From e911caeb1026a2e49d96bdd9c0af24fb37b7d777 Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Wed, 23 Jan 2019 05:05:45 +0100
Subject: [PATCH] Kernel: Fix dumb race in Scheduler::yield() debug code.

It was perfectly possible for Scheduler::yield() to get interrupted after
setting s_in_yield but before disabling interrupts.
---
 Kernel/Scheduler.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Kernel/Scheduler.cpp b/Kernel/Scheduler.cpp
index 24bb48541d..54d137421b 100644
--- a/Kernel/Scheduler.cpp
+++ b/Kernel/Scheduler.cpp
@@ -164,6 +164,7 @@ bool Scheduler::pick_next()
 
 bool Scheduler::yield()
 {
+    InterruptDisabler disabler;
     ASSERT(!s_in_yield);
     s_in_yield = true;
 
@@ -174,7 +175,6 @@ bool Scheduler::yield()
 
     //dbgprintf("%s<%u> yield()\n", current->name().characters(), current->pid());
 
-    InterruptDisabler disabler;
     if (!pick_next()) {
         s_in_yield = false;
         return 1;