From 9a5cf8cf9b9b8a046d3ca7d98340e189d4333f1a Mon Sep 17 00:00:00 2001
From: Anh <zenpoems@gmail.com>
Date: Fri, 8 Feb 2019 10:47:19 -0800
Subject: [PATCH] Fix error in graph optimization
---
afl_transforms/tools/zax/zax_base.cpp | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/afl_transforms/tools/zax/zax_base.cpp b/afl_transforms/tools/zax/zax_base.cpp
index 4ff7000..3466c79 100644
--- a/afl_transforms/tools/zax/zax_base.cpp
+++ b/afl_transforms/tools/zax/zax_base.cpp
@@ -598,6 +598,16 @@ BasicBlockSet_t ZaxBase_t::getBlocksToInstrument(const ControlFlowGraph_t &cfg)
if (m_bb_graph_optimize)
{
+ const auto has_unique_preds=
+ [&](const BasicBlockSet_t& bbs) -> bool
+ {
+ for (const auto & b : bbs)
+ {
+ if (b->getPredecessors().size() != 1)
+ return false;
+ }
+ return true;
+ };
const auto has_ibta=
[&](const BasicBlockSet_t& successors) -> bool
{
@@ -611,6 +621,7 @@ BasicBlockSet_t ZaxBase_t::getBlocksToInstrument(const ControlFlowGraph_t &cfg)
if (bb->getSuccessors().size() == 2 &&
bb->endsInConditionalBranch() &&
+ has_unique_preds(bb->getSuccessors()) &&
!has_ibta(bb->getSuccessors()))
{
// for now, until we get a more principled way of pruning the graph,
--
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