[PATCH] D44520: [MSan] fix the types of RegSaveAreaPtrPtr and OverflowArgAreaPtrPtr

[Alexander Potapenko via Phabricator via llvm-commits]

glider created this revision.
glider added reviewers: dvyukov, vitalybuka.
Herald added a subscriber: llvm-commits.

Despite their names, RegSaveAreaPtrPtr and OverflowArgAreaPtrPtr used to be i8* instead of i8**.
This is important, because these pointers are dereferenced twice (first in CreateLoad(), then in getShadowOriginPtr()), but for some reason MSan allowed this - most certainly because it was possible to optimize getShadowOriginPtr() away at compile time.


Repository:
  rL LLVM

https://reviews.llvm.org/D44520

Files:
  lib/Transforms/Instrumentation/MemorySanitizer.cpp


Index: lib/Transforms/Instrumentation/MemorySanitizer.cpp
===================================================================
--- lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -3235,7 +3235,7 @@
       Value *RegSaveAreaPtrPtr = IRB.CreateIntToPtr(
           IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
                         ConstantInt::get(MS.IntptrTy, 16)),
-          Type::getInt64PtrTy(*MS.C));
+          PointerType::get(Type::getInt64PtrTy(*MS.C), 0));
       Value *RegSaveAreaPtr = IRB.CreateLoad(RegSaveAreaPtrPtr);
       Value *RegSaveAreaShadowPtr, *RegSaveAreaOriginPtr;
       unsigned Alignment = 16;
@@ -3247,7 +3247,7 @@
       Value *OverflowArgAreaPtrPtr = IRB.CreateIntToPtr(
           IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
                         ConstantInt::get(MS.IntptrTy, 8)),
-          Type::getInt64PtrTy(*MS.C));
+          PointerType::get(Type::getInt64PtrTy(*MS.C), 0));
       Value *OverflowArgAreaPtr = IRB.CreateLoad(OverflowArgAreaPtrPtr);
       Value *OverflowArgAreaShadowPtr, *OverflowArgAreaOriginPtr;
       std::tie(OverflowArgAreaShadowPtr, OverflowArgAreaOriginPtr) =
@@ -3357,8 +3357,8 @@
       IRBuilder<> IRB(OrigInst->getNextNode());
       Value *VAListTag = OrigInst->getArgOperand(0);
       Value *RegSaveAreaPtrPtr =
-        IRB.CreateIntToPtr(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
-                        Type::getInt64PtrTy(*MS.C));
+          IRB.CreateIntToPtr(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
+                             PointerType::get(Type::getInt64PtrTy(*MS.C), 0));
       Value *RegSaveAreaPtr = IRB.CreateLoad(RegSaveAreaPtrPtr);
       Value *RegSaveAreaShadowPtr, *RegSaveAreaOriginPtr;
       unsigned Alignment = 8;
@@ -3778,8 +3778,8 @@
       IRBuilder<> IRB(OrigInst->getNextNode());
       Value *VAListTag = OrigInst->getArgOperand(0);
       Value *RegSaveAreaPtrPtr =
-        IRB.CreateIntToPtr(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
-                        Type::getInt64PtrTy(*MS.C));
+          IRB.CreateIntToPtr(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
+                             PointerType::get(Type::getInt64PtrTy(*MS.C), 0));
       Value *RegSaveAreaPtr = IRB.CreateLoad(RegSaveAreaPtrPtr);
       Value *RegSaveAreaShadowPtr, *RegSaveAreaOriginPtr;
       unsigned Alignment = 8;


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