[compiler-rt] [llvm] Fix getShadowAddress computation (PR #162864)

[via llvm-commits]

https://github.com/anoopkg6 created https://github.com/llvm/llvm-project/pull/162864

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

>From a7b4999ee8ffe3e10a2c4a3bd9e63022b3e01716 Mon Sep 17 00:00:00 2001
From: anoopkg6 <anoopkg6 at github.com>
Date: Thu, 9 Oct 2025 17:13:44 +0200
Subject: [PATCH 1/2] Add s390x for rtsan support

---
 compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake b/compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake
index ca45d7bd2af7f..05aa7e153f362 100644
--- a/compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake
+++ b/compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake
@@ -36,7 +36,7 @@ set(ALL_ASAN_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM32} ${ARM64} ${RISCV64}
     ${LOONGARCH64})
 set(ALL_ASAN_ABI_SUPPORTED_ARCH ${X86_64} ${ARM64} ${ARM64_32})
 set(ALL_DFSAN_SUPPORTED_ARCH ${X86_64} ${MIPS64} ${ARM64} ${LOONGARCH64})
-set(ALL_RTSAN_SUPPORTED_ARCH ${X86_64} ${ARM64})
+set(ALL_RTSAN_SUPPORTED_ARCH ${X86_64} ${ARM64}  ${S390X})
 
 if(ANDROID)
   set(OS_NAME "Android")

>From bc4e2ce74ae2ffa24193e5ea4b35d3bd714c6a18 Mon Sep 17 00:00:00 2001
From: anoopkg6 <anoopkg6 at github.com>
Date: Fri, 10 Oct 2025 16:46:49 +0200
Subject: [PATCH 2/2] Fix getShadowAddress computation by adding ShadowBase if
 it is not zero.

---
 llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

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,