[PATCH] do_notify_parent_cldstop() cleanup

From: Oleg Nesterov
Date: Thu Aug 18 2005 - 10:24:44 EST


[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@xxxxxxxxxx>

--- 2.6.13-rc6/kernel/signal.c~1_cldstop 2005-08-18 22:02:26.000000000 +0400
+++ 2.6.13-rc6/kernel/signal.c 2005-08-18 23:10:28.000000000 +0400
@@ -678,7 +678,7 @@ static int check_kill_permission(int sig

/* 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,
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,
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
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, i
!(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.
-
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