From 4e88a7482ce73b9bca242362698a88a6e485b370 Mon Sep 17 00:00:00 2001
From: apio <blobs.trading@gmail.com>
Date: Tue, 14 Feb 2023 20:05:00 +0100
Subject: [PATCH] kernel, luna: Move Spinlock.h to luna

---
 kernel/CMakeLists.txt                         |  1 -
 kernel/src/Log.cpp                            |  2 +-
 kernel/src/memory/KernelVM.cpp                |  2 +-
 kernel/src/memory/MemoryManager.cpp           |  2 +-
 luna/CMakeLists.txt                           |  2 ++
 .../thread => luna/include/luna}/Spinlock.h   | 23 ++++++-------------
 {kernel/src/thread => luna/src}/Spinlock.cpp  | 19 +++++++++------
 7 files changed, 24 insertions(+), 27 deletions(-)
 rename {kernel/src/thread => luna/include/luna}/Spinlock.h (86%)
 rename {kernel/src/thread => luna/src}/Spinlock.cpp (66%)

diff --git a/kernel/CMakeLists.txt b/kernel/CMakeLists.txt
index f71b3d48..7cc661f6 100644
--- a/kernel/CMakeLists.txt
+++ b/kernel/CMakeLists.txt
@@ -18,7 +18,6 @@ set(SOURCES
     src/arch/Serial.cpp
     src/arch/Timer.cpp
     src/arch/PCI.cpp
-    src/thread/Spinlock.cpp
     src/thread/Thread.cpp
     src/thread/Scheduler.cpp
     src/sys/Syscall.cpp
diff --git a/kernel/src/Log.cpp b/kernel/src/Log.cpp
index d28a5e2d..20ecc26a 100644
--- a/kernel/src/Log.cpp
+++ b/kernel/src/Log.cpp
@@ -2,10 +2,10 @@
 #include "arch/CPU.h"
 #include "arch/Serial.h"
 #include "arch/Timer.h"
-#include "thread/Spinlock.h"
 #include "video/TextConsole.h"
 #include <luna/Format.h>
 #include <luna/SourceLocation.h>
+#include <luna/Spinlock.h>
 
 static bool g_debug_enabled = true;
 static bool g_serial_enabled = true;
diff --git a/kernel/src/memory/KernelVM.cpp b/kernel/src/memory/KernelVM.cpp
index 48c4b80a..1773ba14 100644
--- a/kernel/src/memory/KernelVM.cpp
+++ b/kernel/src/memory/KernelVM.cpp
@@ -1,7 +1,7 @@
 #include "memory/KernelVM.h"
 #include "arch/MMU.h"
-#include "thread/Spinlock.h"
 #include <luna/Bitmap.h>
+#include <luna/Spinlock.h>
 
 static const u64 KERNEL_VM_RANGE_START = 0xffffffffc0000000;
 
diff --git a/kernel/src/memory/MemoryManager.cpp b/kernel/src/memory/MemoryManager.cpp
index 3c010cda..96818eb7 100644
--- a/kernel/src/memory/MemoryManager.cpp
+++ b/kernel/src/memory/MemoryManager.cpp
@@ -2,10 +2,10 @@
 #include "arch/MMU.h"
 #include "memory/KernelVM.h"
 #include "memory/MemoryMap.h"
-#include "thread/Spinlock.h"
 #include <luna/Alignment.h>
 #include <luna/Bitmap.h>
 #include <luna/ScopeGuard.h>
+#include <luna/Spinlock.h>
 #include <luna/SystemError.h>
 #include <luna/Types.h>
 
diff --git a/luna/CMakeLists.txt b/luna/CMakeLists.txt
index 1b01daf5..b3eba9a3 100644
--- a/luna/CMakeLists.txt
+++ b/luna/CMakeLists.txt
@@ -16,6 +16,8 @@ set(FREESTANDING_SOURCES
     src/TarStream.cpp
     src/DebugLog.cpp
     src/Heap.cpp
+    src/Spinlock.cpp
+    src/UBSAN.cpp
 )
 
 set(SOURCES
diff --git a/kernel/src/thread/Spinlock.h b/luna/include/luna/Spinlock.h
similarity index 86%
rename from kernel/src/thread/Spinlock.h
rename to luna/include/luna/Spinlock.h
index 2b8f2e5a..0b284c17 100644
--- a/kernel/src/thread/Spinlock.h
+++ b/luna/include/luna/Spinlock.h
@@ -1,6 +1,4 @@
 #pragma once
-#include "Log.h"
-#include "arch/CPU.h"
 #include <luna/Atomic.h>
 #include <luna/Option.h>
 
@@ -30,8 +28,15 @@ class ScopeLock
     ScopeLock(const ScopeLock&) = delete;
     ScopeLock(ScopeLock&&) = delete;
 
+    Spinlock& take_over()
+    {
+        m_taken_over = true;
+        return m_lock;
+    }
+
   private:
     Spinlock& m_lock;
+    bool m_taken_over { false };
 };
 
 class SafeScopeLock
@@ -107,25 +112,11 @@ template <typename T> class LockedValue
     {
     }
 
-#ifndef LOCKED_VALUE_DEBUG
     LockedValueGuard lock()
     {
         m_lock.lock();
         return { *this };
     }
-#else
-    LockedValueGuard lock()
-    {
-        if (m_lock.try_lock()) { return { *this }; }
-
-        kwarnln("Spinning on a locked LockedValue. This might lead to a deadlock...");
-
-        CPU::print_stack_trace();
-
-        m_lock.lock();
-        return { *this };
-    }
-#endif
 
     Option<LockedValueGuard> try_lock()
     {
diff --git a/kernel/src/thread/Spinlock.cpp b/luna/src/Spinlock.cpp
similarity index 66%
rename from kernel/src/thread/Spinlock.cpp
rename to luna/src/Spinlock.cpp
index b1744f09..2896aebe 100644
--- a/kernel/src/thread/Spinlock.cpp
+++ b/luna/src/Spinlock.cpp
@@ -1,6 +1,11 @@
-#include "thread/Spinlock.h"
-#include "Log.h"
-#include "arch/CPU.h"
+#include <luna/DebugLog.h>
+#include <luna/Spinlock.h>
+
+#ifdef ARCH_X86_64
+#define pause() asm volatile("pause")
+#else
+#error "Unsupported architecture"
+#endif
 
 void Spinlock::lock()
 {
@@ -8,7 +13,7 @@ void Spinlock::lock()
     while (!m_lock.compare_exchange_strong(expected, 1))
     {
         expected = 0;
-        CPU::pause();
+        pause();
     }
 }
 
@@ -23,7 +28,7 @@ void Spinlock::unlock()
     int expected = 1;
     if (!m_lock.compare_exchange_strong(expected, 0))
     {
-        kwarnln("Spinlock::unlock() called on an unlocked lock with value %d", expected);
+        dbgln("Spinlock::unlock() called on an unlocked lock with value %d", expected);
     }
 }
 
@@ -34,7 +39,7 @@ ScopeLock::ScopeLock(Spinlock& lock) : m_lock(lock)
 
 ScopeLock::~ScopeLock()
 {
-    m_lock.unlock();
+    if (!m_taken_over) m_lock.unlock();
 }
 
 const u32 RETRIES = 5000000;
@@ -42,7 +47,7 @@ const u32 RETRIES = 5000000;
 SafeScopeLock::SafeScopeLock(Spinlock& lock) : m_lock(lock)
 {
     u32 tries_left = RETRIES;
-    while (!lock.try_lock() && --tries_left) { CPU::pause(); }
+    while (!lock.try_lock() && --tries_left) { pause(); }
 
     if (tries_left) m_success = true;
 }