diff --git a/Kernel/Arch/i386/CPU.cpp b/Kernel/Arch/i386/CPU.cpp index e08a7e6acf8..8a7b18223ef 100644 --- a/Kernel/Arch/i386/CPU.cpp +++ b/Kernel/Arch/i386/CPU.cpp @@ -570,7 +570,6 @@ void detect_cpu_features() g_cpu_supports_umip = (extended_features.ecx() & (1 << 2)); } - void stac() { if (!g_cpu_supports_smap) @@ -586,3 +585,79 @@ void clac() asm volatile("clac" :: : "cc"); } + +void x86_enable_pae() +{ + // Turn on CR4.PAE + asm volatile( + "mov %cr4, %eax\n" + "orl $0x20, %eax\n" + "mov %eax, %cr4\n"); +} + +void x86_enable_pge() +{ + if (g_cpu_supports_pge) { + // Turn on CR4.PGE so the CPU will respect the G bit in page tables. + asm volatile( + "mov %cr4, %eax\n" + "orl $0x80, %eax\n" + "mov %eax, %cr4\n"); + kprintf("x86: PGE support enabled\n"); + } else { + kprintf("x86: PGE support not detected\n"); + } +} + +void x86_enable_smep() +{ + if (g_cpu_supports_smep) { + // Turn on CR4.SMEP + asm volatile( + "mov %cr4, %eax\n" + "orl $0x100000, %eax\n" + "mov %eax, %cr4\n"); + kprintf("x86: SMEP support enabled\n"); + } else { + kprintf("x86: SMEP support not detected\n"); + } +} + +void x86_enable_smap() +{ + if (g_cpu_supports_smap) { + // Turn on CR4.SMAP + kprintf("x86: Enabling SMAP\n"); + asm volatile( + "mov %cr4, %eax\n" + "orl $0x200000, %eax\n" + "mov %eax, %cr4\n"); + kprintf("x86: SMAP support enabled\n"); + } else { + kprintf("x86: SMAP support not detected\n"); + } +} + +void x86_enable_nx() +{ + if (g_cpu_supports_nx) { + // Turn on IA32_EFER.NXE + asm volatile( + "movl $0xc0000080, %ecx\n" + "rdmsr\n" + "orl $0x800, %eax\n" + "wrmsr\n"); + kprintf("x86: NX support enabled\n"); + } else { + kprintf("x86: NX support not detected\n"); + } +} + +void x86_enable_wp() +{ + asm volatile( + "movl %%cr0, %%eax\n" + "orl $0x00010000, %%eax\n" + "movl %%eax, %%cr0\n" :: + : "%eax", "memory"); +} diff --git a/Kernel/Arch/i386/CPU.h b/Kernel/Arch/i386/CPU.h index 583a66d7f90..7a73f2b458b 100644 --- a/Kernel/Arch/i386/CPU.h +++ b/Kernel/Arch/i386/CPU.h @@ -539,8 +539,13 @@ extern bool g_cpu_supports_tsc; extern bool g_cpu_supports_umip; void stac(); - void clac(); +void x86_enable_pae(); +void x86_enable_pge(); +void x86_enable_smep(); +void x86_enable_smap(); +void x86_enable_nx(); +void x86_enable_wp(); class SmapDisabler { public: diff --git a/Kernel/VM/MemoryManager.cpp b/Kernel/VM/MemoryManager.cpp index 71d0c4a23a4..1c64ee60534 100644 --- a/Kernel/VM/MemoryManager.cpp +++ b/Kernel/VM/MemoryManager.cpp @@ -25,100 +25,25 @@ MemoryManager::MemoryManager() { m_kernel_page_directory = PageDirectory::create_kernel_page_directory(); - initialize_paging(); + parse_memory_map(); - kprintf("MM initialized.\n"); + x86_enable_pae(); + x86_enable_pge(); + x86_enable_smep(); + x86_enable_smap(); + x86_enable_nx(); + x86_enable_wp(); + + asm volatile("movl %%eax, %%cr3" ::"a"(kernel_page_directory().cr3())); + + setup_low_1mb(); + protect_kernel_image(); } MemoryManager::~MemoryManager() { } -void MemoryManager::initialize_paging() -{ - if (!g_cpu_supports_pae) { - kprintf("x86: Cannot boot on machines without PAE support.\n"); - hang(); - } - -#ifdef MM_DEBUG - dbgprintf("MM: Kernel page directory @ %p\n", kernel_page_directory().cr3()); -#endif - - parse_memory_map(); - -#ifdef MM_DEBUG - dbgprintf("MM: Installing page directory\n"); -#endif - - // Turn on CR4.PAE - asm volatile( - "mov %cr4, %eax\n" - "orl $0x20, %eax\n" - "mov %eax, %cr4\n"); - - if (g_cpu_supports_pge) { - // Turn on CR4.PGE so the CPU will respect the G bit in page tables. - asm volatile( - "mov %cr4, %eax\n" - "orl $0x80, %eax\n" - "mov %eax, %cr4\n"); - kprintf("x86: PGE support enabled\n"); - } else { - kprintf("x86: PGE support not detected\n"); - } - - if (g_cpu_supports_smep) { - // Turn on CR4.SMEP - asm volatile( - "mov %cr4, %eax\n" - "orl $0x100000, %eax\n" - "mov %eax, %cr4\n"); - kprintf("x86: SMEP support enabled\n"); - } else { - kprintf("x86: SMEP support not detected\n"); - } - - if (g_cpu_supports_smap) { - // Turn on CR4.SMAP - kprintf("x86: Enabling SMAP\n"); - asm volatile( - "mov %cr4, %eax\n" - "orl $0x200000, %eax\n" - "mov %eax, %cr4\n"); - kprintf("x86: SMAP support enabled\n"); - } else { - kprintf("x86: SMAP support not detected\n"); - } - - if (g_cpu_supports_nx) { - // Turn on IA32_EFER.NXE - asm volatile( - "movl $0xc0000080, %ecx\n" - "rdmsr\n" - "orl $0x800, %eax\n" - "wrmsr\n"); - kprintf("x86: NX support enabled\n"); - } else { - kprintf("x86: NX support not detected\n"); - } - - asm volatile("movl %%eax, %%cr3" ::"a"(kernel_page_directory().cr3())); - asm volatile( - "movl %%cr0, %%eax\n" - "orl $0x80010001, %%eax\n" - "movl %%eax, %%cr0\n" :: - : "%eax", "memory"); - - setup_low_1mb(); - - protect_kernel_image(); - -#ifdef MM_DEBUG - dbgprintf("MM: Paging initialized.\n"); -#endif -} - void MemoryManager::protect_kernel_image() { // Disable writing to the kernel text and rodata segments. diff --git a/Kernel/VM/MemoryManager.h b/Kernel/VM/MemoryManager.h index 823d68f937e..f9f292fc646 100644 --- a/Kernel/VM/MemoryManager.h +++ b/Kernel/VM/MemoryManager.h @@ -121,7 +121,6 @@ private: void unregister_region(Region&); void detect_cpu_features(); - void initialize_paging(); void setup_low_1mb(); void protect_kernel_image(); void parse_memory_map();