From 1331f4103f4c59856061bf4e4833ba1f48d9a6e0 Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Sun, 18 Sep 2016 21:05:59 -0600
Subject: [PATCH] Unlock context switch lock without potentially screwing up
 switch_to function

---
 arch/x86_64/src/context.rs | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/x86_64/src/context.rs b/arch/x86_64/src/context.rs
index 004914d..09cca9c 100644
--- a/arch/x86_64/src/context.rs
+++ b/arch/x86_64/src/context.rs
@@ -52,6 +52,7 @@ impl Context {
     }
 
     /// Switch to the next context by restoring its stack and registers
+    #[cold]
     #[inline(never)]
     #[naked]
     pub unsafe fn switch_to(&mut self, next: &mut Context) {
@@ -94,7 +95,12 @@ impl Context {
         asm!("mov $0, rbp" : "=r"(self.rbp) : : "memory" : "intel", "volatile");
         asm!("mov rbp, $0" : : "r"(next.rbp) : "memory" : "intel", "volatile");
 
-        // Unset global lock, set inside of kernel
-        CONTEXT_SWITCH_LOCK.store(false, Ordering::SeqCst);
+        asm!("call context_switch_unlock" : : : "memory" : "intel", "volatile");
     }
 }
+
+/// Unset global lock, set inside of kernel
+#[no_mangle]
+extern fn context_switch_unlock(){
+    CONTEXT_SWITCH_LOCK.store(false, Ordering::SeqCst);
+}