[llvm] [CodeGen][WinEH] Update saved esp for inlined inallocas (PR #116585)

[Reid Kleckner via llvm-commits]

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@@ -774,3 +778,27 @@ void WinEHStatePass::insertStateNumberStore(Instruction *IP, int State) {
                                               RegNode, StateFieldIndex);
   Builder.CreateStore(Builder.getInt32(State), StateField);
 }
+
+void WinEHStatePass::updateEspForInAllocas(Function &F) {
+  for (BasicBlock &BB : F) {
+    for (Instruction &I : BB) {
+      if (auto *Alloca = dyn_cast<AllocaInst>(&I)) {
+        if (!Alloca->isUsedWithInAlloca())
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rnk wrote:

Regarding the security implications, I would just fix the miscompile. The on-stack exception handling records make this platform extremely easy to attack, and I can't say with confidence that LLVM has implemented all of the hardening techniques to protect the exception registration nodes in the FS:00 linked list.

https://github.com/llvm/llvm-project/pull/116585