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clamav/libclamav/c++/bytecode2llvm.cpp

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/*
* JIT compile ClamAV bytecode.
*
* Copyright (C) 2009-2010 Sourcefire, Inc.
*
* Authors: Török Edvin
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
#define DEBUG_TYPE "clamavjit"
#include <pthread.h>
#ifndef _WIN32
#include <sys/time.h>
#endif
#include "ClamBCModule.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/PostOrderIterator.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Triple.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/Verifier.h"
#include "llvm/CallingConv.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/ExecutionEngine/ExecutionEngine.h"
#include "llvm/ExecutionEngine/JIT.h"
#include "llvm/ExecutionEngine/JITEventListener.h"
#include "llvm/LLVMContext.h"
#include "llvm/Intrinsics.h"
#include "llvm/Module.h"
#include "llvm/PassManager.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/IRBuilder.h"
#include "llvm/Support/PrettyStackTrace.h"
#include "llvm/System/DataTypes.h"
#include "llvm/System/Host.h"
#include "llvm/System/Mutex.h"
#include "llvm/System/Signals.h"
#include "llvm/System/Threading.h"
#include "llvm/Target/TargetSelect.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Support/TargetFolder.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/System/ThreadLocal.h"
#include <cstdlib>
#include <csetjmp>
#include <new>
#include <cerrno>
#include "llvm/Config/config.h"
#if !ENABLE_THREADS
#error "Thread support was explicitly disabled. Cannot continue"
#endif
#ifdef _GLIBCXX_PARALLEL
#error "libstdc++ parallel mode is not supported for ClamAV. Please remove -D_GLIBCXX_PARALLEL from CXXFLAGS!"
#endif
#ifdef HAVE_CONFIG_H
#undef PACKAGE_BUGREPORT
#undef PACKAGE_NAME
#undef PACKAGE_STRING
#undef PACKAGE_TARNAME
#undef PACKAGE_VERSION
#undef PACKAGE_URL
#include "clamav-config.h"
#endif
#include "dconf.h"
#include "clamav.h"
#include "clambc.h"
#include "bytecode.h"
#include "bytecode_priv.h"
#include "type_desc.h"
extern "C" {
#include "md5.h"
}
#define MODULE "libclamav JIT: "
extern "C" unsigned int cli_rndnum(unsigned int max);
using namespace llvm;
typedef DenseMap<const struct cli_bc_func*, void*> FunctionMapTy;
struct cli_bcengine {
ExecutionEngine *EE;
JITEventListener *Listener;
LLVMContext Context;
FunctionMapTy compiledFunctions;
union {
unsigned char b[16];
void* align;/* just to align field to ptr */
} guard;
};
extern "C" uint8_t cli_debug_flag;
namespace {
static sys::ThreadLocal<const jmp_buf> ExceptionReturn;
void do_shutdown() {
llvm_shutdown();
}
static void NORETURN jit_exception_handler(void)
{
longjmp(*(jmp_buf*)(ExceptionReturn.get()), 1);
}
static void NORETURN jit_ssp_handler(void)
{
errs() << "Bytecode JIT: *** stack smashing detected, bytecode aborted\n";
jit_exception_handler();
}
void llvm_error_handler(void *user_data, const std::string &reason)
{
// Output it to stderr, it might exceed the 1k/4k limit of cli_errmsg
errs() << MODULE << reason;
jit_exception_handler();
}
// Since libgcc is not available on all compilers (for example on win32),
// just define what these functions should do, the compiler will forward to
// the appropriate libcall if needed.
static int64_t rtlib_sdiv_i64(int64_t a, int64_t b)
{
return a/b;
}
static uint64_t rtlib_udiv_i64(uint64_t a, uint64_t b)
{
return a/b;
}
static int64_t rtlib_srem_i64(int64_t a, int64_t b)
{
return a%b;
}
static uint64_t rtlib_urem_i64(uint64_t a, uint64_t b)
{
return a%b;
}
static int64_t rtlib_mul_i64(uint64_t a, uint64_t b)
{
return a*b;
}
static int64_t rtlib_shl_i64(int64_t a, int32_t b)
{
return a << b;
}
static int64_t rtlib_srl_i64(int64_t a, int32_t b)
{
return (uint64_t)a >> b;
}
/* Implementation independent sign-extended signed right shift */
#ifdef HAVE_SAR
#define CLI_SRS(n,s) ((n)>>(s))
#else
#define CLI_SRS(n,s) ((((n)>>(s)) ^ (1<<(sizeof(n)*8-1-s))) - (1<<(sizeof(n)*8-1-s)))
#endif
static int64_t rtlib_sra_i64(int64_t a, int32_t b)
{
return CLI_SRS(a, b);//CLI_./..
}
// Resolve integer libcalls, but nothing else.
static void* noUnknownFunctions(const std::string& name) {
void *addr =
StringSwitch<void*>(name)
.Case("__divdi3", (void*)(intptr_t)rtlib_sdiv_i64)
.Case("__udivdi3", (void*)(intptr_t)rtlib_udiv_i64)
.Case("__moddi3", (void*)(intptr_t)rtlib_srem_i64)
.Case("__umoddi3", (void*)(intptr_t)rtlib_urem_i64)
.Case("__muldi3", (void*)(intptr_t)rtlib_mul_i64)
.Case("__ashrdi3", (void*)(intptr_t)rtlib_sra_i64)
.Case("__ashldi3", (void*)(intptr_t)rtlib_shl_i64)
.Case("__lshrdi3", (void*)(intptr_t)rtlib_srl_i64)
.Case("memmove", (void*)(intptr_t)memmove)
.Case("memcpy", (void*)(intptr_t)memcpy)
.Case("memset", (void*)(intptr_t)memset)
.Case("abort", (void*)(intptr_t)jit_exception_handler)
.Default(0);
if (addr)
return addr;
std::string reason((Twine("Attempt to call external function ")+name).str());
llvm_error_handler(0, reason);
return 0;
}
class NotifyListener : public JITEventListener {
public:
virtual void NotifyFunctionEmitted(const Function &F,
void *Code, size_t Size,
const EmittedFunctionDetails &Details)
{
if (!cli_debug_flag)
return;
errs() << "bytecode JIT: emitted function " << F.getName() <<
" of " << Size << " bytes at 0x";
errs().write_hex((uintptr_t)Code);
errs() << "\n";
}
};
class LLVMTypeMapper {
private:
std::vector<PATypeHolder> TypeMap;
LLVMContext &Context;
unsigned numTypes;
const Type *getStatic(uint16_t ty)
{
if (!ty)
return Type::getVoidTy(Context);
if (ty <= 64)
return IntegerType::get(Context, ty);
switch (ty) {
case 65:
return PointerType::getUnqual(Type::getInt8Ty(Context));
case 66:
return PointerType::getUnqual(Type::getInt16Ty(Context));
case 67:
return PointerType::getUnqual(Type::getInt32Ty(Context));
case 68:
return PointerType::getUnqual(Type::getInt64Ty(Context));
}
llvm_unreachable("getStatic");
}
public:
LLVMTypeMapper(LLVMContext &Context, const struct cli_bc_type *types,
unsigned count, const Type *Hidden=0) : Context(Context), numTypes(count)
{
TypeMap.reserve(count);
// During recursive type construction pointers to Type* may be
// invalidated, so we must use a TypeHolder to an Opaque type as a
// start.
for (unsigned i=0;i<count;i++) {
TypeMap.push_back(OpaqueType::get(Context));
}
std::vector<const Type*> Elts;
for (unsigned i=0;i<count;i++) {
const struct cli_bc_type *type = &types[i];
Elts.clear();
unsigned n = type->kind == DArrayType ? 1 : type->numElements;
for (unsigned j=0;j<n;j++) {
Elts.push_back(get(type->containedTypes[j]));
}
const Type *Ty;
switch (type->kind) {
case DFunctionType:
{
assert(Elts.size() > 0 && "Function with no return type?");
const Type *RetTy = Elts[0];
if (Hidden)
Elts[0] = Hidden;
else
Elts.erase(Elts.begin());
Ty = FunctionType::get(RetTy, Elts, false);
break;
}
case DPointerType:
if (!PointerType::isValidElementType(Elts[0]))
Ty = PointerType::getUnqual(Type::getInt8Ty(Context));
else
Ty = PointerType::getUnqual(Elts[0]);
break;
case DStructType:
Ty = StructType::get(Context, Elts);
break;
case DPackedStructType:
Ty = StructType::get(Context, Elts, true);
break;
case DArrayType:
Ty = ArrayType::get(Elts[0], type->numElements);
break;
default:
llvm_unreachable("type->kind");
}
// Make the opaque type a concrete type, doing recursive type
// unification if needed.
cast<OpaqueType>(TypeMap[i].get())->refineAbstractTypeTo(Ty);
}
}
const Type *get(uint16_t ty)
{
ty &= 0x7fff;
if (ty < 69)
return getStatic(ty);
ty -= 69;
assert(ty < numTypes && "TypeID out of range");
return TypeMap[ty].get();
}
};
struct CommonFunctions {
Function *FHandler;
Function *FMemset;
Function *FMemmove;
Function *FMemcpy;
Function *FRealmemset;
Function *FRealMemmove;
Function *FRealmemcmp;
Function *FRealmemcpy;
Function *FBSwap16;
Function *FBSwap32;
Function *FBSwap64;
};
// loops with tripcounts higher than this need timeout check
static const unsigned LoopThreshold = 1000;
// after every N API calls we need timeout check
static const unsigned ApiThreshold = 100;
class RuntimeLimits : public FunctionPass {
typedef SmallVector<std::pair<const BasicBlock*, const BasicBlock*>, 16>
BBPairVectorTy;
typedef SmallSet<BasicBlock*, 16> BBSetTy;
typedef DenseMap<const BasicBlock*, unsigned> BBMapTy;
bool loopNeedsTimeoutCheck(ScalarEvolution &SE, const Loop *L, BBMapTy &Map) {
// This BB is a loop header, if trip count is small enough
// no timeout checks are needed here.
const SCEV *S = SE.getMaxBackedgeTakenCount(L);
if (isa<SCEVCouldNotCompute>(S))
return true;
DEBUG(errs() << "Found loop trip count" << *S << "\n");
ConstantRange CR = SE.getUnsignedRange(S);
uint64_t max = CR.getUnsignedMax().getLimitedValue();
DEBUG(errs() << "Found max trip count " << max << "\n");
if (max > LoopThreshold)
return true;
unsigned apicalls = 0;
for (Loop::block_iterator J=L->block_begin(),JE=L->block_end();
J != JE; ++J) {
apicalls += Map[*J];
}
apicalls *= max;
if (apicalls > ApiThreshold) {
DEBUG(errs() << "apicall threshold exceeded: " << apicalls << "\n");
return true;
}
Map[L->getHeader()] = apicalls;
return false;
}
public:
static char ID;
RuntimeLimits() : FunctionPass(&ID) {}
virtual bool runOnFunction(Function &F) {
BBSetTy BackedgeTargets;
if (!F.isDeclaration()) {
// Get the common backedge targets.
// Note that we don't rely on LoopInfo here, since
// it is possible to construct a CFG that doesn't have natural loops,
// yet it does have backedges, and thus can lead to unbounded/high
// execution time.
BBPairVectorTy V;
FindFunctionBackedges(F, V);
for (BBPairVectorTy::iterator I=V.begin(),E=V.end();I != E; ++I) {
BackedgeTargets.insert(const_cast<BasicBlock*>(I->second));
}
}
BBSetTy needsTimeoutCheck;
BBMapTy BBMap;
DominatorTree &DT = getAnalysis<DominatorTree>();
for (Function::iterator I=F.begin(),E=F.end(); I != E; ++I) {
BasicBlock *BB = &*I;
unsigned apicalls = 0;
for (BasicBlock::const_iterator J=BB->begin(),JE=BB->end();
J != JE; ++J) {
if (const CallInst *CI = dyn_cast<CallInst>(J)) {
Function *F = CI->getCalledFunction();
if (!F || F->isDeclaration())
apicalls++;
}
}
if (apicalls > ApiThreshold) {
DEBUG(errs() << "apicall threshold exceeded: " << apicalls << "\n");
needsTimeoutCheck.insert(BB);
apicalls = 0;
}
BBMap[BB] = apicalls;
}
if (!BackedgeTargets.empty()) {
LoopInfo &LI = getAnalysis<LoopInfo>();
ScalarEvolution &SE = getAnalysis<ScalarEvolution>();
// Now check whether any of these backedge targets are part of a loop
// with a small constant trip count
for (BBSetTy::iterator I=BackedgeTargets.begin(),E=BackedgeTargets.end();
I != E; ++I) {
const Loop *L = LI.getLoopFor(*I);
if (L && L->getHeader() == *I &&
!loopNeedsTimeoutCheck(SE, L, BBMap))
continue;
needsTimeoutCheck.insert(*I);
BBMap[*I] = 0;
}
}
// Estimate number of apicalls by walking dominator-tree bottom-up.
// BBs that have timeout checks are considered to have 0 APIcalls
// (since we already checked for timeout).
for (po_iterator<DomTreeNode*> I = po_begin(DT.getRootNode()),
E = po_end(DT.getRootNode()); I != E; ++I) {
if (needsTimeoutCheck.count(I->getBlock()))
continue;
unsigned apicalls = BBMap[I->getBlock()];
for (DomTreeNode::iterator J=I->begin(),JE=I->end();
J != JE; ++J) {
apicalls += BBMap[(*J)->getBlock()];
}
if (apicalls > ApiThreshold) {
needsTimeoutCheck.insert(I->getBlock());
apicalls = 0;
}
BBMap[I->getBlock()] = apicalls;
}
if (needsTimeoutCheck.empty())
return false;
DEBUG(errs() << "needs timeoutcheck:\n");
std::vector<const Type*>args;
FunctionType* abrtTy = FunctionType::get(
Type::getVoidTy(F.getContext()),args,false);
Constant *func_abort =
F.getParent()->getOrInsertFunction("abort", abrtTy);
BasicBlock *AbrtBB = BasicBlock::Create(F.getContext(), "", &F);
CallInst* AbrtC = CallInst::Create(func_abort, "", AbrtBB);
AbrtC->setCallingConv(CallingConv::C);
AbrtC->setTailCall(true);
AbrtC->setDoesNotReturn(true);
AbrtC->setDoesNotThrow(true);
new UnreachableInst(F.getContext(), AbrtBB);
IRBuilder<false> Builder(F.getContext());
Function *LSBarrier = Intrinsic::getDeclaration(F.getParent(),
Intrinsic::memory_barrier);
Value *Flag = F.arg_begin();
Value *MBArgs[] = {
ConstantInt::getFalse(F.getContext()),
ConstantInt::getFalse(F.getContext()),
ConstantInt::getTrue(F.getContext()),
ConstantInt::getFalse(F.getContext()),
ConstantInt::getFalse(F.getContext())
};
verifyFunction(F);
BasicBlock *BB = &F.getEntryBlock();
Builder.SetInsertPoint(BB, BB->getTerminator());
Flag = Builder.CreatePointerCast(Flag, PointerType::getUnqual(
Type::getInt1Ty(F.getContext())));
for (BBSetTy::iterator I=needsTimeoutCheck.begin(),
E=needsTimeoutCheck.end(); I != E; ++I) {
BasicBlock *BB = *I;
Builder.SetInsertPoint(BB, BB->getTerminator());
// store-load barrier: will be a no-op on x86 but not other arches
Builder.CreateCall(LSBarrier, MBArgs, MBArgs+5);
// Load Flag that tells us we timed out (first byte in bc_ctx)
Value *Cond = Builder.CreateLoad(Flag, true);
BasicBlock *newBB = SplitBlock(BB, BB->getTerminator(), this);
TerminatorInst *TI = BB->getTerminator();
BranchInst::Create(AbrtBB, newBB, Cond, TI);
TI->eraseFromParent();
// Update dominator info
DomTreeNode *N = DT.getNode(AbrtBB);
if (!N) {
DT.addNewBlock(AbrtBB, BB);
} else {
BasicBlock *DomBB = DT.findNearestCommonDominator(BB,
N->getIDom()->getBlock());
DT.changeImmediateDominator(AbrtBB, DomBB);
}
DEBUG(errs() << *I << "\n");
}
//verifyFunction(F);
return true;
}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
AU.addRequired<LoopInfo>();
AU.addRequired<ScalarEvolution>();
AU.addRequired<DominatorTree>();
}
};
char RuntimeLimits::ID;
class VISIBILITY_HIDDEN LLVMCodegen {
private:
const struct cli_bc *bc;
Module *M;
LLVMContext &Context;
ExecutionEngine *EE;
FunctionPassManager &PM;
LLVMTypeMapper *TypeMap;
Function **apiFuncs;
LLVMTypeMapper &apiMap;
FunctionMapTy &compiledFunctions;
Twine BytecodeID;
TargetFolder Folder;
IRBuilder<false, TargetFolder> Builder;
std::vector<Value*> globals;
DenseMap<unsigned, unsigned> GVoffsetMap;
DenseMap<unsigned, const Type*> GVtypeMap;
Value **Values;
unsigned numLocals;
unsigned numArgs;
std::vector<MDNode*> mdnodes;
struct CommonFunctions *CF;
Value *getOperand(const struct cli_bc_func *func, const Type *Ty, operand_t operand)
{
unsigned map[] = {0, 1, 2, 3, 3, 4, 4, 4, 4};
if (operand < func->numValues)
return Values[operand];
unsigned w = Ty->getPrimitiveSizeInBits();
if (w > 1)
w = (w+7)/8;
else
w = 0;
return convertOperand(func, map[w], operand);
}
Value *convertOperand(const struct cli_bc_func *func, const Type *Ty, operand_t operand)
{
unsigned map[] = {0, 1, 2, 3, 3, 4, 4, 4, 4};
if (operand < func->numArgs)
return Values[operand];
if (operand < func->numValues) {
Value *V = Values[operand];
if (func->types[operand]&0x8000 && V->getType() == Ty) {
return V;
}
V = Builder.CreateLoad(V);
if (V->getType() != Ty &&
isa<PointerType>(V->getType()) &&
isa<PointerType>(Ty))
V = Builder.CreateBitCast(V, Ty);
if (V->getType() != Ty) {
errs() << operand << " ";
V->dump();
Ty->dump();
llvm_report_error("(libclamav) Type mismatch converting operand");
}
return V;
}
unsigned w = Ty->getPrimitiveSizeInBits();
if (w > 1)
w = (w+7)/8;
else
w = 0;
return convertOperand(func, map[w], operand);
}
Value *convertOperand(const struct cli_bc_func *func,
const struct cli_bc_inst *inst, operand_t operand)
{
return convertOperand(func, inst->interp_op%5, operand);
}
Value *convertOperand(const struct cli_bc_func *func,
unsigned w, operand_t operand) {
if (operand < func->numArgs)
return Values[operand];
if (operand < func->numValues) {
if (func->types[operand]&0x8000)
return Values[operand];
return Builder.CreateLoad(Values[operand]);
}
if (operand & 0x80000000) {
operand &= 0x7fffffff;
assert(operand < globals.size() && "Global index out of range");
// Global
if (!operand)
return ConstantPointerNull::get(PointerType::getUnqual(Type::getInt8Ty(Context)));
assert(globals[operand]);
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(globals[operand])) {
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(GV->getInitializer())) {
return CE;
}
return GV;
}
return globals[operand];
}
// Constant
operand -= func->numValues;
// This was already validated by libclamav.
assert(operand < func->numConstants && "Constant out of range");
uint64_t *c = &func->constants[operand];
uint64_t v;
const Type *Ty;
switch (w) {
case 0:
case 1:
Ty = w ? Type::getInt8Ty(Context) :
Type::getInt1Ty(Context);
v = *(uint8_t*)c;
break;
case 2:
Ty = Type::getInt16Ty(Context);
v = *(uint16_t*)c;
break;
case 3:
Ty = Type::getInt32Ty(Context);
v = *(uint32_t*)c;
break;
case 4:
Ty = Type::getInt64Ty(Context);
v = *(uint64_t*)c;
break;
default:
llvm_unreachable("width");
}
return ConstantInt::get(Ty, v);
}
void Store(uint16_t dest, Value *V)
{
assert(dest >= numArgs && dest < numLocals+numArgs && "Instruction destination out of range");
Builder.CreateStore(V, Values[dest]);
}
// Insert code that calls \arg CF->FHandler if \arg FailCond is true.
void InsertVerify(Value *FailCond, BasicBlock *&Fail, Function *FHandler,
Function *F) {
if (!Fail) {
Fail = BasicBlock::Create(Context, "fail", F);
CallInst::Create(FHandler,"",Fail);
new UnreachableInst(Context, Fail);
}
BasicBlock *OkBB = BasicBlock::Create(Context, "", F);
Builder.CreateCondBr(FailCond, Fail, OkBB);
Builder.SetInsertPoint(OkBB);
}
const Type* mapType(uint16_t typeID)
{
return TypeMap->get(typeID&0x7fffffff);
}
Constant *buildConstant(const Type *Ty, uint64_t *components, unsigned &c)
{
if (const PointerType *PTy = dyn_cast<PointerType>(Ty)) {
Value *idxs[1] = {
ConstantInt::get(Type::getInt64Ty(Context), components[c++])
};
unsigned idx = components[c++];
if (!idx)
return ConstantPointerNull::get(PTy);
assert(idx < globals.size());
GlobalVariable *GV = cast<GlobalVariable>(globals[idx]);
const Type *IP8Ty = PointerType::getUnqual(Type::getInt8Ty(Ty->getContext()));
Constant *C = ConstantExpr::getPointerCast(GV, IP8Ty);
//TODO: check constant bounds here
return ConstantExpr::getPointerCast(
ConstantExpr::getInBoundsGetElementPtr(C, idxs, 1),
PTy);
}
if (isa<IntegerType>(Ty)) {
return ConstantInt::get(Ty, components[c++]);
}
if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
std::vector<Constant*> elements;
elements.reserve(ATy->getNumElements());
for (unsigned i=0;i<ATy->getNumElements();i++) {
elements.push_back(buildConstant(ATy->getElementType(), components, c));
}
return ConstantArray::get(ATy, elements);
}
if (const StructType *STy = dyn_cast<StructType>(Ty)) {
std::vector<Constant*> elements;
elements.reserve(STy->getNumElements());
for (unsigned i=0;i<STy->getNumElements();i++) {
elements.push_back(buildConstant(STy->getElementType(i), components, c));
}
return ConstantStruct::get(STy, elements);
}
Ty->dump();
llvm_unreachable("invalid type");
return 0;
}
public:
LLVMCodegen(const struct cli_bc *bc, Module *M, struct CommonFunctions *CF, FunctionMapTy &cFuncs,
ExecutionEngine *EE, FunctionPassManager &PM,
Function **apiFuncs, LLVMTypeMapper &apiMap)
: bc(bc), M(M), Context(M->getContext()), EE(EE),
PM(PM), apiFuncs(apiFuncs),apiMap(apiMap),
compiledFunctions(cFuncs), BytecodeID("bc"+Twine(bc->id)),
Folder(EE->getTargetData()), Builder(Context, Folder), CF(CF) {
for (unsigned i=0;i<cli_apicall_maxglobal - _FIRST_GLOBAL;i++) {
unsigned id = cli_globals[i].globalid;
GVoffsetMap[id] = cli_globals[i].offset;
}
}
template <typename InputIterator>
Value* createGEP(Value *Base, const Type *ETy, InputIterator Start, InputIterator End) {
const Type *Ty = GetElementPtrInst::getIndexedType(Base->getType(), Start, End);
if (!Ty || (ETy && (Ty != ETy && (!isa<IntegerType>(Ty) || !isa<IntegerType>(ETy))))) {
errs() << MODULE << "Wrong indices for GEP opcode: "
<< " expected type: " << *ETy;
if (Ty)
errs() << " actual type: " << *Ty;
errs() << " base: " << *Base << ";";
Base->getType()->dump();
errs() << "\n indices: ";
for (InputIterator I=Start; I != End; I++) {
errs() << **I << ", ";
}
errs() << "\n";
return 0;
}
return Builder.CreateGEP(Base, Start, End);
}
template <typename InputIterator>
bool createGEP(unsigned dest, Value *Base, InputIterator Start, InputIterator End) {
assert(dest >= numArgs && dest < numLocals+numArgs && "Instruction destination out of range");
const Type *ETy = cast<PointerType>(cast<PointerType>(Values[dest]->getType())->getElementType())->getElementType();
Value *V = createGEP(Base, ETy, Start, End);
if (!V) {
errs() << "@ " << dest << "\n";
return false;
}
V = Builder.CreateBitCast(V, PointerType::getUnqual(ETy));
Store(dest, V);
return true;
}
MDNode *convertMDNode(unsigned i) {
if (i < mdnodes.size()) {
if (mdnodes[i])
return mdnodes[i];
} else
mdnodes.resize(i+1);
assert(i < mdnodes.size());
const struct cli_bc_dbgnode *node = &bc->dbgnodes[i];
Value **Vals = new Value*[node->numelements];
for (unsigned j=0;j<node->numelements;j++) {
const struct cli_bc_dbgnode_element* el = &node->elements[j];
Value *V;
if (!el->len) {
if (el->nodeid == ~0u)
V = 0;
else if (el->nodeid)
V = convertMDNode(el->nodeid);
else
V = MDString::get(Context, "");
} else if (el->string) {
V = MDString::get(Context, StringRef(el->string, el->len));
} else {
V = ConstantInt::get(IntegerType::get(Context, el->len),
el->constant);
}
Vals[j] = V;
}
MDNode *N = MDNode::get(Context, Vals, node->numelements);
delete[] Vals;
mdnodes[i] = N;
return N;
}
void AddStackProtect(Function *F)
{
BasicBlock &BB = F->getEntryBlock();
if (isa<AllocaInst>(BB.begin())) {
// Have an alloca -> some instruction uses its address otherwise
// mem2reg would have converted it to an SSA register.
// Enable stack protector for this function.
F->addFnAttr(Attribute::StackProtect);
F->addFnAttr(Attribute::StackProtectReq);
}
}
bool generate() {
TypeMap = new LLVMTypeMapper(Context, bc->types + 4, bc->num_types - 5);
for (unsigned i=0;i<bc->dbgnode_cnt;i++) {
mdnodes.push_back(convertMDNode(i));
}
for (unsigned i=0;i<cli_apicall_maxglobal - _FIRST_GLOBAL;i++) {
unsigned id = cli_globals[i].globalid;
const Type *Ty = apiMap.get(cli_globals[i].type);
/*if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty))
Ty = PointerType::getUnqual(ATy->getElementType());*/
GVtypeMap[id] = Ty;
}
// The hidden ctx param to all functions
unsigned maxh = cli_globals[0].offset + sizeof(struct cli_bc_hooks);
const Type *HiddenCtx = PointerType::getUnqual(ArrayType::get(Type::getInt8Ty(Context), maxh));
globals.reserve(bc->num_globals);
BitVector FakeGVs;
FakeGVs.resize(bc->num_globals);
globals.push_back(0);
for (unsigned i=1;i<bc->num_globals;i++) {
const Type *Ty = mapType(bc->globaltys[i]);
// TODO: validate number of components against type_components
unsigned c = 0;
GlobalVariable *GV;
if (isa<PointerType>(Ty)) {
unsigned g = bc->globals[i][1];
if (GVoffsetMap.count(g)) {
FakeGVs.set(i);
globals.push_back(0);
continue;
}
}
Constant *C = buildConstant(Ty, bc->globals[i], c);
GV = new GlobalVariable(*M, Ty, true,
GlobalValue::InternalLinkage,
C, "glob"+Twine(i));
globals.push_back(GV);
}
Function **Functions = new Function*[bc->num_func];
for (unsigned j=0;j<bc->num_func;j++) {
PrettyStackTraceString CrashInfo("Generate LLVM IR functions");
// Create LLVM IR Function
const struct cli_bc_func *func = &bc->funcs[j];
std::vector<const Type*> argTypes;
argTypes.push_back(HiddenCtx);
for (unsigned a=0;a<func->numArgs;a++) {
argTypes.push_back(mapType(func->types[a]));
}
const Type *RetTy = mapType(func->returnType);
FunctionType *FTy = FunctionType::get(RetTy, argTypes,
false);
Functions[j] = Function::Create(FTy, Function::InternalLinkage,
BytecodeID+"f"+Twine(j), M);
Functions[j]->setDoesNotThrow();
Functions[j]->setCallingConv(CallingConv::Fast);
}
const Type *I32Ty = Type::getInt32Ty(Context);
if (!bc->trusted)
PM.add(createClamBCRTChecks());
PM.add(new RuntimeLimits());
for (unsigned j=0;j<bc->num_func;j++) {
PrettyStackTraceString CrashInfo("Generate LLVM IR");
const struct cli_bc_func *func = &bc->funcs[j];
// Create all BasicBlocks
Function *F = Functions[j];
BasicBlock **BB = new BasicBlock*[func->numBB];
for (unsigned i=0;i<func->numBB;i++) {
BB[i] = BasicBlock::Create(Context, "", F);
}
BasicBlock *Fail = 0;
Values = new Value*[func->numValues];
Builder.SetInsertPoint(BB[0]);
Function::arg_iterator I = F->arg_begin();
assert(F->arg_size() == (unsigned)(func->numArgs + 1) && "Mismatched args");
++I;
for (unsigned i=0;i<func->numArgs; i++) {
assert(I != F->arg_end());
Values[i] = &*I;
++I;
}
for (unsigned i=func->numArgs;i<func->numValues;i++) {
if (!func->types[i]) {
//instructions without return value, like store
Values[i] = 0;
continue;
}
Values[i] = Builder.CreateAlloca(mapType(func->types[i]));
}
numLocals = func->numLocals;
numArgs = func->numArgs;
if (FakeGVs.any()) {
Argument *Ctx = F->arg_begin();
for (unsigned i=0;i<bc->num_globals;i++) {
if (!FakeGVs[i])
continue;
unsigned g = bc->globals[i][1];
unsigned offset = GVoffsetMap[g];
Constant *Idx = ConstantInt::get(Type::getInt32Ty(Context),
offset);
Value *Idxs[2] = {
ConstantInt::get(Type::getInt32Ty(Context), 0),
Idx
};
Value *GEP = Builder.CreateInBoundsGEP(Ctx, Idxs, Idxs+2);
const Type *Ty = GVtypeMap[g];
Ty = PointerType::getUnqual(PointerType::getUnqual(Ty));
Value *Cast = Builder.CreateBitCast(GEP, Ty);
Value *SpecialGV = Builder.CreateLoad(Cast);
const Type *IP8Ty = Type::getInt8Ty(Context);
IP8Ty = PointerType::getUnqual(IP8Ty);
SpecialGV = Builder.CreateBitCast(SpecialGV, IP8Ty);
SpecialGV->setName("g"+Twine(g-_FIRST_GLOBAL)+"_");
Value *C[] = {
ConstantInt::get(Type::getInt32Ty(Context), bc->globals[i][0])
};
globals[i] = createGEP(SpecialGV, 0, C, C+1);
if (!globals[i]) {
errs() << i << ":" << g << ":" << bc->globals[i][0] <<"\n";
Ty->dump();
llvm_report_error("(libclamav) unable to create fake global");
}
globals[i] = Builder.CreateBitCast(globals[i], Ty);
if(GetElementPtrInst *GI = dyn_cast<GetElementPtrInst>(globals[i])) {
GI->setIsInBounds(true);
GI->setName("geped"+Twine(i)+"_");
}
}
}
// Generate LLVM IR for each BB
for (unsigned i=0;i<func->numBB;i++) {
bool unreachable = false;
const struct cli_bc_bb *bb = &func->BB[i];
Builder.SetInsertPoint(BB[i]);
unsigned c = 0;
for (unsigned j=0;j<bb->numInsts;j++) {
const struct cli_bc_inst *inst = &bb->insts[j];
Value *Op0=0, *Op1=0, *Op2=0;
// libclamav has already validated this.
assert(inst->opcode < OP_BC_INVALID && "Invalid opcode");
if (func->dbgnodes) {
if (func->dbgnodes[c] != ~0u) {
unsigned j = func->dbgnodes[c];
assert(j < mdnodes.size());
Builder.SetCurrentDebugLocation(mdnodes[j]);
} else
Builder.SetCurrentDebugLocation(0);
}
c++;
switch (inst->opcode) {
case OP_BC_JMP:
case OP_BC_BRANCH:
case OP_BC_CALL_API:
case OP_BC_CALL_DIRECT:
case OP_BC_ZEXT:
case OP_BC_SEXT:
case OP_BC_TRUNC:
case OP_BC_GEP1:
case OP_BC_GEPZ:
case OP_BC_GEPN:
case OP_BC_STORE:
case OP_BC_COPY:
case OP_BC_RET:
case OP_BC_PTRDIFF32:
// these instructions represents operands differently
break;
default:
switch (operand_counts[inst->opcode]) {
case 1:
Op0 = convertOperand(func, inst, inst->u.unaryop);
break;
case 2:
Op0 = convertOperand(func, inst, inst->u.binop[0]);
Op1 = convertOperand(func, inst, inst->u.binop[1]);
if (Op0->getType() != Op1->getType()) {
Op0->dump();
Op1->dump();
llvm_report_error("(libclamav) binop type mismatch");
}
break;
case 3:
Op0 = convertOperand(func, inst, inst->u.three[0]);
Op1 = convertOperand(func, inst, inst->u.three[1]);
Op2 = convertOperand(func, inst, inst->u.three[2]);
break;
}
}
switch (inst->opcode) {
case OP_BC_ADD:
Store(inst->dest, Builder.CreateAdd(Op0, Op1));
break;
case OP_BC_SUB:
Store(inst->dest, Builder.CreateSub(Op0, Op1));
break;
case OP_BC_MUL:
Store(inst->dest, Builder.CreateMul(Op0, Op1));
break;
case OP_BC_UDIV:
{
Value *Bad = Builder.CreateICmpEQ(Op1, ConstantInt::get(Op1->getType(), 0));
InsertVerify(Bad, Fail, CF->FHandler, F);
Store(inst->dest, Builder.CreateUDiv(Op0, Op1));
break;
}
case OP_BC_SDIV:
{
//TODO: also verify Op0 == -1 && Op1 = INT_MIN
Value *Bad = Builder.CreateICmpEQ(Op1, ConstantInt::get(Op1->getType(), 0));
InsertVerify(Bad, Fail, CF->FHandler, F);
Store(inst->dest, Builder.CreateSDiv(Op0, Op1));
break;
}
case OP_BC_UREM:
{
Value *Bad = Builder.CreateICmpEQ(Op1, ConstantInt::get(Op1->getType(), 0));
InsertVerify(Bad, Fail, CF->FHandler, F);
Store(inst->dest, Builder.CreateURem(Op0, Op1));
break;
}
case OP_BC_SREM:
{
//TODO: also verify Op0 == -1 && Op1 = INT_MIN
Value *Bad = Builder.CreateICmpEQ(Op1, ConstantInt::get(Op1->getType(), 0));
InsertVerify(Bad, Fail, CF->FHandler, F);
Store(inst->dest, Builder.CreateSRem(Op0, Op1));
break;
}
case OP_BC_SHL:
Store(inst->dest, Builder.CreateShl(Op0, Op1));
break;
case OP_BC_LSHR:
Store(inst->dest, Builder.CreateLShr(Op0, Op1));
break;
case OP_BC_ASHR:
Store(inst->dest, Builder.CreateAShr(Op0, Op1));
break;
case OP_BC_AND:
Store(inst->dest, Builder.CreateAnd(Op0, Op1));
break;
case OP_BC_OR:
Store(inst->dest, Builder.CreateOr(Op0, Op1));
break;
case OP_BC_XOR:
Store(inst->dest, Builder.CreateXor(Op0, Op1));
break;
case OP_BC_TRUNC:
{
Value *Src = convertOperand(func, inst, inst->u.cast.source);
const Type *Ty = mapType(func->types[inst->dest]);
Store(inst->dest, Builder.CreateTrunc(Src, Ty));
break;
}
case OP_BC_ZEXT:
{
Value *Src = convertOperand(func, inst, inst->u.cast.source);
const Type *Ty = mapType(func->types[inst->dest]);
Store(inst->dest, Builder.CreateZExt(Src, Ty));
break;
}
case OP_BC_SEXT:
{
Value *Src = convertOperand(func, inst, inst->u.cast.source);
const Type *Ty = mapType(func->types[inst->dest]);
Store(inst->dest, Builder.CreateSExt(Src, Ty));
break;
}
case OP_BC_BRANCH:
{
Value *Cond = convertOperand(func, inst, inst->u.branch.condition);
BasicBlock *True = BB[inst->u.branch.br_true];
BasicBlock *False = BB[inst->u.branch.br_false];
if (Cond->getType() != Type::getInt1Ty(Context)) {
errs() << MODULE << "type mismatch in condition\n";
return false;
}
Builder.CreateCondBr(Cond, True, False);
break;
}
case OP_BC_JMP:
{
BasicBlock *Jmp = BB[inst->u.jump];
Builder.CreateBr(Jmp);
break;
}
case OP_BC_RET:
{
Op0 = convertOperand(func, F->getReturnType(), inst->u.unaryop);
Builder.CreateRet(Op0);
break;
}
case OP_BC_RET_VOID:
Builder.CreateRetVoid();
break;
case OP_BC_ICMP_EQ:
Store(inst->dest, Builder.CreateICmpEQ(Op0, Op1));
break;
case OP_BC_ICMP_NE:
Store(inst->dest, Builder.CreateICmpNE(Op0, Op1));
break;
case OP_BC_ICMP_UGT:
Store(inst->dest, Builder.CreateICmpUGT(Op0, Op1));
break;
case OP_BC_ICMP_UGE:
Store(inst->dest, Builder.CreateICmpUGE(Op0, Op1));
break;
case OP_BC_ICMP_ULT:
Store(inst->dest, Builder.CreateICmpULT(Op0, Op1));
break;
case OP_BC_ICMP_ULE:
Store(inst->dest, Builder.CreateICmpULE(Op0, Op1));
break;
case OP_BC_ICMP_SGT:
Store(inst->dest, Builder.CreateICmpSGT(Op0, Op1));
break;
case OP_BC_ICMP_SGE:
Store(inst->dest, Builder.CreateICmpSGE(Op0, Op1));
break;
case OP_BC_ICMP_SLT:
Store(inst->dest, Builder.CreateICmpSLT(Op0, Op1));
break;
case OP_BC_SELECT:
Store(inst->dest, Builder.CreateSelect(Op0, Op1, Op2));
break;
case OP_BC_COPY:
{
Value *Dest = Values[inst->u.binop[1]];
const PointerType *PTy = cast<PointerType>(Dest->getType());
Op0 = convertOperand(func, PTy->getElementType(), inst->u.binop[0]);
Builder.CreateStore(Op0, Dest);
break;
}
case OP_BC_CALL_DIRECT:
{
Function *DestF = Functions[inst->u.ops.funcid];
SmallVector<Value*, 2> args;
args.push_back(&*F->arg_begin()); // pass hidden arg
for (unsigned a=0;a<inst->u.ops.numOps;a++) {
operand_t op = inst->u.ops.ops[a];
args.push_back(convertOperand(func, DestF->getFunctionType()->getParamType(a+1), op));
}
CallInst *CI = Builder.CreateCall(DestF, args.begin(), args.end());
CI->setCallingConv(CallingConv::Fast);
if (CI->getType()->getTypeID() != Type::VoidTyID)
Store(inst->dest, CI);
break;
}
case OP_BC_CALL_API:
{
assert(inst->u.ops.funcid < cli_apicall_maxapi && "APICall out of range");
std::vector<Value*> args;
Function *DestF = apiFuncs[inst->u.ops.funcid];
args.push_back(&*F->arg_begin()); // pass hidden arg
for (unsigned a=0;a<inst->u.ops.numOps;a++) {
operand_t op = inst->u.ops.ops[a];
args.push_back(convertOperand(func, DestF->getFunctionType()->getParamType(a+1), op));
}
Store(inst->dest, Builder.CreateCall(DestF, args.begin(), args.end()));
break;
}
case OP_BC_GEP1:
{
const Type *SrcTy = mapType(inst->u.three[0]);
Value *V = convertOperand(func, SrcTy, inst->u.three[1]);
Value *Op = convertOperand(func, I32Ty, inst->u.three[2]);
// Op = Builder.CreateTrunc(Op, I32Ty);
if (!createGEP(inst->dest, V, &Op, &Op+1))
return false;
break;
}
case OP_BC_GEPZ:
{
Value *Ops[2];
Ops[0] = ConstantInt::get(Type::getInt32Ty(Context), 0);
const Type *SrcTy = mapType(inst->u.three[0]);
Value *V = convertOperand(func, SrcTy, inst->u.three[1]);
Ops[1] = convertOperand(func, I32Ty, inst->u.three[2]);
// Ops[1] = Builder.CreateTrunc(Ops[1], I32Ty);
if (!createGEP(inst->dest, V, Ops, Ops+2))
return false;
break;
}
case OP_BC_GEPN:
{
std::vector<Value*> Idxs;
assert(inst->u.ops.numOps > 2);
const Type *SrcTy = mapType(inst->u.ops.ops[0]);
Value *V = convertOperand(func, SrcTy, inst->u.ops.ops[1]);
for (unsigned a=2;a<inst->u.ops.numOps;a++) {
Value *Op = convertOperand(func, I32Ty, inst->u.ops.ops[a]);
// Op = Builder.CreateTrunc(Op, I32Ty);
Idxs.push_back(Op);
}
if (!createGEP(inst->dest, V, Idxs.begin(), Idxs.end()))
return false;
break;
}
case OP_BC_STORE:
{
Value *Dest = convertOperand(func, inst, inst->u.binop[1]);
Value *V = convertOperand(func, inst, inst->u.binop[0]);
const Type *VPTy = PointerType::getUnqual(V->getType());
if (VPTy != Dest->getType())
Dest = Builder.CreateBitCast(Dest, VPTy);
Builder.CreateStore(V, Dest);
break;
}
case OP_BC_LOAD:
{
Op0 = Builder.CreateBitCast(Op0,
Values[inst->dest]->getType());
Op0 = Builder.CreateLoad(Op0);
Store(inst->dest, Op0);
break;
}
case OP_BC_MEMSET:
{
Value *Dst = convertOperand(func, inst, inst->u.three[0]);
Dst = Builder.CreatePointerCast(Dst, PointerType::getUnqual(Type::getInt8Ty(Context)));
Value *Val = convertOperand(func, Type::getInt8Ty(Context), inst->u.three[1]);
Value *Len = convertOperand(func, Type::getInt32Ty(Context), inst->u.three[2]);
CallInst *c = Builder.CreateCall4(CF->FMemset, Dst, Val, Len,
ConstantInt::get(Type::getInt32Ty(Context), 1));
c->setTailCall(true);
c->setDoesNotThrow();
break;
}
case OP_BC_MEMCPY:
{
Value *Dst = convertOperand(func, inst, inst->u.three[0]);
Dst = Builder.CreatePointerCast(Dst, PointerType::getUnqual(Type::getInt8Ty(Context)));
Value *Src = convertOperand(func, inst, inst->u.three[1]);
Src = Builder.CreatePointerCast(Src, PointerType::getUnqual(Type::getInt8Ty(Context)));
Value *Len = convertOperand(func, Type::getInt32Ty(Context), inst->u.three[2]);
CallInst *c = Builder.CreateCall4(CF->FMemcpy, Dst, Src, Len,
ConstantInt::get(Type::getInt32Ty(Context), 1));
c->setTailCall(true);
c->setDoesNotThrow();
break;
}
case OP_BC_MEMMOVE:
{
Value *Dst = convertOperand(func, inst, inst->u.three[0]);
Dst = Builder.CreatePointerCast(Dst, PointerType::getUnqual(Type::getInt8Ty(Context)));
Value *Src = convertOperand(func, inst, inst->u.three[1]);
Src = Builder.CreatePointerCast(Dst, PointerType::getUnqual(Type::getInt8Ty(Context)));
Value *Len = convertOperand(func, Type::getInt32Ty(Context), inst->u.three[2]);
CallInst *c = Builder.CreateCall4(CF->FMemmove, Dst, Src, Len,
ConstantInt::get(Type::getInt32Ty(Context), 1));
c->setTailCall(true);
c->setDoesNotThrow();
break;
}
case OP_BC_MEMCMP:
{
Value *Dst = convertOperand(func, inst, inst->u.three[0]);
Dst = Builder.CreatePointerCast(Dst, PointerType::getUnqual(Type::getInt8Ty(Context)));
Value *Src = convertOperand(func, inst, inst->u.three[1]);
Src = Builder.CreatePointerCast(Dst, PointerType::getUnqual(Type::getInt8Ty(Context)));
Value *Len = convertOperand(func, EE->getTargetData()->getIntPtrType(Context), inst->u.three[2]);
CallInst *c = Builder.CreateCall3(CF->FRealmemcmp, Dst, Src, Len);
c->setTailCall(true);
c->setDoesNotThrow();
Store(inst->dest, c);
break;
}
case OP_BC_ISBIGENDIAN:
Store(inst->dest, WORDS_BIGENDIAN ?
ConstantInt::getTrue(Context) :
ConstantInt::getFalse(Context));
break;
case OP_BC_ABORT:
if (!unreachable) {
CallInst *CI = Builder.CreateCall(CF->FHandler);
CI->setDoesNotReturn();
CI->setDoesNotThrow();
Builder.CreateUnreachable();
unreachable = true;
}
break;
case OP_BC_BSWAP16:
{
CallInst *C = Builder.CreateCall(CF->FBSwap16, convertOperand(func, inst, inst->u.unaryop));
C->setTailCall(true);
C->setDoesNotThrow(true);
Store(inst->dest, C);
break;
}
case OP_BC_BSWAP32:
{
CallInst *C = Builder.CreateCall(CF->FBSwap32, convertOperand(func, inst, inst->u.unaryop));
C->setTailCall(true);
C->setDoesNotThrow(true);
Store(inst->dest, C);
break;
}
case OP_BC_BSWAP64:
{
CallInst *C = Builder.CreateCall(CF->FBSwap64, convertOperand(func, inst, inst->u.unaryop));
C->setTailCall(true);
C->setDoesNotThrow(true);
Store(inst->dest, C);
break;
}
case OP_BC_PTRDIFF32:
{
Value *P1 = convertOperand(func, inst, inst->u.binop[0]);
Value *P2 = convertOperand(func, inst, inst->u.binop[1]);
P1 = Builder.CreatePtrToInt(P1, Type::getInt64Ty(Context));
P2 = Builder.CreatePtrToInt(P2, Type::getInt64Ty(Context));
Value *R = Builder.CreateSub(P1, P2);
R = Builder.CreateTrunc(R, Type::getInt32Ty(Context));
Store(inst->dest, R);
break;
}
default:
errs() << MODULE << "JIT doesn't implement opcode " <<
inst->opcode << " yet!\n";
return false;
}
}
}
if (verifyFunction(*F, PrintMessageAction)) {
errs() << MODULE << "Verification failed\n";
F->dump();
// verification failed
return false;
}
PM.run(*F);
AddStackProtect(F);
delete [] Values;
delete [] BB;
}
DEBUG(M->dump());
delete TypeMap;
std::vector<const Type*> args;
args.clear();
args.push_back(HiddenCtx);
FunctionType *Callable = FunctionType::get(Type::getInt32Ty(Context),
args, false);
for (unsigned j=0;j<bc->num_func;j++) {
const struct cli_bc_func *func = &bc->funcs[j];
PrettyStackTraceString CrashInfo2("Native machine codegen");
// If prototype matches, add to callable functions
if (Functions[j]->getFunctionType() == Callable) {
// All functions have the Fast calling convention, however
// entrypoint can only be C, emit wrapper
Function *F = Function::Create(Functions[j]->getFunctionType(),
Function::ExternalLinkage,
Functions[j]->getName()+"_wrap", M);
F->setDoesNotThrow();
BasicBlock *BB = BasicBlock::Create(Context, "", F);
std::vector<Value*> args;
for (Function::arg_iterator J=F->arg_begin(),
JE=F->arg_end(); J != JE; ++JE) {
args.push_back(&*J);
}
CallInst *CI = CallInst::Create(Functions[j], args.begin(), args.end(), "", BB);
CI->setCallingConv(CallingConv::Fast);
ReturnInst::Create(Context, CI, BB);
if (verifyFunction(*F, PrintMessageAction) == 0) {
DEBUG(errs() << "Generating code\n");
// Codegen current function as executable machine code.
void *code = EE->getPointerToFunction(F);
DEBUG(errs() << "Code generation finished\n");
compiledFunctions[func] = code;
}
}
}
delete [] Functions;
return true;
}
};
static sys::Mutex llvm_api_lock;
// This class automatically acquires the lock when instantiated,
// and releases the lock when leaving scope.
class LLVMApiScopedLock {
public:
// when multithreaded mode is false (no atomics available),
// we need to wrap all LLVM API calls with a giant mutex lock, but
// only then.
LLVMApiScopedLock() {
if (!llvm_is_multithreaded())
llvm_api_lock.acquire();
}
~LLVMApiScopedLock() {
if (!llvm_is_multithreaded())
llvm_api_lock.release();
}
};
static void addFunctionProtos(struct CommonFunctions *CF, ExecutionEngine *EE, Module *M)
{
LLVMContext &Context = M->getContext();
FunctionType *FTy = FunctionType::get(Type::getVoidTy(Context),
false);
CF->FHandler = Function::Create(FTy, Function::ExternalLinkage,
"clamjit.fail", M);
CF->FHandler->setDoesNotReturn();
CF->FHandler->setDoesNotThrow();
CF->FHandler->addFnAttr(Attribute::NoInline);
EE->addGlobalMapping(CF->FHandler, (void*)(intptr_t)jit_exception_handler);
EE->InstallLazyFunctionCreator(noUnknownFunctions);
std::vector<const Type*> args;
args.push_back(PointerType::getUnqual(Type::getInt8Ty(Context)));
args.push_back(Type::getInt8Ty(Context));
args.push_back(Type::getInt32Ty(Context));
args.push_back(Type::getInt32Ty(Context));
FunctionType* FuncTy_3 = FunctionType::get(Type::getVoidTy(Context),
args, false);
CF->FMemset = Function::Create(FuncTy_3, GlobalValue::ExternalLinkage,
"llvm.memset.i32", M);
CF->FMemset->setDoesNotThrow();
CF->FMemset->setDoesNotCapture(1, true);
args.clear();
args.push_back(PointerType::getUnqual(Type::getInt8Ty(Context)));
args.push_back(PointerType::getUnqual(Type::getInt8Ty(Context)));
args.push_back(Type::getInt32Ty(Context));
args.push_back(Type::getInt32Ty(Context));
FunctionType* FuncTy_4 = FunctionType::get(Type::getVoidTy(Context),
args, false);
CF->FMemmove = Function::Create(FuncTy_4, GlobalValue::ExternalLinkage,
"llvm.memmove.i32", M);
CF->FMemmove->setDoesNotThrow();
CF->FMemmove->setDoesNotCapture(1, true);
CF->FMemcpy = Function::Create(FuncTy_4, GlobalValue::ExternalLinkage,
"llvm.memcpy.i32", M);
CF->FMemcpy->setDoesNotThrow();
CF->FMemcpy->setDoesNotCapture(1, true);
args.clear();
args.push_back(Type::getInt16Ty(Context));
FunctionType *FuncTy_5 = FunctionType::get(Type::getInt16Ty(Context), args, false);
CF->FBSwap16 = Function::Create(FuncTy_5, GlobalValue::ExternalLinkage,
"llvm.bswap.i16", M);
CF->FBSwap16->setDoesNotThrow();
args.clear();
args.push_back(Type::getInt32Ty(Context));
FunctionType *FuncTy_6 = FunctionType::get(Type::getInt32Ty(Context), args, false);
CF->FBSwap32 = Function::Create(FuncTy_6, GlobalValue::ExternalLinkage,
"llvm.bswap.i32", M);
CF->FBSwap32->setDoesNotThrow();
args.clear();
args.push_back(Type::getInt64Ty(Context));
FunctionType *FuncTy_7 = FunctionType::get(Type::getInt64Ty(Context), args, false);
CF->FBSwap64 = Function::Create(FuncTy_7, GlobalValue::ExternalLinkage,
"llvm.bswap.i64", M);
CF->FBSwap64->setDoesNotThrow();
FunctionType* DummyTy = FunctionType::get(Type::getVoidTy(Context), false);
CF->FRealmemset = Function::Create(DummyTy, GlobalValue::ExternalLinkage,
"memset", M);
EE->addGlobalMapping(CF->FRealmemset, (void*)(intptr_t)memset);
CF->FRealMemmove = Function::Create(DummyTy, GlobalValue::ExternalLinkage,
"memmove", M);
EE->addGlobalMapping(CF->FRealMemmove, (void*)(intptr_t)memmove);
CF->FRealmemcpy = Function::Create(DummyTy, GlobalValue::ExternalLinkage,
"memcpy", M);
EE->addGlobalMapping(CF->FRealmemcpy, (void*)(intptr_t)memcpy);
args.clear();
args.push_back(PointerType::getUnqual(Type::getInt8Ty(Context)));
args.push_back(PointerType::getUnqual(Type::getInt8Ty(Context)));
args.push_back(EE->getTargetData()->getIntPtrType(Context));
FuncTy_5 = FunctionType::get(Type::getInt32Ty(Context),
args, false);
CF->FRealmemcmp = Function::Create(FuncTy_5, GlobalValue::ExternalLinkage, "memcmp", M);
EE->addGlobalMapping(CF->FRealmemcmp, (void*)(intptr_t)memcmp);
}
}
struct bc_watchdog {
volatile uint8_t* timeout;
struct timespec * abstimeout;
pthread_mutex_t mutex;
pthread_cond_t cond;
int finished;
};
static void *bytecode_watchdog(void *arg)
{
int ret = 0;
struct bc_watchdog *w = (struct bc_watchdog*)arg;
pthread_mutex_lock(&w->mutex);
while (!w->finished && ret != ETIMEDOUT) {
ret = pthread_cond_timedwait(&w->cond, &w->mutex, w->abstimeout);
}
pthread_mutex_unlock(&w->mutex);
if (ret == ETIMEDOUT) {
*w->timeout = 1;
errs() << "Bytecode run timed out, timeout flag set\n";
}
return NULL;
}
static int bytecode_execute(intptr_t code, struct cli_bc_ctx *ctx)
{
jmp_buf env;
// execute;
if (setjmp(env) == 0) {
// setup exception handler to longjmp back here
ExceptionReturn.set((const jmp_buf*)&env);
uint32_t result = ((uint32_t (*)(struct cli_bc_ctx *))(intptr_t)code)(ctx);
*(uint32_t*)ctx->values = result;
return 0;
}
errs() << "\n";
errs().changeColor(raw_ostream::RED, true) << MODULE
<< "*** JITed code intercepted runtime error!\n";
errs().resetColor();
return CL_EBYTECODE;
}
extern "C" const char *cli_strerror(int errnum, char* buf, size_t len);
int cli_vm_execute_jit(const struct cli_all_bc *bcs, struct cli_bc_ctx *ctx,
const struct cli_bc_func *func)
{
char buf[1024];
int ret;
pthread_t thread;
struct timeval tv0, tv1;
uint32_t timeoutus;
// no locks needed here, since LLVM automatically acquires a JIT lock
// if needed.
void *code = bcs->engine->compiledFunctions[func];
if (!code) {
errs() << MODULE << "Unable to find compiled function\n";
if (func->numArgs)
errs() << MODULE << "Function has "
<< (unsigned)func->numArgs << " arguments, it must have 0 to be called as entrypoint\n";
return CL_EBYTECODE;
}
gettimeofday(&tv0, NULL);
struct timespec abstime;
timeoutus = (ctx->bytecode_timeout%1000)*1000 + tv0.tv_usec;
abstime.tv_sec = tv0.tv_sec + ctx->bytecode_timeout/1000 + timeoutus/1000000;
abstime.tv_nsec = 1000*(timeoutus%1000000);
ctx->timeout = 0;
struct bc_watchdog w = {
&ctx->timeout,
&abstime,
PTHREAD_MUTEX_INITIALIZER,
PTHREAD_COND_INITIALIZER,
0
};
if ((ret = pthread_create(&thread, NULL, bytecode_watchdog, &w))) {
errs() << "Bytecode: failed to create new thread!";
errs() << cli_strerror(ret, buf, sizeof(buf));
errs() << "\n";
return CL_EBYTECODE;
}
ret = bytecode_execute((intptr_t)code, ctx);
pthread_mutex_lock(&w.mutex);
w.finished = 1;
pthread_cond_signal(&w.cond);
pthread_mutex_unlock(&w.mutex);
pthread_join(thread, NULL);
if (cli_debug_flag) {
gettimeofday(&tv1, NULL);
tv1.tv_sec -= tv0.tv_sec;
tv1.tv_usec -= tv0.tv_usec;
errs() << "bytecode finished in " << (tv1.tv_sec*1000000 + tv1.tv_usec) << "us\n";
}
return ctx->timeout ? CL_ETIMEOUT : ret;
}
static unsigned char name_salt[16] = { 16, 38, 97, 12, 8, 4, 72, 196, 217, 144, 33, 124, 18, 11, 17, 253 };
static void setGuard(unsigned char* guardbuf)
{
cli_md5_ctx ctx;
char salt[48];
memcpy(salt, name_salt, 16);
for(unsigned i = 16; i < 48; i++)
salt[i] = cli_rndnum(255);
cli_md5_init(&ctx);
cli_md5_update(&ctx, salt, 48);
cli_md5_final(guardbuf, &ctx);
}
int cli_bytecode_prepare_jit(struct cli_all_bc *bcs)
{
if (!bcs->engine)
return CL_EBYTECODE;
jmp_buf env;
LLVMApiScopedLock scopedLock;
// setup exception handler to longjmp back here
ExceptionReturn.set((const jmp_buf*)&env);
if (setjmp(env) != 0) {
errs() << "\n";
errs().changeColor(raw_ostream::RED, true) << MODULE
<< "*** FATAL error encountered during bytecode generation\n";
errs().resetColor();
return CL_EBYTECODE;
}
// LLVM itself never throws exceptions, but operator new may throw bad_alloc
try {
Module *M = new Module("ClamAV jit module", bcs->engine->Context);
{
// Create the JIT.
std::string ErrorMsg;
EngineBuilder builder(M);
builder.setErrorStr(&ErrorMsg);
builder.setEngineKind(EngineKind::JIT);
builder.setOptLevel(CodeGenOpt::Default);
ExecutionEngine *EE = bcs->engine->EE = builder.create();
if (!EE) {
if (!ErrorMsg.empty())
errs() << MODULE << "error creating execution engine: " << ErrorMsg << "\n";
else
errs() << MODULE << "JIT not registered?\n";
return CL_EBYTECODE;
}
bcs->engine->Listener = new NotifyListener();
EE->RegisterJITEventListener(bcs->engine->Listener);
// EE->RegisterJITEventListener(createOProfileJITEventListener());
// Due to LLVM PR4816 only X86 supports non-lazy compilation, disable
// for now.
EE->DisableLazyCompilation();
EE->DisableSymbolSearching();
struct CommonFunctions CF;
addFunctionProtos(&CF, EE, M);
FunctionPassManager OurFPM(M);
// Set up the optimizer pipeline. Start with registering info about how
// the target lays out data structures.
OurFPM.add(new TargetData(*EE->getTargetData()));
// Promote allocas to registers.
OurFPM.add(createPromoteMemoryToRegisterPass());
OurFPM.add(createDeadCodeEliminationPass());
OurFPM.doInitialization();
//TODO: create a wrapper that calls pthread_getspecific
unsigned maxh = cli_globals[0].offset + sizeof(struct cli_bc_hooks);
const Type *HiddenCtx = PointerType::getUnqual(ArrayType::get(Type::getInt8Ty(bcs->engine->Context), maxh));
LLVMTypeMapper apiMap(bcs->engine->Context, cli_apicall_types, cli_apicall_maxtypes, HiddenCtx);
Function **apiFuncs = new Function *[cli_apicall_maxapi];
for (unsigned i=0;i<cli_apicall_maxapi;i++) {
const struct cli_apicall *api = &cli_apicalls[i];
const FunctionType *FTy = cast<FunctionType>(apiMap.get(69+api->type));
Function *F = Function::Create(FTy, Function::ExternalLinkage,
api->name, M);
void *dest;
switch (api->kind) {
case 0:
dest = (void*)(intptr_t)cli_apicalls0[api->idx];
break;
case 1:
dest = (void*)(intptr_t)cli_apicalls1[api->idx];
break;
case 2:
dest = (void*)(intptr_t)cli_apicalls2[api->idx];
break;
case 3:
dest = (void*)(intptr_t)cli_apicalls3[api->idx];
break;
case 4:
dest = (void*)(intptr_t)cli_apicalls4[api->idx];
break;
case 5:
dest = (void*)(intptr_t)cli_apicalls5[api->idx];
break;
case 6:
dest = (void*)(intptr_t)cli_apicalls6[api->idx];
break;
case 7:
dest = (void*)(intptr_t)cli_apicalls7[api->idx];
break;
default:
llvm_unreachable("invalid api type");
}
EE->addGlobalMapping(F, dest);
apiFuncs[i] = F;
}
// stack protector
FunctionType *FTy = FunctionType::get(Type::getVoidTy(M->getContext()),
false);
GlobalVariable *Guard = new GlobalVariable(*M, PointerType::getUnqual(Type::getInt8Ty(M->getContext())),
true, GlobalValue::ExternalLinkage, 0, "__stack_chk_guard");
unsigned plus = 0;
if (2*sizeof(void*) <= 16 && cli_rndnum(2)==2) {
plus = sizeof(void*);
}
EE->addGlobalMapping(Guard, (void*)(&bcs->engine->guard.b[plus]));
setGuard(bcs->engine->guard.b);
bcs->engine->guard.b[plus+sizeof(void*)-1] = 0x00;
// printf("%p\n", *(void**)(&bcs->engine->guard.b[plus]));
Function *SFail = Function::Create(FTy, Function::ExternalLinkage,
"__stack_chk_fail", M);
EE->addGlobalMapping(SFail, (void*)(intptr_t)jit_ssp_handler);
for (unsigned i=0;i<bcs->count;i++) {
const struct cli_bc *bc = &bcs->all_bcs[i];
if (bc->state == bc_skip)
continue;
LLVMCodegen Codegen(bc, M, &CF, bcs->engine->compiledFunctions, EE,
OurFPM, apiFuncs, apiMap);
if (!Codegen.generate()) {
errs() << MODULE << "JIT codegen failed\n";
return CL_EBYTECODE;
}
}
for (unsigned i=0;i<bcs->count;i++) {
bcs->all_bcs[i].state = bc_jit;
}
// compile all functions now, not lazily!
for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I) {
Function *Fn = &*I;
if (!Fn->isDeclaration())
EE->getPointerToFunction(Fn);
}
delete [] apiFuncs;
}
return -1;
} catch (std::bad_alloc &badalloc) {
errs() << MODULE << badalloc.what() << "\n";
return CL_EMEM;
} catch (...) {
errs() << MODULE << "Unexpected unknown exception occurred.\n";
return CL_EBYTECODE;
}
}
int bytecode_init(void)
{
// If already initialized return
if (llvm_is_multithreaded()) {
errs() << "bytecode_init: already initialized";
return CL_EARG;
}
llvm_install_error_handler(llvm_error_handler);
#ifdef CL_DEBUG
sys::PrintStackTraceOnErrorSignal();
#else
llvm::DisablePrettyStackTrace = true;
#endif
atexit(do_shutdown);
#ifdef CL_DEBUG
//disable this for now, it leaks
llvm::JITEmitDebugInfo = false;
// llvm::JITEmitDebugInfo = true;
#else
llvm::JITEmitDebugInfo = false;
#endif
llvm::DwarfExceptionHandling = false;
llvm_start_multithreaded();
// If we have a native target, initialize it to ensure it is linked in and
// usable by the JIT.
InitializeNativeTarget();
if (!llvm_is_multithreaded()) {
//TODO:cli_dbgmsg
DEBUG(errs() << "WARNING: ClamAV JIT built w/o atomic builtins\n"
<< "On x86 for best performance ClamAV should be built for i686, not i386!\n");
}
return 0;
}
// Called once when loading a new set of BC files
int cli_bytecode_init_jit(struct cli_all_bc *bcs, unsigned dconfmask)
{
LLVMApiScopedLock scopedLock;
Triple triple(sys::getHostTriple());
if (cli_debug_flag)
errs() << "host triple is: " << sys::getHostTriple() << "\n";
enum Triple::ArchType arch = triple.getArch();
switch (arch) {
case Triple::arm:
if (!(dconfmask & BYTECODE_JIT_ARM)) {
if (cli_debug_flag)
errs() << "host triple is: " << sys::getHostTriple() << "\n";
return 0;
}
break;
case Triple::ppc:
case Triple::ppc64:
if (!(dconfmask & BYTECODE_JIT_PPC)) {
if (cli_debug_flag)
errs() << "JIT disabled for ppc\n";
return 0;
}
break;
case Triple::x86:
case Triple::x86_64:
if (!(dconfmask & BYTECODE_JIT_X86)) {
if (cli_debug_flag)
errs() << "JIT disabled for x86\n";
return 0;
}
break;
default:
errs() << "Not supported architecture for " << triple.str() << "\n";
return CL_EBYTECODE;
}
std::string cpu = sys::getHostCPUName();
if (cli_debug_flag)
errs() << "host cpu is: " << cpu << "\n";
if (!cpu.compare("i386") ||
!cpu.compare("i486")) {
bcs->engine = 0;
DEBUG(errs() << "i[34]86 detected, falling back to interpreter (JIT needs pentium or better\n");
/* i386 and i486 has to fallback to interpreter */
return 0;
}
bcs->engine = new(std::nothrow) cli_bcengine;
if (!bcs->engine)
return CL_EMEM;
bcs->engine->EE = 0;
bcs->engine->Listener = 0;
return 0;
}
int cli_bytecode_done_jit(struct cli_all_bc *bcs)
{
LLVMApiScopedLock scopedLock;
if (bcs->engine) {
if (bcs->engine->EE) {
if (bcs->engine->Listener)
bcs->engine->EE->UnregisterJITEventListener(bcs->engine->Listener);
delete bcs->engine->EE;
}
delete bcs->engine->Listener;
delete bcs->engine;
bcs->engine = 0;
}
return 0;
}
void cli_bytecode_debug(int argc, char **argv)
{
cl::ParseCommandLineOptions(argc, argv);
}
typedef struct lines {
MemoryBuffer *buffer;
std::vector<const char*> linev;
} linesTy;
static struct lineprinter {
StringMap<linesTy*> files;
} LinePrinter;
void cli_bytecode_debug_printsrc(const struct cli_bc_ctx *ctx)
{
if (!ctx->file || !ctx->directory || !ctx->line) {
errs() << (ctx->directory ? "d":"null") << ":" << (ctx->file ? "f" : "null")<< ":" << ctx->line << "\n";
return;
}
// acquire a mutex here
sys::Mutex mtx(false);
sys::SmartScopedLock<false> lock(mtx);
std::string path = std::string(ctx->directory) + "/" + std::string(ctx->file);
StringMap<linesTy*>::iterator I = LinePrinter.files.find(path);
linesTy *lines;
if (I == LinePrinter.files.end()) {
lines = new linesTy;
std::string ErrorMessage;
lines->buffer = MemoryBuffer::getFile(path, &ErrorMessage);
if (!lines->buffer) {
errs() << "Unable to open file '" << path << "'\n";
return ;
}
LinePrinter.files[path] = lines;
} else {
lines = I->getValue();
}
while (lines->linev.size() <= ctx->line+1) {
const char *p;
if (lines->linev.empty()) {
p = lines->buffer->getBufferStart();
lines->linev.push_back(p);
} else {
p = lines->linev.back();
if (p == lines->buffer->getBufferEnd())
break;
p = strchr(p, '\n');
if (!p) {
p = lines->buffer->getBufferEnd();
lines->linev.push_back(p);
} else
lines->linev.push_back(p+1);
}
}
if (ctx->line >= lines->linev.size()) {
errs() << "Line number " << ctx->line << "out of file\n";
return;
}
assert(ctx->line < lines->linev.size());
SMDiagnostic diag(ctx->file, ctx->line ? ctx->line : -1,
ctx->col ? ctx->col-1 : -1,
"", std::string(lines->linev[ctx->line-1], lines->linev[ctx->line]-1));
diag.Print("[trace]", errs());
}
int have_clamjit=1;
void cli_bytecode_printversion()
{
cl::PrintVersionMessage();
}
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