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#define AFL_LLVM_PASS
#include "config.h"
#include "debug.h"
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/time.h>
#include <fnmatch.h>
#include <list>
#include <string>
#include <fstream>
#include <llvm/Support/raw_ostream.h>
#include "afl-llvm-common.h"
using namespace llvm;
static std::list<std::string> myInstrumentList;
char *getBBName(const llvm::BasicBlock *BB) {
static char *name;
if (!BB->getName().empty()) {
name = strdup(BB->getName().str().c_str());
return name;
}
std::string Str;
raw_string_ostream OS(Str);
#if LLVM_VERSION_MAJOR >= 4 || \
(LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR >= 7)
BB->printAsOperand(OS, false);
#endif
name = strdup(OS.str().c_str());
return name;
}
/* Function that we never instrument or analyze */
/* Note: this ignore check is also called in isInInstrumentList() */
bool isIgnoreFunction(const llvm::Function *F) {
// Starting from "LLVMFuzzer" these are functions used in libfuzzer based
// fuzzing campaign installations, e.g. oss-fuzz
static const char *ignoreList[] = {
"asan.",
"llvm.",
"sancov.",
"__ubsan_handle_",
"ign.",
"__afl_",
"_fini",
"__libc_csu",
"__asan",
"__msan",
"msan.",
"LLVMFuzzer",
"maybe_duplicate_stderr",
"discard_output",
"close_stdout",
"dup_and_close_stderr",
"maybe_close_fd_mask",
"ExecuteFilesOnyByOne"
};
for (auto const &ignoreListFunc : ignoreList) {
if (F->getName().startswith(ignoreListFunc)) { return true; }
}
return false;
}
void initInstrumentList() {
char *instrumentListFilename = getenv("AFL_LLVM_INSTRUMENT_FILE");
if (!instrumentListFilename)
instrumentListFilename = getenv("AFL_LLVM_WHITELIST");
if (instrumentListFilename) {
std::string line;
std::ifstream fileStream;
fileStream.open(instrumentListFilename);
if (!fileStream)
report_fatal_error("Unable to open AFL_LLVM_INSTRUMENT_FILE");
getline(fileStream, line);
while (fileStream) {
myInstrumentList.push_back(line);
getline(fileStream, line);
}
}
}
bool isInInstrumentList(llvm::Function *F) {
// is this a function with code? If it is external we dont instrument it
// anyway and cant be in the the instrument file list. Or if it is ignored.
if (!F->size() || isIgnoreFunction(F)) return false;
// if we do not have a the instrument file list return true
if (myInstrumentList.empty()) return true;
// let's try to get the filename for the function
auto bb = &F->getEntryBlock();
BasicBlock::iterator IP = bb->getFirstInsertionPt();
IRBuilder<> IRB(&(*IP));
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 = myInstrumentList.begin();
it != myInstrumentList.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. We also allow UNIX-style pattern
* matching */
if (instFilename.str().length() >= it->length()) {
if (fnmatch(("*" + *it).c_str(), instFilename.str().c_str(), 0) ==
0) {
return true;
}
}
}
}
}
#else
if (!Loc.isUnknown()) {
DILocation cDILoc(Loc.getAsMDNode(F->getContext()));
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 = myInstrumentList.begin();
it != myInstrumentList.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. We also allow UNIX-style pattern
* matching */
if (instFilename.str().length() >= it->length()) {
if (fnmatch(("*" + *it).c_str(), instFilename.str().c_str(), 0) ==
0) {
return true;
}
}
}
}
}
#endif
else {
// we could not find out the location. in this case we say it is not
// in the the instrument file list
return false;
}
//
return false;
}
// Calculate the number of average collisions that would occur if all
// location IDs would be assigned randomly (like normal afl/afl++).
// This uses the "balls in bins" algorithm.
unsigned long long int calculateCollisions(uint32_t edges) {
double bins = MAP_SIZE;
double balls = edges;
double step1 = 1 - (1 / bins);
double step2 = pow(step1, balls);
double step3 = bins * step2;
double step4 = round(step3);
unsigned long long int empty = step4;
unsigned long long int collisions = edges - (MAP_SIZE - empty);
return collisions;
}
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