[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>

diff --git a/kernel/signal.c b/kernel/signal.c
index d282fea..56e33df 100644 (file)
--- 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.