diff options
author | Florian Mayer <fmayer@google.com> | 2024-03-14 16:18:43 -0700 |
---|---|---|
committer | GitHub <noreply@github.com> | 2024-03-14 16:18:43 -0700 |
commit | 26e8913c413579cdafda2f69adbdeb6d06a2559c (patch) | |
tree | e9d9632ceab60023776c0d4642f45831981f4148 | |
parent | cda55ad8c34e30539d505020aeb99ace7cf9d032 (diff) |
[NFC] [hwasan] factor get[PC|FP] out of HWASan class (#84404)upstream/users/fmayer/spr/main.nfc-hwasan-factor-getpcfp-out-of-hwasan-class
Also be consistent about naming SP / FP.
This is to prepare for stack history buffer for memtag-stack
3 files changed, 59 insertions, 49 deletions
diff --git a/llvm/include/llvm/Transforms/Utils/MemoryTaggingSupport.h b/llvm/include/llvm/Transforms/Utils/MemoryTaggingSupport.h index eb00e6c4e856..8c77e5efc96a 100644 --- a/llvm/include/llvm/Transforms/Utils/MemoryTaggingSupport.h +++ b/llvm/include/llvm/Transforms/Utils/MemoryTaggingSupport.h @@ -17,6 +17,7 @@ #include "llvm/ADT/SmallVector.h" #include "llvm/Analysis/LoopInfo.h" #include "llvm/Analysis/StackSafetyAnalysis.h" +#include "llvm/IR/IRBuilder.h" #include "llvm/Support/Alignment.h" namespace llvm { @@ -79,6 +80,10 @@ private: uint64_t getAllocaSizeInBytes(const AllocaInst &AI); void alignAndPadAlloca(memtag::AllocaInfo &Info, llvm::Align Align); +Value *readRegister(IRBuilder<> &IRB, StringRef Name); +Value *getFP(IRBuilder<> &IRB); +Value *getPC(const Triple &TargetTriple, IRBuilder<> &IRB); + } // namespace memtag } // namespace llvm diff --git a/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp index 436dcf6d6ff2..0656960df534 100644 --- a/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp +++ b/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp @@ -356,7 +356,6 @@ private: bool instrumentStack(memtag::StackInfo &Info, Value *StackTag, Value *UARTag, const DominatorTree &DT, const PostDominatorTree &PDT, const LoopInfo &LI); - Value *readRegister(IRBuilder<> &IRB, StringRef Name); bool instrumentLandingPads(SmallVectorImpl<Instruction *> &RetVec); Value *getNextTagWithCall(IRBuilder<> &IRB); Value *getStackBaseTag(IRBuilder<> &IRB); @@ -372,8 +371,7 @@ private: void instrumentGlobal(GlobalVariable *GV, uint8_t Tag); void instrumentGlobals(); - Value *getPC(IRBuilder<> &IRB); - Value *getFP(IRBuilder<> &IRB); + Value *getCachedFP(IRBuilder<> &IRB); Value *getFrameRecordInfo(IRBuilder<> &IRB); void instrumentPersonalityFunctions(); @@ -448,7 +446,7 @@ private: Value *ShadowBase = nullptr; Value *StackBaseTag = nullptr; - Value *CachedSP = nullptr; + Value *CachedFP = nullptr; GlobalValue *ThreadPtrGlobal = nullptr; }; @@ -1168,10 +1166,10 @@ Value *HWAddressSanitizer::getStackBaseTag(IRBuilder<> &IRB) { // Extract some entropy from the stack pointer for the tags. // Take bits 20..28 (ASLR entropy) and xor with bits 0..8 (these differ // between functions). - Value *StackPointerLong = getFP(IRB); + Value *FramePointerLong = getCachedFP(IRB); Value *StackTag = - applyTagMask(IRB, IRB.CreateXor(StackPointerLong, - IRB.CreateLShr(StackPointerLong, 20))); + applyTagMask(IRB, IRB.CreateXor(FramePointerLong, + IRB.CreateLShr(FramePointerLong, 20))); StackTag->setName("hwasan.stack.base.tag"); return StackTag; } @@ -1185,9 +1183,9 @@ Value *HWAddressSanitizer::getAllocaTag(IRBuilder<> &IRB, Value *StackTag, } Value *HWAddressSanitizer::getUARTag(IRBuilder<> &IRB) { - Value *StackPointerLong = getFP(IRB); + Value *FramePointerLong = getCachedFP(IRB); Value *UARTag = - applyTagMask(IRB, IRB.CreateLShr(StackPointerLong, PointerTagShift)); + applyTagMask(IRB, IRB.CreateLShr(FramePointerLong, PointerTagShift)); UARTag->setName("hwasan.uar.tag"); return UARTag; @@ -1246,41 +1244,25 @@ Value *HWAddressSanitizer::getHwasanThreadSlotPtr(IRBuilder<> &IRB, Type *Ty) { return nullptr; } -Value *HWAddressSanitizer::getPC(IRBuilder<> &IRB) { - if (TargetTriple.getArch() == Triple::aarch64) - return readRegister(IRB, "pc"); - return IRB.CreatePtrToInt(IRB.GetInsertBlock()->getParent(), IntptrTy); -} - -Value *HWAddressSanitizer::getFP(IRBuilder<> &IRB) { - if (!CachedSP) { - // FIXME: use addressofreturnaddress (but implement it in aarch64 backend - // first). - Function *F = IRB.GetInsertBlock()->getParent(); - Module *M = F->getParent(); - auto *GetStackPointerFn = Intrinsic::getDeclaration( - M, Intrinsic::frameaddress, - IRB.getPtrTy(M->getDataLayout().getAllocaAddrSpace())); - CachedSP = IRB.CreatePtrToInt( - IRB.CreateCall(GetStackPointerFn, {Constant::getNullValue(Int32Ty)}), - IntptrTy); - } - return CachedSP; +Value *HWAddressSanitizer::getCachedFP(IRBuilder<> &IRB) { + if (!CachedFP) + CachedFP = memtag::getFP(IRB); + return CachedFP; } Value *HWAddressSanitizer::getFrameRecordInfo(IRBuilder<> &IRB) { // Prepare ring buffer data. - Value *PC = getPC(IRB); - Value *SP = getFP(IRB); + Value *PC = memtag::getPC(TargetTriple, IRB); + Value *FP = getCachedFP(IRB); - // Mix SP and PC. + // Mix FP and PC. // Assumptions: // PC is 0x0000PPPPPPPPPPPP (48 bits are meaningful, others are zero) - // SP is 0xsssssssssssSSSS0 (4 lower bits are zero) - // We only really need ~20 lower non-zero bits (SSSS), so we mix like this: - // 0xSSSSPPPPPPPPPPPP - SP = IRB.CreateShl(SP, 44); - return IRB.CreateOr(PC, SP); + // FP is 0xfffffffffffFFFF0 (4 lower bits are zero) + // We only really need ~20 lower non-zero bits (FFFF), so we mix like this: + // 0xFFFFPPPPPPPPPPPP + FP = IRB.CreateShl(FP, 44); + return IRB.CreateOr(PC, FP); } void HWAddressSanitizer::emitPrologue(IRBuilder<> &IRB, bool WithFrameRecord) { @@ -1365,23 +1347,14 @@ void HWAddressSanitizer::emitPrologue(IRBuilder<> &IRB, bool WithFrameRecord) { } } -Value *HWAddressSanitizer::readRegister(IRBuilder<> &IRB, StringRef Name) { - Module *M = IRB.GetInsertBlock()->getParent()->getParent(); - Function *ReadRegister = - Intrinsic::getDeclaration(M, Intrinsic::read_register, IntptrTy); - MDNode *MD = MDNode::get(*C, {MDString::get(*C, Name)}); - Value *Args[] = {MetadataAsValue::get(*C, MD)}; - return IRB.CreateCall(ReadRegister, Args); -} - bool HWAddressSanitizer::instrumentLandingPads( SmallVectorImpl<Instruction *> &LandingPadVec) { for (auto *LP : LandingPadVec) { IRBuilder<> IRB(LP->getNextNonDebugInstruction()); IRB.CreateCall( HwasanHandleVfork, - {readRegister(IRB, (TargetTriple.getArch() == Triple::x86_64) ? "rsp" - : "sp")}); + {memtag::readRegister( + IRB, (TargetTriple.getArch() == Triple::x86_64) ? "rsp" : "sp")}); } return true; } @@ -1642,7 +1615,7 @@ void HWAddressSanitizer::sanitizeFunction(Function &F, ShadowBase = nullptr; StackBaseTag = nullptr; - CachedSP = nullptr; + CachedFP = nullptr; } void HWAddressSanitizer::instrumentGlobal(GlobalVariable *GV, uint8_t Tag) { diff --git a/llvm/lib/Transforms/Utils/MemoryTaggingSupport.cpp b/llvm/lib/Transforms/Utils/MemoryTaggingSupport.cpp index bfe474d82045..14cb965ff167 100644 --- a/llvm/lib/Transforms/Utils/MemoryTaggingSupport.cpp +++ b/llvm/lib/Transforms/Utils/MemoryTaggingSupport.cpp @@ -18,7 +18,9 @@ #include "llvm/Analysis/StackSafetyAnalysis.h" #include "llvm/Analysis/ValueTracking.h" #include "llvm/IR/BasicBlock.h" +#include "llvm/IR/IRBuilder.h" #include "llvm/IR/IntrinsicInst.h" +#include "llvm/TargetParser/Triple.h" #include "llvm/Transforms/Utils/PromoteMemToReg.h" namespace llvm { @@ -236,5 +238,35 @@ void alignAndPadAlloca(memtag::AllocaInfo &Info, llvm::Align Alignment) { Info.AI = NewAI; } +Value *readRegister(IRBuilder<> &IRB, StringRef Name) { + Module *M = IRB.GetInsertBlock()->getParent()->getParent(); + Function *ReadRegister = Intrinsic::getDeclaration( + M, Intrinsic::read_register, IRB.getIntPtrTy(M->getDataLayout())); + MDNode *MD = + MDNode::get(M->getContext(), {MDString::get(M->getContext(), Name)}); + Value *Args[] = {MetadataAsValue::get(M->getContext(), MD)}; + return IRB.CreateCall(ReadRegister, Args); +} + +Value *getPC(const Triple &TargetTriple, IRBuilder<> &IRB) { + Module *M = IRB.GetInsertBlock()->getParent()->getParent(); + if (TargetTriple.getArch() == Triple::aarch64) + return memtag::readRegister(IRB, "pc"); + return IRB.CreatePtrToInt(IRB.GetInsertBlock()->getParent(), + IRB.getIntPtrTy(M->getDataLayout())); +} + +Value *getFP(IRBuilder<> &IRB) { + Function *F = IRB.GetInsertBlock()->getParent(); + Module *M = F->getParent(); + auto *GetStackPointerFn = Intrinsic::getDeclaration( + M, Intrinsic::frameaddress, + IRB.getPtrTy(M->getDataLayout().getAllocaAddrSpace())); + return IRB.CreatePtrToInt( + IRB.CreateCall(GetStackPointerFn, + {Constant::getNullValue(IRB.getInt32Ty())}), + IRB.getIntPtrTy(M->getDataLayout())); +} + } // namespace memtag } // namespace llvm |