs, cookie);
-
-	/* Let the debugger run.  */
-	ptrace_stop(signr, 0, info);
+	/*
+	 * We do not check sig_kernel_stop(signr) but set this marker
+	 * unconditionally because we do not know whether debugger will
+	 * change signr. This flag has no meaning unless we are going
+	 * to stop after return from ptrace_stop(). In this case it will
+	 * be checked in do_signal_stop(), we should only stop if it was
+	 * not cleared by SIGCONT while we were sleeping. See also the
+	 * comment in dequeue_signal().
+	 */
+	current->jobctl |= JOBCTL_STOP_DEQUEUED;
+	ptrace_stop(signr, CLD_TRAPPED, 0, info);
 
 	/* We're back.  Did the debugger cancel the sig?  */
 	signr = current->exit_code;
@@ -1869,54 +2157,63 @@ relock:
 	 * the CLD_ si_code into SIGNAL_CLD_MASK bits.
 	 */
 	if (unlikely(signal->flags & SIGNAL_CLD_MASK)) {
-		int why = (signal->flags & SIGNAL_STOP_CONTINUED)
-				? CLD_CONTINUED : CLD_STOPPED;
+		int why;
+
+		if (signal->flags & SIGNAL_CLD_CONTINUED)
+			why = CLD_CONTINUED;
+		else
+			why = CLD_STOPPED;
+
 		signal->flags &= ~SIGNAL_CLD_MASK;
 
-		why = tracehook_notify_jctl(why, CLD_CONTINUED);
 		spin_unlock_irq(&sighand->siglock);
 
-		if (why) {
-			read_lock(&tasklist_lock);
-			do_notify_parent_cldstop(current->group_leader, why);
-			read_unlock(&tasklist_lock);
-		}
+		/*
+		 * Notify the parent that we're continuing.  This event is
+		 * always per-process and doesn't make whole lot of sense
+		 * for ptracers, who shouldn't consume the state via
+		 * wait(2) either, but, for backward compatibility, notify
+		 * the ptracer of the group leader too unless it's gonna be
+		 * a duplicate.
+		 */
+		read_lock(&tasklist_lock);
+		do_notify_parent_cldstop(current, false, why);
+
+		if (ptrace_reparented(current->group_leader))
+			do_notify_parent_cldstop(current->group_leader,
+						true, why);
+		read_unlock(&tasklist_lock);
+
 		goto relock;
 	}
 
 	for (;;) {
 		struct k_sigaction *ka;
-		/*
-		 * Tracing can induce an artificial signal and choose sigaction.
-		 * The return value in @signr determines the default action,
-		 * but @info->si_signo is the signal number we will report.
-		 */
-		signr = tracehook_get_signal(current, regs, info, return_ka);
-		if (unlikely(signr < 0))
+
+		if (unlikely(current->jobctl & JOBCTL_STOP_PENDING) &&
+		    do_signal_stop(0))
 			goto relock;
-		if (unlikely(signr != 0))
-			ka = return_ka;
-		else {
-			if (unlikely(signal->group_stop_count > 0) &&
-			    do_signal_stop(0))
-				goto relock;
 
-			signr = dequeue_signal(current, &current->blocked,
-					       info);
+		if (unlikely(current->jobctl & JOBCTL_TRAP_MASK)) {
+			do_jobctl_trap();
+			spin_unlock_irq(&sighand->siglock);
+			goto relock;
+		}
 
-			if (!signr)
-				break; /* will return 0 */
+		signr = dequeue_signal(current, &current->blocked, info);
 
-			if (signr != SIGKILL) {
-				signr = ptrace_signal(signr, info,
-						      regs, cookie);
-				if (!signr)
-					continue;
-			}
+		if (!signr)
+			break; /* will return 0 */
 
-			ka = &sighand->action[signr-1];
+		if (unlikely(current->ptrace) && signr != SIGKILL) {
+			signr = ptrace_signal(signr, info,
+					      regs, cookie);
+			if (!signr)
+				continue;
 		}
 
+		ka = &sighand->action[signr-1];
+
 		/* Trace actually delivered signals. */
 		trace_signal_deliver(signr, info, ka);
 
@@ -2017,10 +2314,42 @@ relock:
 	return signr;
 }
 
+/*
+ * It could be that complete_signal() picked us to notify about the
+ * group-wide signal. Other threads should be notified now to take
+ * the shared signals in @which since we will not.
+ */
+static void retarget_shared_pending(struct task_struct *tsk, sigset_t *which)
+{
+	sigset_t retarget;
+	struct task_struct *t;
+
+	sigandsets(&retarget, &tsk->signal->shared_pending.signal, which);
+	if (sigisemptyset(&retarget))
+		return;
+
+	t = tsk;
+	while_each_thread(tsk, t) {
+		if (t->flags & PF_EXITING)
+			continue;
+
+		if (!has_pending_signals(&retarget, &t->blocked))
+			continue;
+		/* Remove the signals this thread can handle. */
+		sigandsets(&retarget, &retarget, &t->blocked);
+
+		if (!signal_pending(t))
+			signal_wake_up(t, 0);
+
+		if (sigisemptyset(&retarget))
+			break;
+	}
+}
+
 void exit_signals(struct task_struct *tsk)
 {
 	int group_stop = 0;
-	struct task_struct *t;
+	sigset_t unblocked;
 
 	if (thread_group_empty(tsk) || signal_group_exit(tsk->signal)) {
 		tsk->flags |= PF_EXITING;
@@ -2036,26 +2365,23 @@ void exit_signals(struct task_struct *tsk)
 	if (!signal_pending(tsk))
 		goto out;
 
-	/*
-	 * It could be that __group_complete_signal() choose us to
-	 * notify about group-wide signal. Another thread should be
-	 * woken now to take the signal since we will not.
-	 */
-	for (t = tsk; (t = next_thread(t)) != tsk; )
-		if (!signal_pending(t) && !(t->flags & PF_EXITING))
-			recalc_sigpending_and_wake(t);
+	unblocked = tsk->blocked;
+	signotset(&unblocked);
+	retarget_shared_pending(tsk, &unblocked);
 
-	if (unlikely(tsk->signal->group_stop_count) &&
-			!--tsk->signal->group_stop_count) {
-		tsk->signal->flags = SIGNAL_STOP_STOPPED;
-		group_stop = tracehook_notify_jctl(CLD_STOPPED, CLD_STOPPED);
-	}
+	if (unlikely(tsk->jobctl & JOBCTL_STOP_PENDING) &&
+	    task_participate_group_stop(tsk))
+		group_stop = CLD_STOPPED;
 out:
 	spin_unlock_irq(&tsk->sighand->siglock);
 
+	/*
+	 * If group stop has completed, deliver the notification.  This
+	 * should always go to the real parent of the group leader.
+	 */
 	if (unlikely(group_stop)) {
 		read_lock(&tasklist_lock);
-		do_notify_parent_cldstop(tsk, group_stop);
+		do_notify_parent_cldstop(tsk, false, group_stop);
 		read_unlock(&tasklist_lock);
 	}
 }
@@ -2089,11 +2415,33 @@ long do_no_restart_syscall(struct restart_block *param)
 	return -EINTR;
 }
 
-/*
- * We don't need to get the kernel lock - this is all local to this
- * particular thread.. (and that's good, because this is _heavily_
- * used by various programs)
+static void __set_task_blocked(struct task_struct *tsk, const sigset_t *newset)
+{
+	if (signal_pending(tsk) && !thread_group_empty(tsk)) {
+		sigset_t newblocked;
+		/* A set of now blocked but previously unblocked signals. */
+		sigandnsets(&newblocked, newset, &current->blocked);
+		retarget_shared_pending(tsk, &newblocked);
+	}
+	tsk->blocked = *newset;
+	recalc_sigpending();
+}
+
+/**
+ * set_current_blocked - change current->blocked mask
+ * @newset: new mask
+ *
+ * It is wrong to change ->blocked directly, this helper should be used
+ * to ensure the process can't miss a shared signal we are going to block.
  */
+void set_current_blocked(const sigset_t *newset)
+{
+	struct task_struct *tsk = current;
+
+	spin_lock_irq(&tsk->sighand->siglock);
+	__set_task_blocked(tsk, newset);
+	spin_unlock_irq(&tsk->sighand->siglock);
+}
 
 /*
  * This is also useful for kernel threads that want to temporarily
@@ -2105,73 +2453,66 @@ long do_no_restart_syscall(struct restart_block *param)
  */
 int sigprocmask(int how, sigset_t *set, sigset_t *oldset)
 {
-	int error;
+	struct task_struct *tsk = current;
+	sigset_t newset;
 
-	spin_lock_irq(&current->sighand->siglock);
+	/* Lockless, only current can change ->blocked, never from irq */
 	if (oldset)
-		*oldset = current->blocked;
+		*oldset = tsk->blocked;
 
-	error = 0;
 	switch (how) {
 	case SIG_BLOCK:
-		sigorsets(&current->blocked, &current->blocked, set);
+		sigorsets(&newset, &tsk->blocked, set);
 		break;
 	case SIG_UNBLOCK:
-		signandsets(&current->blocked, &current->blocked, set);
+		sigandnsets(&newset, &tsk->blocked, set);
 		break;
 	case SIG_SETMASK:
-		current->blocked = *set;
+		newset = *set;
 		break;
 	default:
-		error = -EINVAL;
+		return -EINVAL;
 	}
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
 
-	return error;
+	set_current_blocked(&newset);
+	return 0;
 }
 
 /**
  *  sys_rt_sigprocmask - change the list of currently blocked signals
  *  @how: whether to add, remove, or set signals
- *  @set: stores pending signals
+ *  @nset: stores pending signals
  *  @oset: previous value of signal mask if non-null
  *  @sigsetsize: size of sigset_t type
  */
-SYSCALL_DEFINE4(rt_sigprocmask, int, how, sigset_t __user *, set,
+SYSCALL_DEFINE4(rt_sigprocmask, int, how, sigset_t __user *, nset,
 		sigset_t __user *, oset, size_t, sigsetsize)
 {
-	int error = -EINVAL;
 	sigset_t old_set, new_set;
+	int error;
 
 	/* XXX: Don't preclude handling different sized sigset_t's.  */
 	if (sigsetsize != sizeof(sigset_t))
-		goto out;
+		return -EINVAL;
 
-	if (set) {
-		error = -EFAULT;
-		if (copy_from_user(&new_set, set, sizeof(*set)))
-			goto out;
+	old_set = current->blocked;
+
+	if (nset) {
+		if (copy_from_user(&new_set, nset, sizeof(sigset_t)))
+			return -EFAULT;
 		sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
 
-		error = sigprocmask(how, &new_set, &old_set);
+		error = sigprocmask(how, &new_set, NULL);
 		if (error)
-			goto out;
-		if (oset)
-			goto set_old;
-	} else if (oset) {
-		spin_lock_irq(&current->sighand->siglock);
-		old_set = current->blocked;
-		spin_unlock_irq(&current->sighand->siglock);
+			return error;
+	}
 
-	set_old:
-		error = -EFAULT;
-		if (copy_to_user(oset, &old_set, sizeof(*oset)))
-			goto out;
+	if (oset) {
+		if (copy_to_user(oset, &old_set, sizeof(sigset_t)))
+			return -EFAULT;
 	}
-	error = 0;
-out:
-	return error;
+
+	return 0;
 }
 
 long do_sigpending(void __user *set, unsigned long sigsetsize)
@@ -2284,6 +2625,66 @@ int copy_siginfo_to_user(siginfo_t __user *to, siginfo_t *from)
 #endif
 
 /**
+ *  do_sigtimedwait - wait for queued signals specified in @which
+ *  @which: queued signals to wait for
+ *  @info: if non-null, the signal's siginfo is returned here
+ *  @ts: upper bound on process time suspension
+ */
+int do_sigtimedwait(const sigset_t *which, siginfo_t *info,
+			const struct timespec *ts)
+{
+	struct task_struct *tsk = current;
+	long timeout = MAX_SCHEDULE_TIMEOUT;
+	sigset_t mask = *which;
+	int sig;
+
+	if (ts) {
+		if (!timespec_valid(ts))
+			return -EINVAL;
+		timeout = timespec_to_jiffies(ts);
+		/*
+		 * We can be close to the next tick, add another one
+		 * to ensure we will wait at least the time asked for.
+		 */
+		if (ts->tv_sec || ts->tv_nsec)
+			timeout++;
+	}
+
+	/*
+	 * Invert the set of allowed signals to get those we want to block.
+	 */
+	sigdelsetmask(&mask, sigmask(SIGKILL) | sigmask(SIGSTOP));
+	signotset(&mask);
+
+	spin_lock_irq(&tsk->sighand->siglock);
+	sig = dequeue_signal(tsk, &mask, info);
+	if (!sig && timeout) {
+		/*
+		 * None ready, temporarily unblock those we're interested
+		 * while we are sleeping in so that we'll be awakened when
+		 * they arrive. Unblocking is always fine, we can avoid
+		 * set_current_blocked().
+		 */
+		tsk->real_blocked = tsk->blocked;
+		sigandsets(&tsk->blocked, &tsk->blocked, &mask);
+		recalc_sigpending();
+		spin_unlock_irq(&tsk->sighand->siglock);
+
+		timeout = schedule_timeout_interruptible(timeout);
+
+		spin_lock_irq(&tsk->sighand->siglock);
+		__set_task_blocked(tsk, &tsk->real_blocked);
+		siginitset(&tsk->real_blocked, 0);
+		sig = dequeue_signal(tsk, &mask, info);
+	}
+	spin_unlock_irq(&tsk->sighand->siglock);
+
+	if (sig)
+		return sig;
+	return timeout ? -EINTR : -EAGAIN;
+}
+
+/**
  *  sys_rt_sigtimedwait - synchronously wait for queued signals specified
  *			in @uthese
  *  @uthese: queued signals to wait for
@@ -2295,11 +2696,10 @@ SYSCALL_DEFINE4(rt_sigtimedwait, const sigset_t __user *, uthese,
 		siginfo_t __user *, uinfo, const struct timespec __user *, uts,
 		size_t, sigsetsize)
 {
-	int ret, sig;
 	sigset_t these;
 	struct timespec ts;
 	siginfo_t info;
-	long timeout = 0;
+	int ret;
 
 	/* XXX: Don't preclude handling different sized sigset_t's.  */
 	if (sigsetsize != sizeof(sigset_t))
@@ -2308,61 +2708,16 @@ SYSCALL_DEFINE4(rt_sigtimedwait, const sigset_t __user *, uthese,
 	if (copy_from_user(&these, uthese, sizeof(these)))
 		return -EFAULT;
 
-	/*
-	 * Invert the set of allowed signals to get those we
-	 * want to block.
-	 */
-	sigdelsetmask(&these, sigmask(SIGKILL)|sigmask(SIGSTOP));
-	signotset(&these);
-
 	if (uts) {
 		if (copy_from_user(&ts, uts, sizeof(ts)))
 			return -EFAULT;
-		if (ts.tv_nsec >= 1000000000L || ts.tv_nsec < 0
-		    || ts.tv_sec < 0)
-			return -EINVAL;
 	}
 
-	spin_lock_irq(&current->sighand->siglock);
-	sig = dequeue_signal(current, &these, &info);
-	if (!sig) {
-		timeout = MAX_SCHEDULE_TIMEOUT;
-		if (uts)
-			timeout = (timespec_to_jiffies(&ts)
-				   + (ts.tv_sec || ts.tv_nsec));
-
-		if (timeout) {
-			/*
-			 * None ready -- temporarily unblock those we're
-			 * interested while we are sleeping in so that we'll
-			 * be awakened when they arrive.
-			 */
-			current->real_blocked = current->blocked;
-			sigandsets(&current->blocked, &current->blocked, &these);
-			recalc_sigpending();
-			spin_unlock_irq(&current->sighand->siglock);
-
-			timeout = schedule_timeout_interruptible(timeout);
-
-			spin_lock_irq(&current->sighand->siglock);
-			sig = dequeue_signal(current, &these, &info);
-			current->blocked = current->real_blocked;
-			siginitset(&current->real_blocked, 0);
-			recalc_sigpending();
-		}
-	}
-	spin_unlock_irq(&current->sighand->siglock);
+	ret = do_sigtimedwait(&these, &info, uts ? &ts : NULL);
 
-	if (sig) {
-		ret = sig;
-		if (uinfo) {
-			if (copy_siginfo_to_user(uinfo, &info))
-				ret = -EFAULT;
-		}
-	} else {
-		ret = -EAGAIN;
-		if (timeout)
-			ret = -EINTR;
+	if (ret > 0 && uinfo) {
+		if (copy_siginfo_to_user(uinfo, &info))
+			ret = -EFAULT;
 	}
 
 	return ret;
@@ -2650,60 +3005,51 @@ SYSCALL_DEFINE1(sigpending, old_sigset_t __user *, set)
 /**
  *  sys_sigprocmask - examine and change blocked signals
  *  @how: whether to add, remove, or set signals
- *  @set: signals to add or remove (if non-null)
+ *  @nset: signals to add or remove (if non-null)
  *  @oset: previous value of signal mask if non-null
  *
  * Some platforms have their own version with special arguments;
  * others support only sys_rt_sigprocmask.
  */
 
-SYSCALL_DEFINE3(sigprocmask, int, how, old_sigset_t __user *, set,
+SYSCALL_DEFINE3(sigprocmask, int, how, old_sigset_t __user *, nset,
 		old_sigset_t __user *, oset)
 {
-	int error;
 	old_sigset_t old_set, new_set;
+	sigset_t new_blocked;
 
-	if (set) {
-		error = -EFAULT;
-		if (copy_from_user(&new_set, set, sizeof(*set)))
-			goto out;
+	old_set = current->blocked.sig[0];
+
+	if (nset) {
+		if (copy_from_user(&new_set, nset, sizeof(*nset)))
+			return -EFAULT;
 		new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP));
 
-		spin_lock_irq(&current->sighand->siglock);
-		old_set = current->blocked.sig[0];
+		new_blocked = current->blocked;
 
-		error = 0;
 		switch (how) {
-		default:
-			error = -EINVAL;
-			break;
 		case SIG_BLOCK:
-			sigaddsetmask(&current->blocked, new_set);
+			sigaddsetmask(&new_blocked, new_set);
 			break;
 		case SIG_UNBLOCK:
-			sigdelsetmask(&current->blocked, new_set);
+			sigdelsetmask(&new_blocked, new_set);
 			break;
 		case SIG_SETMASK:
-			current->blocked.sig[0] = new_set;
+			new_blocked.sig[0] = new_set;
 			break;
+		default:
+			return -EINVAL;
 		}
 
-		recalc_sigpending();
-		spin_unlock_irq(&current->sighand->siglock);
-		if (error)
-			goto out;
-		if (oset)
-			goto set_old;
-	} else if (oset) {
-		old_set = current->blocked.sig[0];
-	set_old:
-		error = -EFAULT;
+		set_current_blocked(&new_blocked);
+	}
+
+	if (oset) {
 		if (copy_to_user(oset, &old_set, sizeof(*oset)))
-			goto out;
+			return -EFAULT;
 	}
-	error = 0;
-out:
-	return error;
+
+	return 0;
 }
 #endif /* __ARCH_WANT_SYS_SIGPROCMASK */
 
@@ -2756,15 +3102,11 @@ SYSCALL_DEFINE0(sgetmask)
 
 SYSCALL_DEFINE1(ssetmask, int, newmask)
 {
-	int old;
-
-	spin_lock_irq(&current->sighand->siglock);
-	old = current->blocked.sig[0];
+	int old = current->blocked.sig[0];
+	sigset_t newset;
 
-	siginitset(&current->blocked, newmask & ~(sigmask(SIGKILL)|
-						  sigmask(SIGSTOP)));
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
+	siginitset(&newset, newmask & ~(sigmask(SIGKILL) | sigmask(SIGSTOP)));
+	set_current_blocked(&newset);
 
 	return old;
 }
@@ -2793,8 +3135,10 @@ SYSCALL_DEFINE2(signal, int, sig, __sighandler_t, handler)
 
 SYSCALL_DEFINE0(pause)
 {
-	current->state = TASK_INTERRUPTIBLE;
-	schedule();
+	while (!signal_pending(current)) {
+		current->state = TASK_INTERRUPTIBLE;
+		schedule();
+	}
 	return -ERESTARTNOHAND;
 }
 
@@ -2819,11 +3163,8 @@ SYSCALL_DEFINE2(rt_sigsuspend, sigset_t __user *, unewset, size_t, sigsetsize)
 		return -EFAULT;
 	sigdelsetmask(&newset, sigmask(SIGKILL)|sigmask(SIGSTOP));
 
-	spin_lock_irq(&current->sighand->siglock);
 	current->saved_sigmask = current->blocked;
-	current->blocked = newset;
-	recalc_sigpending();
-	spin_unlock_irq(&current->sighand->siglock);
+	set_current_blocked(&newset);
 
 	current->state = TASK_INTERRUPTIBLE;
 	schedule();