x86_64: Add a getter for the initial page directory

kernel/src/arch/MMU.h

@@ -32,4 +32,6 @@ namespace MMU
 
     Result<PageDirectory*> create_page_directory_for_userspace();
     void setup_initial_page_directory();
+
+    PageDirectory* kernel_page_directory();
 }

kernel/src/arch/x86_64/MMU.cpp

@@ -7,6 +7,8 @@
 #pragma GCC push_options
 #pragma GCC diagnostic ignored "-Wconversion"
 
+PageDirectory* g_kernel_directory;
+
 void PageTableEntry::set_address(u64 addr)
 {
     this->address = (addr >> 12);
@@ -259,6 +261,7 @@ namespace MMU
     void setup_initial_page_directory()
     {
         PageDirectory* const dir = get_page_directory();
+        g_kernel_directory = dir;
         const u64 paddr = (u64)dir;
         PageTableEntry& recursive_entry = dir->entries[rindex];
         recursive_entry.read_write = true;
@@ -266,4 +269,9 @@ namespace MMU
         recursive_entry.set_address(paddr);
         flush_all();
     }
+
+    PageDirectory* kernel_page_directory()
+    {
+        return g_kernel_directory;
+    }
 }

kernel/src/arch/x86_64/Thread.cpp

@@ -34,6 +34,14 @@ void Thread::init_regs_kernel()
     regs.rflags = 1 << 9; // IF (Interrupt enable flag)
 }
 
+void Thread::init_regs_user()
+{
+    memset(&regs, 0, sizeof(Registers));
+    regs.cs = 0x18 | 3;
+    regs.ss = 0x20 | 3;
+    regs.rflags = 1 << 9; // IF (Interrupt enable flag)
+}
+
 void Thread::set_arguments(u64 arg1, u64 arg2, u64 arg3, u64 arg4)
 {
     regs.rdi = arg1;

luna/include/luna/LinkedList.h

@@ -41,8 +41,8 @@ template <typename T> class LinkedListNode
 
     void detach_from_list()
     {
-        m_next_node->m_last_node = m_last_node;
-        m_last_node->m_next_node = m_next_node;
+        if (m_next_node) m_next_node->m_last_node = m_last_node;
+        if (m_last_node) m_last_node->m_next_node = m_next_node;
     }
 
     void append_to_list(SelfType* end_node)