[llvm] [CodeGen] Port `ShadowStackGCLowering` to new pass manager (PR #75324)
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llvm-commits at lists.llvm.org
Mon Dec 18 23:07:03 PST 2023
https://github.com/paperchalice updated https://github.com/llvm/llvm-project/pull/75324
>From 32bfbb02845d15f1ccc66c0c5bf37ec3c985c879 Mon Sep 17 00:00:00 2001
From: PaperChalice <liujunchang97 at outlook.com>
Date: Wed, 13 Dec 2023 18:42:47 +0800
Subject: [PATCH] [CodeGen] Port `ShadowStackGCLowering` to new pass manager
IIUC the new pass system was designed with parallelism.
This pass needs to add some global variables into the current module,
this is not allowed by
[WritingAnLLVMPass](https://llvm.org/docs/WritingAnLLVMPass.html#the-functionpass-class),
so convert it to module pass, see FIXME in `GetFrameMap`.
Therefore, this will trigger assertion in `CodeGenPassBuilder`
https://github.com/llvm/llvm-project/blob/effd47ed45e3badd756103346a7c3b9e1e939e5e/llvm/include/llvm/CodeGen/CodeGenPassBuilder.h#L200-L207.
Will fix it in future.
---
.../include/llvm/CodeGen/CodeGenPassBuilder.h | 4 +
.../llvm/CodeGen/MachinePassRegistry.def | 2 +-
.../llvm/CodeGen/ShadowStackGCLowering.h | 24 +++++
llvm/lib/CodeGen/ShadowStackGCLowering.cpp | 97 +++++++++++++------
llvm/lib/Passes/PassBuilder.cpp | 1 +
llvm/lib/Passes/PassRegistry.def | 1 +
6 files changed, 97 insertions(+), 32 deletions(-)
create mode 100644 llvm/include/llvm/CodeGen/ShadowStackGCLowering.h
diff --git a/llvm/include/llvm/CodeGen/CodeGenPassBuilder.h b/llvm/include/llvm/CodeGen/CodeGenPassBuilder.h
index 32d6e5f91f7b09..d1d9f581000d8e 100644
--- a/llvm/include/llvm/CodeGen/CodeGenPassBuilder.h
+++ b/llvm/include/llvm/CodeGen/CodeGenPassBuilder.h
@@ -38,6 +38,7 @@
#include "llvm/CodeGen/ReplaceWithVeclib.h"
#include "llvm/CodeGen/SafeStack.h"
#include "llvm/CodeGen/SelectOptimize.h"
+#include "llvm/CodeGen/ShadowStackGCLowering.h"
#include "llvm/CodeGen/SjLjEHPrepare.h"
#include "llvm/CodeGen/UnreachableBlockElim.h"
#include "llvm/CodeGen/WasmEHPrepare.h"
@@ -640,6 +641,9 @@ void CodeGenPassBuilder<Derived>::addIRPasses(AddIRPass &addPass) const {
// Run GC lowering passes for builtin collectors
// TODO: add a pass insertion point here
addPass(GCLoweringPass());
+ // FIXME: `ShadowStackGCLoweringPass` now is a
+ // module pass, so it will trigger assertion.
+ // See comment of `AddingFunctionPasses`
addPass(ShadowStackGCLoweringPass());
addPass(LowerConstantIntrinsicsPass());
diff --git a/llvm/include/llvm/CodeGen/MachinePassRegistry.def b/llvm/include/llvm/CodeGen/MachinePassRegistry.def
index f950dfae7e338b..b1b8ee8df29d16 100644
--- a/llvm/include/llvm/CodeGen/MachinePassRegistry.def
+++ b/llvm/include/llvm/CodeGen/MachinePassRegistry.def
@@ -26,6 +26,7 @@ MODULE_ANALYSIS("pass-instrumentation", PassInstrumentationAnalysis, (PIC))
MODULE_PASS("pre-isel-intrinsic-lowering", PreISelIntrinsicLoweringPass, ())
MODULE_PASS("jmc-instrumenter", JMCInstrumenterPass, ())
MODULE_PASS("lower-emutls", LowerEmuTLSPass, ())
+MODULE_PASS("shadow-stack-gc-lowering", ShadowStackGCLoweringPass, ())
#undef MODULE_PASS
#ifndef FUNCTION_ANALYSIS
@@ -133,7 +134,6 @@ MACHINE_FUNCTION_ANALYSIS("pass-instrumentation", PassInstrumentationAnalysis,
DUMMY_FUNCTION_PASS("atomic-expand", AtomicExpandPass, ())
DUMMY_FUNCTION_PASS("codegenprepare", CodeGenPreparePass, ())
DUMMY_FUNCTION_PASS("gc-lowering", GCLoweringPass, ())
-DUMMY_FUNCTION_PASS("shadow-stack-gc-lowering", ShadowStackGCLoweringPass, ())
DUMMY_FUNCTION_PASS("stack-protector", StackProtectorPass, ())
#undef DUMMY_FUNCTION_PASS
diff --git a/llvm/include/llvm/CodeGen/ShadowStackGCLowering.h b/llvm/include/llvm/CodeGen/ShadowStackGCLowering.h
new file mode 100644
index 00000000000000..1586c6cf545bfb
--- /dev/null
+++ b/llvm/include/llvm/CodeGen/ShadowStackGCLowering.h
@@ -0,0 +1,24 @@
+//===- llvm/CodeGen/ShadowStackGCLowering.h ---------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_SHADOWSTACKGCLOWERING_H
+#define LLVM_CODEGEN_SHADOWSTACKGCLOWERING_H
+
+#include "llvm/IR/PassManager.h"
+
+namespace llvm {
+
+class ShadowStackGCLoweringPass
+ : public PassInfoMixin<ShadowStackGCLoweringPass> {
+public:
+ PreservedAnalyses run(Module &M, ModuleAnalysisManager &MAM);
+};
+
+} // namespace llvm
+
+#endif // LLVM_CODEGEN_SHADOWSTACKGCLOWERING_H
diff --git a/llvm/lib/CodeGen/ShadowStackGCLowering.cpp b/llvm/lib/CodeGen/ShadowStackGCLowering.cpp
index 38f658084294d3..06846da57cb710 100644
--- a/llvm/lib/CodeGen/ShadowStackGCLowering.cpp
+++ b/llvm/lib/CodeGen/ShadowStackGCLowering.cpp
@@ -15,9 +15,11 @@
//
//===----------------------------------------------------------------------===//
+#include "llvm/CodeGen/ShadowStackGCLowering.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Analysis/DomTreeUpdater.h"
+#include "llvm/CodeGen/GCMetadata.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Constant.h"
@@ -50,7 +52,7 @@ using namespace llvm;
namespace {
-class ShadowStackGCLowering : public FunctionPass {
+class ShadowStackGCLoweringImpl {
/// RootChain - This is the global linked-list that contains the chain of GC
/// roots.
GlobalVariable *Head = nullptr;
@@ -64,13 +66,10 @@ class ShadowStackGCLowering : public FunctionPass {
std::vector<std::pair<CallInst *, AllocaInst *>> Roots;
public:
- static char ID;
-
- ShadowStackGCLowering();
+ ShadowStackGCLoweringImpl() = default;
- bool doInitialization(Module &M) override;
- void getAnalysisUsage(AnalysisUsage &AU) const override;
- bool runOnFunction(Function &F) override;
+ bool doInitialization(Module &M);
+ bool runOnFunction(Function &F, DomTreeUpdater *DTU);
private:
bool IsNullValue(Value *V);
@@ -86,8 +85,51 @@ class ShadowStackGCLowering : public FunctionPass {
const char *Name);
};
+class ShadowStackGCLowering : public FunctionPass {
+ ShadowStackGCLoweringImpl Impl;
+
+public:
+ static char ID;
+
+ ShadowStackGCLowering();
+
+ bool doInitialization(Module &M) override { return Impl.doInitialization(M); }
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
+ AU.addPreserved<DominatorTreeWrapperPass>();
+ }
+ bool runOnFunction(Function &F) override {
+ std::optional<DomTreeUpdater> DTU;
+ if (auto *DTWP = getAnalysisIfAvailable<DominatorTreeWrapperPass>())
+ DTU.emplace(DTWP->getDomTree(), DomTreeUpdater::UpdateStrategy::Lazy);
+ return Impl.runOnFunction(F, DTU ? &*DTU : nullptr);
+ }
+};
+
} // end anonymous namespace
+PreservedAnalyses ShadowStackGCLoweringPass::run(Module &M,
+ ModuleAnalysisManager &MAM) {
+ auto &Map = MAM.getResult<CollectorMetadataAnalysis>(M);
+ if (Map.StrategyMap.contains("shadow-stack"))
+ return PreservedAnalyses::all();
+
+ ShadowStackGCLoweringImpl Impl;
+ bool Changed = Impl.doInitialization(M);
+ for (auto &F : M) {
+ auto &FAM =
+ MAM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
+ auto *DT = FAM.getCachedResult<DominatorTreeAnalysis>(F);
+ DomTreeUpdater DTU(DT, DomTreeUpdater::UpdateStrategy::Lazy);
+ Changed |= Impl.runOnFunction(F, DT ? &DTU : nullptr);
+ }
+
+ if (!Changed)
+ return PreservedAnalyses::all();
+ PreservedAnalyses PA;
+ PA.preserve<DominatorTreeAnalysis>();
+ return PA;
+}
+
char ShadowStackGCLowering::ID = 0;
char &llvm::ShadowStackGCLoweringID = ShadowStackGCLowering::ID;
@@ -104,7 +146,7 @@ ShadowStackGCLowering::ShadowStackGCLowering() : FunctionPass(ID) {
initializeShadowStackGCLoweringPass(*PassRegistry::getPassRegistry());
}
-Constant *ShadowStackGCLowering::GetFrameMap(Function &F) {
+Constant *ShadowStackGCLoweringImpl::GetFrameMap(Function &F) {
// doInitialization creates the abstract type of this value.
Type *VoidPtr = PointerType::getUnqual(F.getContext());
@@ -158,7 +200,7 @@ Constant *ShadowStackGCLowering::GetFrameMap(Function &F) {
return ConstantExpr::getGetElementPtr(FrameMap->getType(), GV, GEPIndices);
}
-Type *ShadowStackGCLowering::GetConcreteStackEntryType(Function &F) {
+Type *ShadowStackGCLoweringImpl::GetConcreteStackEntryType(Function &F) {
// doInitialization creates the generic version of this type.
std::vector<Type *> EltTys;
EltTys.push_back(StackEntryTy);
@@ -170,7 +212,7 @@ Type *ShadowStackGCLowering::GetConcreteStackEntryType(Function &F) {
/// doInitialization - If this module uses the GC intrinsics, find them now. If
/// not, exit fast.
-bool ShadowStackGCLowering::doInitialization(Module &M) {
+bool ShadowStackGCLoweringImpl::doInitialization(Module &M) {
bool Active = false;
for (Function &F : M) {
if (F.hasGC() && F.getGC() == std::string("shadow-stack")) {
@@ -224,13 +266,13 @@ bool ShadowStackGCLowering::doInitialization(Module &M) {
return true;
}
-bool ShadowStackGCLowering::IsNullValue(Value *V) {
+bool ShadowStackGCLoweringImpl::IsNullValue(Value *V) {
if (Constant *C = dyn_cast<Constant>(V))
return C->isNullValue();
return false;
}
-void ShadowStackGCLowering::CollectRoots(Function &F) {
+void ShadowStackGCLoweringImpl::CollectRoots(Function &F) {
// FIXME: Account for original alignment. Could fragment the root array.
// Approach 1: Null initialize empty slots at runtime. Yuck.
// Approach 2: Emit a map of the array instead of just a count.
@@ -258,11 +300,10 @@ void ShadowStackGCLowering::CollectRoots(Function &F) {
Roots.insert(Roots.begin(), MetaRoots.begin(), MetaRoots.end());
}
-GetElementPtrInst *ShadowStackGCLowering::CreateGEP(LLVMContext &Context,
- IRBuilder<> &B, Type *Ty,
- Value *BasePtr, int Idx,
- int Idx2,
- const char *Name) {
+GetElementPtrInst *
+ShadowStackGCLoweringImpl::CreateGEP(LLVMContext &Context, IRBuilder<> &B,
+ Type *Ty, Value *BasePtr, int Idx,
+ int Idx2, const char *Name) {
Value *Indices[] = {ConstantInt::get(Type::getInt32Ty(Context), 0),
ConstantInt::get(Type::getInt32Ty(Context), Idx),
ConstantInt::get(Type::getInt32Ty(Context), Idx2)};
@@ -273,9 +314,11 @@ GetElementPtrInst *ShadowStackGCLowering::CreateGEP(LLVMContext &Context,
return dyn_cast<GetElementPtrInst>(Val);
}
-GetElementPtrInst *ShadowStackGCLowering::CreateGEP(LLVMContext &Context,
- IRBuilder<> &B, Type *Ty, Value *BasePtr,
- int Idx, const char *Name) {
+GetElementPtrInst *ShadowStackGCLoweringImpl::CreateGEP(LLVMContext &Context,
+ IRBuilder<> &B,
+ Type *Ty,
+ Value *BasePtr, int Idx,
+ const char *Name) {
Value *Indices[] = {ConstantInt::get(Type::getInt32Ty(Context), 0),
ConstantInt::get(Type::getInt32Ty(Context), Idx)};
Value *Val = B.CreateGEP(Ty, BasePtr, Indices, Name);
@@ -285,12 +328,9 @@ GetElementPtrInst *ShadowStackGCLowering::CreateGEP(LLVMContext &Context,
return dyn_cast<GetElementPtrInst>(Val);
}
-void ShadowStackGCLowering::getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addPreserved<DominatorTreeWrapperPass>();
-}
-
/// runOnFunction - Insert code to maintain the shadow stack.
-bool ShadowStackGCLowering::runOnFunction(Function &F) {
+bool ShadowStackGCLoweringImpl::runOnFunction(Function &F,
+ DomTreeUpdater *DTU) {
// Quick exit for functions that do not use the shadow stack GC.
if (!F.hasGC() ||
F.getGC() != std::string("shadow-stack"))
@@ -306,10 +346,6 @@ bool ShadowStackGCLowering::runOnFunction(Function &F) {
if (Roots.empty())
return false;
- std::optional<DomTreeUpdater> DTU;
- if (auto *DTWP = getAnalysisIfAvailable<DominatorTreeWrapperPass>())
- DTU.emplace(DTWP->getDomTree(), DomTreeUpdater::UpdateStrategy::Lazy);
-
// Build the constant map and figure the type of the shadow stack entry.
Value *FrameMap = GetFrameMap(F);
Type *ConcreteStackEntryTy = GetConcreteStackEntryType(F);
@@ -360,8 +396,7 @@ bool ShadowStackGCLowering::runOnFunction(Function &F) {
AtEntry.CreateStore(NewHeadVal, Head);
// For each instruction that escapes...
- EscapeEnumerator EE(F, "gc_cleanup", /*HandleExceptions=*/true,
- DTU ? &*DTU : nullptr);
+ EscapeEnumerator EE(F, "gc_cleanup", /*HandleExceptions=*/true, DTU);
while (IRBuilder<> *AtExit = EE.Next()) {
// Pop the entry from the shadow stack. Don't reuse CurrentHead from
// AtEntry, since that would make the value live for the entire function.
diff --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
index f94bd422c6b592..034ed70bfd73d2 100644
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -86,6 +86,7 @@
#include "llvm/CodeGen/LowerEmuTLS.h"
#include "llvm/CodeGen/SafeStack.h"
#include "llvm/CodeGen/SelectOptimize.h"
+#include "llvm/CodeGen/ShadowStackGCLowering.h"
#include "llvm/CodeGen/SjLjEHPrepare.h"
#include "llvm/CodeGen/TypePromotion.h"
#include "llvm/CodeGen/WasmEHPrepare.h"
diff --git a/llvm/lib/Passes/PassRegistry.def b/llvm/lib/Passes/PassRegistry.def
index 82ce040c649626..eaa7c3fc89241b 100644
--- a/llvm/lib/Passes/PassRegistry.def
+++ b/llvm/lib/Passes/PassRegistry.def
@@ -128,6 +128,7 @@ MODULE_PASS("sanmd-module", SanitizerBinaryMetadataPass())
MODULE_PASS("scc-oz-module-inliner",
buildInlinerPipeline(OptimizationLevel::Oz,
ThinOrFullLTOPhase::None))
+MODULE_PASS("shadow-stack-gc-lowering", ShadowStackGCLoweringPass())
MODULE_PASS("strip", StripSymbolsPass())
MODULE_PASS("strip-dead-debug-info", StripDeadDebugInfoPass())
MODULE_PASS("strip-dead-prototypes", StripDeadPrototypesPass())
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