Swsusp should not wake up stopped processes

From: Pavel Machek
Date: Wed Apr 07 2004 - 16:32:28 EST


Hi!

If you stop process with ^Z, then suspend, process is awakened. Thats
a bug. Solution is to simply leave already stopped processes
alone. Plus we no longer use TASK_STOPPED for processes in
refrigerator. Userland might see us and get confused... Please apply,

Pavel

--- clean/kernel/power/process.c 2003-08-27 12:00:53.000000000 +0200
+++ linux/kernel/power/process.c 2004-04-07 23:14:19.000000000 +0200
@@ -30,7 +30,8 @@
if ((p == current) ||
(p->flags & PF_IOTHREAD) ||
(p->state == TASK_ZOMBIE) ||
- (p->state == TASK_DEAD))
+ (p->state == TASK_DEAD) ||
+ (p->state == TASK_STOPPED))
return 0;
return 1;
}
@@ -38,21 +39,19 @@
/* Refrigerator is place where frozen processes are stored :-). */
void refrigerator(unsigned long flag)
{
- /* You need correct to work with real-time processes.
- OTOH, this way one process may see (via /proc/) some other
- process in stopped state (and thereby discovered we were
- suspended. We probably do not care.
- */
+ /* Hmm, should we be allowed to suspend when there are realtime
+ processes around? */
long save;
save = current->state;
- current->state = TASK_STOPPED;
+ current->state = TASK_UNINTERRUPTIBLE;
pr_debug("%s entered refrigerator\n", current->comm);
printk("=");
current->flags &= ~PF_FREEZE;
- if (flag)
- flush_signals(current); /* We have signaled a kernel thread, which isn't normal behaviour
- and that may lead to 100%CPU sucking because those threads
- just don't manage signals. */
+
+ spin_lock_irq(&current->sighand->siglock);
+ recalc_sigpending(); /* We sent fake signal, clean it up */
+ spin_unlock_irq(&current->sighand->siglock);
+
current->flags |= PF_FROZEN;
while (current->flags & PF_FROZEN)
schedule();



--
When do you have a heart between your knees?
[Johanka's followup: and *two* hearts?]
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