Fix bug where level 4 to level 2 entries are not mapped user accesible.

8 files changed, 15 insertions, 31 deletions

diff --git a/arch/x86_64/include/arch/memory/heap/user_heap_allocator.hpp b/arch/x86_64/include/arch/memory/heap/user_heap_allocator.hpp
index 9c04718..42af23f 100644
--- a/arch/x86_64/include/arch/memory/heap/user_heap_allocator.hpp
+++ b/arch/x86_64/include/arch/memory/heap/user_heap_allocator.hpp
@@ -32,6 +32,9 @@ namespace teachos::arch::memory::heap
     [[gnu::section(".user_text")]]
     auto allocate(std::size_t size) -> void *;
 
+    /**
+     *  @copybrief heap_allocator::deallocate
+     */
     [[gnu::section(".user_text")]]
     auto deallocate(void * pointer) noexcept -> void;
 
diff --git a/arch/x86_64/include/arch/memory/paging/active_page_table.hpp b/arch/x86_64/include/arch/memory/paging/active_page_table.hpp
index d77b76c..f68d8b6 100644
--- a/arch/x86_64/include/arch/memory/paging/active_page_table.hpp
+++ b/arch/x86_64/include/arch/memory/paging/active_page_table.hpp
@@ -82,10 +82,7 @@ namespace teachos::arch::memory::paging
 
       for (auto level = page_table_handle::LEVEL4; level != page_table_handle::LEVEL1; --level)
       {
-        // Ignore all bits passed besides the entry::USER_ACCESSIBLE bit, because for the entry into the Level 4 up to
-        // Level 2 page, we always have to set the entry::PRESENT and entry::WRITABLE bit anyway.
-        current_handle = current_handle.next_table_or_create(allocator, page.get_level_index(level),
-                                                             flags.to_ulong() & entry::USER_ACCESSIBLE);
+        current_handle = current_handle.next_table_or_create(allocator, page.get_level_index(level), flags);
       }
 
       auto & level1_entry = current_handle[page.get_level_index(page_table_handle::LEVEL1)];
diff --git a/arch/x86_64/include/arch/memory/paging/kernel_mapper.hpp b/arch/x86_64/include/arch/memory/paging/kernel_mapper.hpp
index 94c937d..5bf14fb 100644
--- a/arch/x86_64/include/arch/memory/paging/kernel_mapper.hpp
+++ b/arch/x86_64/include/arch/memory/paging/kernel_mapper.hpp
@@ -142,17 +142,14 @@ namespace teachos::arch::memory::paging
         entry entry{section.flags};
 
         // Required to be accessible in User Mode:
-        // - .boot_rodata (Contains constant data stored in ROM)
         // - .boot_bss (Contains statically allocated variables)
         // - .user_text (Contains the actual user code executed)
         // - .user_data (Contains static user variables)
         // - .stl_text (Contains code for custom std implementations and standard library code)
-        if (section.physical_address == 0x100000 /* .boot_rodata */ ||
-            section.physical_address == 0x102000 /* .boot_bss */ ||
+        if (section.physical_address == 0x102000 /* .boot_bss */ ||
             section.physical_address == 0x209000 /* .stl_text */)
         {
           entry.set_user_accessible();
-          entry.set_global();
         }
 
         // TODO: Can be removed once stl has been completly mapped into stl text
diff --git a/arch/x86_64/include/arch/memory/paging/page_entry.hpp b/arch/x86_64/include/arch/memory/paging/page_entry.hpp
index 03cdb1a..8147c5c 100644
--- a/arch/x86_64/include/arch/memory/paging/page_entry.hpp
+++ b/arch/x86_64/include/arch/memory/paging/page_entry.hpp
@@ -77,8 +77,6 @@ namespace teachos::arch::memory::paging
      */
     auto set_user_accessible() -> void;
 
-    auto set_global() -> void;
-
     /**
      * @brief Calculates the physical frame this entry is pointing too, can be null if the page is not present in
      * memory.
diff --git a/arch/x86_64/include/arch/memory/paging/page_table.hpp b/arch/x86_64/include/arch/memory/paging/page_table.hpp
index 7b7e29e..b972337 100644
--- a/arch/x86_64/include/arch/memory/paging/page_table.hpp
+++ b/arch/x86_64/include/arch/memory/paging/page_table.hpp
@@ -95,13 +95,20 @@ namespace teachos::arch::memory::paging
       {
         auto const allocated_frame = allocator.allocate_frame();
         exception_handling::assert(allocated_frame.has_value(), "[Page mapper] Unable to allocate frame");
-        this->operator[](table_index)
-            .set_entry(allocated_frame.value(), flags.to_ulong() | entry::PRESENT | entry::WRITABLE);
+        this->operator[](table_index).set_entry(allocated_frame.value(), entry::PRESENT | entry::WRITABLE);
         // There should now be an entry at the previously not existent index, therefore we can simply access it again.
         next_handle = next_table(table_index);
         exception_handling::assert(next_handle.has_value(), "[Page mapper] Unable to create new entry into page table");
         next_handle.value().zero_entries();
       }
+
+      // Check if the now created or previously created  level 4, level 3 or level 2 page entry is used by user
+      // accessible code. If it is that page entry needs to be user accesible as well.
+      entry entry{flags.to_ulong()};
+      if (entry.contains_flags(entry::USER_ACCESSIBLE))
+      {
+        this->operator[](table_index).set_user_accessible();
+      }
       return next_handle.value();
     }
 
diff --git a/arch/x86_64/scripts/kernel.ld b/arch/x86_64/scripts/kernel.ld
index e5cbc73..23f9681 100644
--- a/arch/x86_64/scripts/kernel.ld
+++ b/arch/x86_64/scripts/kernel.ld
@@ -89,7 +89,7 @@ SECTIONS
   {
     *(.stl_text)
     KEEP(*libstdc++.a:*(.text .text.*))
-    KEEP(*libatomic.a:*(.text .text.*)) /* Attempt to move atomic stl into stl_text as well, doesn't work */
+    KEEP(*libatomic.a:*(.text .text.*)) /* TODO: Attempt to move atomic stl into stl_text as well, doesn't work */
   }
 
   .text ALIGN(4K) : AT(ADDR (.text))
diff --git a/arch/x86_64/src/memory/paging/page_entry.cpp b/arch/x86_64/src/memory/paging/page_entry.cpp
index a5b44fa..57045ca 100644
--- a/arch/x86_64/src/memory/paging/page_entry.cpp
+++ b/arch/x86_64/src/memory/paging/page_entry.cpp
@@ -39,8 +39,6 @@ namespace teachos::arch::memory::paging
 
   auto entry::set_user_accessible() -> void { flags |= entry::USER_ACCESSIBLE; }
 
-  auto entry::set_global() -> void { flags |= entry::GLOBAL; }
-
   auto entry::calculate_pointed_to_frame() const -> std::optional<allocator::physical_frame>
   {
     if (contains_flags(PRESENT))
diff --git a/arch/x86_64/src/user/main.cpp b/arch/x86_64/src/user/main.cpp
index a435a41..747a8a4 100644
--- a/arch/x86_64/src/user/main.cpp
+++ b/arch/x86_64/src/user/main.cpp
@@ -6,10 +6,6 @@
 #include <algorithm>
 #include <atomic>
 
-// TODO: Disallow these imports
-#include "arch/kernel/cpu/if.hpp"
-#include "arch/video/vga/text.hpp"
-
 namespace teachos::arch::user
 {
   auto main() -> void
@@ -18,8 +14,6 @@ namespace teachos::arch::user
     context_switching::syscall::syscall(context_switching::syscall::type::WRITE,
                                         {reinterpret_cast<uint64_t>(&syscall_message)});
 
-    // kernel::cpu::clear_interrupt_flag();  // Causes crash Kernel Code (.text) is not mapped in User mMde
-
     int test = std::max(5, 10);
     (void)test;
 
@@ -29,16 +23,6 @@ namespace teachos::arch::user
     auto address = memory::heap::global_heap_allocator::malloc(8U);
     (void)address;
 
-    // auto test = new int{20};  // Causes crash Heap is not mapped in User Mode
-    // (void)test;
-
-    // if (!error)
-    // {
-    //   // Causes crash vga is not mapped in User Mode
-    //   video::vga::text::write("Successfully made a SYSCALL and returned with SYSRETQ!",
-    //                           video::vga::text::common_attributes::green_on_black);
-    // }
-
     for (;;)
     {
     }