MdePkg/BaseLib: Add Shadow Stack Support for X86.

[mirror_edk2.git] / MdePkg / Library / BaseLib / X64 / LongJump.nasm

diff --git a/MdePkg/Library/BaseLib/X64/LongJump.nasm b/MdePkg/Library/BaseLib/X64/LongJump.nasm
index 3bac27469e3a8f1108c218807e1ef986318e604e..2b38ef0b25e39051b14d00b05a15bb0cf1001d04 100644 (file)
--- a/MdePkg/Library/BaseLib/X64/LongJump.nasm
+++ b/MdePkg/Library/BaseLib/X64/LongJump.nasm
@@ -1,6 +1,6 @@
 ;------------------------------------------------------------------------------\r
 ;\r
-; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>\r
+; Copyright (c) 2006 - 2019, 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
@@ -19,9 +19,13 @@
 ;\r
 ;------------------------------------------------------------------------------\r
 \r
+%include "Nasm.inc"\r
+\r
     DEFAULT REL\r
     SECTION .text\r
 \r
+extern ASM_PFX(PcdGet32 (PcdControlFlowEnforcementPropertyMask))\r
+\r
 ;------------------------------------------------------------------------------\r
 ; VOID\r
 ; EFIAPI\r
@@ -32,6 +36,27 @@
 ;------------------------------------------------------------------------------\r
 global ASM_PFX(InternalLongJump)\r
 ASM_PFX(InternalLongJump):\r
+\r
+    mov     eax, [ASM_PFX(PcdGet32 (PcdControlFlowEnforcementPropertyMask))]\r
+    test    eax, eax\r
+    jz      CetDone\r
+    mov     rax, cr4\r
+    bt      eax, 23                      ; check if CET is enabled\r
+    jnc     CetDone\r
+\r
+    push    rdx                          ; save rdx\r
+\r
+    mov     rdx, [rcx + 0xF8]            ; rdx = target SSP\r
+    READSSP_RAX\r
+    sub     rdx, rax                     ; rdx = delta\r
+    mov     rax, rdx                     ; rax = delta\r
+\r
+    shr     rax, 3                       ; rax = delta/sizeof(UINT64)\r
+    INCSSP_RAX\r
+\r
+    pop     rdx                          ; restore rdx\r
+CetDone:\r
+\r
     mov     rbx, [rcx]\r
     mov     rsp, [rcx + 8]\r
     mov     rbp, [rcx + 0x10]\r