kernel: keep track of cr3 in AMD HAL/HEL.

why?

To keep track of it, avoid security issues in the future.

Signed-off-by: Amlal <amlal@nekernel.org>

6 files changed, 13 insertions, 9 deletions

diff --git a/dev/kernel/FirmwareKit/Handover.h b/dev/kernel/FirmwareKit/Handover.h
index fbf4bb28..d3ccc724 100644
--- a/dev/kernel/FirmwareKit/Handover.h
+++ b/dev/kernel/FirmwareKit/Handover.h
@@ -20,8 +20,8 @@
 #include <FirmwareKit/EFI/EFI.h>
 #include <NewKit/Defines.h>
 
-#define kHandoverMagic 0xBADCC
-#define kHandoverVersion 0x0117
+#define kHandoverMagic (0xBADCC)
+#define kHandoverVersion (0x0117)
 
 /* Initial bitmap pointer location and size. */
 #define kHandoverBitMapSz (gib_cast(4))
diff --git a/dev/kernel/HALKit/AMD64/HalKernelMain.cc b/dev/kernel/HALKit/AMD64/HalKernelMain.cc
index fba02bc1..29244add 100644
--- a/dev/kernel/HALKit/AMD64/HalKernelMain.cc
+++ b/dev/kernel/HALKit/AMD64/HalKernelMain.cc
@@ -27,7 +27,8 @@ STATIC Kernel::Void hal_pre_init_scheduler() noexcept {
   }
 }
 
-/// @brief Kernel init procedure.
+/// @brief Kernel init function.
+/// @param handover_hdr Handover boot header.
 EXTERN_C Int32 hal_init_platform(Kernel::HEL::BootInfoHeader* handover_hdr) {
   if (handover_hdr->f_Magic != kHandoverMagic && handover_hdr->f_Version != kHandoverVersion) {
     return kEfiFail;
@@ -42,6 +43,10 @@ EXTERN_C Int32 hal_init_platform(Kernel::HEL::BootInfoHeader* handover_hdr) {
   Boot::ExitBootServices(handover_hdr->f_HardwareTables.f_ImageKey,
                          handover_hdr->f_HardwareTables.f_ImageHandle);
 
+  kKernelCR3 = kHandoverHeader->f_PageStart;
+
+  hal_write_cr3(kKernelCR3);
+
   /************************************** */
   /*     INITIALIZE BIT MAP.              */
   /************************************** */
diff --git a/dev/kernel/HALKit/AMD64/Paging.h b/dev/kernel/HALKit/AMD64/Paging.h
index 074c1113..3c7107bc 100644
--- a/dev/kernel/HALKit/AMD64/Paging.h
+++ b/dev/kernel/HALKit/AMD64/Paging.h
@@ -37,7 +37,7 @@ EXTERN_C void hal_write_cr0(Kernel::VoidPtr bit);
 
 EXTERN_C Kernel::VoidPtr hal_read_cr0();  // @brief CPU control register.
 EXTERN_C Kernel::VoidPtr hal_read_cr2();  // @brief Fault address.
-EXTERN_C Kernel::VoidPtr hal_read_cr3();  // @brief Page table.
+EXTERN_C Kernel::VoidPtr hal_read_cr3();  // @brief Page directory inside cr3 register.
 
 namespace Kernel::HAL {
 namespace Detail {
diff --git a/dev/kernel/HALKit/AMD64/Processor.h b/dev/kernel/HALKit/AMD64/Processor.h
index b57e9abf..d7d594d9 100644
--- a/dev/kernel/HALKit/AMD64/Processor.h
+++ b/dev/kernel/HALKit/AMD64/Processor.h
@@ -286,3 +286,5 @@ EXTERN_C ATTRIBUTE(naked) Kernel::Void hal_load_gdt(Kernel::HAL::Register64 ptr)
 
 inline Kernel::VoidPtr kKernelBitMpStart = nullptr;
 inline Kernel::UIntPtr kKernelBitMpSize  = 0UL;
+
+inline Kernel::VoidPtr kKernelCR3 = nullptr;
\ No newline at end of file
diff --git a/dev/kernel/src/FS/HeFS.cc b/dev/kernel/src/FS/HeFS.cc
index d1e41d1f..605df480 100644
--- a/dev/kernel/src/FS/HeFS.cc
+++ b/dev/kernel/src/FS/HeFS.cc
@@ -4,7 +4,6 @@
 
 ------------------------------------------- */
 
-#include "NewKit/Macros.h"
 #ifdef __FSKIT_INCLUDES_HEFS__
 
 #include <FSKit/HeFS.h>
diff --git a/dev/kernel/src/UserProcessScheduler.cc b/dev/kernel/src/UserProcessScheduler.cc
index 4b206317..23ab22fa 100644
--- a/dev/kernel/src/UserProcessScheduler.cc
+++ b/dev/kernel/src/UserProcessScheduler.cc
@@ -20,8 +20,6 @@
 #include <KernelKit/MemoryMgr.h>
 #include <KernelKit/ProcessScheduler.h>
 #include <NewKit/KString.h>
-#include "KernelKit/CoreProcessScheduler.h"
-#include "NewKit/Defines.h"
 
 ///! BUGS: 0
 
@@ -130,7 +128,7 @@ ErrorOr<VoidPtr> USER_PROCESS::New(SizeT sz, SizeT pad_amount) {
   if (this->UsedMemory > kSchedMaxMemoryLimit) return ErrorOr<VoidPtr>(-kErrorHeapOutOfMemory);
 
 #ifdef __NE_VIRTUAL_MEMORY_SUPPORT__
-  auto vm_register = hal_read_cr3();
+  auto vm_register = kKernelCR3;
   hal_write_cr3(this->VMRegister);
 
   auto ptr = mm_new_heap(sz, Yes, Yes, pad_amount);
@@ -267,7 +265,7 @@ Void USER_PROCESS::Exit(const Int32& exit_code) {
   auto memory_heap_list = this->HeapTree;
 
 #ifdef __NE_VIRTUAL_MEMORY_SUPPORT__
-  auto pd = hal_read_cr3();
+  auto pd = kKernelCR3;
   hal_write_cr3(this->VMRegister);
 #endif