[PATCH] fix refrigerator() vs thaw_process() race

[Oleg Nesterov <oleg@tv-sign.ru>]

refrigerator() can miss a wakeup, "wait event" loop needs a proper memory
ordering.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>

--- WQ/kernel/power/process.c~WAKE	2007-02-18 22:56:49.000000000 +0300
+++ WQ/kernel/power/process.c	2007-02-19 01:04:26.000000000 +0300
@@ -46,8 +46,10 @@ void refrigerator(void)
 	recalc_sigpending(); /* We sent fake signal, clean it up */
 	spin_unlock_irq(&current->sighand->siglock);
 
-	while (frozen(current)) {
-		current->state = TASK_UNINTERRUPTIBLE;
+	for (;;) {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		if (!frozen(current))
+			break;
 		schedule();
 	}
 	pr_debug("%s left refrigerator\n", current->comm);

-
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