[edk2-devel] [PATCH] UefiCpuPkg/PiSmmCpuDxeSmm: Update mPatchCetSupported set condition

[Wenxing Hou]

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=3584


Function AsmCpuid should frist check the
Value for Basic CPUID Information.The fix is to
update the mPatchCetSupported judgment statement.


Signed-off-by: Wenxing Hou <wenxing....@intel.com>
Cc: Eric Dong   <eric.d...@intel.com>
Cc: Ray Ni      <ray...@intel.com>
Cc: Rahul Kumar <rahul1.ku...@intel.com>
Cc: Sheng W     <w.sh...@intel.com>
Cc: Yao Jiewen  <jiewen....@intel.com>
---
 UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 11 +++++++----
 UefiCpuPkg/PiSmmCpuDxeSmm/SmmProfile.c     | 14 ++++++++------
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c 
b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
index db68e1316e..e394da7095 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
@@ -729,10 +729,10 @@ PiCpuSmmEntry (
 
   DEBUG ((DEBUG_INFO, "PcdControlFlowEnforcementPropertyMask = %d\n", PcdGet32 
(PcdControlFlowEnforcementPropertyMask)));
   if (PcdGet32 (PcdControlFlowEnforcementPropertyMask) != 0) {
-    AsmCpuid (CPUID_EXTENDED_FUNCTION, &RegEax, NULL, NULL, NULL);
-    if (RegEax > CPUID_EXTENDED_FUNCTION) {
+  AsmCpuid(CPUID_SIGNATURE, &RegEax, NULL, NULL, NULL);
+  if (RegEax >= CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS) {
       AsmCpuidEx (CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS, 
CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS_SUB_LEAF_INFO, NULL, NULL, &RegEcx, 
&RegEdx);
-      DEBUG ((DEBUG_INFO, "CPUID[7/0] ECX - 0x%08x\n", RegEcx));
+      DEBUG ((DEBUG_INFO, "  CPUID[7/0] ECX - 0x%08x\n", RegEcx));
       DEBUG ((DEBUG_INFO, "  CET_SS  - 0x%08x\n", RegEcx & CPUID_CET_SS));
       DEBUG ((DEBUG_INFO, "  CET_IBT - 0x%08x\n", RegEdx & CPUID_CET_IBT));
       if ((RegEcx & CPUID_CET_SS) == 0) {
@@ -747,7 +747,10 @@ PiCpuSmmEntry (
         AsmCpuidEx(CPUID_EXTENDED_STATE, 12, &RegEax, NULL, &RegEcx, NULL);
         DEBUG ((DEBUG_INFO, "CPUID[D/12] EAX - 0x%08x, ECX - 0x%08x\n", 
RegEax, RegEcx));
       }
-    }
+  } else {
+    mCetSupported = FALSE;
+   PatchInstructionX86(mPatchCetSupported, mCetSupported, 1);
+         }
   } else {
     mCetSupported = FALSE;
     PatchInstructionX86 (mPatchCetSupported, mCetSupported, 1);
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmProfile.c 
b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmProfile.c
index d7ed9ab7a7..f4d39c6967 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmProfile.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmProfile.c
@@ -985,13 +985,15 @@ CheckFeatureSupported (
   MSR_IA32_MISC_ENABLE_REGISTER  MiscEnableMsr;
 
   if ((PcdGet32 (PcdControlFlowEnforcementPropertyMask) != 0) && 
mCetSupported) {
-    AsmCpuid (CPUID_EXTENDED_FUNCTION, &RegEax, NULL, NULL, NULL);
-    if (RegEax <= CPUID_EXTENDED_FUNCTION) {
-      mCetSupported = FALSE;
-      PatchInstructionX86 (mPatchCetSupported, mCetSupported, 1);
+  AsmCpuid(CPUID_SIGNATURE, &RegEax, NULL, NULL, NULL);
+  if (RegEax >= CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS) {
+     AsmCpuidEx(CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS, 
CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS_SUB_LEAF_INFO, NULL, NULL, &RegEcx, 
NULL);
+     if ((RegEcx & CPUID_CET_SS) == 0) {
+     mCetSupported = FALSE;
+     PatchInstructionX86(mPatchCetSupported, mCetSupported, 1);
+    }
     }
-    AsmCpuidEx (CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS, 
CPUID_STRUCTURED_EXTENDED_FEATURE_FLAGS_SUB_LEAF_INFO, NULL, NULL, &RegEcx, 
NULL);
-    if ((RegEcx & CPUID_CET_SS) == 0) {
+    else {
       mCetSupported = FALSE;
       PatchInstructionX86 (mPatchCetSupported, mCetSupported, 1);
     }
-- 
2.26.2.windows.1



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