[llvm] 71be1c1 - [dfsan] Fix getShadowAddress computation (#162864)

[via llvm-commits]

Author: anoopkg6
Date: 2025-10-29T14:38:41-07:00
New Revision: 71be1c10ffb60b92edce8d20d5354f14a53c5506

URL: https://github.com/llvm/llvm-project/commit/71be1c10ffb60b92edce8d20d5354f14a53c5506
DIFF: https://github.com/llvm/llvm-project/commit/71be1c10ffb60b92edce8d20d5354f14a53c5506.diff

LOG: [dfsan] Fix getShadowAddress computation (#162864)

Fix getShadowAddress computation by adding ShadowBase if it is not zero.

Co-authored-by: anoopkg6 <anoopkg6 at github.com>

Added: 
    

Modified: 
    llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
index 5ba2167859490..cc53ec2c0f2f3 100644
--- a/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
@@ -1957,8 +1957,12 @@ Value *DataFlowSanitizer::getShadowAddress(Value *Addr,
 Value *DataFlowSanitizer::getShadowAddress(Value *Addr,
                                            BasicBlock::iterator Pos) {
   IRBuilder<> IRB(Pos->getParent(), Pos);
-  Value *ShadowOffset = getShadowOffset(Addr, IRB);
-  return getShadowAddress(Addr, Pos, ShadowOffset);
+  Value *ShadowAddr = getShadowOffset(Addr, IRB);
+  uint64_t ShadowBase = MapParams->ShadowBase;
+  if (ShadowBase != 0)
+    ShadowAddr =
+        IRB.CreateAdd(ShadowAddr, ConstantInt::get(IntptrTy, ShadowBase));
+  return getShadowAddress(Addr, Pos, ShadowAddr);
 }
 
 Value *DFSanFunction::combineShadowsThenConvert(Type *T, Value *V1, Value *V2,