mirror of
https://github.com/AFLplusplus/AFLplusplus.git
synced 2025-06-08 16:21:32 +00:00
809 lines
23 KiB
C++
809 lines
23 KiB
C++
/*
|
|
american fuzzy lop++ - LLVM-mode instrumentation pass
|
|
---------------------------------------------------
|
|
|
|
Written by Laszlo Szekeres <lszekeres@google.com>,
|
|
Adrian Herrera <adrian.herrera@anu.edu.au>,
|
|
Michal Zalewski
|
|
|
|
LLVM integration design comes from Laszlo Szekeres. C bits copied-and-pasted
|
|
from afl-as.c are Michal's fault.
|
|
|
|
NGRAM previous location coverage comes from Adrian Herrera.
|
|
|
|
Copyright 2015, 2016 Google Inc. All rights reserved.
|
|
Copyright 2019-2020 AFLplusplus Project. All rights reserved.
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at:
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
This library is plugged into LLVM when invoking clang through afl-clang-fast.
|
|
It tells the compiler to add code roughly equivalent to the bits discussed
|
|
in ../afl-as.h.
|
|
|
|
*/
|
|
|
|
#define AFL_LLVM_PASS
|
|
|
|
#include "config.h"
|
|
#include "debug.h"
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
|
|
#include <list>
|
|
#include <string>
|
|
#include <fstream>
|
|
#include <sys/time.h>
|
|
|
|
#include "llvm/Config/llvm-config.h"
|
|
#if LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR < 5
|
|
typedef long double max_align_t;
|
|
#endif
|
|
|
|
#include "llvm/IR/IRBuilder.h"
|
|
#include "llvm/IR/LegacyPassManager.h"
|
|
#include "llvm/IR/BasicBlock.h"
|
|
#include "llvm/IR/Module.h"
|
|
#include "llvm/Support/Debug.h"
|
|
#include "llvm/Support/MathExtras.h"
|
|
#include "llvm/Transforms/IPO/PassManagerBuilder.h"
|
|
|
|
#if LLVM_VERSION_MAJOR > 3 || \
|
|
(LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR > 4)
|
|
#include "llvm/IR/DebugInfo.h"
|
|
#include "llvm/IR/CFG.h"
|
|
#else
|
|
#include "llvm/DebugInfo.h"
|
|
#include "llvm/Support/CFG.h"
|
|
#endif
|
|
|
|
#include "llvm-ngram-coverage.h"
|
|
|
|
using namespace llvm;
|
|
|
|
namespace {
|
|
|
|
class AFLCoverage : public ModulePass {
|
|
|
|
public:
|
|
static char ID;
|
|
AFLCoverage() : ModulePass(ID) {
|
|
|
|
char *instWhiteListFilename = getenv("AFL_LLVM_WHITELIST");
|
|
if (instWhiteListFilename) {
|
|
|
|
std::string line;
|
|
std::ifstream fileStream;
|
|
fileStream.open(instWhiteListFilename);
|
|
if (!fileStream) report_fatal_error("Unable to open AFL_LLVM_WHITELIST");
|
|
getline(fileStream, line);
|
|
while (fileStream) {
|
|
|
|
myWhitelist.push_back(line);
|
|
getline(fileStream, line);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
// ripped from aflgo
|
|
static bool isBlacklisted(const Function *F) {
|
|
|
|
static const char *Blacklist[] = {
|
|
|
|
"asan.", "llvm.", "sancov.", "__ubsan_handle_", "ign.", "__afl_",
|
|
"_fini", "__libc_csu", "__asan", "__msan", "msan."
|
|
|
|
};
|
|
|
|
for (auto const &BlacklistFunc : Blacklist) {
|
|
|
|
if (F->getName().startswith(BlacklistFunc)) { return true; }
|
|
|
|
}
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
bool runOnModule(Module &M) override;
|
|
|
|
// StringRef getPassName() const override {
|
|
|
|
// return "American Fuzzy Lop Instrumentation";
|
|
// }
|
|
|
|
protected:
|
|
std::list<std::string> myWhitelist;
|
|
uint32_t ngram_size = 0;
|
|
uint32_t debug = 0;
|
|
uint32_t map_size = MAP_SIZE;
|
|
char * ctx_str = NULL;
|
|
|
|
};
|
|
|
|
} // namespace
|
|
|
|
char AFLCoverage::ID = 0;
|
|
|
|
/* needed up to 3.9.0 */
|
|
#if LLVM_VERSION_MAJOR == 3 && \
|
|
(LLVM_VERSION_MINOR < 9 || \
|
|
(LLVM_VERSION_MINOR == 9 && LLVM_VERSION_PATCH < 1))
|
|
uint64_t PowerOf2Ceil(unsigned in) {
|
|
|
|
uint64_t in64 = in - 1;
|
|
in64 |= (in64 >> 1);
|
|
in64 |= (in64 >> 2);
|
|
in64 |= (in64 >> 4);
|
|
in64 |= (in64 >> 8);
|
|
in64 |= (in64 >> 16);
|
|
in64 |= (in64 >> 32);
|
|
return in64 + 1;
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
/* #if LLVM_VERSION_STRING >= "4.0.1" */
|
|
#if LLVM_VERSION_MAJOR >= 4 || \
|
|
(LLVM_VERSION_MAJOR == 4 && LLVM_VERSION_PATCH >= 1)
|
|
#define AFL_HAVE_VECTOR_INTRINSICS 1
|
|
#endif
|
|
bool AFLCoverage::runOnModule(Module &M) {
|
|
|
|
LLVMContext &C = M.getContext();
|
|
|
|
IntegerType *Int8Ty = IntegerType::getInt8Ty(C);
|
|
IntegerType *Int32Ty = IntegerType::getInt32Ty(C);
|
|
#ifdef AFL_HAVE_VECTOR_INTRINSICS
|
|
IntegerType *IntLocTy =
|
|
IntegerType::getIntNTy(C, sizeof(PREV_LOC_T) * CHAR_BIT);
|
|
#endif
|
|
struct timeval tv;
|
|
struct timezone tz;
|
|
u32 rand_seed;
|
|
unsigned int cur_loc = 0;
|
|
|
|
/* Setup random() so we get Actually Random(TM) outputs from AFL_R() */
|
|
gettimeofday(&tv, &tz);
|
|
rand_seed = tv.tv_sec ^ tv.tv_usec ^ getpid();
|
|
AFL_SR(rand_seed);
|
|
|
|
/* Show a banner */
|
|
|
|
char be_quiet = 0;
|
|
|
|
if (getenv("AFL_DEBUG")) debug = 1;
|
|
|
|
if ((isatty(2) && !getenv("AFL_QUIET")) || getenv("AFL_DEBUG") != NULL) {
|
|
|
|
SAYF(cCYA "afl-llvm-pass" VERSION cRST
|
|
" by <lszekeres@google.com> and <adrian.herrera@anu.edu.au>\n");
|
|
|
|
} else
|
|
|
|
be_quiet = 1;
|
|
|
|
/*
|
|
char *ptr;
|
|
if ((ptr = getenv("AFL_MAP_SIZE")) || (ptr = getenv("AFL_MAPSIZE"))) {
|
|
|
|
map_size = atoi(ptr);
|
|
if (map_size < 8 || map_size > (1 << 29))
|
|
FATAL("illegal AFL_MAP_SIZE %u, must be between 2^3 and 2^30",
|
|
map_size); if (map_size % 8) map_size = (((map_size >> 3) + 1) << 3);
|
|
|
|
}
|
|
|
|
*/
|
|
|
|
/* Decide instrumentation ratio */
|
|
|
|
char * inst_ratio_str = getenv("AFL_INST_RATIO");
|
|
unsigned int inst_ratio = 100;
|
|
|
|
if (inst_ratio_str) {
|
|
|
|
if (sscanf(inst_ratio_str, "%u", &inst_ratio) != 1 || !inst_ratio ||
|
|
inst_ratio > 100)
|
|
FATAL("Bad value of AFL_INST_RATIO (must be between 1 and 100)");
|
|
|
|
}
|
|
|
|
#if LLVM_VERSION_MAJOR < 9
|
|
char *neverZero_counters_str = getenv("AFL_LLVM_NOT_ZERO");
|
|
#endif
|
|
|
|
unsigned PrevLocSize;
|
|
|
|
char *ngram_size_str = getenv("AFL_LLVM_NGRAM_SIZE");
|
|
if (!ngram_size_str) ngram_size_str = getenv("AFL_NGRAM_SIZE");
|
|
ctx_str = getenv("AFL_LLVM_CTX");
|
|
|
|
#ifdef AFL_HAVE_VECTOR_INTRINSICS
|
|
/* Decide previous location vector size (must be a power of two) */
|
|
VectorType *PrevLocTy;
|
|
|
|
if (ngram_size_str)
|
|
if (sscanf(ngram_size_str, "%u", &ngram_size) != 1 || ngram_size < 2 ||
|
|
ngram_size > NGRAM_SIZE_MAX)
|
|
FATAL(
|
|
"Bad value of AFL_NGRAM_SIZE (must be between 2 and NGRAM_SIZE_MAX "
|
|
"(%u))",
|
|
NGRAM_SIZE_MAX);
|
|
|
|
if (ngram_size == 1) ngram_size = 0;
|
|
if (ngram_size)
|
|
PrevLocSize = ngram_size - 1;
|
|
else
|
|
#else
|
|
if (ngram_size_str)
|
|
FATAL("Sorry, NGRAM branch coverage is not supported with llvm version %s!",
|
|
LLVM_VERSION_STRING);
|
|
#endif
|
|
PrevLocSize = 1;
|
|
|
|
#ifdef AFL_HAVE_VECTOR_INTRINSICS
|
|
uint64_t PrevLocVecSize = PowerOf2Ceil(PrevLocSize);
|
|
if (ngram_size) PrevLocTy = VectorType::get(IntLocTy, PrevLocVecSize);
|
|
#endif
|
|
|
|
if (ctx_str && ngram_size_str)
|
|
FATAL("you must decide between NGRAM and CTX instrumentation");
|
|
|
|
/* Get globals for the SHM region and the previous location. Note that
|
|
__afl_prev_loc is thread-local. */
|
|
|
|
GlobalVariable *AFLMapPtr =
|
|
new GlobalVariable(M, PointerType::get(Int8Ty, 0), false,
|
|
GlobalValue::ExternalLinkage, 0, "__afl_area_ptr");
|
|
GlobalVariable *AFLPrevLoc;
|
|
GlobalVariable *AFLContext;
|
|
|
|
if (ctx_str)
|
|
#ifdef __ANDROID__
|
|
AFLContext = new GlobalVariable(
|
|
M, Int32Ty, false, GlobalValue::ExternalLinkage, 0, "__afl_prev_ctx");
|
|
#else
|
|
AFLContext = new GlobalVariable(
|
|
M, Int32Ty, false, GlobalValue::ExternalLinkage, 0, "__afl_prev_ctx", 0,
|
|
GlobalVariable::GeneralDynamicTLSModel, 0, false);
|
|
#endif
|
|
|
|
#ifdef AFL_HAVE_VECTOR_INTRINSICS
|
|
if (ngram_size)
|
|
#ifdef __ANDROID__
|
|
AFLPrevLoc = new GlobalVariable(
|
|
M, PrevLocTy, /* isConstant */ false, GlobalValue::ExternalLinkage,
|
|
/* Initializer */ nullptr, "__afl_prev_loc");
|
|
#else
|
|
AFLPrevLoc = new GlobalVariable(
|
|
M, PrevLocTy, /* isConstant */ false, GlobalValue::ExternalLinkage,
|
|
/* Initializer */ nullptr, "__afl_prev_loc",
|
|
/* InsertBefore */ nullptr, GlobalVariable::GeneralDynamicTLSModel,
|
|
/* AddressSpace */ 0, /* IsExternallyInitialized */ false);
|
|
#endif
|
|
else
|
|
#endif
|
|
#ifdef __ANDROID__
|
|
AFLPrevLoc = new GlobalVariable(
|
|
M, Int32Ty, false, GlobalValue::ExternalLinkage, 0, "__afl_prev_loc");
|
|
#else
|
|
AFLPrevLoc = new GlobalVariable(
|
|
M, Int32Ty, false, GlobalValue::ExternalLinkage, 0, "__afl_prev_loc", 0,
|
|
GlobalVariable::GeneralDynamicTLSModel, 0, false);
|
|
#endif
|
|
|
|
#ifdef AFL_HAVE_VECTOR_INTRINSICS
|
|
/* Create the vector shuffle mask for updating the previous block history.
|
|
Note that the first element of the vector will store cur_loc, so just set
|
|
it to undef to allow the optimizer to do its thing. */
|
|
|
|
SmallVector<Constant *, 32> PrevLocShuffle = {UndefValue::get(Int32Ty)};
|
|
|
|
for (unsigned I = 0; I < PrevLocSize - 1; ++I)
|
|
PrevLocShuffle.push_back(ConstantInt::get(Int32Ty, I));
|
|
|
|
for (unsigned I = PrevLocSize; I < PrevLocVecSize; ++I)
|
|
PrevLocShuffle.push_back(ConstantInt::get(Int32Ty, PrevLocSize));
|
|
|
|
Constant *PrevLocShuffleMask = ConstantVector::get(PrevLocShuffle);
|
|
#endif
|
|
|
|
// other constants we need
|
|
ConstantInt *Zero = ConstantInt::get(Int8Ty, 0);
|
|
ConstantInt *One = ConstantInt::get(Int8Ty, 1);
|
|
|
|
LoadInst *PrevCtx; // CTX sensitive coverage
|
|
|
|
/* Instrument all the things! */
|
|
|
|
int inst_blocks = 0;
|
|
|
|
for (auto &F : M) {
|
|
|
|
int has_calls = 0;
|
|
if (debug)
|
|
fprintf(stderr, "FUNCTION: %s (%zu)\n", F.getName().str().c_str(),
|
|
F.size());
|
|
|
|
if (isBlacklisted(&F)) continue;
|
|
|
|
// AllocaInst *CallingContext = nullptr;
|
|
|
|
if (ctx_str && F.size() > 1) { // Context sensitive coverage
|
|
// load the context ID of the previous function and write to to a local
|
|
// variable on the stack
|
|
auto bb = &F.getEntryBlock();
|
|
BasicBlock::iterator IP = bb->getFirstInsertionPt();
|
|
IRBuilder<> IRB(&(*IP));
|
|
PrevCtx = IRB.CreateLoad(AFLContext);
|
|
PrevCtx->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None));
|
|
|
|
// does the function have calls? and is any of the calls larger than one
|
|
// basic block?
|
|
has_calls = 0;
|
|
for (auto &BB : F) {
|
|
|
|
if (has_calls) break;
|
|
for (auto &IN : BB) {
|
|
|
|
CallInst *callInst = nullptr;
|
|
if ((callInst = dyn_cast<CallInst>(&IN))) {
|
|
|
|
Function *Callee = callInst->getCalledFunction();
|
|
if (!Callee || Callee->size() < 2)
|
|
continue;
|
|
else {
|
|
|
|
has_calls = 1;
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
// if yes we store a context ID for this function in the global var
|
|
if (has_calls) {
|
|
|
|
ConstantInt *NewCtx = ConstantInt::get(Int32Ty, AFL_R(map_size));
|
|
StoreInst * StoreCtx = IRB.CreateStore(NewCtx, AFLContext);
|
|
StoreCtx->setMetadata(M.getMDKindID("nosanitize"),
|
|
MDNode::get(C, None));
|
|
|
|
}
|
|
|
|
}
|
|
|
|
for (auto &BB : F) {
|
|
|
|
BasicBlock::iterator IP = BB.getFirstInsertionPt();
|
|
IRBuilder<> IRB(&(*IP));
|
|
|
|
if (!myWhitelist.empty()) {
|
|
|
|
bool instrumentBlock = false;
|
|
|
|
/* Get the current location using debug information.
|
|
* For now, just instrument the block if we are not able
|
|
* to determine our location. */
|
|
DebugLoc Loc = IP->getDebugLoc();
|
|
#if LLVM_VERSION_MAJOR >= 4 || \
|
|
(LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR >= 7)
|
|
if (Loc) {
|
|
|
|
DILocation *cDILoc = dyn_cast<DILocation>(Loc.getAsMDNode());
|
|
|
|
unsigned int instLine = cDILoc->getLine();
|
|
StringRef instFilename = cDILoc->getFilename();
|
|
|
|
if (instFilename.str().empty()) {
|
|
|
|
/* If the original location is empty, try using the inlined location
|
|
*/
|
|
DILocation *oDILoc = cDILoc->getInlinedAt();
|
|
if (oDILoc) {
|
|
|
|
instFilename = oDILoc->getFilename();
|
|
instLine = oDILoc->getLine();
|
|
|
|
}
|
|
|
|
}
|
|
|
|
(void)instLine;
|
|
|
|
/* Continue only if we know where we actually are */
|
|
if (!instFilename.str().empty()) {
|
|
|
|
for (std::list<std::string>::iterator it = myWhitelist.begin();
|
|
it != myWhitelist.end(); ++it) {
|
|
|
|
/* We don't check for filename equality here because
|
|
* filenames might actually be full paths. Instead we
|
|
* check that the actual filename ends in the filename
|
|
* specified in the list. */
|
|
if (instFilename.str().length() >= it->length()) {
|
|
|
|
if (instFilename.str().compare(
|
|
instFilename.str().length() - it->length(),
|
|
it->length(), *it) == 0) {
|
|
|
|
instrumentBlock = true;
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
#else
|
|
if (!Loc.isUnknown()) {
|
|
|
|
DILocation cDILoc(Loc.getAsMDNode(C));
|
|
|
|
unsigned int instLine = cDILoc.getLineNumber();
|
|
StringRef instFilename = cDILoc.getFilename();
|
|
|
|
(void)instLine;
|
|
|
|
/* Continue only if we know where we actually are */
|
|
if (!instFilename.str().empty()) {
|
|
|
|
for (std::list<std::string>::iterator it = myWhitelist.begin();
|
|
it != myWhitelist.end(); ++it) {
|
|
|
|
/* We don't check for filename equality here because
|
|
* filenames might actually be full paths. Instead we
|
|
* check that the actual filename ends in the filename
|
|
* specified in the list. */
|
|
if (instFilename.str().length() >= it->length()) {
|
|
|
|
if (instFilename.str().compare(
|
|
instFilename.str().length() - it->length(),
|
|
it->length(), *it) == 0) {
|
|
|
|
instrumentBlock = true;
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
/* Either we couldn't figure out our location or the location is
|
|
* not whitelisted, so we skip instrumentation. */
|
|
if (!instrumentBlock) continue;
|
|
|
|
}
|
|
|
|
// in CTX mode we have to restore the original context for the caller -
|
|
// she might be calling other functions which need the correct CTX
|
|
if (ctx_str && has_calls) {
|
|
|
|
Instruction *Inst = BB.getTerminator();
|
|
if (isa<ReturnInst>(Inst) || isa<ResumeInst>(Inst)) {
|
|
|
|
IRBuilder<> Post_IRB(Inst);
|
|
StoreInst * RestoreCtx = Post_IRB.CreateStore(PrevCtx, AFLContext);
|
|
RestoreCtx->setMetadata(M.getMDKindID("nosanitize"),
|
|
MDNode::get(C, None));
|
|
|
|
}
|
|
|
|
}
|
|
|
|
if (AFL_R(100) >= inst_ratio) continue;
|
|
|
|
/* Make up cur_loc */
|
|
|
|
// cur_loc++;
|
|
cur_loc = AFL_R(map_size);
|
|
|
|
/* There is a problem with Ubuntu 18.04 and llvm 6.0 (see issue #63).
|
|
The inline function successors() is not inlined and also not found at runtime
|
|
:-( As I am unable to detect Ubuntu18.04 heree, the next best thing is to
|
|
disable this optional optimization for LLVM 6.0.0 and Linux */
|
|
#if !(LLVM_VERSION_MAJOR == 6 && LLVM_VERSION_MINOR == 0) || !defined __linux__
|
|
// only instrument if this basic block is the destination of a previous
|
|
// basic block that has multiple successors
|
|
// this gets rid of ~5-10% of instrumentations that are unnecessary
|
|
// result: a little more speed and less map pollution
|
|
int more_than_one = -1;
|
|
// fprintf(stderr, "BB %u: ", cur_loc);
|
|
for (pred_iterator PI = pred_begin(&BB), E = pred_end(&BB); PI != E;
|
|
++PI) {
|
|
|
|
BasicBlock *Pred = *PI;
|
|
|
|
int count = 0;
|
|
if (more_than_one == -1) more_than_one = 0;
|
|
// fprintf(stderr, " %p=>", Pred);
|
|
|
|
for (succ_iterator SI = succ_begin(Pred), E = succ_end(Pred); SI != E;
|
|
++SI) {
|
|
|
|
BasicBlock *Succ = *SI;
|
|
|
|
// if (count > 0)
|
|
// fprintf(stderr, "|");
|
|
if (Succ != NULL) count++;
|
|
// fprintf(stderr, "%p", Succ);
|
|
|
|
}
|
|
|
|
if (count > 1) more_than_one = 1;
|
|
|
|
}
|
|
|
|
// fprintf(stderr, " == %d\n", more_than_one);
|
|
if (more_than_one != 1) continue;
|
|
#endif
|
|
|
|
ConstantInt *CurLoc;
|
|
|
|
#ifdef AFL_HAVE_VECTOR_INTRINSICS
|
|
if (ngram_size)
|
|
CurLoc = ConstantInt::get(IntLocTy, cur_loc);
|
|
else
|
|
#endif
|
|
CurLoc = ConstantInt::get(Int32Ty, cur_loc);
|
|
|
|
/* Load prev_loc */
|
|
|
|
LoadInst *PrevLoc = IRB.CreateLoad(AFLPrevLoc);
|
|
PrevLoc->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None));
|
|
Value *PrevLocTrans;
|
|
|
|
#ifdef AFL_HAVE_VECTOR_INTRINSICS
|
|
/* "For efficiency, we propose to hash the tuple as a key into the
|
|
hit_count map as (prev_block_trans << 1) ^ curr_block_trans, where
|
|
prev_block_trans = (block_trans_1 ^ ... ^ block_trans_(n-1)" */
|
|
|
|
if (ngram_size)
|
|
PrevLocTrans = IRB.CreateXorReduce(PrevLoc);
|
|
else
|
|
#endif
|
|
if (ctx_str)
|
|
PrevLocTrans = IRB.CreateZExt(IRB.CreateXor(PrevLoc, PrevCtx), Int32Ty);
|
|
else
|
|
PrevLocTrans = IRB.CreateZExt(PrevLoc, IRB.getInt32Ty());
|
|
|
|
/* Load SHM pointer */
|
|
|
|
LoadInst *MapPtr = IRB.CreateLoad(AFLMapPtr);
|
|
MapPtr->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None));
|
|
|
|
Value *MapPtrIdx;
|
|
#ifdef AFL_HAVE_VECTOR_INTRINSICS
|
|
if (ngram_size)
|
|
MapPtrIdx = IRB.CreateGEP(
|
|
MapPtr,
|
|
IRB.CreateZExt(IRB.CreateXor(PrevLocTrans, CurLoc), Int32Ty));
|
|
else
|
|
#endif
|
|
MapPtrIdx = IRB.CreateGEP(MapPtr, IRB.CreateXor(PrevLocTrans, CurLoc));
|
|
|
|
/* Update bitmap */
|
|
|
|
LoadInst *Counter = IRB.CreateLoad(MapPtrIdx);
|
|
Counter->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None));
|
|
|
|
Value *Incr = IRB.CreateAdd(Counter, One);
|
|
|
|
#if LLVM_VERSION_MAJOR < 9
|
|
if (neverZero_counters_str !=
|
|
NULL) { // with llvm 9 we make this the default as the bug in llvm is
|
|
// then fixed
|
|
#endif
|
|
/* hexcoder: Realize a counter that skips zero during overflow.
|
|
* Once this counter reaches its maximum value, it next increments to 1
|
|
*
|
|
* Instead of
|
|
* Counter + 1 -> Counter
|
|
* we inject now this
|
|
* Counter + 1 -> {Counter, OverflowFlag}
|
|
* Counter + OverflowFlag -> Counter
|
|
*/
|
|
/* // we keep the old solutions just in case
|
|
// Solution #1
|
|
if (neverZero_counters_str[0] == '1') {
|
|
|
|
CallInst *AddOv =
|
|
IRB.CreateBinaryIntrinsic(Intrinsic::uadd_with_overflow, Counter,
|
|
ConstantInt::get(Int8Ty, 1));
|
|
AddOv->setMetadata(M.getMDKindID("nosanitize"),
|
|
MDNode::get(C, None)); Value *SumWithOverflowBit = AddOv; Incr =
|
|
IRB.CreateAdd(IRB.CreateExtractValue(SumWithOverflowBit, 0), // sum
|
|
IRB.CreateZExt( // convert from one bit
|
|
type to 8 bits type IRB.CreateExtractValue(SumWithOverflowBit, 1), //
|
|
overflow Int8Ty));
|
|
// Solution #2
|
|
|
|
} else if (neverZero_counters_str[0] == '2') {
|
|
|
|
auto cf = IRB.CreateICmpEQ(Counter,
|
|
ConstantInt::get(Int8Ty, 255)); Value *HowMuch =
|
|
IRB.CreateAdd(ConstantInt::get(Int8Ty, 1), cf); Incr =
|
|
IRB.CreateAdd(Counter, HowMuch);
|
|
// Solution #3
|
|
|
|
} else if (neverZero_counters_str[0] == '3') {
|
|
|
|
*/
|
|
// this is the solution we choose because llvm9 should do the right
|
|
// thing here
|
|
auto cf = IRB.CreateICmpEQ(Incr, Zero);
|
|
auto carry = IRB.CreateZExt(cf, Int8Ty);
|
|
Incr = IRB.CreateAdd(Incr, carry);
|
|
/*
|
|
// Solution #4
|
|
|
|
} else if (neverZero_counters_str[0] == '4') {
|
|
|
|
auto cf = IRB.CreateICmpULT(Incr, ConstantInt::get(Int8Ty, 1));
|
|
auto carry = IRB.CreateZExt(cf, Int8Ty);
|
|
Incr = IRB.CreateAdd(Incr, carry);
|
|
|
|
} else {
|
|
|
|
fprintf(stderr, "Error: unknown value for AFL_NZERO_COUNTS: %s
|
|
(valid is 1-4)\n", neverZero_counters_str); exit(-1);
|
|
|
|
}
|
|
|
|
*/
|
|
#if LLVM_VERSION_MAJOR < 9
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
IRB.CreateStore(Incr, MapPtrIdx)
|
|
->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None));
|
|
|
|
/* Update prev_loc history vector (by placing cur_loc at the head of the
|
|
vector and shuffle the other elements back by one) */
|
|
|
|
StoreInst *Store;
|
|
|
|
#ifdef AFL_HAVE_VECTOR_INTRINSICS
|
|
if (ngram_size) {
|
|
|
|
Value *ShuffledPrevLoc = IRB.CreateShuffleVector(
|
|
PrevLoc, UndefValue::get(PrevLocTy), PrevLocShuffleMask);
|
|
Value *UpdatedPrevLoc = IRB.CreateInsertElement(
|
|
ShuffledPrevLoc, IRB.CreateLShr(CurLoc, (uint64_t)1), (uint64_t)0);
|
|
|
|
Store = IRB.CreateStore(UpdatedPrevLoc, AFLPrevLoc);
|
|
Store->setMetadata(M.getMDKindID("nosanitize"), MDNode::get(C, None));
|
|
|
|
} else
|
|
|
|
#endif
|
|
{
|
|
|
|
Store = IRB.CreateStore(ConstantInt::get(Int32Ty, cur_loc >> 1),
|
|
AFLPrevLoc);
|
|
|
|
}
|
|
|
|
inst_blocks++;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
/*
|
|
// This is currently disabled because we not only need to create/insert a
|
|
// function (easy), but also add it as a constructor with an ID < 5
|
|
|
|
if (getenv("AFL_LLVM_DONTWRITEID") == NULL) {
|
|
|
|
// yes we could create our own function, insert it into ctors ...
|
|
// but this would be a pain in the butt ... so we use afl-llvm-rt.o
|
|
|
|
Function *f = ...
|
|
|
|
if (!f) {
|
|
|
|
fprintf(stderr,
|
|
"Error: init function could not be created (this should not
|
|
happen)\n"); exit(-1);
|
|
|
|
}
|
|
|
|
... constructor for f = 4
|
|
|
|
BasicBlock *bb = &f->getEntryBlock();
|
|
if (!bb) {
|
|
|
|
fprintf(stderr,
|
|
"Error: init function does not have an EntryBlock (this should
|
|
not happen)\n"); exit(-1);
|
|
|
|
}
|
|
|
|
BasicBlock::iterator IP = bb->getFirstInsertionPt();
|
|
IRBuilder<> IRB(&(*IP));
|
|
|
|
if (map_size <= 0x800000) {
|
|
|
|
GlobalVariable *AFLFinalLoc = new GlobalVariable(
|
|
M, Int32Ty, true, GlobalValue::ExternalLinkage, 0,
|
|
"__afl_final_loc", 0, GlobalVariable::GeneralDynamicTLSModel, 0,
|
|
false);
|
|
ConstantInt *const_loc = ConstantInt::get(Int32Ty, map_size);
|
|
StoreInst * StoreFinalLoc = IRB.CreateStore(const_loc, AFLFinalLoc);
|
|
StoreFinalLoc->setMetadata(M.getMDKindID("nosanitize"),
|
|
MDNode::get(C, None));
|
|
|
|
}
|
|
|
|
}
|
|
|
|
*/
|
|
|
|
/* Say something nice. */
|
|
|
|
if (!be_quiet) {
|
|
|
|
if (!inst_blocks)
|
|
WARNF("No instrumentation targets found.");
|
|
else {
|
|
|
|
char modeline[100];
|
|
snprintf(modeline, sizeof(modeline), "%s%s%s%s%s",
|
|
getenv("AFL_HARDEN") ? "hardened" : "non-hardened",
|
|
getenv("AFL_USE_ASAN") ? ", ASAN" : "",
|
|
getenv("AFL_USE_MSAN") ? ", MSAN" : "",
|
|
getenv("AFL_USE_CFISAN") ? ", CFISAN" : "",
|
|
getenv("AFL_USE_UBSAN") ? ", UBSAN" : "");
|
|
OKF("Instrumented %u locations (%s mode, ratio %u%%).", inst_blocks,
|
|
modeline, inst_ratio);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return true;
|
|
|
|
}
|
|
|
|
static void registerAFLPass(const PassManagerBuilder &,
|
|
legacy::PassManagerBase &PM) {
|
|
|
|
PM.add(new AFLCoverage());
|
|
|
|
}
|
|
|
|
static RegisterStandardPasses RegisterAFLPass(
|
|
PassManagerBuilder::EP_OptimizerLast, registerAFLPass);
|
|
|
|
static RegisterStandardPasses RegisterAFLPass0(
|
|
PassManagerBuilder::EP_EnabledOnOptLevel0, registerAFLPass);
|
|
|