UefiCpuPkg PiSmmCpuDxeSmm: Fixed #double fault on #page fault for IA32

[mirror_edk2.git] / UefiCpuPkg / PiSmmCpuDxeSmm / Ia32 / SmmFuncsArch.c

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmFuncsArch.c b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmFuncsArch.c
index f4db6c8b60cc0f7d6b0e2de54d85a6fab4ae8fbd..4c1499939b1b4d0eeb76ca620fadbc12d1b486f6 100644 (file)
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmFuncsArch.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmFuncsArch.c
@@ -1,7 +1,7 @@
 /** @file\r
   SMM CPU misc functions for Ia32 arch specific.\r
   \r
-Copyright (c) 2015 - 2016, Intel Corporation. All rights reserved.<BR>\r
+Copyright (c) 2015 - 2018, Intel Corporation. All rights reserved.<BR>\r
 This program and the accompanying materials\r
 are licensed and made available under the terms and conditions of the BSD License\r
 which accompanies this distribution.  The full text of the license may be found at\r
@@ -77,7 +77,12 @@ InitGdt (
 \r
     GdtTssTableSize = (gcSmiGdtr.Limit + 1 + TSS_SIZE * 2 + 7) & ~7; // 8 bytes aligned\r
     mGdtBufferSize = GdtTssTableSize * gSmmCpuPrivate->SmmCoreEntryContext.NumberOfCpus;\r
-    GdtTssTables = (UINT8*)AllocateCodePages (EFI_SIZE_TO_PAGES (mGdtBufferSize));\r
+    //\r
+    // IA32 Stack Guard need use task switch to switch stack that need\r
+    // write GDT and TSS, so AllocateCodePages() could not be used here\r
+    // as code pages will be set to RO. \r
+    //\r
+    GdtTssTables = (UINT8*)AllocatePages (EFI_SIZE_TO_PAGES (mGdtBufferSize));\r
     ASSERT (GdtTssTables != NULL);\r
     mGdtBuffer = (UINTN)GdtTssTables;\r
     GdtTableStepSize = GdtTssTableSize;\r