audk/UefiCpuPkg/PiSmmCpuDxeSmm
Sheng Wei 0930e7ff64 UefiCpuPkg/CpuExceptionHandlerLib: Clear CET shadow stack token busy bit
If CET shadows stack feature enabled in SMM and stack switch is enabled.
When code execute from SMM handler to SMM exception, CPU will check SMM
exception shadow stack token busy bit if it is cleared or not.
If it is set, it will trigger #DF exception.
If it is not set, CPU will set the busy bit when enter SMM exception.
So, the busy bit should be cleared when return back form SMM exception to
SMM handler. Otherwise, keeping busy bit 1 will cause to trigger #DF
exception when enter SMM exception next time.
So, we use instruction SAVEPREVSSP, CLRSSBSY and RSTORSSP to clear the
shadow stack token busy bit before RETF instruction in SMM exception.

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3192

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: Roger Feng <roger.feng@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
2021-03-02 05:11:55 +00:00
..
Ia32 UefiCpuPkg/PiSmmCpuDxeSmm: Reflect page table depth with page table address 2020-11-18 04:52:26 +00:00
X64 UefiCpuPkg/CpuExceptionHandlerLib: Clear CET shadow stack token busy bit 2021-03-02 05:11:55 +00:00
CpuS3.c UefiCpuPkg PiSmmCpuDxeSmm: Reduce SMRAM consumption in CpuS3.c 2021-01-11 09:13:48 +00:00
CpuService.c UefiCpuPkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:28 -07:00
CpuService.h UefiCpuPkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:28 -07:00
MpService.c UefiCpuPkg/PiSmmCpuDxeSmm: pause in WaitForSemaphore() before re-fetch 2020-07-31 13:27:50 +00:00
PiSmmCpuDxeSmm.c UefiCpuPkg/PiSmm: Fix various typos 2020-02-10 22:30:07 +00:00
PiSmmCpuDxeSmm.h UefiCpuPkg/PiSmmCpuDxeSmm: Reflect page table depth with page table address 2020-11-18 04:52:26 +00:00
PiSmmCpuDxeSmm.inf UefiCpuPkg/PiSmmCpuDxeSmm: Avoid allocate Token every time 2019-12-06 06:41:16 +00:00
PiSmmCpuDxeSmm.uni UefiCpuPkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:28 -07:00
PiSmmCpuDxeSmmExtra.uni UefiCpuPkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:28 -07:00
SmmCpuMemoryManagement.c UefiCpuPkg/PiSmmCpuDxeSmm: Reflect page table depth with page table address 2020-11-18 04:52:26 +00:00
SmmMp.c UefiCpuPkg/PiSmmCpuDxeSmm: Enable MM MP Protocol 2019-07-16 11:54:55 +08:00
SmmMp.h UefiCpuPkg/PiSmmCpuDxeSmm: Keep function comment and declaration adjacent 2019-08-02 14:19:13 +08:00
SmmProfile.c UefiCpuPkg: PiSmmCpuDxeSmm skip MSR_IA32_MISC_ENABLE manipulation on AMD 2020-07-07 23:25:16 +00:00
SmmProfile.h UefiCpuPkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:28 -07:00
SmmProfileInternal.h UefiCpuPkg: PiSmmCpuDxeSmm skip MSR_IA32_MISC_ENABLE manipulation on AMD 2020-07-07 23:25:16 +00:00
SmramSaveState.c UefiCpuPkg/PiSmm: Fix various typos 2020-02-10 22:30:07 +00:00
SyncTimer.c UefiCpuPkg: Replace BSD License with BSD+Patent License 2019-04-09 10:58:28 -07:00