1 files changed, 12 insertions, 0 deletions
diff --git a/instrumentation/SanitizerCoverageLTO.so.cc b/instrumentation/SanitizerCoverageLTO.so.cc
index bff85a0a..8d7f0c80 100644
--- a/instrumentation/SanitizerCoverageLTO.so.cc
+++ b/instrumentation/SanitizerCoverageLTO.so.cc
@@ -1289,6 +1289,18 @@ void ModuleSanitizerCoverage::instrumentFunction(
         if (!Callee) continue;
         if (callInst->getCallingConv() != llvm::CallingConv::C) continue;
         StringRef FuncName = Callee->getName();
+        if (!FuncName.compare(StringRef("dlopen")) ||
+            !FuncName.compare(StringRef("_dlopen"))) {
+
+          fprintf(stderr,
+                  "WARNING: dlopen() detected. To have coverage for a library "
+                  "that your target dlopen()'s this must either happen before "
+                  "__AFL_INIT() or you must use AFL_PRELOAD to preload all "
+                  "dlopen()'ed libraries!\n");
+          continue;
+
+        }
+
         if (FuncName.compare(StringRef("__afl_coverage_interesting"))) continue;
 
         Value *val = ConstantInt::get(Int32Ty, ++afl_global_id);