audk/UefiCpuPkg/Library
Sheng Wei 0a6b303dce UefiCpuPkg/ExceptionLib: Conditionally clear shadow stack token busy bit
When enter SMM exception, there will be a stack switch only if the IST
field of the interrupt gate is set. When CET shadow stack feature is
enabled, if there is a stack switch between SMM exception and SMM, the
shadow stack token busy bit needs to be cleared when return from SMM
exception to SMM. In UEFI BIOS, only page fault exception does the stack
swith when SMM shack guard feature is enabled. The condition of clear
shadow stack token busy bit should be SMM stack guard enabled, CET shadows
stack feature enabled and page fault exception.
The shadow stack token should be initialized by UINT64.

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3462

Signed-off-by: Sheng Wei <w.sheng@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Qihua Zhuang <qihua.zhuang@intel.com>
Cc: Daquan Dong <daquan.dong@intel.com>
Cc: Justin Tong <justin.tong@intel.com>
Cc: Tom Xu <tom.xu@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
2021-07-06 08:18:21 +00:00
..
BaseUefiCpuLib
BaseXApicLib
BaseXApicX2ApicLib
CpuCacheInfoLib
CpuCommonFeaturesLib UefiCpuPkg/CpuCommonFeaturesLib: Correct the CPU location check 2021-06-21 03:12:17 +00:00
CpuExceptionHandlerLib UefiCpuPkg/ExceptionLib: Conditionally clear shadow stack token busy bit 2021-07-06 08:18:21 +00:00
CpuTimerLib UefiCpuPkg/CpuTimerLib: Update LIBRARY_CLASS of Base instance. 2021-04-12 03:20:24 +00:00
MicrocodeLib
MpInitLib UefiCpuPkg/MpInitLib: Allocate a separate SEV-ES AP reset stack area 2021-05-29 11:33:16 +00:00
MpInitLibUp
MtrrLib
PlatformSecLibNull
RegisterCpuFeaturesLib
SecPeiDxeTimerLibUefiCpu
SmmCpuFeaturesLib
SmmCpuPlatformHookLibNull
VmgExitLibNull