diff options
Diffstat (limited to 'Kernel')
| -rw-r--r-- | Kernel/Arch/i386/CPU.h | 12 | ||||
| -rw-r--r-- | Kernel/VM/MemoryManager.cpp | 9 |
2 files changed, 19 insertions, 2 deletions
diff --git a/Kernel/Arch/i386/CPU.h b/Kernel/Arch/i386/CPU.h index 5cdcfa4467..2af084c7a3 100644 --- a/Kernel/Arch/i386/CPU.h +++ b/Kernel/Arch/i386/CPU.h @@ -104,6 +104,7 @@ public: UserSupervisor = 1 << 2, WriteThrough = 1 << 3, CacheDisabled = 1 << 4, + Global = 1 << 8, }; bool is_present() const { return raw() & Present; } @@ -121,7 +122,10 @@ public: bool is_cache_disabled() const { return raw() & CacheDisabled; } void set_cache_disabled(bool b) { set_bit(CacheDisabled, b); } - void set_bit(u8 bit, bool value) + bool is_global() const { return raw() & Global; } + void set_global(bool b) { set_bit(Global, b); } + + void set_bit(u32 bit, bool value) { if (value) m_raw |= bit; @@ -152,6 +156,7 @@ public: UserSupervisor = 1 << 2, WriteThrough = 1 << 3, CacheDisabled = 1 << 4, + Global = 1 << 8, }; bool is_present() const { return raw() & Present; } @@ -169,7 +174,10 @@ public: bool is_cache_disabled() const { return raw() & CacheDisabled; } void set_cache_disabled(bool b) { set_bit(CacheDisabled, b); } - void set_bit(u8 bit, bool value) + bool is_global() const { return raw() & Global; } + void set_global(bool b) { set_bit(Global, b); } + + void set_bit(u32 bit, bool value) { if (value) m_raw |= bit; diff --git a/Kernel/VM/MemoryManager.cpp b/Kernel/VM/MemoryManager.cpp index 67cddbf144..1d7f87e8c3 100644 --- a/Kernel/VM/MemoryManager.cpp +++ b/Kernel/VM/MemoryManager.cpp @@ -158,6 +158,12 @@ void MemoryManager::initialize_paging() dbgprintf("MM: Installing page directory\n"); #endif + // Turn on CR4.PGE so the CPU will respect the G bit in page tables. + asm volatile( + "mov %cr4, %eax\n" + "orl $0x10, %eax\n" + "mov %eax, %cr4\n"); + asm volatile("movl %%eax, %%cr3" ::"a"(kernel_page_directory().cr3())); asm volatile( "movl %%cr0, %%eax\n" @@ -187,12 +193,14 @@ PageTableEntry& MemoryManager::ensure_pte(PageDirectory& page_directory, Virtual pde.set_user_allowed(false); pde.set_present(true); pde.set_writable(true); + pde.set_global(true); } else if (page_directory_index == 1) { ASSERT(&page_directory == m_kernel_page_directory); pde.set_page_table_base((u32)m_page_table_one); pde.set_user_allowed(false); pde.set_present(true); pde.set_writable(true); + pde.set_global(true); } else { //ASSERT(&page_directory != m_kernel_page_directory.ptr()); auto page_table = allocate_supervisor_physical_page(); @@ -210,6 +218,7 @@ PageTableEntry& MemoryManager::ensure_pte(PageDirectory& page_directory, Virtual pde.set_user_allowed(true); pde.set_present(true); pde.set_writable(true); + pde.set_global(&page_directory == m_kernel_page_directory.ptr()); page_directory.m_physical_pages.set(page_directory_index, move(page_table)); } } |