[llvm] [hwasan] Invalidate DominatorTreeAnalysis after each function is sanitized (PR #66935)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-compiler-rt-sanitizer

<details>
<summary>Changes</summary>

HWAddressSanitizerPass::run sanitizes functions one by one. The sanitization of each function - which may split blocks via insertShadowTagCheck - may result in some cached analyses are invalid. This matters because sanitizeFunction(F', FAM) may indirectly call the global stack safety analysis, hence we need to make sure the analyses of F are up to date.

Bug report: https://github.com/llvm/llvm-project/issues/66934


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Full diff: https://github.com/llvm/llvm-project/pull/66935.diff


1 Files Affected:

- (modified) llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp (+9-1) 


``````````diff
diff --git a/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
index 29770ece9c61eb2..1dc550ba8b54ea6 100644
--- a/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
@@ -430,8 +430,16 @@ PreservedAnalyses HWAddressSanitizerPass::run(Module &M,
 
   HWAddressSanitizer HWASan(M, Options.CompileKernel, Options.Recover, SSI);
   auto &FAM = MAM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
-  for (Function &F : M)
+  for (Function &F : M) {
     HWASan.sanitizeFunction(F, FAM);
+    // After sanitizing F - which may split blocks via insertShadowTagCheck -
+    // some cached analyses are invalid. This matters because
+    // sanitizeFunction(F', FAM) may indirectly call the global stack safety
+    // analysis, hence we need to make sure the analyses of F are up to date.
+    PreservedAnalyses PA = PreservedAnalyses::all();
+    PA.abandon<DominatorTreeAnalysis>();
+    FAM.invalidate(F, PA);
+  }
 
   PreservedAnalyses PA = PreservedAnalyses::none();
   // GlobalsAA is considered stateless and does not get invalidated unless

``````````

</details>


https://github.com/llvm/llvm-project/pull/66935