refactored whitelist and blacklist in llvm_mode

1 files changed, 202 insertions, 0 deletions

diff --git a/llvm_mode/afl-llvm-common.cc b/llvm_mode/afl-llvm-common.cc
new file mode 100644
index 00000000..9b7a444a
--- /dev/null
+++ b/llvm_mode/afl-llvm-common.cc
@@ -0,0 +1,202 @@
+#define AFL_LLVM_PASS
+
+#include "config.h"
+#include "debug.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/time.h>
+
+#include <list>
+#include <string>
+#include <fstream>
+
+#include "afl-llvm-common.h"
+
+using namespace llvm;
+
+static std::list<std::string> myWhitelist;
+
+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);
+
+  BB->printAsOperand(OS, false);
+  name = strdup(OS.str().c_str());
+  return name;
+
+}
+
+/* Function that we never instrument or analyze */
+/* Note: this blacklist check is also called in isInWhitelist() */
+bool isBlacklisted(const llvm::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;
+
+}
+
+void initWhitelist() {
+
+  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);
+
+    }
+
+  }
+
+}
+
+bool isInWhitelist(llvm::Function *F) {
+
+  // is this a function with code? If it is external we dont instrument it
+  // anyway and cant be in the whitelist. Or if it is blacklisted.
+  if (!F->size() || isBlacklisted(F)) return false;
+
+  // if we do not have a whitelist return true
+  if (myWhitelist.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 = 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) {
+
+            return true;
+
+          }
+
+        }
+
+      }
+
+    }
+
+  }
+
+#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) {
+
+            return true;
+
+          }
+
+        }
+
+      }
+
+    }
+
+  }
+
+#endif
+  else {
+
+    // we could not find out the location. in this case we say it is not
+    // in the whitelist
+
+    return false;
+
+  }
+
+  //
+  return false;
+
+}
+