UefiCpuPkg/PiSmmCpuDxeSmm: Add paging protection.

[mirror_edk2.git] / UefiCpuPkg / PiSmmCpuDxeSmm / X64 / SmmFuncsArch.c

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmFuncsArch.c b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmFuncsArch.c
index 6844c3fc499d810bb041a38ae04084f934f090e7..d6d6a1a5035ca07c1d82175c427196a061062a8f 100644 (file)
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmFuncsArch.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmFuncsArch.c
@@ -14,6 +14,30 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 \r
 #include "PiSmmCpuDxeSmm.h"\r
 \r
+EFI_PHYSICAL_ADDRESS                mGdtBuffer;\r
+UINTN                               mGdtBufferSize;\r
+\r
+/**\r
+  Initialize IDT for SMM Stack Guard.\r
+\r
+**/\r
+VOID\r
+EFIAPI\r
+InitializeIDTSmmStackGuard (\r
+  VOID\r
+  )\r
+{\r
+  IA32_IDT_GATE_DESCRIPTOR  *IdtGate;\r
+\r
+  //\r
+  // If SMM Stack Guard feature is enabled, set the IST field of\r
+  // the interrupt gate for Page Fault Exception to be 1\r
+  //\r
+  IdtGate = (IA32_IDT_GATE_DESCRIPTOR *)gcSmiIdtr.Base;\r
+  IdtGate += EXCEPT_IA32_PAGE_FAULT;\r
+  IdtGate->Bits.Reserved_0 = 1;\r
+}\r
+\r
 /**\r
   Initialize Gdt for all processors.\r
   \r
@@ -41,8 +65,10 @@ InitGdt (
   // on each SMI entry.\r
   //\r
   GdtTssTableSize = (gcSmiGdtr.Limit + 1 + TSS_SIZE + 7) & ~7; // 8 bytes aligned\r
-  GdtTssTables = (UINT8*)AllocatePages (EFI_SIZE_TO_PAGES (GdtTssTableSize * gSmmCpuPrivate->SmmCoreEntryContext.NumberOfCpus));\r
+  mGdtBufferSize = GdtTssTableSize * gSmmCpuPrivate->SmmCoreEntryContext.NumberOfCpus;\r
+  GdtTssTables = (UINT8*)AllocateCodePages (EFI_SIZE_TO_PAGES (mGdtBufferSize));\r
   ASSERT (GdtTssTables != NULL);\r
+  mGdtBuffer = (UINTN)GdtTssTables;\r
   GdtTableStepSize = GdtTssTableSize;\r
 \r
   for (Index = 0; Index < gSmmCpuPrivate->SmmCoreEntryContext.NumberOfCpus; Index++) {\r