signals: use __group_complete_signal() for the specific signals too
Based on Pavel Emelyanov's suggestion.
Rename __group_complete_signal() to complete_signal() and use it to process
the specific signals too. To do this we simply add the "int group" argument.
This allows us to greatly simply the signal-sending code and adds a useful
behaviour change. We can avoid the unneeded wakeups for the private signals
because wants_signal() is more clever than sigismember(blocked), but more
importantly we now take into account the fatal specific signals too.
The latter allows us to kill some subtle checks in handle_stop_signal() and
makes the specific/group signal's behaviour more consistent. For example,
currently sigtimedwait(FATAL_SIGNAL) behaves differently depending on was the
signal sent by kill() or tkill() if the signal was not blocked.
And. This allows us to tweak/fix the behaviour when the specific signal is
sent to the dying/dead ->group_leader.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/signal.c b/kernel/signal.c
index f2fc3a9..fc1cb03 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -673,8 +673,7 @@
return task_curr(p) || !signal_pending(p);
}
-static void
-__group_complete_signal(int sig, struct task_struct *p)
+static void complete_signal(int sig, struct task_struct *p, int group)
{
struct signal_struct *signal = p->signal;
struct task_struct *t;
@@ -687,7 +686,7 @@
*/
if (wants_signal(sig, p))
t = p;
- else if (thread_group_empty(p))
+ else if (!group || thread_group_empty(p))
/*
* There is just one thread and it does not need to be woken.
* It will dequeue unblocked signals before it runs again.
@@ -871,8 +870,7 @@
if (ret <= 0)
return ret;
- if (!sigismember(&t->blocked, sig))
- signal_wake_up(t, sig == SIGKILL);
+ complete_signal(sig, t, 0);
return 0;
}
@@ -930,7 +928,7 @@
if (ret <= 0)
return ret;
- __group_complete_signal(sig, p);
+ complete_signal(sig, p, 1);
return 0;
}
@@ -1309,8 +1307,7 @@
ret = do_send_sigqueue(sig, q, p, 0);
- if (!sigismember(&p->blocked, sig))
- signal_wake_up(p, sig == SIGKILL);
+ complete_signal(sig, p, 0);
unlock_task_sighand(p, &flags);
out_err:
@@ -1330,7 +1327,7 @@
ret = do_send_sigqueue(sig, q, p, 1);
- __group_complete_signal(sig, p);
+ complete_signal(sig, p, 1);
spin_unlock_irqrestore(&p->sighand->siglock, flags);