[PATCH] do_notify_parent_cldstop() cleanup

This patch simplifies the usage of do_notify_parent_cldstop(), it lessens
the source and .text size slightly, and makes the code (in my opinion) a
bit more readable.

I am sending this patch now because I'm afraid Paul will touch
do_notify_parent_cldstop() really soon, It's better to cleanup first.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 26 insertions, 35 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index d282fea81138..56e33df2b67f 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -678,7 +678,7 @@ static int check_kill_permission(int sig, struct siginfo *info,
 
 /* forward decl */
 static void do_notify_parent_cldstop(struct task_struct *tsk,
-                                     struct task_struct *parent,
+                                     int to_self,
                                      int why);
 
 /*
@@ -729,14 +729,7 @@ static void handle_stop_signal(int sig, struct task_struct *p)
                         p->signal->group_stop_count = 0;
                         p->signal->flags = SIGNAL_STOP_CONTINUED;
                         spin_unlock(&p->sighand->siglock);
-                        if (p->ptrace & PT_PTRACED)
-                                do_notify_parent_cldstop(p, p->parent,
-                                                         CLD_STOPPED);
-                        else
-                                do_notify_parent_cldstop(
-                                        p->group_leader,
-                                        p->group_leader->real_parent,
-                                                         CLD_STOPPED);
+                        do_notify_parent_cldstop(p, (p->ptrace & PT_PTRACED), CLD_STOPPED);
                         spin_lock(&p->sighand->siglock);
                 }
                 rm_from_queue(SIG_KERNEL_STOP_MASK, &p->signal->shared_pending);
@@ -777,14 +770,7 @@ static void handle_stop_signal(int sig, struct task_struct *p)
                         p->signal->flags = SIGNAL_STOP_CONTINUED;
                         p->signal->group_exit_code = 0;
                         spin_unlock(&p->sighand->siglock);
-                        if (p->ptrace & PT_PTRACED)
-                                do_notify_parent_cldstop(p, p->parent,
-                                                         CLD_CONTINUED);
-                        else
-                                do_notify_parent_cldstop(
-                                        p->group_leader,
-                                        p->group_leader->real_parent,
-                                                         CLD_CONTINUED);
+                        do_notify_parent_cldstop(p, (p->ptrace & PT_PTRACED), CLD_CONTINUED);
                         spin_lock(&p->sighand->siglock);
                 } else {
                         /*
@@ -1542,14 +1528,20 @@ void do_notify_parent(struct task_struct *tsk, int sig)
         spin_unlock_irqrestore(&psig->siglock, flags);
 }
 
-static void
-do_notify_parent_cldstop(struct task_struct *tsk, struct task_struct *parent,
-                         int why)
+static void do_notify_parent_cldstop(struct task_struct *tsk, int to_self, int why)
 {
         struct siginfo info;
         unsigned long flags;
+        struct task_struct *parent;
         struct sighand_struct *sighand;
 
+        if (to_self)
+                parent = tsk->parent;
+        else {
+                tsk = tsk->group_leader;
+                parent = tsk->real_parent;
+        }
+
         info.si_signo = SIGCHLD;
         info.si_errno = 0;
         info.si_pid = tsk->pid;
@@ -1618,8 +1610,7 @@ static void ptrace_stop(int exit_code, int nostop_code, siginfo_t *info)
                    !(current->ptrace & PT_ATTACHED)) &&
             (likely(current->parent->signal != current->signal) ||
              !unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))) {
-                do_notify_parent_cldstop(current, current->parent,
-                                         CLD_TRAPPED);
+                do_notify_parent_cldstop(current, 1, CLD_TRAPPED);
                 read_unlock(&tasklist_lock);
                 schedule();
         } else {
@@ -1668,25 +1659,25 @@ void ptrace_notify(int exit_code)
 static void
 finish_stop(int stop_count)
 {
+        int to_self;
+
         /*
          * 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.
          */
-        if (stop_count < 0 || (current->ptrace & PT_PTRACED)) {
-                read_lock(&tasklist_lock);
-                do_notify_parent_cldstop(current, current->parent,
-                                         CLD_STOPPED);
-                read_unlock(&tasklist_lock);
-        }
-        else if (stop_count == 0) {
-                read_lock(&tasklist_lock);
-                do_notify_parent_cldstop(current->group_leader,
-                                         current->group_leader->real_parent,
-                                         CLD_STOPPED);
-                read_unlock(&tasklist_lock);
-        }
+        if (stop_count < 0 || (current->ptrace & PT_PTRACED))
+                to_self = 1;
+        else if (stop_count == 0)
+                to_self = 0;
+        else
+                goto out;
 
+        read_lock(&tasklist_lock);
+        do_notify_parent_cldstop(current, to_self, CLD_STOPPED);
+        read_unlock(&tasklist_lock);
+
+out:
         schedule();
         /*
          * Now we don't run again until continued.