remove handle_group_stop() in favor of do_signal_stop()

Every time we set SIGNAL_GROUP_EXIT or clear SIGNAL_STOP_DEQUEUED we also
reset ->group_stop_count.

This means that the SIGNAL_GROUP_EXIT check in handle_group_stop() is not
needed, and do_signal_stop() should check SIGNAL_STOP_DEQUEUED only when
->group_stop_count == 0. With these changes handle_group_stop() becomes the
subset of do_signal_stop(), we can kill it and use do_signal_stop() instead.

Also, a preparation for the next patch.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Robin Holt <holt@sgi.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 38 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index ea90c34e9348..1117b28488c2 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1688,9 +1688,6 @@ static int do_signal_stop(int signr)
         struct signal_struct *sig = current->signal;
         int stop_count;
 
-        if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED))
-                return 0;
-
         if (sig->group_stop_count > 0) {
                 /*
                  * There is a group stop in progress.  We don't need to
@@ -1698,12 +1695,14 @@ static int do_signal_stop(int signr)
                  */
                 stop_count = --sig->group_stop_count;
         } else {
+                struct task_struct *t;
+
+                if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED))
+                        return 0;
                 /*
                  * There is no group stop already in progress.
                  * We must initiate one now.
                  */
-                struct task_struct *t;
-
                 sig->group_exit_code = signr;
 
                 stop_count = 0;
@@ -1731,38 +1730,6 @@ static int do_signal_stop(int signr)
         return 1;
 }
 
-/*
- * Do appropriate magic when group_stop_count > 0.
- * We return nonzero if we stopped, after releasing the siglock.
- * We return zero if we still hold the siglock and should look
- * for another signal without checking group_stop_count again.
- */
-static int handle_group_stop(void)
-{
-        int stop_count;
-
-        if (current->signal->flags & SIGNAL_GROUP_EXIT)
-                /*
-                 * Group stop is so another thread can do a core dump,
-                 * or else we are racing against a death signal.
-                 * Just punt the stop so we can get the next signal.
-                 */
-                return 0;
-
-        /*
-         * There is a group stop in progress.  We stop
-         * without any associated signal being in our queue.
-         */
-        stop_count = --current->signal->group_stop_count;
-        if (stop_count == 0)
-                current->signal->flags = SIGNAL_STOP_STOPPED;
-        current->exit_code = current->signal->group_exit_code;
-        set_current_state(TASK_STOPPED);
-        spin_unlock_irq(&current->sighand->siglock);
-        finish_stop(stop_count);
-        return 1;
-}
-
 int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka,
                           struct pt_regs *regs, void *cookie)
 {
@@ -1777,7 +1744,7 @@ relock:
                 struct k_sigaction *ka;
 
                 if (unlikely(current->signal->group_stop_count > 0) &&
-                    handle_group_stop())
+                    do_signal_stop(0))
                         goto relock;
 
                 signr = dequeue_signal(current, mask, info);