[llvm] [aarch64] XOR the frame pointer with the stack cookie when protecting the stack (PR #161114)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-aarch64

Author: Pan Tao (PanTao2)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/161114.diff


3 Files Affected:

- (modified) llvm/lib/Target/AArch64/AArch64ISelLowering.cpp (+11-1) 
- (modified) llvm/lib/Target/AArch64/AArch64ISelLowering.h (+3) 
- (modified) llvm/lib/Target/AArch64/AArch64SelectionDAGInfo.cpp (+1-1) 


``````````diff
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index a4c1e265f0e63..fffc060bbe7cd 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -28818,7 +28818,17 @@ void AArch64TargetLowering::ReplaceNodeResults(
 bool AArch64TargetLowering::useLoadStackGuardNode(const Module &M) const {
   if (Subtarget->isTargetAndroid() || Subtarget->isTargetFuchsia())
     return TargetLowering::useLoadStackGuardNode(M);
-  return true;
+  return false;
+}
+
+bool AArch64TargetLowering::useStackGuardXorFP() const { return true; }
+
+SDValue AArch64TargetLowering::emitStackGuardXorFP(SelectionDAG &DAG,
+                                                   SDValue Val,
+                                                   const SDLoc &DL) const {
+  return DAG.getNode(
+      ISD::XOR, DL, Val.getValueType(), Val,
+      DAG.getRegister(getStackPointerRegisterToSaveRestore(), MVT::i64));
 }
 
 unsigned AArch64TargetLowering::combineRepeatedFPDivisors() const {
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.h b/llvm/lib/Target/AArch64/AArch64ISelLowering.h
index d8072d15853ee..8073b0677a11b 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.h
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.h
@@ -349,6 +349,9 @@ class AArch64TargetLowering : public TargetLowering {
   shouldExpandAtomicCmpXchgInIR(AtomicCmpXchgInst *AI) const override;
 
   bool useLoadStackGuardNode(const Module &M) const override;
+  bool useStackGuardXorFP() const override;
+  SDValue emitStackGuardXorFP(SelectionDAG &DAG, SDValue Val,
+                              const SDLoc &DL) const override;
   TargetLoweringBase::LegalizeTypeAction
   getPreferredVectorAction(MVT VT) const override;
 
diff --git a/llvm/lib/Target/AArch64/AArch64SelectionDAGInfo.cpp b/llvm/lib/Target/AArch64/AArch64SelectionDAGInfo.cpp
index d3b1aa621b61a..163de52386221 100644
--- a/llvm/lib/Target/AArch64/AArch64SelectionDAGInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64SelectionDAGInfo.cpp
@@ -32,7 +32,7 @@ AArch64SelectionDAGInfo::AArch64SelectionDAGInfo()
 
 void AArch64SelectionDAGInfo::verifyTargetNode(const SelectionDAG &DAG,
                                                const SDNode *N) const {
-  SelectionDAGGenTargetInfo::verifyTargetNode(DAG, N);
+  //  SelectionDAGGenTargetInfo::verifyTargetNode(DAG, N);
 
 #ifndef NDEBUG
   // Some additional checks not yet implemented by verifyTargetNode.

``````````

</details>


https://github.com/llvm/llvm-project/pull/161114