UefiCpuPkg/PiSmmCpuDxeSmm: Add paging protection.

[mirror_edk2.git] / UefiCpuPkg / PiSmmCpuDxeSmm / Ia32 / SmiEntry.nasm

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmiEntry.nasm b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmiEntry.nasm
index 4fb0c13508fc51480555b54c0bcb0388c265b84d..d50a3170aa8f39b8cb3ea48c8238481f8d27a262 100644 (file)
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmiEntry.nasm
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmiEntry.nasm
@@ -18,6 +18,10 @@
 ;\r
 ;-------------------------------------------------------------------------------\r
 \r
+%define MSR_IA32_MISC_ENABLE 0x1A0\r
+%define MSR_EFER      0xc0000080\r
+%define MSR_EFER_XD   0x800\r
+\r
 %define DSC_OFFSET 0xfb00\r
 %define DSC_GDTPTR 0x30\r
 %define DSC_GDTSIZ 0x38\r
@@ -40,6 +44,7 @@ global ASM_PFX(gcSmiHandlerSize)
 global ASM_PFX(gSmiCr3)\r
 global ASM_PFX(gSmiStack)\r
 global ASM_PFX(gSmbase)\r
+global ASM_PFX(mXdSupported)\r
 extern ASM_PFX(gSmiHandlerIdtr)\r
 \r
     SECTION .text\r
@@ -56,7 +61,7 @@ _SmiEntryPoint:
     mov     ebp, eax                      ; ebp = GDT base\r
 o32 lgdt    [cs:bx]                       ; lgdt fword ptr cs:[bx]\r
     mov     ax, PROTECT_MODE_CS\r
-    mov     [cs:bx-0x2],ax    \r
+    mov     [cs:bx-0x2],ax\r
     DB      0x66, 0xbf                   ; mov edi, SMBASE\r
 ASM_PFX(gSmbase): DD 0\r
     lea     eax, [edi + (@32bit - _SmiEntryPoint) + 0x8000]\r
@@ -66,7 +71,7 @@ ASM_PFX(gSmbase): DD 0
     or      ebx, 0x23\r
     mov     cr0, ebx\r
     jmp     dword 0x0:0x0\r
-_GdtDesc:   \r
+_GdtDesc:\r
     DW 0\r
     DD 0\r
 \r
@@ -115,8 +120,42 @@ ASM_PFX(gSmiCr3): DD 0
     or      eax, BIT10\r
 .4:                                     ; as cr4.PGE is not set here, refresh cr3\r
     mov     cr4, eax                    ; in PreModifyMtrrs() to flush TLB.\r
+\r
+    cmp     byte [dword ASM_PFX(FeaturePcdGet (PcdCpuSmmStackGuard))], 0\r
+    jz      .6\r
+; Load TSS\r
+    mov     byte [ebp + TSS_SEGMENT + 5], 0x89 ; clear busy flag\r
+    mov     eax, TSS_SEGMENT\r
+    ltr     ax\r
+.6:\r
+\r
+; enable NXE if supported\r
+    DB      0b0h                        ; mov al, imm8\r
+ASM_PFX(mXdSupported):     DB      1\r
+    cmp     al, 0\r
+    jz      @SkipXd\r
+;\r
+; Check XD disable bit\r
+;\r
+    mov     ecx, MSR_IA32_MISC_ENABLE\r
+    rdmsr\r
+    push    edx                        ; save MSR_IA32_MISC_ENABLE[63-32]\r
+    test    edx, BIT2                  ; MSR_IA32_MISC_ENABLE[34]\r
+    jz      .5\r
+    and     dx, 0xFFFB                 ; clear XD Disable bit if it is set\r
+    wrmsr\r
+.5:\r
+    mov     ecx, MSR_EFER\r
+    rdmsr\r
+    or      ax, MSR_EFER_XD             ; enable NXE\r
+    wrmsr\r
+    jmp     @XdDone\r
+@SkipXd:\r
+    sub     esp, 4\r
+@XdDone:\r
+\r
     mov     ebx, cr0\r
-    or      ebx, 0x080010000            ; enable paging + WP\r
+    or      ebx, 0x80010023             ; enable paging + WP + NE + MP + PE\r
     mov     cr0, ebx\r
     lea     ebx, [edi + DSC_OFFSET]\r
     mov     ax, [ebx + DSC_DS]\r
@@ -128,35 +167,39 @@ ASM_PFX(gSmiCr3): DD 0
     mov     ax, [ebx + DSC_SS]\r
     mov     ss, eax\r
 \r
-    cmp     byte [dword ASM_PFX(FeaturePcdGet (PcdCpuSmmStackGuard))], 0\r
-    jz      .5\r
-\r
-; Load TSS\r
-    mov     byte [ebp + TSS_SEGMENT + 5], 0x89 ; clear busy flag\r
-    mov     eax, TSS_SEGMENT\r
-    ltr     ax\r
-.5:\r
 ;   jmp     _SmiHandler                 ; instruction is not needed\r
 \r
 global ASM_PFX(SmiHandler)\r
 ASM_PFX(SmiHandler):\r
-    mov     ebx, [esp]                  ; CPU Index\r
-\r
+    mov     ebx, [esp + 4]                  ; CPU Index\r
     push    ebx\r
     mov     eax, ASM_PFX(CpuSmmDebugEntry)\r
     call    eax\r
-    pop     ecx\r
+    add     esp, 4\r
 \r
     push    ebx\r
     mov     eax, ASM_PFX(SmiRendezvous)\r
     call    eax\r
-    pop     ecx\r
-    \r
+    add     esp, 4\r
+\r
     push    ebx\r
     mov     eax, ASM_PFX(CpuSmmDebugExit)\r
     call    eax\r
-    pop     ecx\r
-\r
+    add     esp, 4\r
+\r
+    mov     eax, ASM_PFX(mXdSupported)\r
+    mov     al, [eax]\r
+    cmp     al, 0\r
+    jz      .7\r
+    pop     edx                       ; get saved MSR_IA32_MISC_ENABLE[63-32]\r
+    test    edx, BIT2\r
+    jz      .7\r
+    mov     ecx, MSR_IA32_MISC_ENABLE\r
+    rdmsr\r
+    or      dx, BIT2                  ; set XD Disable bit if it was set before entering into SMM\r
+    wrmsr\r
+\r
+.7:\r
     rsm\r
 \r
 ASM_PFX(gcSmiHandlerSize): DW $ - _SmiEntryPoint\r