van Hauser 9d686ba523
Add LTO collision free llvm_mode (#223)
* first new implementation, only works with AFL_DONT_OPTIMIZE

* bug hunting

* interim commit

* finalized LTO non-collision solution

* update documentation

* merge resulted in some problems, fixing these

* added lto env to env check

* fixed llvm weirdness to messes up our instrumentation due CFG rewrite optimizations

* all llvm instrumentation issues have been resolved! :-)

* llvm 9 is required (so far)

* update lto readme
2020-03-05 10:52:26 +01:00

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markNodes
->
whitelist:
set meta information/context to functions? ask llvm-dev
setAttribute/hasAttribute?
afl-ld:
handle(=instrument) .a archives on the cmdline
afl-pass-lto-instrument.so:
either a or b:
a) use instrim
b) start in main() or _init() and first otherwise (warn!)
keep list of done functions
final: go through function list and instrument those missing
---------------------------
for (auto &module : Ctx.getModules()) {
auto &functionList = module->getModule()->getFunctionList();
for (auto &function : functionList) {
for (auto &bb : function) {
for (auto &instruction : bb) {
if (CallInst *callInst = dyn_cast<CallInst>(&instruction)) {
if (Function *calledFunction = callInst->getCalledFunction()) {
if (calledFunction->getName().startswith("llvm.dbg.declare")) {
for (auto &U : F.getUsers()) { <- unbekannt
if (auto CS = CallSite(U)) {
if (CS->getCalledFunction() == F)
getCalledValue()->stripPointerCasts()
-> for indirect calls
CallGraph(M)
#include "llvm/IR/CallSite.h"
unsigned int indirect_call_cnt = 0;
printf("Function: %s\n", F.getName().str().c_str());
int cnt=0;
for (auto *U : F.users()) {
// auto *I = dyn_cast<Instruction>(U);
// if (I) {
// if (cast<CallInst>(I)->getCalledFunction()->getName() == F.getName()) {
// printf("DIRECT CALL %s->%s->%s\n", cast<CallInst>(I)->getParent()->getParent()->getName().str().c_str(), cast<CallInst>(I)->getCalledFunction()->getName().str().c_str(), F.getName().str().c_str());
// }
printf("Callsite #%d\n", ++cnt);
CallSite CS(U);
auto *I = CS.getInstruction();
if (I) {
Value *called = CS.getCalledValue()->stripPointerCasts();
Function* f = dyn_cast<Function>(called);
if (f->getName().size() > 0) {
printf("test %s->%s->%s\n", cast<CallInst>(I)->getParent()->getParent()->getName().str().c_str(), f->getName().str().c_str(), F.getName().str().c_str());
if (f->getName() == F.getName()) {
printf("CALL %s->%s->%s\n", cast<CallInst>(I)->getParent()->getParent()->getName().str().c_str(), f->getName().str().c_str(), F.getName().str().c_str());
}
} else
printf("FOO %s->...->%s\n", cast<CallInst>(I)->getParent()->getParent()->getName().str().c_str(), F.getName().str().c_str());
if (cast<CallInst>(I)->getCalledFunction()->getName() == F.getName()) {
printf("DIRECT %s->%s->%s\n", cast<CallInst>(I)->getParent()->getParent()->getName().str().c_str(), cast<CallInst>(I)->getCalledFunction()->getName().str().c_str(), F.getName().str().c_str());
}
} else {
printf("WE MISSED SOMETHING HERE!!\n");
indirect_call_cnt++;
}
}
oder:
for (auto *U : F.users()) {
if (auto CS = CallSite(U->getUser())) {
if (CS->isCallee(&U)) {
// foo
}
}
}