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authorSheng Wei <w.sheng@intel.com>2021-06-21 09:44:07 +0800
committermergify[bot] <37929162+mergify[bot]@users.noreply.github.com>2021-07-06 08:18:21 +0000
commit0a6b303dcedb7af238ad485d545802befb797b3a (patch)
treebe8743794a0014612a435e744ba6fe481676afa0 /UefiCpuPkg/PiSmmCpuDxeSmm
parentb3db0cb1f8d163f22b769c205c6347376a315dcd (diff)
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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>
Diffstat (limited to 'UefiCpuPkg/PiSmmCpuDxeSmm')
-rw-r--r--UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmFuncsArch.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmFuncsArch.c b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmFuncsArch.c
index 661c1ba294..ca3f5ff91a 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmFuncsArch.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmFuncsArch.c
@@ -202,7 +202,7 @@ InitShadowStack (
// Please refer to UefiCpuPkg/Library/CpuExceptionHandlerLib/X64 for the full stack frame at runtime.
//
InterruptSsp = (UINT32)((UINTN)ShadowStack + EFI_PAGES_TO_SIZE(1) - sizeof(UINT64));
- *(UINT32 *)(UINTN)InterruptSsp = (InterruptSsp - sizeof(UINT64) * 4) | 0x2;
+ *(UINT64 *)(UINTN)InterruptSsp = (InterruptSsp - sizeof(UINT64) * 4) | 0x2;
mCetInterruptSsp = InterruptSsp - sizeof(UINT64);
mCetInterruptSspTable = (UINT32)(UINTN)(mSmmInterruptSspTables + sizeof(UINT64) * 8 * CpuIndex);