#include <linux/interrupt.h>
#include <linux/suspend.h>
#include <linux/module.h>
+#include <linux/syscalls.h>
/*
* Timeout for stopping processes
*/
-#define TIMEOUT (6 * HZ)
+#define TIMEOUT (20 * HZ)
static inline int freezeable(struct task_struct * p)
{
if ((p == current) ||
(p->flags & PF_NOFREEZE) ||
- (p->state == TASK_ZOMBIE) ||
- (p->state == TASK_DEAD) ||
+ (p->exit_state == EXIT_ZOMBIE) ||
+ (p->exit_state == EXIT_DEAD) ||
(p->state == TASK_STOPPED))
return 0;
return 1;
}
/* Refrigerator is place where frozen processes are stored :-). */
-void refrigerator(unsigned long flag)
+void refrigerator(void)
{
/* Hmm, should we be allowed to suspend when there are realtime
processes around? */
long save;
save = current->state;
- current->state = TASK_UNINTERRUPTIBLE;
pr_debug("%s entered refrigerator\n", current->comm);
printk("=");
- current->flags &= ~PF_FREEZE;
+ frozen_process(current);
spin_lock_irq(¤t->sighand->siglock);
recalc_sigpending(); /* We sent fake signal, clean it up */
spin_unlock_irq(¤t->sighand->siglock);
- current->flags |= PF_FROZEN;
- while (current->flags & PF_FROZEN)
+ while (frozen(current)) {
+ current->state = TASK_UNINTERRUPTIBLE;
schedule();
+ }
pr_debug("%s left refrigerator\n", current->comm);
current->state = save;
}
+static inline void freeze_process(struct task_struct *p)
+{
+ unsigned long flags;
+
+ if (!freezing(p)) {
+ freeze(p);
+ spin_lock_irqsave(&p->sighand->siglock, flags);
+ signal_wake_up(p, 0);
+ spin_unlock_irqrestore(&p->sighand->siglock, flags);
+ }
+}
+
/* 0 = success, else # of processes that we failed to stop */
int freeze_processes(void)
{
- int todo;
- unsigned long start_time;
+ int todo, nr_user, user_frozen;
+ unsigned long start_time;
struct task_struct *g, *p;
-
+ unsigned long flags;
+
printk( "Stopping tasks: " );
start_time = jiffies;
+ user_frozen = 0;
do {
- todo = 0;
+ nr_user = todo = 0;
read_lock(&tasklist_lock);
do_each_thread(g, p) {
- unsigned long flags;
if (!freezeable(p))
continue;
- if ((p->flags & PF_FROZEN) ||
- (p->state == TASK_STOPPED))
+ if (frozen(p))
continue;
-
- /* FIXME: smp problem here: we may not access other process' flags
- without locking */
- p->flags |= PF_FREEZE;
- spin_lock_irqsave(&p->sighand->siglock, flags);
- signal_wake_up(p, 0);
- spin_unlock_irqrestore(&p->sighand->siglock, flags);
- todo++;
+ if (p->mm && !(p->flags & PF_BORROWED_MM)) {
+ /* The task is a user-space one.
+ * Freeze it unless there's a vfork completion
+ * pending
+ */
+ if (!p->vfork_done)
+ freeze_process(p);
+ nr_user++;
+ } else {
+ /* Freeze only if the user space is frozen */
+ if (user_frozen)
+ freeze_process(p);
+ todo++;
+ }
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
- yield(); /* Yield is okay here */
- if (time_after(jiffies, start_time + TIMEOUT)) {
- printk( "\n" );
- printk(KERN_ERR " stopping tasks failed (%d tasks remaining)\n", todo );
- return todo;
+ todo += nr_user;
+ if (!user_frozen && !nr_user) {
+ sys_sync();
+ start_time = jiffies;
}
+ user_frozen = !nr_user;
+ yield(); /* Yield is okay here */
+ if (todo && time_after(jiffies, start_time + TIMEOUT))
+ break;
} while(todo);
-
+
+ /* This does not unfreeze processes that are already frozen
+ * (we have slightly ugly calling convention in that respect,
+ * and caller must call thaw_processes() if something fails),
+ * but it cleans up leftover PF_FREEZE requests.
+ */
+ if (todo) {
+ printk( "\n" );
+ printk(KERN_ERR " stopping tasks timed out "
+ "after %d seconds (%d tasks remaining):\n",
+ TIMEOUT / HZ, todo);
+ read_lock(&tasklist_lock);
+ do_each_thread(g, p) {
+ if (freezeable(p) && !frozen(p))
+ printk(KERN_ERR " %s\n", p->comm);
+ if (freezing(p)) {
+ pr_debug(" clean up: %s\n", p->comm);
+ p->flags &= ~PF_FREEZE;
+ spin_lock_irqsave(&p->sighand->siglock, flags);
+ recalc_sigpending_tsk(p);
+ spin_unlock_irqrestore(&p->sighand->siglock, flags);
+ }
+ } while_each_thread(g, p);
+ read_unlock(&tasklist_lock);
+ return todo;
+ }
+
printk( "|\n" );
BUG_ON(in_atomic());
return 0;
do_each_thread(g, p) {
if (!freezeable(p))
continue;
- if (p->flags & PF_FROZEN) {
- p->flags &= ~PF_FROZEN;
- wake_up_process(p);
- } else
+ if (!thaw_process(p))
printk(KERN_INFO " Strange, %s not stopped\n", p->comm );
- wake_up_process(p);
} while_each_thread(g, p);
read_unlock(&tasklist_lock);