[PATCH] D55418: [GlobalISel] Set stack protector index when translating Intrinsic::stackprotector

[Petr Pavlu via Phabricator via llvm-commits]

petpav01 created this revision.
petpav01 added reviewers: t.p.northover, aemerson.
Herald added subscribers: llvm-commits, arphaman, javed.absar, kristof.beyls, rovka.

Record the stack protector index in `MachineFrameInfo` when translating `Intrinsic::stackprotector` similarly as is done by SelectionDAG when processing the same intrinsic.

Setting this index allows the Prologue/Epilogue Insertion to recognize that the stack protection is enabled. The pass can then make sure that the stack protector comes before local variables on the stack and assigns potentially vulnerable objects first so they are close to the stack protector slot.


Repository:
  rL LLVM

https://reviews.llvm.org/D55418

Files:
  lib/CodeGen/GlobalISel/IRTranslator.cpp
  test/CodeGen/AArch64/GlobalISel/arm64-irtranslator-stackprotect.ll


Index: test/CodeGen/AArch64/GlobalISel/arm64-irtranslator-stackprotect.ll
===================================================================
--- test/CodeGen/AArch64/GlobalISel/arm64-irtranslator-stackprotect.ll
+++ test/CodeGen/AArch64/GlobalISel/arm64-irtranslator-stackprotect.ll
@@ -3,6 +3,9 @@
 
 ; CHECK: name: test_stack_guard
 
+; CHECK: frameInfo:
+; CHECK: stackProtector:  '%stack.0.StackGuardSlot'
+
 ; CHECK: stack:
 ; CHECK:  - { id: 0, name: StackGuardSlot,  type: default, offset: 0, size: 8, alignment: 8,
 ; CHECK-NOT: id: 1
Index: lib/CodeGen/GlobalISel/IRTranslator.cpp
===================================================================
--- lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -968,13 +968,15 @@
     getStackGuard(GuardVal, MIRBuilder);
 
     AllocaInst *Slot = cast<AllocaInst>(CI.getArgOperand(1));
+    int FI = getOrCreateFrameIndex(*Slot);
+    MF->getFrameInfo().setStackProtectorIndex(FI);
+
     MIRBuilder.buildStore(
         GuardVal, getOrCreateVReg(*Slot),
-        *MF->getMachineMemOperand(
-            MachinePointerInfo::getFixedStack(*MF,
-                                              getOrCreateFrameIndex(*Slot)),
-            MachineMemOperand::MOStore | MachineMemOperand::MOVolatile,
-            PtrTy.getSizeInBits() / 8, 8));
+        *MF->getMachineMemOperand(MachinePointerInfo::getFixedStack(*MF, FI),
+                                  MachineMemOperand::MOStore |
+                                      MachineMemOperand::MOVolatile,
+                                  PtrTy.getSizeInBits() / 8, 8));
     return true;
   }
   case Intrinsic::cttz:


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