commit 8bb19a984b558fcac06929c187c3d34ebb1e4974
author Kostya Serebryany <kcc@google.com> Sat Feb 16 01:23:41 2019 +0000
committer Copybara-Service <copybara-worker@google.com> Thu Mar 25 23:19:13 2021 -0700
tree f96b1517bbe47f0ec6198e7373c0648912bf1aa9
parent 5af95f47a52cb0aa940dbe8950b0cc708cc4a834

[libFuzzer] make len_control less agressive: set the initial max len to the length of the largest seed. This was the original intent, but... Now, with a test, to ensure it stays this way

llvm-svn: 354191
GitOrigin-RevId: b6ca1e72594a3b79fbe37cd2e70f531c448f3e76

FuzzerLoop.cpp

diff --git a/FuzzerLoop.cpp b/FuzzerLoop.cpp
index 75dc600..b86512b 100644
--- a/FuzzerLoop.cpp
+++ b/FuzzerLoop.cpp
@@ -153,7 +153,7 @@
   if (!Options.OutputCorpus.empty() && Options.ReloadIntervalSec)
     EpochOfLastReadOfOutputCorpus = GetEpoch(Options.OutputCorpus);
   MaxInputLen = MaxMutationLen = Options.MaxLen;
-  TmpMaxMutationLen = Max(size_t(4), Corpus.MaxInputSize());
+  TmpMaxMutationLen = 0;  // Will be set once we load the corpus.
   AllocateCurrentUnitData();
   CurrentUnitSize = 0;
   memset(BaseSha1, 0, sizeof(BaseSha1));
@@ -781,6 +781,10 @@
   TPC.SetPrintNewPCs(Options.PrintNewCovPcs);
   TPC.SetPrintNewFuncs(Options.PrintNewCovFuncs);
   system_clock::time_point LastCorpusReload = system_clock::now();
+
+  TmpMaxMutationLen =
+      Min(MaxMutationLen, Max(size_t(4), Corpus.MaxInputSize()));
+
   while (true) {
     auto Now = system_clock::now();
     if (duration_cast<seconds>(Now - LastCorpusReload).count() >=