[llvm-commits] [llvm] r168866 - in /llvm/trunk: include/llvm/InitializePasses.h include/llvm/Transforms/Instrumentation.h lib/Transforms/Instrumentation/CMakeLists.txt lib/Transforms/Instrumentation/Instrumentation.cpp lib/Transforms/Instrumentation/MemorySanitizer.cpp test/Instrumentation/MemorySanitizer/ test/Instrumentation/MemorySanitizer/lit.local.cfg test/Instrumentation/MemorySanitizer/msan_basic.ll
NAKAMURA Takumi
geek4civic at gmail.com
Thu Nov 29 04:44:59 PST 2012
Evgeniy, could you apply patches to suppress warnings?
...Takumi
2012/11/29 Evgeniy Stepanov <eugeni.stepanov at gmail.com>:
> Author: eugenis
> Date: Thu Nov 29 03:57:20 2012
> New Revision: 168866
>
> URL: http://llvm.org/viewvc/llvm-project?rev=168866&view=rev
> Log:
> Initial commit of MemorySanitizer.
>
> Compiler pass only.
>
> Added:
> llvm/trunk/lib/Transforms/Instrumentation/MemorySanitizer.cpp (with props)
> llvm/trunk/test/Instrumentation/MemorySanitizer/
> llvm/trunk/test/Instrumentation/MemorySanitizer/lit.local.cfg
> llvm/trunk/test/Instrumentation/MemorySanitizer/msan_basic.ll
> Modified:
> llvm/trunk/include/llvm/InitializePasses.h
> llvm/trunk/include/llvm/Transforms/Instrumentation.h
> llvm/trunk/lib/Transforms/Instrumentation/CMakeLists.txt
> llvm/trunk/lib/Transforms/Instrumentation/Instrumentation.cpp
>
> Modified: llvm/trunk/include/llvm/InitializePasses.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/InitializePasses.h?rev=168866&r1=168865&r2=168866&view=diff
> ==============================================================================
> --- llvm/trunk/include/llvm/InitializePasses.h (original)
> +++ llvm/trunk/include/llvm/InitializePasses.h Thu Nov 29 03:57:20 2012
> @@ -111,6 +111,7 @@
> void initializeGCOVProfilerPass(PassRegistry&);
> void initializeAddressSanitizerPass(PassRegistry&);
> void initializeAddressSanitizerModulePass(PassRegistry&);
> +void initializeMemorySanitizerPass(PassRegistry&);
> void initializeThreadSanitizerPass(PassRegistry&);
> void initializeEarlyCSEPass(PassRegistry&);
> void initializeExpandISelPseudosPass(PassRegistry&);
>
> Modified: llvm/trunk/include/llvm/Transforms/Instrumentation.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Instrumentation.h?rev=168866&r1=168865&r2=168866&view=diff
> ==============================================================================
> --- llvm/trunk/include/llvm/Transforms/Instrumentation.h (original)
> +++ llvm/trunk/include/llvm/Transforms/Instrumentation.h Thu Nov 29 03:57:20 2012
> @@ -36,6 +36,8 @@
> // Insert AddressSanitizer (address sanity checking) instrumentation
> FunctionPass *createAddressSanitizerFunctionPass();
> ModulePass *createAddressSanitizerModulePass();
> +// Insert MemorySanitizer instrumentation (detection of uninitialized reads)
> +FunctionPass *createMemorySanitizerPass();
> // Insert ThreadSanitizer (race detection) instrumentation
> FunctionPass *createThreadSanitizerPass();
>
>
> Modified: llvm/trunk/lib/Transforms/Instrumentation/CMakeLists.txt
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/CMakeLists.txt?rev=168866&r1=168865&r2=168866&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Transforms/Instrumentation/CMakeLists.txt (original)
> +++ llvm/trunk/lib/Transforms/Instrumentation/CMakeLists.txt Thu Nov 29 03:57:20 2012
> @@ -4,6 +4,7 @@
> BoundsChecking.cpp
> EdgeProfiling.cpp
> GCOVProfiling.cpp
> + MemorySanitizer.cpp
> Instrumentation.cpp
> OptimalEdgeProfiling.cpp
> PathProfiling.cpp
>
> Modified: llvm/trunk/lib/Transforms/Instrumentation/Instrumentation.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/Instrumentation.cpp?rev=168866&r1=168865&r2=168866&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Transforms/Instrumentation/Instrumentation.cpp (original)
> +++ llvm/trunk/lib/Transforms/Instrumentation/Instrumentation.cpp Thu Nov 29 03:57:20 2012
> @@ -27,6 +27,7 @@
> initializeGCOVProfilerPass(Registry);
> initializeOptimalEdgeProfilerPass(Registry);
> initializePathProfilerPass(Registry);
> + initializeMemorySanitizerPass(Registry);
> initializeThreadSanitizerPass(Registry);
> }
>
>
> Added: llvm/trunk/lib/Transforms/Instrumentation/MemorySanitizer.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/MemorySanitizer.cpp?rev=168866&view=auto
> ==============================================================================
> --- llvm/trunk/lib/Transforms/Instrumentation/MemorySanitizer.cpp (added)
> +++ llvm/trunk/lib/Transforms/Instrumentation/MemorySanitizer.cpp Thu Nov 29 03:57:20 2012
> @@ -0,0 +1,1419 @@
> +//===-- MemorySanitizer.cpp - detector of uninitialized reads -------------===//
> +//
> +// The LLVM Compiler Infrastructure
> +//
> +// This file is distributed under the University of Illinois Open Source
> +// License. See LICENSE.TXT for details.
> +//
> +//===----------------------------------------------------------------------===//
> +/// \file
> +/// This file is a part of MemorySanitizer, a detector of uninitialized
> +/// reads.
> +///
> +/// Status: early prototype.
> +///
> +/// The algorithm of the tool is similar to Memcheck
> +/// (http://goo.gl/QKbem). We associate a few shadow bits with every
> +/// byte of the application memory, poison the shadow of the malloc-ed
> +/// or alloca-ed memory, load the shadow bits on every memory read,
> +/// propagate the shadow bits through some of the arithmetic
> +/// instruction (including MOV), store the shadow bits on every memory
> +/// write, report a bug on some other instructions (e.g. JMP) if the
> +/// associated shadow is poisoned.
> +///
> +/// But there are differences too. The first and the major one:
> +/// compiler instrumentation instead of binary instrumentation. This
> +/// gives us much better register allocation, possible compiler
> +/// optimizations and a fast start-up. But this brings the major issue
> +/// as well: msan needs to see all program events, including system
> +/// calls and reads/writes in system libraries, so we either need to
> +/// compile *everything* with msan or use a binary translation
> +/// component (e.g. DynamoRIO) to instrument pre-built libraries.
> +/// Another difference from Memcheck is that we use 8 shadow bits per
> +/// byte of application memory and use a direct shadow mapping. This
> +/// greatly simplifies the instrumentation code and avoids races on
> +/// shadow updates (Memcheck is single-threaded so races are not a
> +/// concern there. Memcheck uses 2 shadow bits per byte with a slow
> +/// path storage that uses 8 bits per byte).
> +///
> +/// The default value of shadow is 0, which means "clean" (not poisoned).
> +///
> +/// Every module initializer should call __msan_init to ensure that the
> +/// shadow memory is ready. On error, __msan_warning is called. Since
> +/// parameters and return values may be passed via registers, we have a
> +/// specialized thread-local shadow for return values
> +/// (__msan_retval_tls) and parameters (__msan_param_tls).
> +//===----------------------------------------------------------------------===//
> +
> +#define DEBUG_TYPE "msan"
> +
> +#include "BlackList.h"
> +#include "llvm/DataLayout.h"
> +#include "llvm/Function.h"
> +#include "llvm/InlineAsm.h"
> +#include "llvm/IntrinsicInst.h"
> +#include "llvm/IRBuilder.h"
> +#include "llvm/LLVMContext.h"
> +#include "llvm/MDBuilder.h"
> +#include "llvm/Module.h"
> +#include "llvm/Type.h"
> +#include "llvm/ADT/DepthFirstIterator.h"
> +#include "llvm/ADT/SmallString.h"
> +#include "llvm/ADT/SmallVector.h"
> +#include "llvm/ADT/ValueMap.h"
> +#include "llvm/Transforms/Instrumentation.h"
> +#include "llvm/Transforms/Utils/BasicBlockUtils.h"
> +#include "llvm/Transforms/Utils/ModuleUtils.h"
> +#include "llvm/Support/CommandLine.h"
> +#include "llvm/Support/Compiler.h"
> +#include "llvm/Support/Debug.h"
> +#include "llvm/Support/InstVisitor.h"
> +#include "llvm/Support/raw_ostream.h"
> +#include "llvm/Transforms/Instrumentation.h"
> +#include "llvm/Transforms/Utils/BasicBlockUtils.h"
> +#include "llvm/Transforms/Utils/ModuleUtils.h"
> +
> +using namespace llvm;
> +
> +static const uint64_t kShadowMask32 = 1ULL << 31;
> +static const uint64_t kShadowMask64 = 1ULL << 46;
> +static const uint64_t kOriginOffset32 = 1ULL << 30;
> +static const uint64_t kOriginOffset64 = 1ULL << 45;
> +
> +// This is an important flag that makes the reports much more
> +// informative at the cost of greater slowdown. Not fully implemented
> +// yet.
> +// FIXME: this should be a top-level clang flag, e.g.
> +// -fmemory-sanitizer-full.
> +static cl::opt<bool> ClTrackOrigins("msan-track-origins",
> + cl::desc("Track origins (allocation sites) of poisoned memory"),
> + cl::Hidden, cl::init(false));
> +static cl::opt<bool> ClKeepGoing("msan-keep-going",
> + cl::desc("keep going after reporting a UMR"),
> + cl::Hidden, cl::init(false));
> +static cl::opt<bool> ClPoisonStack("msan-poison-stack",
> + cl::desc("poison uninitialized stack variables"),
> + cl::Hidden, cl::init(true));
> +static cl::opt<bool> ClPoisonStackWithCall("msan-poison-stack-with-call",
> + cl::desc("poison uninitialized stack variables with a call"),
> + cl::Hidden, cl::init(false));
> +static cl::opt<int> ClPoisonStackPattern("msan-poison-stack-pattern",
> + cl::desc("poison uninitialized stack variables with the given patter"),
> + cl::Hidden, cl::init(0xff));
> +
> +static cl::opt<bool> ClHandleICmp("msan-handle-icmp",
> + cl::desc("propagate shadow through ICmpEQ and ICmpNE"),
> + cl::Hidden, cl::init(true));
> +
> +// This flag controls whether we check the shadow of the address
> +// operand of load or store. Such bugs are very rare, since load from
> +// a garbage address typically results in SEGV, but still happen
> +// (e.g. only lower bits of address are garbage, or the access happens
> +// early at program startup where malloc-ed memory is more likely to
> +// be zeroed. As of 2012-08-28 this flag adds 20% slowdown.
> +static cl::opt<bool> ClCheckAccessAddress("msan-check-access-address",
> + cl::desc("report accesses through a pointer which has poisoned shadow"),
> + cl::Hidden, cl::init(true));
> +
> +static cl::opt<bool> ClDumpStrictInstructions("msan-dump-strict-instructions",
> + cl::desc("print out instructions with default strict semantics"),
> + cl::Hidden, cl::init(false));
> +
> +static cl::opt<std::string> ClBlackListFile("msan-blacklist",
> + cl::desc("File containing the list of functions where MemorySanitizer "
> + "should not report bugs"), cl::Hidden);
> +
> +namespace {
> +
> +/// \brief An instrumentation pass implementing detection of uninitialized
> +/// reads.
> +///
> +/// MemorySanitizer: instrument the code in module to find
> +/// uninitialized reads.
> +class MemorySanitizer : public FunctionPass {
> +public:
> + MemorySanitizer() : FunctionPass(ID), TD(0) { }
> + const char *getPassName() const { return "MemorySanitizer"; }
> + bool runOnFunction(Function &F);
> + bool doInitialization(Module &M);
> + static char ID; // Pass identification, replacement for typeid.
> +
> +private:
> + DataLayout *TD;
> + LLVMContext *C;
> + Type *IntptrTy;
> + Type *OriginTy;
> + /// \brief Thread-local shadow storage for function parameters.
> + GlobalVariable *ParamTLS;
> + /// \brief Thread-local origin storage for function parameters.
> + GlobalVariable *ParamOriginTLS;
> + /// \brief Thread-local shadow storage for function return value.
> + GlobalVariable *RetvalTLS;
> + /// \brief Thread-local origin storage for function return value.
> + GlobalVariable *RetvalOriginTLS;
> + /// \brief Thread-local shadow storage for in-register va_arg function
> + /// parameters (x86_64-specific).
> + GlobalVariable *VAArgTLS;
> + /// \brief Thread-local shadow storage for va_arg overflow area
> + /// (x86_64-specific).
> + GlobalVariable *VAArgOverflowSizeTLS;
> + /// \brief Thread-local space used to pass origin value to the UMR reporting
> + /// function.
> + GlobalVariable *OriginTLS;
> +
> + /// \brief The run-time callback to print a warning.
> + Value *WarningFn;
> + /// \brief Run-time helper that copies origin info for a memory range.
> + Value *MsanCopyOriginFn;
> + /// \brief Run-time helper that generates a new origin value for a stack
> + /// allocation.
> + Value *MsanSetAllocaOriginFn;
> + /// \brief Run-time helper that poisons stack on function entry.
> + Value *MsanPoisonStackFn;
> + /// \brief The actual "memmove" function.
> + Value *MemmoveFn;
> +
> + /// \brief Address mask used in application-to-shadow address calculation.
> + /// ShadowAddr is computed as ApplicationAddr & ~ShadowMask.
> + uint64_t ShadowMask;
> + /// \brief Offset of the origin shadow from the "normal" shadow.
> + /// OriginAddr is computed as (ShadowAddr + OriginOffset) & ~3ULL
> + uint64_t OriginOffset;
> + /// \brief Branch weights for error reporting.
> + MDNode *ColdCallWeights;
> + /// \brief The blacklist.
> + OwningPtr<BlackList> BL;
> +
> + friend class MemorySanitizerVisitor;
> + friend class VarArgAMD64Helper;
> +};
> +} // namespace
> +
> +char MemorySanitizer::ID = 0;
> +INITIALIZE_PASS(MemorySanitizer, "msan",
> + "MemorySanitizer: detects uninitialized reads.",
> + false, false)
> +
> +FunctionPass *llvm::createMemorySanitizerPass() {
> + return new MemorySanitizer();
> +}
> +
> +/// \brief Create a non-const global initialized with the given string.
> +///
> +/// Creates a writable global for Str so that we can pass it to the
> +/// run-time lib. Runtime uses first 4 bytes of the string to store the
> +/// frame ID, so the string needs to be mutable.
> +static GlobalVariable *createPrivateNonConstGlobalForString(Module &M,
> + StringRef Str) {
> + Constant *StrConst = ConstantDataArray::getString(M.getContext(), Str);
> + return new GlobalVariable(M, StrConst->getType(), /*isConstant=*/false,
> + GlobalValue::PrivateLinkage, StrConst, "");
> +}
> +
> +/// \brief Module-level initialization.
> +///
> +/// Obtains pointers to the required runtime library functions, and
> +/// inserts a call to __msan_init to the module's constructor list.
> +bool MemorySanitizer::doInitialization(Module &M) {
> + TD = getAnalysisIfAvailable<DataLayout>();
> + if (!TD)
> + return false;
> + BL.reset(new BlackList(ClBlackListFile));
> + C = &(M.getContext());
> + unsigned PtrSize = TD->getPointerSizeInBits(/* AddressSpace */0);
> + switch (PtrSize) {
> + case 64:
> + ShadowMask = kShadowMask64;
> + OriginOffset = kOriginOffset64;
> + break;
> + case 32:
> + ShadowMask = kShadowMask32;
> + OriginOffset = kOriginOffset32;
> + break;
> + default:
> + report_fatal_error("unsupported pointer size");
> + break;
> + }
> +
> + IRBuilder<> IRB(*C);
> + IntptrTy = IRB.getIntPtrTy(TD);
> + OriginTy = IRB.getInt32Ty();
> +
> + ColdCallWeights = MDBuilder(*C).createBranchWeights(1, 1000);
> +
> + // Insert a call to __msan_init/__msan_track_origins into the module's CTORs.
> + appendToGlobalCtors(M, cast<Function>(M.getOrInsertFunction(
> + "__msan_init", IRB.getVoidTy(), NULL)), 0);
> +
> + new GlobalVariable(M, IRB.getInt32Ty(), true, GlobalValue::LinkOnceODRLinkage,
> + IRB.getInt32(ClTrackOrigins), "__msan_track_origins");
> +
> + // Create the callback.
> + // FIXME: this function should have "Cold" calling conv,
> + // which is not yet implemented.
> + StringRef WarningFnName = ClKeepGoing ? "__msan_warning"
> + : "__msan_warning_noreturn";
> + WarningFn = M.getOrInsertFunction(WarningFnName, IRB.getVoidTy(), NULL);
> +
> + MsanCopyOriginFn = M.getOrInsertFunction(
> + "__msan_copy_origin", IRB.getVoidTy(), IRB.getInt8PtrTy(),
> + IRB.getInt8PtrTy(), IntptrTy, NULL);
> + MsanSetAllocaOriginFn = M.getOrInsertFunction(
> + "__msan_set_alloca_origin", IRB.getVoidTy(), IRB.getInt8PtrTy(), IntptrTy,
> + IRB.getInt8PtrTy(), NULL);
> + MsanPoisonStackFn = M.getOrInsertFunction(
> + "__msan_poison_stack", IRB.getVoidTy(), IRB.getInt8PtrTy(), IntptrTy, NULL);
> + MemmoveFn = M.getOrInsertFunction(
> + "memmove", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
> + IntptrTy, NULL);
> +
> + // Create globals.
> + RetvalTLS = new GlobalVariable(
> + M, ArrayType::get(IRB.getInt64Ty(), 8), false,
> + GlobalVariable::ExternalLinkage, 0, "__msan_retval_tls", 0,
> + GlobalVariable::GeneralDynamicTLSModel);
> + RetvalOriginTLS = new GlobalVariable(
> + M, OriginTy, false, GlobalVariable::ExternalLinkage, 0,
> + "__msan_retval_origin_tls", 0, GlobalVariable::GeneralDynamicTLSModel);
> +
> + ParamTLS = new GlobalVariable(
> + M, ArrayType::get(IRB.getInt64Ty(), 1000), false,
> + GlobalVariable::ExternalLinkage, 0, "__msan_param_tls", 0,
> + GlobalVariable::GeneralDynamicTLSModel);
> + ParamOriginTLS = new GlobalVariable(
> + M, ArrayType::get(OriginTy, 1000), false, GlobalVariable::ExternalLinkage,
> + 0, "__msan_param_origin_tls", 0, GlobalVariable::GeneralDynamicTLSModel);
> +
> + VAArgTLS = new GlobalVariable(
> + M, ArrayType::get(IRB.getInt64Ty(), 1000), false,
> + GlobalVariable::ExternalLinkage, 0, "__msan_va_arg_tls", 0,
> + GlobalVariable::GeneralDynamicTLSModel);
> + VAArgOverflowSizeTLS = new GlobalVariable(
> + M, IRB.getInt64Ty(), false, GlobalVariable::ExternalLinkage, 0,
> + "__msan_va_arg_overflow_size_tls", 0,
> + GlobalVariable::GeneralDynamicTLSModel);
> + OriginTLS = new GlobalVariable(
> + M, IRB.getInt32Ty(), false, GlobalVariable::ExternalLinkage, 0,
> + "__msan_origin_tls", 0, GlobalVariable::GeneralDynamicTLSModel);
> + return true;
> +}
> +
> +namespace {
> +
> +/// \brief A helper class that handles instrumentation of VarArg
> +/// functions on a particular platform.
> +///
> +/// Implementations are expected to insert the instrumentation
> +/// necessary to propagate argument shadow through VarArg function
> +/// calls. Visit* methods are called during an InstVisitor pass over
> +/// the function, and should avoid creating new basic blocks. A new
> +/// instance of this class is created for each instrumented function.
> +struct VarArgHelper {
> + /// \brief Visit a CallSite.
> + virtual void visitCallSite(CallSite &CS, IRBuilder<> &IRB) = 0;
> +
> + /// \brief Visit a va_start call.
> + virtual void visitVAStartInst(VAStartInst &I) = 0;
> +
> + /// \brief Visit a va_copy call.
> + virtual void visitVACopyInst(VACopyInst &I) = 0;
> +
> + /// \brief Finalize function instrumentation.
> + ///
> + /// This method is called after visiting all interesting (see above)
> + /// instructions in a function.
> + virtual void finalizeInstrumentation() = 0;
> +};
> +
> +struct MemorySanitizerVisitor;
> +
> +VarArgHelper*
> +CreateVarArgHelper(Function &Func, MemorySanitizer &Msan,
> + MemorySanitizerVisitor &Visitor);
> +
> +/// This class does all the work for a given function. Store and Load
> +/// instructions store and load corresponding shadow and origin
> +/// values. Most instructions propagate shadow from arguments to their
> +/// return values. Certain instructions (most importantly, BranchInst)
> +/// test their argument shadow and print reports (with a runtime call) if it's
> +/// non-zero.
> +struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
> + Function &F;
> + MemorySanitizer &MS;
> + SmallVector<PHINode *, 16> ShadowPHINodes, OriginPHINodes;
> + ValueMap<Value*, Value*> ShadowMap, OriginMap;
> + bool InsertChecks;
> + OwningPtr<VarArgHelper> VAHelper;
> +
> + // An unfortunate workaround for asymmetric lowering of va_arg stuff.
> + // See a comment in visitCallSite for more details.
> + static const unsigned AMD64GpEndOffset = 48; // AMD64 ABI Draft 0.99.6 p3.5.7
> + static const unsigned AMD64FpEndOffset = 176;
> +
> + struct ShadowOriginAndInsertPoint {
> + Instruction *Shadow;
> + Instruction *Origin;
> + Instruction *OrigIns;
> + ShadowOriginAndInsertPoint(Instruction *S, Instruction *O, Instruction *I)
> + : Shadow(S), Origin(O), OrigIns(I) { }
> + ShadowOriginAndInsertPoint() : Shadow(0), Origin(0), OrigIns(0) { }
> + };
> + SmallVector<ShadowOriginAndInsertPoint, 16> InstrumentationList;
> +
> + MemorySanitizerVisitor(Function &F, MemorySanitizer &MS)
> + : F(F), MS(MS), VAHelper(CreateVarArgHelper(F, MS, *this)) {
> + InsertChecks = !MS.BL->isIn(F);
> + DEBUG(if (!InsertChecks)
> + dbgs() << "MemorySanitizer is not inserting checks into '"
> + << F.getName() << "'\n");
> + }
> +
> + void materializeChecks() {
> + for (size_t i = 0, n = InstrumentationList.size(); i < n; i++) {
> + Instruction *Shadow = InstrumentationList[i].Shadow;
> + Instruction *OrigIns = InstrumentationList[i].OrigIns;
> + IRBuilder<> IRB(OrigIns);
> + DEBUG(dbgs() << " SHAD0 : " << *Shadow << "\n");
> + Value *ConvertedShadow = convertToShadowTyNoVec(Shadow, IRB);
> + DEBUG(dbgs() << " SHAD1 : " << *ConvertedShadow << "\n");
> + Value *Cmp = IRB.CreateICmpNE(ConvertedShadow,
> + getCleanShadow(ConvertedShadow), "_mscmp");
> + Instruction *CheckTerm =
> + SplitBlockAndInsertIfThen(cast<Instruction>(Cmp),
> + /* Unreachable */ !ClKeepGoing,
> + MS.ColdCallWeights);
> +
> + IRB.SetInsertPoint(CheckTerm);
> + if (ClTrackOrigins) {
> + Instruction *Origin = InstrumentationList[i].Origin;
> + IRB.CreateStore(Origin ? (Value*)Origin : (Value*)IRB.getInt32(0),
> + MS.OriginTLS);
> + }
> + CallInst *Call = IRB.CreateCall(MS.WarningFn);
> + Call->setDebugLoc(OrigIns->getDebugLoc());
> + DEBUG(dbgs() << " CHECK: " << *Cmp << "\n");
> + }
> + DEBUG(dbgs() << "DONE:\n" << F);
> + }
> +
> + /// \brief Add MemorySanitizer instrumentation to a function.
> + bool runOnFunction() {
> + if (!MS.TD) return false;
> + // Iterate all BBs in depth-first order and create shadow instructions
> + // for all instructions (where applicable).
> + // For PHI nodes we create dummy shadow PHIs which will be finalized later.
> + for (df_iterator<BasicBlock*> DI = df_begin(&F.getEntryBlock()),
> + DE = df_end(&F.getEntryBlock()); DI != DE; ++DI) {
> + BasicBlock *BB = *DI;
> + visit(*BB);
> + }
> +
> + // Finalize PHI nodes.
> + for (size_t i = 0, n = ShadowPHINodes.size(); i < n; i++) {
> + PHINode *PN = ShadowPHINodes[i];
> + PHINode *PNS = cast<PHINode>(getShadow(PN));
> + PHINode *PNO = ClTrackOrigins ? cast<PHINode>(getOrigin(PN)) : 0;
> + size_t NumValues = PN->getNumIncomingValues();
> + for (size_t v = 0; v < NumValues; v++) {
> + PNS->addIncoming(getShadow(PN, v), PN->getIncomingBlock(v));
> + if (PNO)
> + PNO->addIncoming(getOrigin(PN, v), PN->getIncomingBlock(v));
> + }
> + }
> +
> + VAHelper->finalizeInstrumentation();
> +
> + materializeChecks();
> +
> + return true;
> + }
> +
> + /// \brief Compute the shadow type that corresponds to a given Value.
> + Type *getShadowTy(Value *V) {
> + return getShadowTy(V->getType());
> + }
> +
> + /// \brief Compute the shadow type that corresponds to a given Type.
> + Type *getShadowTy(Type *OrigTy) {
> + if (!OrigTy->isSized()) {
> + return 0;
> + }
> + // For integer type, shadow is the same as the original type.
> + // This may return weird-sized types like i1.
> + if (IntegerType *IT = dyn_cast<IntegerType>(OrigTy))
> + return IT;
> + if (VectorType *VT = dyn_cast<VectorType>(OrigTy))
> + return VectorType::getInteger(VT);
> + if (StructType *ST = dyn_cast<StructType>(OrigTy)) {
> + SmallVector<Type*, 4> Elements;
> + for (unsigned i = 0, n = ST->getNumElements(); i < n; i++)
> + Elements.push_back(getShadowTy(ST->getElementType(i)));
> + StructType *Res = StructType::get(*MS.C, Elements, ST->isPacked());
> + DEBUG(dbgs() << "getShadowTy: " << *ST << " ===> " << *Res << "\n");
> + return Res;
> + }
> + uint32_t TypeSize = MS.TD->getTypeStoreSizeInBits(OrigTy);
> + return IntegerType::get(*MS.C, TypeSize);
> + }
> +
> + /// \brief Flatten a vector type.
> + Type *getShadowTyNoVec(Type *ty) {
> + if (VectorType *vt = dyn_cast<VectorType>(ty))
> + return IntegerType::get(*MS.C, vt->getBitWidth());
> + return ty;
> + }
> +
> + /// \brief Convert a shadow value to it's flattened variant.
> + Value *convertToShadowTyNoVec(Value *V, IRBuilder<> &IRB) {
> + Type *Ty = V->getType();
> + Type *NoVecTy = getShadowTyNoVec(Ty);
> + if (Ty == NoVecTy) return V;
> + return IRB.CreateBitCast(V, NoVecTy);
> + }
> +
> + /// \brief Compute the shadow address that corresponds to a given application
> + /// address.
> + ///
> + /// Shadow = Addr & ~ShadowMask.
> + Value *getShadowPtr(Value *Addr, Type *ShadowTy,
> + IRBuilder<> &IRB) {
> + Value *ShadowLong =
> + IRB.CreateAnd(IRB.CreatePointerCast(Addr, MS.IntptrTy),
> + ConstantInt::get(MS.IntptrTy, ~MS.ShadowMask));
> + return IRB.CreateIntToPtr(ShadowLong, PointerType::get(ShadowTy, 0));
> + }
> +
> + /// \brief Compute the origin address that corresponds to a given application
> + /// address.
> + ///
> + /// OriginAddr = (ShadowAddr + OriginOffset) & ~3ULL
> + /// = Addr & (~ShadowMask & ~3ULL) + OriginOffset
> + Value *getOriginPtr(Value *Addr, IRBuilder<> &IRB) {
> + Value *ShadowLong =
> + IRB.CreateAnd(IRB.CreatePointerCast(Addr, MS.IntptrTy),
> + ConstantInt::get(MS.IntptrTy, ~MS.ShadowMask & ~3ULL));
> + Value *Add =
> + IRB.CreateAdd(ShadowLong,
> + ConstantInt::get(MS.IntptrTy, MS.OriginOffset));
> + return IRB.CreateIntToPtr(Add, PointerType::get(IRB.getInt32Ty(), 0));
> + }
> +
> + /// \brief Compute the shadow address for a given function argument.
> + ///
> + /// Shadow = ParamTLS+ArgOffset.
> + Value *getShadowPtrForArgument(Value *A, IRBuilder<> &IRB,
> + int ArgOffset) {
> + Value *Base = IRB.CreatePointerCast(MS.ParamTLS, MS.IntptrTy);
> + Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
> + return IRB.CreateIntToPtr(Base, PointerType::get(getShadowTy(A), 0),
> + "_msarg");
> + }
> +
> + /// \brief Compute the origin address for a given function argument.
> + Value *getOriginPtrForArgument(Value *A, IRBuilder<> &IRB,
> + int ArgOffset) {
> + if (!ClTrackOrigins) return 0;
> + Value *Base = IRB.CreatePointerCast(MS.ParamOriginTLS, MS.IntptrTy);
> + Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
> + return IRB.CreateIntToPtr(Base, PointerType::get(MS.OriginTy, 0),
> + "_msarg_o");
> + }
> +
> + /// \brief Compute the shadow address for a retval.
> + Value *getShadowPtrForRetval(Value *A, IRBuilder<> &IRB) {
> + Value *Base = IRB.CreatePointerCast(MS.RetvalTLS, MS.IntptrTy);
> + return IRB.CreateIntToPtr(Base, PointerType::get(getShadowTy(A), 0),
> + "_msret");
> + }
> +
> + /// \brief Compute the origin address for a retval.
> + Value *getOriginPtrForRetval(IRBuilder<> &IRB) {
> + // We keep a single origin for the entire retval. Might be too optimistic.
> + return MS.RetvalOriginTLS;
> + }
> +
> + /// \brief Set SV to be the shadow value for V.
> + void setShadow(Value *V, Value *SV) {
> + assert(!ShadowMap.count(V) && "Values may only have one shadow");
> + ShadowMap[V] = SV;
> + }
> +
> + /// \brief Set Origin to be the origin value for V.
> + void setOrigin(Value *V, Value *Origin) {
> + if (!ClTrackOrigins) return;
> + assert(!OriginMap.count(V) && "Values may only have one origin");
> + DEBUG(dbgs() << "ORIGIN: " << *V << " ==> " << *Origin << "\n");
> + OriginMap[V] = Origin;
> + }
> +
> + /// \brief Create a clean shadow value for a given value.
> + ///
> + /// Clean shadow (all zeroes) means all bits of the value are defined
> + /// (initialized).
> + Value *getCleanShadow(Value *V) {
> + Type *ShadowTy = getShadowTy(V);
> + if (!ShadowTy)
> + return 0;
> + return Constant::getNullValue(ShadowTy);
> + }
> +
> + /// \brief Create a dirty shadow of a given shadow type.
> + Constant *getPoisonedShadow(Type *ShadowTy) {
> + assert(ShadowTy);
> + if (isa<IntegerType>(ShadowTy) || isa<VectorType>(ShadowTy))
> + return Constant::getAllOnesValue(ShadowTy);
> + StructType *ST = cast<StructType>(ShadowTy);
> + SmallVector<Constant *, 4> Vals;
> + for (unsigned i = 0, n = ST->getNumElements(); i < n; i++)
> + Vals.push_back(getPoisonedShadow(ST->getElementType(i)));
> + return ConstantStruct::get(ST, Vals);
> + }
> +
> + /// \brief Create a clean (zero) origin.
> + Value *getCleanOrigin() {
> + return Constant::getNullValue(MS.OriginTy);
> + }
> +
> + /// \brief Get the shadow value for a given Value.
> + ///
> + /// This function either returns the value set earlier with setShadow,
> + /// or extracts if from ParamTLS (for function arguments).
> + Value *getShadow(Value *V) {
> + if (Instruction *I = dyn_cast<Instruction>(V)) {
> + // For instructions the shadow is already stored in the map.
> + Value *Shadow = ShadowMap[V];
> + if (!Shadow) {
> + DEBUG(dbgs() << "No shadow: " << *V << "\n" << *(I->getParent()));
> + assert(Shadow && "No shadow for a value");
> + }
> + return Shadow;
> + }
> + if (UndefValue *U = dyn_cast<UndefValue>(V)) {
> + Value *AllOnes = getPoisonedShadow(getShadowTy(V));
> + DEBUG(dbgs() << "Undef: " << *U << " ==> " << *AllOnes << "\n");
> + return AllOnes;
> + }
> + if (Argument *A = dyn_cast<Argument>(V)) {
> + // For arguments we compute the shadow on demand and store it in the map.
> + Value **ShadowPtr = &ShadowMap[V];
> + if (*ShadowPtr)
> + return *ShadowPtr;
> + Function *F = A->getParent();
> + IRBuilder<> EntryIRB(F->getEntryBlock().getFirstNonPHI());
> + unsigned ArgOffset = 0;
> + for (Function::arg_iterator AI = F->arg_begin(), AE = F->arg_end();
> + AI != AE; ++AI) {
> + if (!AI->getType()->isSized()) {
> + DEBUG(dbgs() << "Arg is not sized\n");
> + continue;
> + }
> + unsigned Size = AI->hasByValAttr()
> + ? MS.TD->getTypeAllocSize(AI->getType()->getPointerElementType())
> + : MS.TD->getTypeAllocSize(AI->getType());
> + if (A == AI) {
> + Value *Base = getShadowPtrForArgument(AI, EntryIRB, ArgOffset);
> + if (AI->hasByValAttr()) {
> + // ByVal pointer itself has clean shadow. We copy the actual
> + // argument shadow to the underlying memory.
> + Value *Cpy = EntryIRB.CreateMemCpy(
> + getShadowPtr(V, EntryIRB.getInt8Ty(), EntryIRB),
> + Base, Size, AI->getParamAlignment());
> + DEBUG(dbgs() << " ByValCpy: " << *Cpy << "\n");
> + *ShadowPtr = getCleanShadow(V);
> + } else {
> + *ShadowPtr = EntryIRB.CreateLoad(Base);
> + }
> + DEBUG(dbgs() << " ARG: " << *AI << " ==> " <<
> + **ShadowPtr << "\n");
> + if (ClTrackOrigins) {
> + Value* OriginPtr = getOriginPtrForArgument(AI, EntryIRB, ArgOffset);
> + setOrigin(A, EntryIRB.CreateLoad(OriginPtr));
> + }
> + }
> + ArgOffset += DataLayout::RoundUpAlignment(Size, 8);
> + }
> + assert(*ShadowPtr && "Could not find shadow for an argument");
> + return *ShadowPtr;
> + }
> + // For everything else the shadow is zero.
> + return getCleanShadow(V);
> + }
> +
> + /// \brief Get the shadow for i-th argument of the instruction I.
> + Value *getShadow(Instruction *I, int i) {
> + return getShadow(I->getOperand(i));
> + }
> +
> + /// \brief Get the origin for a value.
> + Value *getOrigin(Value *V) {
> + if (!ClTrackOrigins) return 0;
> + if (isa<Instruction>(V) || isa<Argument>(V)) {
> + Value *Origin = OriginMap[V];
> + if (!Origin) {
> + DEBUG(dbgs() << "NO ORIGIN: " << *V << "\n");
> + Origin = getCleanOrigin();
> + }
> + return Origin;
> + }
> + return getCleanOrigin();
> + }
> +
> + /// \brief Get the origin for i-th argument of the instruction I.
> + Value *getOrigin(Instruction *I, int i) {
> + return getOrigin(I->getOperand(i));
> + }
> +
> + /// \brief Remember the place where a shadow check should be inserted.
> + ///
> + /// This location will be later instrumented with a check that will print a
> + /// UMR warning in runtime if the value is not fully defined.
> + void insertCheck(Value *Val, Instruction *OrigIns) {
> + assert(Val);
> + if (!InsertChecks) return;
> + Instruction *Shadow = dyn_cast_or_null<Instruction>(getShadow(Val));
> + if (!Shadow) return;
> + Type *ShadowTy = Shadow->getType();
> + assert((isa<IntegerType>(ShadowTy) || isa<VectorType>(ShadowTy)) &&
> + "Can only insert checks for integer and vector shadow types");
> + Instruction *Origin = dyn_cast_or_null<Instruction>(getOrigin(Val));
> + InstrumentationList.push_back(
> + ShadowOriginAndInsertPoint(Shadow, Origin, OrigIns));
> + }
> +
> + //------------------- Visitors.
> +
> + /// \brief Instrument LoadInst
> + ///
> + /// Loads the corresponding shadow and (optionally) origin.
> + /// Optionally, checks that the load address is fully defined.
> + void visitLoadInst(LoadInst &I) {
> + Type *LoadTy = I.getType();
> + assert(LoadTy->isSized() && "Load type must have size");
> + IRBuilder<> IRB(&I);
> + Type *ShadowTy = getShadowTy(&I);
> + Value *Addr = I.getPointerOperand();
> + Value *ShadowPtr = getShadowPtr(Addr, ShadowTy, IRB);
> + setShadow(&I, IRB.CreateLoad(ShadowPtr, "_msld"));
> +
> + if (ClCheckAccessAddress)
> + insertCheck(I.getPointerOperand(), &I);
> +
> + if (ClTrackOrigins)
> + setOrigin(&I, IRB.CreateLoad(getOriginPtr(Addr, IRB)));
> + }
> +
> + /// \brief Instrument StoreInst
> + ///
> + /// Stores the corresponding shadow and (optionally) origin.
> + /// Optionally, checks that the store address is fully defined.
> + /// Volatile stores check that the value being stored is fully defined.
> + void visitStoreInst(StoreInst &I) {
> + IRBuilder<> IRB(&I);
> + Value *Val = I.getValueOperand();
> + Value *Addr = I.getPointerOperand();
> + Value *Shadow = getShadow(Val);
> + Value *ShadowPtr = getShadowPtr(Addr, Shadow->getType(), IRB);
> +
> + StoreInst *NewSI = IRB.CreateStore(Shadow, ShadowPtr);
> + DEBUG(dbgs() << " STORE: " << *NewSI << "\n");
> + // If the store is volatile, add a check.
> + if (I.isVolatile())
> + insertCheck(Val, &I);
> + if (ClCheckAccessAddress)
> + insertCheck(Addr, &I);
> +
> + if (ClTrackOrigins)
> + IRB.CreateStore(getOrigin(Val), getOriginPtr(Addr, IRB));
> + }
> +
> + // Casts.
> + void visitSExtInst(SExtInst &I) {
> + IRBuilder<> IRB(&I);
> + setShadow(&I, IRB.CreateSExt(getShadow(&I, 0), I.getType(), "_msprop"));
> + setOrigin(&I, getOrigin(&I, 0));
> + }
> +
> + void visitZExtInst(ZExtInst &I) {
> + IRBuilder<> IRB(&I);
> + setShadow(&I, IRB.CreateZExt(getShadow(&I, 0), I.getType(), "_msprop"));
> + setOrigin(&I, getOrigin(&I, 0));
> + }
> +
> + void visitTruncInst(TruncInst &I) {
> + IRBuilder<> IRB(&I);
> + setShadow(&I, IRB.CreateTrunc(getShadow(&I, 0), I.getType(), "_msprop"));
> + setOrigin(&I, getOrigin(&I, 0));
> + }
> +
> + void visitBitCastInst(BitCastInst &I) {
> + IRBuilder<> IRB(&I);
> + setShadow(&I, IRB.CreateBitCast(getShadow(&I, 0), getShadowTy(&I)));
> + setOrigin(&I, getOrigin(&I, 0));
> + }
> +
> + void visitPtrToIntInst(PtrToIntInst &I) {
> + IRBuilder<> IRB(&I);
> + setShadow(&I, IRB.CreateIntCast(getShadow(&I, 0), getShadowTy(&I), false,
> + "_msprop_ptrtoint"));
> + setOrigin(&I, getOrigin(&I, 0));
> + }
> +
> + void visitIntToPtrInst(IntToPtrInst &I) {
> + IRBuilder<> IRB(&I);
> + setShadow(&I, IRB.CreateIntCast(getShadow(&I, 0), getShadowTy(&I), false,
> + "_msprop_inttoptr"));
> + setOrigin(&I, getOrigin(&I, 0));
> + }
> +
> + void visitFPToSIInst(CastInst& I) { handleShadowOr(I); }
> + void visitFPToUIInst(CastInst& I) { handleShadowOr(I); }
> + void visitSIToFPInst(CastInst& I) { handleShadowOr(I); }
> + void visitUIToFPInst(CastInst& I) { handleShadowOr(I); }
> + void visitFPExtInst(CastInst& I) { handleShadowOr(I); }
> + void visitFPTruncInst(CastInst& I) { handleShadowOr(I); }
> +
> + /// \brief Propagate shadow for bitwise AND.
> + ///
> + /// This code is exact, i.e. if, for example, a bit in the left argument
> + /// is defined and 0, then neither the value not definedness of the
> + /// corresponding bit in B don't affect the resulting shadow.
> + void visitAnd(BinaryOperator &I) {
> + IRBuilder<> IRB(&I);
> + // "And" of 0 and a poisoned value results in unpoisoned value.
> + // 1&1 => 1; 0&1 => 0; p&1 => p;
> + // 1&0 => 0; 0&0 => 0; p&0 => 0;
> + // 1&p => p; 0&p => 0; p&p => p;
> + // S = (S1 & S2) | (V1 & S2) | (S1 & V2)
> + Value *S1 = getShadow(&I, 0);
> + Value *S2 = getShadow(&I, 1);
> + Value *V1 = I.getOperand(0);
> + Value *V2 = I.getOperand(1);
> + if (V1->getType() != S1->getType()) {
> + V1 = IRB.CreateIntCast(V1, S1->getType(), false);
> + V2 = IRB.CreateIntCast(V2, S2->getType(), false);
> + }
> + Value *S1S2 = IRB.CreateAnd(S1, S2);
> + Value *V1S2 = IRB.CreateAnd(V1, S2);
> + Value *S1V2 = IRB.CreateAnd(S1, V2);
> + setShadow(&I, IRB.CreateOr(S1S2, IRB.CreateOr(V1S2, S1V2)));
> + setOriginForNaryOp(I);
> + }
> +
> + void visitOr(BinaryOperator &I) {
> + IRBuilder<> IRB(&I);
> + // "Or" of 1 and a poisoned value results in unpoisoned value.
> + // 1|1 => 1; 0|1 => 1; p|1 => 1;
> + // 1|0 => 1; 0|0 => 0; p|0 => p;
> + // 1|p => 1; 0|p => p; p|p => p;
> + // S = (S1 & S2) | (~V1 & S2) | (S1 & ~V2)
> + Value *S1 = getShadow(&I, 0);
> + Value *S2 = getShadow(&I, 1);
> + Value *V1 = IRB.CreateNot(I.getOperand(0));
> + Value *V2 = IRB.CreateNot(I.getOperand(1));
> + if (V1->getType() != S1->getType()) {
> + V1 = IRB.CreateIntCast(V1, S1->getType(), false);
> + V2 = IRB.CreateIntCast(V2, S2->getType(), false);
> + }
> + Value *S1S2 = IRB.CreateAnd(S1, S2);
> + Value *V1S2 = IRB.CreateAnd(V1, S2);
> + Value *S1V2 = IRB.CreateAnd(S1, V2);
> + setShadow(&I, IRB.CreateOr(S1S2, IRB.CreateOr(V1S2, S1V2)));
> + setOriginForNaryOp(I);
> + }
> +
> + /// \brief Propagate origin for an instruction.
> + ///
> + /// This is a general case of origin propagation. For an Nary operation,
> + /// is set to the origin of an argument that is not entirely initialized.
> + /// It does not matter which one is picked if all arguments are initialized.
> + void setOriginForNaryOp(Instruction &I) {
> + if (!ClTrackOrigins) return;
> + IRBuilder<> IRB(&I);
> + Value *Origin = getOrigin(&I, 0);
> + for (unsigned Op = 1, n = I.getNumOperands(); Op < n; ++Op) {
> + Value *S = convertToShadowTyNoVec(getShadow(&I, Op - 1), IRB);
> + Origin = IRB.CreateSelect(IRB.CreateICmpNE(S, getCleanShadow(S)),
> + Origin, getOrigin(&I, Op));
> + }
> + setOrigin(&I, Origin);
> + }
> +
> + /// \brief Propagate shadow for a binary operation.
> + ///
> + /// Shadow = Shadow0 | Shadow1, all 3 must have the same type.
> + /// Bitwise OR is selected as an operation that will never lose even a bit of
> + /// poison.
> + void handleShadowOrBinary(Instruction &I) {
> + IRBuilder<> IRB(&I);
> + Value *Shadow0 = getShadow(&I, 0);
> + Value *Shadow1 = getShadow(&I, 1);
> + setShadow(&I, IRB.CreateOr(Shadow0, Shadow1, "_msprop"));
> + setOriginForNaryOp(I);
> + }
> +
> + /// \brief Propagate shadow for arbitrary operation.
> + ///
> + /// This is a general case of shadow propagation, used in all cases where we
> + /// don't know and/or care about what the operation actually does.
> + /// It converts all input shadow values to a common type (extending or
> + /// truncating as necessary), and bitwise OR's them.
> + ///
> + /// This is much cheaper than inserting checks (i.e. requiring inputs to be
> + /// fully initialized), and less prone to false positives.
> + // FIXME: is the casting actually correct?
> + // FIXME: merge this with handleShadowOrBinary.
> + void handleShadowOr(Instruction &I) {
> + IRBuilder<> IRB(&I);
> + Value *Shadow = getShadow(&I, 0);
> + for (unsigned Op = 1, n = I.getNumOperands(); Op < n; ++Op)
> + Shadow = IRB.CreateOr(
> + Shadow, IRB.CreateIntCast(getShadow(&I, Op), Shadow->getType(), false),
> + "_msprop");
> + Shadow = IRB.CreateIntCast(Shadow, getShadowTy(&I), false);
> + setShadow(&I, Shadow);
> + setOriginForNaryOp(I);
> + }
> +
> + void visitFAdd(BinaryOperator &I) { handleShadowOrBinary(I); }
> + void visitFSub(BinaryOperator &I) { handleShadowOrBinary(I); }
> + void visitFMul(BinaryOperator &I) { handleShadowOrBinary(I); }
> + void visitAdd(BinaryOperator &I) { handleShadowOrBinary(I); }
> + void visitSub(BinaryOperator &I) { handleShadowOrBinary(I); }
> + void visitXor(BinaryOperator &I) { handleShadowOrBinary(I); }
> + void visitMul(BinaryOperator &I) { handleShadowOrBinary(I); }
> +
> + void handleDiv(Instruction &I) {
> + IRBuilder<> IRB(&I);
> + // Strict on the second argument.
> + insertCheck(I.getOperand(1), &I);
> + setShadow(&I, getShadow(&I, 0));
> + setOrigin(&I, getOrigin(&I, 0));
> + }
> +
> + void visitUDiv(BinaryOperator &I) { handleDiv(I); }
> + void visitSDiv(BinaryOperator &I) { handleDiv(I); }
> + void visitFDiv(BinaryOperator &I) { handleDiv(I); }
> + void visitURem(BinaryOperator &I) { handleDiv(I); }
> + void visitSRem(BinaryOperator &I) { handleDiv(I); }
> + void visitFRem(BinaryOperator &I) { handleDiv(I); }
> +
> + /// \brief Instrument == and != comparisons.
> + ///
> + /// Sometimes the comparison result is known even if some of the bits of the
> + /// arguments are not.
> + void handleEqualityComparison(ICmpInst &I) {
> + IRBuilder<> IRB(&I);
> + Value *A = I.getOperand(0);
> + Value *B = I.getOperand(1);
> + Value *Sa = getShadow(A);
> + Value *Sb = getShadow(B);
> + if (A->getType()->isPointerTy())
> + A = IRB.CreatePointerCast(A, MS.IntptrTy);
> + if (B->getType()->isPointerTy())
> + B = IRB.CreatePointerCast(B, MS.IntptrTy);
> + // A == B <==> (C = A^B) == 0
> + // A != B <==> (C = A^B) != 0
> + // Sc = Sa | Sb
> + Value *C = IRB.CreateXor(A, B);
> + Value *Sc = IRB.CreateOr(Sa, Sb);
> + // Now dealing with i = (C == 0) comparison (or C != 0, does not matter now)
> + // Result is defined if one of the following is true
> + // * there is a defined 1 bit in C
> + // * C is fully defined
> + // Si = !(C & ~Sc) && Sc
> + Value *Zero = Constant::getNullValue(Sc->getType());
> + Value *MinusOne = Constant::getAllOnesValue(Sc->getType());
> + Value *Si =
> + IRB.CreateAnd(IRB.CreateICmpNE(Sc, Zero),
> + IRB.CreateICmpEQ(
> + IRB.CreateAnd(IRB.CreateXor(Sc, MinusOne), C), Zero));
> + Si->setName("_msprop_icmp");
> + setShadow(&I, Si);
> + setOriginForNaryOp(I);
> + }
> +
> + void visitICmpInst(ICmpInst &I) {
> + if (ClHandleICmp && I.isEquality())
> + handleEqualityComparison(I);
> + else
> + handleShadowOr(I);
> + }
> +
> + void visitFCmpInst(FCmpInst &I) {
> + handleShadowOr(I);
> + }
> +
> + void handleShift(BinaryOperator &I) {
> + IRBuilder<> IRB(&I);
> + // If any of the S2 bits are poisoned, the whole thing is poisoned.
> + // Otherwise perform the same shift on S1.
> + Value *S1 = getShadow(&I, 0);
> + Value *S2 = getShadow(&I, 1);
> + Value *S2Conv = IRB.CreateSExt(IRB.CreateICmpNE(S2, getCleanShadow(S2)),
> + S2->getType());
> + Value *V2 = I.getOperand(1);
> + Value *Shift = IRB.CreateBinOp(I.getOpcode(), S1, V2);
> + setShadow(&I, IRB.CreateOr(Shift, S2Conv));
> + setOriginForNaryOp(I);
> + }
> +
> + void visitShl(BinaryOperator &I) { handleShift(I); }
> + void visitAShr(BinaryOperator &I) { handleShift(I); }
> + void visitLShr(BinaryOperator &I) { handleShift(I); }
> +
> + void visitMemSetInst(MemSetInst &I) {
> + IRBuilder<> IRB(&I);
> + Value *Ptr = I.getArgOperand(0);
> + Value *Val = I.getArgOperand(1);
> + Value *ShadowPtr = getShadowPtr(Ptr, Val->getType(), IRB);
> + Value *ShadowVal = getCleanShadow(Val);
> + Value *Size = I.getArgOperand(2);
> + unsigned Align = I.getAlignment();
> + bool isVolatile = I.isVolatile();
> +
> + IRB.CreateMemSet(ShadowPtr, ShadowVal, Size, Align, isVolatile);
> + }
> +
> + void visitMemCpyInst(MemCpyInst &I) {
> + IRBuilder<> IRB(&I);
> + Value *Dst = I.getArgOperand(0);
> + Value *Src = I.getArgOperand(1);
> + Type *ElementType = dyn_cast<PointerType>(Dst->getType())->getElementType();
> + Value *ShadowDst = getShadowPtr(Dst, ElementType, IRB);
> + Value *ShadowSrc = getShadowPtr(Src, ElementType, IRB);
> + Value *Size = I.getArgOperand(2);
> + unsigned Align = I.getAlignment();
> + bool isVolatile = I.isVolatile();
> +
> + IRB.CreateMemCpy(ShadowDst, ShadowSrc, Size, Align, isVolatile);
> + if (ClTrackOrigins)
> + IRB.CreateCall3(MS.MsanCopyOriginFn, Dst, Src, Size);
> + }
> +
> + /// \brief Instrument llvm.memmove
> + ///
> + /// At this point we don't know if llvm.memmove will be inlined or not.
> + /// If we don't instrument it and it gets inlined,
> + /// our interceptor will not kick in and we will lose the memmove.
> + /// If we instrument the call here, but it does not get inlined,
> + /// we will memove the shadow twice: which is bad in case
> + /// of overlapping regions. So, we simply lower the intrinsic to a call.
> + ///
> + /// Similar situation exists for memcpy and memset, but for those functions
> + /// calling instrumentation twice does not lead to incorrect results.
> + void visitMemMoveInst(MemMoveInst &I) {
> + IRBuilder<> IRB(&I);
> + IRB.CreateCall3(
> + MS.MemmoveFn,
> + IRB.CreatePointerCast(I.getArgOperand(0), IRB.getInt8PtrTy()),
> + IRB.CreatePointerCast(I.getArgOperand(1), IRB.getInt8PtrTy()),
> + IRB.CreateIntCast(I.getArgOperand(2), MS.IntptrTy, false));
> + I.eraseFromParent();
> + }
> +
> + void visitVAStartInst(VAStartInst &I) {
> + VAHelper->visitVAStartInst(I);
> + }
> +
> + void visitVACopyInst(VACopyInst &I) {
> + VAHelper->visitVACopyInst(I);
> + }
> +
> + void visitCallSite(CallSite CS) {
> + Instruction &I = *CS.getInstruction();
> + assert((CS.isCall() || CS.isInvoke()) && "Unknown type of CallSite");
> + if (CS.isCall()) {
> + // Allow only tail calls with the same types, otherwise
> + // we may have a false positive: shadow for a non-void RetVal
> + // will get propagated to a void RetVal.
> + CallInst *Call = cast<CallInst>(&I);
> + if (Call->isTailCall() && Call->getType() != Call->getParent()->getType())
> + Call->setTailCall(false);
> + if (isa<IntrinsicInst>(&I)) {
> + // All intrinsics we care about are handled in corresponding visit*
> + // methods. Add checks for the arguments, mark retval as clean.
> + visitInstruction(I);
> + return;
> + }
> + }
> + IRBuilder<> IRB(&I);
> + unsigned ArgOffset = 0;
> + DEBUG(dbgs() << " CallSite: " << I << "\n");
> + for (CallSite::arg_iterator ArgIt = CS.arg_begin(), End = CS.arg_end();
> + ArgIt != End; ++ArgIt) {
> + Value *A = *ArgIt;
> + unsigned i = ArgIt - CS.arg_begin();
> + if (!A->getType()->isSized()) {
> + DEBUG(dbgs() << "Arg " << i << " is not sized: " << I << "\n");
> + continue;
> + }
> + unsigned Size = 0;
> + Value *Store = 0;
> + // Compute the Shadow for arg even if it is ByVal, because
> + // in that case getShadow() will copy the actual arg shadow to
> + // __msan_param_tls.
> + Value *ArgShadow = getShadow(A);
> + Value *ArgShadowBase = getShadowPtrForArgument(A, IRB, ArgOffset);
> + DEBUG(dbgs() << " Arg#" << i << ": " << *A <<
> + " Shadow: " << *ArgShadow << "\n");
> + if (CS.paramHasAttr(i + 1, Attributes::ByVal)) {
> + assert(A->getType()->isPointerTy() &&
> + "ByVal argument is not a pointer!");
> + Size = MS.TD->getTypeAllocSize(A->getType()->getPointerElementType());
> + unsigned Alignment = CS.getParamAlignment(i + 1);
> + Store = IRB.CreateMemCpy(ArgShadowBase,
> + getShadowPtr(A, Type::getInt8Ty(*MS.C), IRB),
> + Size, Alignment);
> + } else {
> + Size = MS.TD->getTypeAllocSize(A->getType());
> + Store = IRB.CreateStore(ArgShadow, ArgShadowBase);
> + }
> + if (ClTrackOrigins)
> + IRB.CreateStore(getOrigin(A),
> + getOriginPtrForArgument(A, IRB, ArgOffset));
> + assert(Size != 0 && Store != 0);
> + DEBUG(dbgs() << " Param:" << *Store << "\n");
> + ArgOffset += DataLayout::RoundUpAlignment(Size, 8);
> + }
> + DEBUG(dbgs() << " done with call args\n");
> +
> + FunctionType *FT =
> + cast<FunctionType>(CS.getCalledValue()->getType()-> getContainedType(0));
> + if (FT->isVarArg()) {
> + VAHelper->visitCallSite(CS, IRB);
> + }
> +
> + // Now, get the shadow for the RetVal.
> + if (!I.getType()->isSized()) return;
> + IRBuilder<> IRBBefore(&I);
> + // Untill we have full dynamic coverage, make sure the retval shadow is 0.
> + Value *Base = getShadowPtrForRetval(&I, IRBBefore);
> + IRBBefore.CreateStore(getCleanShadow(&I), Base);
> + Instruction *NextInsn = 0;
> + if (CS.isCall()) {
> + NextInsn = I.getNextNode();
> + } else {
> + BasicBlock *NormalDest = cast<InvokeInst>(&I)->getNormalDest();
> + if (!NormalDest->getSinglePredecessor()) {
> + // FIXME: this case is tricky, so we are just conservative here.
> + // Perhaps we need to split the edge between this BB and NormalDest,
> + // but a naive attempt to use SplitEdge leads to a crash.
> + setShadow(&I, getCleanShadow(&I));
> + setOrigin(&I, getCleanOrigin());
> + return;
> + }
> + NextInsn = NormalDest->getFirstInsertionPt();
> + assert(NextInsn &&
> + "Could not find insertion point for retval shadow load");
> + }
> + IRBuilder<> IRBAfter(NextInsn);
> + setShadow(&I, IRBAfter.CreateLoad(getShadowPtrForRetval(&I, IRBAfter),
> + "_msret"));
> + if (ClTrackOrigins)
> + setOrigin(&I, IRBAfter.CreateLoad(getOriginPtrForRetval(IRBAfter)));
> + }
> +
> + void visitReturnInst(ReturnInst &I) {
> + IRBuilder<> IRB(&I);
> + if (Value *RetVal = I.getReturnValue()) {
> + // Set the shadow for the RetVal.
> + Value *Shadow = getShadow(RetVal);
> + Value *ShadowPtr = getShadowPtrForRetval(RetVal, IRB);
> + DEBUG(dbgs() << "Return: " << *Shadow << "\n" << *ShadowPtr << "\n");
> + IRB.CreateStore(Shadow, ShadowPtr);
> + if (ClTrackOrigins)
> + IRB.CreateStore(getOrigin(RetVal), getOriginPtrForRetval(IRB));
> + }
> + }
> +
> + void visitPHINode(PHINode &I) {
> + IRBuilder<> IRB(&I);
> + ShadowPHINodes.push_back(&I);
> + setShadow(&I, IRB.CreatePHI(getShadowTy(&I), I.getNumIncomingValues(),
> + "_msphi_s"));
> + if (ClTrackOrigins)
> + setOrigin(&I, IRB.CreatePHI(MS.OriginTy, I.getNumIncomingValues(),
> + "_msphi_o"));
> + }
> +
> + void visitAllocaInst(AllocaInst &I) {
> + setShadow(&I, getCleanShadow(&I));
> + if (!ClPoisonStack) return;
> + IRBuilder<> IRB(I.getNextNode());
> + uint64_t Size = MS.TD->getTypeAllocSize(I.getAllocatedType());
> + if (ClPoisonStackWithCall) {
> + IRB.CreateCall2(MS.MsanPoisonStackFn,
> + IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()),
> + ConstantInt::get(MS.IntptrTy, Size));
> + } else {
> + Value *ShadowBase = getShadowPtr(&I, Type::getInt8PtrTy(*MS.C), IRB);
> + IRB.CreateMemSet(ShadowBase, IRB.getInt8(ClPoisonStackPattern),
> + Size, I.getAlignment());
> + }
> +
> + if (ClTrackOrigins) {
> + setOrigin(&I, getCleanOrigin());
> + SmallString<2048> StackDescriptionStorage;
> + raw_svector_ostream StackDescription(StackDescriptionStorage);
> + // We create a string with a description of the stack allocation and
> + // pass it into __msan_set_alloca_origin.
> + // It will be printed by the run-time if stack-originated UMR is found.
> + // The first 4 bytes of the string are set to '----' and will be replaced
> + // by __msan_va_arg_overflow_size_tls at the first call.
> + StackDescription << "----" << I.getName() << "@" << F.getName();
> + Value *Descr =
> + createPrivateNonConstGlobalForString(*F.getParent(),
> + StackDescription.str());
> + IRB.CreateCall3(MS.MsanSetAllocaOriginFn,
> + IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()),
> + ConstantInt::get(MS.IntptrTy, Size),
> + IRB.CreatePointerCast(Descr, IRB.getInt8PtrTy()));
> + }
> + }
> +
> + void visitSelectInst(SelectInst& I) {
> + IRBuilder<> IRB(&I);
> + setShadow(&I, IRB.CreateSelect(I.getCondition(),
> + getShadow(I.getTrueValue()), getShadow(I.getFalseValue()),
> + "_msprop"));
> + if (ClTrackOrigins)
> + setOrigin(&I, IRB.CreateSelect(I.getCondition(),
> + getOrigin(I.getTrueValue()), getOrigin(I.getFalseValue())));
> + }
> +
> + void visitLandingPadInst(LandingPadInst &I) {
> + // Do nothing.
> + // See http://code.google.com/p/memory-sanitizer/issues/detail?id=1
> + setShadow(&I, getCleanShadow(&I));
> + setOrigin(&I, getCleanOrigin());
> + }
> +
> + void visitGetElementPtrInst(GetElementPtrInst &I) {
> + handleShadowOr(I);
> + }
> +
> + void visitExtractValueInst(ExtractValueInst &I) {
> + IRBuilder<> IRB(&I);
> + Value *Agg = I.getAggregateOperand();
> + DEBUG(dbgs() << "ExtractValue: " << I << "\n");
> + Value *AggShadow = getShadow(Agg);
> + DEBUG(dbgs() << " AggShadow: " << *AggShadow << "\n");
> + Value *ResShadow = IRB.CreateExtractValue(AggShadow, I.getIndices());
> + DEBUG(dbgs() << " ResShadow: " << *ResShadow << "\n");
> + setShadow(&I, ResShadow);
> + setOrigin(&I, getCleanOrigin());
> + }
> +
> + void visitInsertValueInst(InsertValueInst &I) {
> + IRBuilder<> IRB(&I);
> + DEBUG(dbgs() << "InsertValue: " << I << "\n");
> + Value *AggShadow = getShadow(I.getAggregateOperand());
> + Value *InsShadow = getShadow(I.getInsertedValueOperand());
> + DEBUG(dbgs() << " AggShadow: " << *AggShadow << "\n");
> + DEBUG(dbgs() << " InsShadow: " << *InsShadow << "\n");
> + Value *Res = IRB.CreateInsertValue(AggShadow, InsShadow, I.getIndices());
> + DEBUG(dbgs() << " Res: " << *Res << "\n");
> + setShadow(&I, Res);
> + setOrigin(&I, getCleanOrigin());
> + }
> +
> + void dumpInst(Instruction &I) {
> + if (CallInst *CI = dyn_cast<CallInst>(&I)) {
> + errs() << "ZZZ call " << CI->getCalledFunction()->getName() << "\n";
> + } else {
> + errs() << "ZZZ " << I.getOpcodeName() << "\n";
> + }
> + errs() << "QQQ " << I << "\n";
> + }
> +
> + void visitResumeInst(ResumeInst &I) {
> + DEBUG(dbgs() << "Resume: " << I << "\n");
> + // Nothing to do here.
> + }
> +
> + void visitInstruction(Instruction &I) {
> + // Everything else: stop propagating and check for poisoned shadow.
> + if (ClDumpStrictInstructions)
> + dumpInst(I);
> + DEBUG(dbgs() << "DEFAULT: " << I << "\n");
> + for (size_t i = 0, n = I.getNumOperands(); i < n; i++)
> + insertCheck(I.getOperand(i), &I);
> + setShadow(&I, getCleanShadow(&I));
> + setOrigin(&I, getCleanOrigin());
> + }
> +};
> +
> +/// \brief AMD64-specific implementation of VarArgHelper.
> +struct VarArgAMD64Helper : public VarArgHelper {
> + // An unfortunate workaround for asymmetric lowering of va_arg stuff.
> + // See a comment in visitCallSite for more details.
> + static const unsigned AMD64GpEndOffset = 48; // AMD64 ABI Draft 0.99.6 p3.5.7
> + static const unsigned AMD64FpEndOffset = 176;
> +
> + Function &F;
> + MemorySanitizer &MS;
> + MemorySanitizerVisitor &MSV;
> + Value *VAArgTLSCopy;
> + Value *VAArgOverflowSize;
> +
> + SmallVector<CallInst*, 16> VAStartInstrumentationList;
> +
> + VarArgAMD64Helper(Function &F, MemorySanitizer &MS,
> + MemorySanitizerVisitor &MSV)
> + : F(F), MS(MS), MSV(MSV), VAArgTLSCopy(0), VAArgOverflowSize(0) { }
> +
> + enum ArgKind { AK_GeneralPurpose, AK_FloatingPoint, AK_Memory };
> +
> + ArgKind classifyArgument(Value* arg) {
> + // A very rough approximation of X86_64 argument classification rules.
> + Type *T = arg->getType();
> + if (T->isFPOrFPVectorTy() || T->isX86_MMXTy())
> + return AK_FloatingPoint;
> + if (T->isIntegerTy() && T->getPrimitiveSizeInBits() <= 64)
> + return AK_GeneralPurpose;
> + if (T->isPointerTy())
> + return AK_GeneralPurpose;
> + return AK_Memory;
> + }
> +
> + // For VarArg functions, store the argument shadow in an ABI-specific format
> + // that corresponds to va_list layout.
> + // We do this because Clang lowers va_arg in the frontend, and this pass
> + // only sees the low level code that deals with va_list internals.
> + // A much easier alternative (provided that Clang emits va_arg instructions)
> + // would have been to associate each live instance of va_list with a copy of
> + // MSanParamTLS, and extract shadow on va_arg() call in the argument list
> + // order.
> + void visitCallSite(CallSite &CS, IRBuilder<> &IRB) {
> + unsigned GpOffset = 0;
> + unsigned FpOffset = AMD64GpEndOffset;
> + unsigned OverflowOffset = AMD64FpEndOffset;
> + for (CallSite::arg_iterator ArgIt = CS.arg_begin(), End = CS.arg_end();
> + ArgIt != End; ++ArgIt) {
> + Value *A = *ArgIt;
> + ArgKind AK = classifyArgument(A);
> + if (AK == AK_GeneralPurpose && GpOffset >= AMD64GpEndOffset)
> + AK = AK_Memory;
> + if (AK == AK_FloatingPoint && FpOffset >= AMD64FpEndOffset)
> + AK = AK_Memory;
> + Value *Base;
> + switch (AK) {
> + case AK_GeneralPurpose:
> + Base = getShadowPtrForVAArgument(A, IRB, GpOffset);
> + GpOffset += 8;
> + break;
> + case AK_FloatingPoint:
> + Base = getShadowPtrForVAArgument(A, IRB, FpOffset);
> + FpOffset += 16;
> + break;
> + case AK_Memory:
> + uint64_t ArgSize = MS.TD->getTypeAllocSize(A->getType());
> + Base = getShadowPtrForVAArgument(A, IRB, OverflowOffset);
> + OverflowOffset += DataLayout::RoundUpAlignment(ArgSize, 8);
> + }
> + IRB.CreateStore(MSV.getShadow(A), Base);
> + }
> + Constant *OverflowSize =
> + ConstantInt::get(IRB.getInt64Ty(), OverflowOffset - AMD64FpEndOffset);
> + IRB.CreateStore(OverflowSize, MS.VAArgOverflowSizeTLS);
> + }
> +
> + /// \brief Compute the shadow address for a given va_arg.
> + Value *getShadowPtrForVAArgument(Value *A, IRBuilder<> &IRB,
> + int ArgOffset) {
> + Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy);
> + Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
> + return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(A), 0),
> + "_msarg");
> + }
> +
> + void visitVAStartInst(VAStartInst &I) {
> + IRBuilder<> IRB(&I);
> + VAStartInstrumentationList.push_back(&I);
> + Value *VAListTag = I.getArgOperand(0);
> + Value *ShadowPtr = MSV.getShadowPtr(VAListTag, IRB.getInt8Ty(), IRB);
> +
> + // Unpoison the whole __va_list_tag.
> + // FIXME: magic ABI constants.
> + IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
> + /* size */24, /* alignment */16, false);
> + }
> +
> + void visitVACopyInst(VACopyInst &I) {
> + IRBuilder<> IRB(&I);
> + Value *VAListTag = I.getArgOperand(0);
> + Value *ShadowPtr = MSV.getShadowPtr(VAListTag, IRB.getInt8Ty(), IRB);
> +
> + // Unpoison the whole __va_list_tag.
> + // FIXME: magic ABI constants.
> + IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
> + /* size */ 24, /* alignment */ 16, false);
> + }
> +
> + void finalizeInstrumentation() {
> + assert(!VAArgOverflowSize && !VAArgTLSCopy &&
> + "finalizeInstrumentation called twice");
> + if (!VAStartInstrumentationList.empty()) {
> + // If there is a va_start in this function, make a backup copy of
> + // va_arg_tls somewhere in the function entry block.
> + IRBuilder<> IRB(F.getEntryBlock().getFirstNonPHI());
> + VAArgOverflowSize = IRB.CreateLoad(MS.VAArgOverflowSizeTLS);
> + Value *CopySize =
> + IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, AMD64FpEndOffset),
> + VAArgOverflowSize);
> + VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize);
> + IRB.CreateMemCpy(VAArgTLSCopy, MS.VAArgTLS, CopySize, 8);
> + }
> +
> + // Instrument va_start.
> + // Copy va_list shadow from the backup copy of the TLS contents.
> + for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) {
> + CallInst *OrigInst = VAStartInstrumentationList[i];
> + IRBuilder<> IRB(OrigInst->getNextNode());
> + Value *VAListTag = OrigInst->getArgOperand(0);
> +
> + Value *RegSaveAreaPtrPtr =
> + IRB.CreateIntToPtr(
> + IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
> + ConstantInt::get(MS.IntptrTy, 16)),
> + Type::getInt64PtrTy(*MS.C));
> + Value *RegSaveAreaPtr = IRB.CreateLoad(RegSaveAreaPtrPtr);
> + Value *RegSaveAreaShadowPtr =
> + MSV.getShadowPtr(RegSaveAreaPtr, IRB.getInt8Ty(), IRB);
> + IRB.CreateMemCpy(RegSaveAreaShadowPtr, VAArgTLSCopy,
> + AMD64FpEndOffset, 16);
> +
> + Value *OverflowArgAreaPtrPtr =
> + IRB.CreateIntToPtr(
> + IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
> + ConstantInt::get(MS.IntptrTy, 8)),
> + Type::getInt64PtrTy(*MS.C));
> + Value *OverflowArgAreaPtr = IRB.CreateLoad(OverflowArgAreaPtrPtr);
> + Value *OverflowArgAreaShadowPtr =
> + MSV.getShadowPtr(OverflowArgAreaPtr, IRB.getInt8Ty(), IRB);
> + Value *SrcPtr =
> + getShadowPtrForVAArgument(VAArgTLSCopy, IRB, AMD64FpEndOffset);
> + IRB.CreateMemCpy(OverflowArgAreaShadowPtr, SrcPtr, VAArgOverflowSize, 16);
> + }
> + }
> +};
> +
> +VarArgHelper* CreateVarArgHelper(Function &Func, MemorySanitizer &Msan,
> + MemorySanitizerVisitor &Visitor) {
> + return new VarArgAMD64Helper(Func, Msan, Visitor);
> +}
> +
> +} // namespace
> +
> +bool MemorySanitizer::runOnFunction(Function &F) {
> + MemorySanitizerVisitor Visitor(F, *this);
> +
> + // Clear out readonly/readnone attributes.
> + AttrBuilder B;
> + B.addAttribute(Attributes::ReadOnly)
> + .addAttribute(Attributes::ReadNone);
> + F.removeAttribute(AttrListPtr::FunctionIndex,
> + Attributes::get(F.getContext(), B));
> +
> + return Visitor.runOnFunction();
> +}
>
> Propchange: llvm/trunk/lib/Transforms/Instrumentation/MemorySanitizer.cpp
> ------------------------------------------------------------------------------
> svn:eol-style = LF
>
> Added: llvm/trunk/test/Instrumentation/MemorySanitizer/lit.local.cfg
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/MemorySanitizer/lit.local.cfg?rev=168866&view=auto
> ==============================================================================
> --- llvm/trunk/test/Instrumentation/MemorySanitizer/lit.local.cfg (added)
> +++ llvm/trunk/test/Instrumentation/MemorySanitizer/lit.local.cfg Thu Nov 29 03:57:20 2012
> @@ -0,0 +1 @@
> +config.suffixes = ['.ll', '.c', '.cpp']
>
> Added: llvm/trunk/test/Instrumentation/MemorySanitizer/msan_basic.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/MemorySanitizer/msan_basic.ll?rev=168866&view=auto
> ==============================================================================
> --- llvm/trunk/test/Instrumentation/MemorySanitizer/msan_basic.ll (added)
> +++ llvm/trunk/test/Instrumentation/MemorySanitizer/msan_basic.ll Thu Nov 29 03:57:20 2012
> @@ -0,0 +1,235 @@
> +; RUN: opt < %s -msan -S | FileCheck %s
> +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
> +
> +; Check the presence of __msan_init
> +; CHECK: @llvm.global_ctors {{.*}} @__msan_init
> +
> +; load followed by cmp: check that we load the shadow and call __msan_warning.
> +define void @LoadAndCmp(i32* nocapture %a) nounwind uwtable {
> +entry:
> + %0 = load i32* %a, align 4
> + %tobool = icmp eq i32 %0, 0
> + br i1 %tobool, label %if.end, label %if.then
> +
> +if.then: ; preds = %entry
> + tail call void (...)* @foo() nounwind
> + br label %if.end
> +
> +if.end: ; preds = %entry, %if.then
> + ret void
> +}
> +
> +declare void @foo(...)
> +
> +; CHECK: define void @LoadAndCmp
> +; CHECK: = load
> +; CHECK: = load
> +; CHECK: call void @__msan_warning_noreturn()
> +; CHECK: }
> +
> +; Check that we store the shadow for the retval.
> +define i32 @ReturnInt() nounwind uwtable readnone {
> +entry:
> + ret i32 123
> +}
> +
> +; CHECK: define i32 @ReturnInt()
> +; CHECK: store i32 0,{{.*}}__msan_retval_tls
> +; CHECK: }
> +
> +; Check that we get the shadow for the retval.
> +define void @CopyRetVal(i32* nocapture %a) nounwind uwtable {
> +entry:
> + %call = tail call i32 @ReturnInt() nounwind
> + store i32 %call, i32* %a, align 4
> + ret void
> +}
> +
> +; CHECK: define void @CopyRetVal
> +; CHECK: load{{.*}}__msan_retval_tls
> +; CHECK: store
> +; CHECK: store
> +; CHECK: }
> +
> +
> +; Check that we generate PHIs for shadow.
> +define void @FuncWithPhi(i32* nocapture %a, i32* %b, i32* nocapture %c) nounwind uwtable {
> +entry:
> + %tobool = icmp eq i32* %b, null
> + br i1 %tobool, label %if.else, label %if.then
> +
> + if.then: ; preds = %entry
> + %0 = load i32* %b, align 4
> + br label %if.end
> +
> + if.else: ; preds = %entry
> + %1 = load i32* %c, align 4
> + br label %if.end
> +
> + if.end: ; preds = %if.else, %if.then
> + %t.0 = phi i32 [ %0, %if.then ], [ %1, %if.else ]
> + store i32 %t.0, i32* %a, align 4
> + ret void
> +}
> +
> +; CHECK: define void @FuncWithPhi
> +; CHECK: = phi
> +; CHECK-NEXT: = phi
> +; CHECK: store
> +; CHECK: store
> +; CHECK: }
> +
> +; Compute shadow for "x << 10"
> +define void @ShlConst(i32* nocapture %x) nounwind uwtable {
> +entry:
> + %0 = load i32* %x, align 4
> + %1 = shl i32 %0, 10
> + store i32 %1, i32* %x, align 4
> + ret void
> +}
> +
> +; CHECK: define void @ShlConst
> +; CHECK: = load
> +; CHECK: = load
> +; CHECK: shl
> +; CHECK: shl
> +; CHECK: store
> +; CHECK: store
> +; CHECK: }
> +
> +; Compute shadow for "10 << x": it should have 'sext i1'.
> +define void @ShlNonConst(i32* nocapture %x) nounwind uwtable {
> +entry:
> + %0 = load i32* %x, align 4
> + %1 = shl i32 10, %0
> + store i32 %1, i32* %x, align 4
> + ret void
> +}
> +
> +; CHECK: define void @ShlNonConst
> +; CHECK: = load
> +; CHECK: = load
> +; CHECK: = sext i1
> +; CHECK: store
> +; CHECK: store
> +; CHECK: }
> +
> +; SExt
> +define void @SExt(i32* nocapture %a, i16* nocapture %b) nounwind uwtable {
> +entry:
> + %0 = load i16* %b, align 2
> + %1 = sext i16 %0 to i32
> + store i32 %1, i32* %a, align 4
> + ret void
> +}
> +
> +; CHECK: define void @SExt
> +; CHECK: = load
> +; CHECK: = load
> +; CHECK: = sext
> +; CHECK: = sext
> +; CHECK: store
> +; CHECK: store
> +; CHECK: }
> +
> +
> +; memset
> +define void @MemSet(i8* nocapture %x) nounwind uwtable {
> +entry:
> + call void @llvm.memset.p0i8.i64(i8* %x, i8 42, i64 10, i32 1, i1 false)
> + ret void
> +}
> +
> +declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) nounwind
> +
> +; CHECK: define void @MemSet
> +; CHECK: call void @llvm.memset.p0i8.i64
> +; CHECK: call void @llvm.memset.p0i8.i64
> +; CHECK: }
> +
> +
> +; memcpy
> +define void @MemCpy(i8* nocapture %x, i8* nocapture %y) nounwind uwtable {
> +entry:
> + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %x, i8* %y, i64 10, i32 1, i1 false)
> + ret void
> +}
> +
> +declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind
> +
> +; CHECK: define void @MemCpy
> +; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64
> +; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64
> +; CHECK: }
> +
> +
> +; memmove is lowered to a call
> +define void @MemMove(i8* nocapture %x, i8* nocapture %y) nounwind uwtable {
> +entry:
> + call void @llvm.memmove.p0i8.p0i8.i64(i8* %x, i8* %y, i64 10, i32 1, i1 false)
> + ret void
> +}
> +
> +declare void @llvm.memmove.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind
> +
> +; CHECK: define void @MemMove
> +; CHECK: call i8* @memmove
> +; CHECK: }
> +
> +
> +; Check that we propagate shadow for "select"
> +
> +define i32 @Select(i32 %a, i32 %b, i32 %c) nounwind uwtable readnone {
> +entry:
> + %tobool = icmp ne i32 %c, 0
> + %cond = select i1 %tobool, i32 %a, i32 %b
> + ret i32 %cond
> +}
> +
> +; CHECK: define i32 @Select
> +; CHECK: select
> +; CHECK-NEXT: select
> +; CHECK: }
> +
> +
> +define i8* @IntToPtr(i64 %x) nounwind uwtable readnone {
> +entry:
> + %0 = inttoptr i64 %x to i8*
> + ret i8* %0
> +}
> +
> +; CHECK: define i8* @IntToPtr
> +; CHECK: load i64*{{.*}}__msan_param_tls
> +; CHECK-NEXT: inttoptr
> +; CHECK-NEXT: store i64{{.*}}__msan_retval_tls
> +; CHECK: }
> +
> +
> +define i8* @IntToPtr_ZExt(i16 %x) nounwind uwtable readnone {
> +entry:
> + %0 = inttoptr i16 %x to i8*
> + ret i8* %0
> +}
> +
> +; CHECK: define i8* @IntToPtr_ZExt
> +; CHECK: zext
> +; CHECK-NEXT: inttoptr
> +; CHECK: }
> +
> +
> +; Check that we insert exactly one check on udiv
> +; (2nd arg shadow is checked, 1st arg shadow is propagated)
> +
> +define i32 @Div(i32 %a, i32 %b) nounwind uwtable readnone {
> +entry:
> + %div = udiv i32 %a, %b
> + ret i32 %div
> +}
> +
> +; CHECK: define i32 @Div
> +; CHECK: icmp
> +; CHECK: br
> +; CHECK-NOT: icmp
> +; CHECK: udiv
> +; CHECK-NOT: icmp
> +; CHECK: }
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
-------------- next part --------------
From 5b04edd251d134a98ac96c993ef07735e795a36c Mon Sep 17 00:00:00 2001
From: NAKAMURA Takumi <geek4civic at gmail.com>
Date: Thu, 29 Nov 2012 21:37:51 +0900
Subject: [PATCH 1/3] MemorySanitizer.cpp: [-Wdelete-non-virtual-dtor]
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="------------1.7.4.1"
This is a multi-part message in MIME format.
--------------1.7.4.1
Content-Type: text/plain; charset=UTF-8; format=fixed
Content-Transfer-Encoding: 8bit
---
.../Transforms/Instrumentation/MemorySanitizer.cpp | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)
--------------1.7.4.1
Content-Type: text/x-patch; name="0001-MemorySanitizer.cpp-Wdelete-non-virtual-dtor.patch.txt"
Content-Transfer-Encoding: 8bit
Content-Disposition: attachment; filename="0001-MemorySanitizer.cpp-Wdelete-non-virtual-dtor.patch.txt"
diff --git a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
index bc9e709..b6cc67a 100644
--- a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -330,6 +330,8 @@ struct VarArgHelper {
/// This method is called after visiting all interesting (see above)
/// instructions in a function.
virtual void finalizeInstrumentation() = 0;
+
+ virtual ~VarArgHelper() {}
};
struct MemorySanitizerVisitor;
--------------1.7.4.1--
-------------- next part --------------
From d5a65baa43d55cb14f9bb142f94cbd5e1ea76fe1 Mon Sep 17 00:00:00 2001
From: NAKAMURA Takumi <geek4civic at gmail.com>
Date: Thu, 29 Nov 2012 21:39:14 +0900
Subject: [PATCH 2/3] MemorySanitizer.cpp: [-Wmismatched-tags]
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="------------1.7.4.1"
This is a multi-part message in MIME format.
--------------1.7.4.1
Content-Type: text/plain; charset=UTF-8; format=fixed
Content-Transfer-Encoding: 8bit
---
.../Transforms/Instrumentation/MemorySanitizer.cpp | 8 +++++---
1 files changed, 5 insertions(+), 3 deletions(-)
--------------1.7.4.1
Content-Type: text/x-patch; name="0002-MemorySanitizer.cpp-Wmismatched-tags.patch.txt"
Content-Transfer-Encoding: 8bit
Content-Disposition: attachment; filename="0002-MemorySanitizer.cpp-Wmismatched-tags.patch.txt"
diff --git a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
index b6cc67a..be9b6e4 100644
--- a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -334,7 +334,7 @@ struct VarArgHelper {
virtual ~VarArgHelper() {}
};
-struct MemorySanitizerVisitor;
+class MemorySanitizerVisitor;
VarArgHelper*
CreateVarArgHelper(Function &Func, MemorySanitizer &Msan,
@@ -346,7 +346,8 @@ CreateVarArgHelper(Function &Func, MemorySanitizer &Msan,
/// return values. Certain instructions (most importantly, BranchInst)
/// test their argument shadow and print reports (with a runtime call) if it's
/// non-zero.
-struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
+class MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
+public:
Function &F;
MemorySanitizer &MS;
SmallVector<PHINode *, 16> ShadowPHINodes, OriginPHINodes;
@@ -1254,7 +1255,8 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
};
/// \brief AMD64-specific implementation of VarArgHelper.
-struct VarArgAMD64Helper : public VarArgHelper {
+class VarArgAMD64Helper : public VarArgHelper {
+public:
// An unfortunate workaround for asymmetric lowering of va_arg stuff.
// See a comment in visitCallSite for more details.
static const unsigned AMD64GpEndOffset = 48; // AMD64 ABI Draft 0.99.6 p3.5.7
--------------1.7.4.1--
-------------- next part --------------
From 51a5da4c9ac6c84fcc71dc0b2f5ba1d733abe179 Mon Sep 17 00:00:00 2001
From: NAKAMURA Takumi <geek4civic at gmail.com>
Date: Thu, 29 Nov 2012 21:40:14 +0900
Subject: [PATCH 3/3] MemorySanitizer.cpp: [-Wunused-variable]
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="------------1.7.4.1"
This is a multi-part message in MIME format.
--------------1.7.4.1
Content-Type: text/plain; charset=UTF-8; format=fixed
Content-Transfer-Encoding: 8bit
---
.../Transforms/Instrumentation/MemorySanitizer.cpp | 9 +++++++--
1 files changed, 7 insertions(+), 2 deletions(-)
--------------1.7.4.1
Content-Type: text/x-patch; name="0003-MemorySanitizer.cpp-Wunused-variable.patch.txt"
Content-Transfer-Encoding: 8bit
Content-Disposition: attachment; filename="0003-MemorySanitizer.cpp-Wunused-variable.patch.txt"
diff --git a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
index be9b6e4..2cfafd6 100644
--- a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -595,6 +595,7 @@ public:
Value *Shadow = ShadowMap[V];
if (!Shadow) {
DEBUG(dbgs() << "No shadow: " << *V << "\n" << *(I->getParent()));
+ (void)I;
assert(Shadow && "No shadow for a value");
}
return Shadow;
@@ -602,6 +603,7 @@ public:
if (UndefValue *U = dyn_cast<UndefValue>(V)) {
Value *AllOnes = getPoisonedShadow(getShadowTy(V));
DEBUG(dbgs() << "Undef: " << *U << " ==> " << *AllOnes << "\n");
+ (void)U;
return AllOnes;
}
if (Argument *A = dyn_cast<Argument>(V)) {
@@ -630,6 +632,7 @@ public:
getShadowPtr(V, EntryIRB.getInt8Ty(), EntryIRB),
Base, Size, AI->getParamAlignment());
DEBUG(dbgs() << " ByValCpy: " << *Cpy << "\n");
+ (void)Cpy;
*ShadowPtr = getCleanShadow(V);
} else {
*ShadowPtr = EntryIRB.CreateLoad(Base);
@@ -683,9 +686,11 @@ public:
if (!InsertChecks) return;
Instruction *Shadow = dyn_cast_or_null<Instruction>(getShadow(Val));
if (!Shadow) return;
+#ifndef NDEBUG
Type *ShadowTy = Shadow->getType();
assert((isa<IntegerType>(ShadowTy) || isa<VectorType>(ShadowTy)) &&
"Can only insert checks for integer and vector shadow types");
+#endif
Instruction *Origin = dyn_cast_or_null<Instruction>(getOrigin(Val));
InstrumentationList.push_back(
ShadowOriginAndInsertPoint(Shadow, Origin, OrigIns));
@@ -698,8 +703,7 @@ public:
/// Loads the corresponding shadow and (optionally) origin.
/// Optionally, checks that the load address is fully defined.
void visitLoadInst(LoadInst &I) {
- Type *LoadTy = I.getType();
- assert(LoadTy->isSized() && "Load type must have size");
+ assert(I.getType()->isSized() && "Load type must have size");
IRBuilder<> IRB(&I);
Type *ShadowTy = getShadowTy(&I);
Value *Addr = I.getPointerOperand();
@@ -727,6 +731,7 @@ public:
StoreInst *NewSI = IRB.CreateStore(Shadow, ShadowPtr);
DEBUG(dbgs() << " STORE: " << *NewSI << "\n");
+ (void)NewSI;
// If the store is volatile, add a check.
if (I.isVolatile())
insertCheck(Val, &I);
--------------1.7.4.1--
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