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UefiCpuPkg/PiSmmCpuDxeSmm: Add paging protection.

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PiSmmCpuDxeSmm consumes SmmAttributesTable and setup page table:
1) Code region is marked as read-only and Data region is non-executable,
if the PE image is 4K aligned.
2) Important data structure is set to RO, such as GDT/IDT.
3) SmmSaveState is set to non-executable,
and SmmEntrypoint is set to read-only.
4) If static page is supported, page table is read-only.

We use page table to protect other components, and itself.

If we use dynamic paging, we can still provide *partial* protection.
And hope page table is not modified by other components.

The XD enabling code is moved to SmiEntry to let NX take effect.

Cc: Jeff Fan <jeff.fan@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
This commit is contained in:
Jiewen Yao
2016-10-23 23:19:52 +08:00
parent 28b020b5de
commit 717fb60443
25 changed files with 2042 additions and 775 deletions
Download Patch File Download Diff File Expand all files Collapse all files

75
UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmiEntry.asm
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@@ -1,5 +1,5 @@
;------------------------------------------------------------------------------ ;
; Copyright (c) 2009 - 2015, Intel Corporation. All rights reserved.<BR>
; Copyright (c) 2009 - 2016, Intel Corporation. All rights reserved.<BR>
; This program and the accompanying materials
; are licensed and made available under the terms and conditions of the BSD License
; which accompanies this distribution. The full text of the license may be found at
@@ -22,6 +22,10 @@
.model flat,C
.xmm
MSR_IA32_MISC_ENABLE EQU 1A0h
MSR_EFER EQU 0c0000080h
MSR_EFER_XD EQU 0800h
DSC_OFFSET EQU 0fb00h
DSC_GDTPTR EQU 30h
DSC_GDTSIZ EQU 38h
@@ -43,6 +47,7 @@ EXTERNDEF gcSmiHandlerSize:WORD
EXTERNDEF gSmiCr3:DWORD
EXTERNDEF gSmiStack:DWORD
EXTERNDEF gSmbase:DWORD
EXTERNDEF mXdSupported:BYTE
EXTERNDEF FeaturePcdGet (PcdCpuSmmStackGuard):BYTE
EXTERNDEF gSmiHandlerIdtr:FWORD
@@ -128,8 +133,42 @@ gSmiCr3 DD ?
or eax, BIT10
@@: ; as cr4.PGE is not set here, refresh cr3
mov cr4, eax ; in PreModifyMtrrs() to flush TLB.
cmp FeaturePcdGet (PcdCpuSmmStackGuard), 0
jz @F
; Load TSS
mov byte ptr [ebp + TSS_SEGMENT + 5], 89h ; clear busy flag
mov eax, TSS_SEGMENT
ltr ax
@@:
; enable NXE if supported
DB 0b0h ; mov al, imm8
mXdSupported DB 1
cmp al, 0
jz @SkipXd
;
; Check XD disable bit
;
mov ecx, MSR_IA32_MISC_ENABLE
rdmsr
push edx ; save MSR_IA32_MISC_ENABLE[63-32]
test edx, BIT2 ; MSR_IA32_MISC_ENABLE[34]
jz @f
and dx, 0FFFBh ; clear XD Disable bit if it is set
wrmsr
@@:
mov ecx, MSR_EFER
rdmsr
or ax, MSR_EFER_XD ; enable NXE
wrmsr
jmp @XdDone
@SkipXd:
sub esp, 4
@XdDone:
mov ebx, cr0
or ebx, 080010000h ; enable paging + WP
or ebx, 080010023h ; enable paging + WP + NE + MP + PE
mov cr0, ebx
lea ebx, [edi + DSC_OFFSET]
mov ax, [ebx + DSC_DS]
@@ -141,34 +180,38 @@ gSmiCr3 DD ?
mov ax, [ebx + DSC_SS]
mov ss, eax
cmp FeaturePcdGet (PcdCpuSmmStackGuard), 0
jz @F
; Load TSS
mov byte ptr [ebp + TSS_SEGMENT + 5], 89h ; clear busy flag
mov eax, TSS_SEGMENT
ltr ax
@@:
; jmp _SmiHandler ; instruction is not needed
_SmiHandler PROC
mov ebx, [esp] ; CPU Index
mov ebx, [esp + 4] ; CPU Index
push ebx
mov eax, CpuSmmDebugEntry
call eax
pop ecx
add esp, 4
push ebx
mov eax, SmiRendezvous
call eax
pop ecx
add esp, 4
push ebx
mov eax, CpuSmmDebugExit
call eax
pop ecx
add esp, 4
mov eax, mXdSupported
mov al, [eax]
cmp al, 0
jz @f
pop edx ; get saved MSR_IA32_MISC_ENABLE[63-32]
test edx, BIT2
jz @f
mov ecx, MSR_IA32_MISC_ENABLE
rdmsr
or dx, BIT2 ; set XD Disable bit if it was set before entering into SMM
wrmsr
@@:
rsm
_SmiHandler ENDP