tyler.durden/audk
1
0
Fork 0
mirror of https://github.com/acidanthera/audk.git synced 2025-04-08 17:05:09 +02:00
Code Issues Packages Projects Releases Wiki Activity

UefiCpuPkg: Disable PG in IA32 ApLoopCode

Browse Source 
Disable paging in IA32 RelocateApLoop assembly
code to fix the issue that the AP page table is
unavailiable after boot OS under IA32 execution mode.

This issue exist in IA32 PEI + IA32 DXE normal boot
(also S3 boot with IA32 PEI after previous three commits
are accepted). In current MpLib code, the IA32 execution
mode code did not create page table in reserved memory
like what X64 code did. If PcdCpuStackGuard is TRUE, the
PG is enabled for AP in current RelocateApLoop assembly
code. And the page table for AP is unavailiable after
boot OS. This might cause potential issue. So disable PG
in IA32 RelocateApLoop.

Signed-off-by: Dun Tan <dun.tan@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiaxin Wu <jiaxin.wu@intel.com>
This commit is contained in:
Dun Tan 2024-05-10 11:59:25 +08:00 committed by mergify[bot]
parent 7421ea1f2a
commit ffb8481ba8
1 changed files with 5 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm
View File

@ -1,5 +1,5 @@
;------------------------------------------------------------------------------ ;
; Copyright (c) 2015 - 2023, Intel Corporation. All rights reserved.<BR>
; Copyright (c) 2015 - 2024, Intel Corporation. All rights reserved.<BR>
; SPDX-License-Identifier: BSD-2-Clause-Patent
;
; Module Name:
@ -225,6 +225,10 @@ RendezvousFunnelProcEnd:
; specific to SEV-ES support and are not applicable on IA32.
;-------------------------------------------------------------------------------------
AsmRelocateApLoopGenericStart:
mov eax, cr0
btr eax, 31 ; Clear CR0.PG
mov cr0, eax ; Disable paging since the page table might be unavailiable
mov eax, esp
mov esp, [eax + 12] ; TopOfApStack
push dword [eax] ; push return address for stack trace