From e53806a25b988acd67fe57b42eaa611f2ba96a75 Mon Sep 17 00:00:00 2001
From: Etienne Pierre-doray <etiennep@chromium.org>
Date: Fri, 5 Oct 2018 20:15:13 +0000
Subject: [Zucchini]: Fix discrepancy in reference width for Elf reloc and
 abs32.

Adds kVAWidth to Elf32Traits and use it in
DisassemblerElfIntel::MakeReferenceGroups as the width of
kReloc and kAbs32 reference types.

Bug: 892359

Change-Id: I28930b8978393c16ee29051c48496e4f696a3fcd
Reviewed-on: https://chromium-review.googlesource.com/c/1264816
Commit-Queue: Etienne Pierre-Doray <etiennep@chromium.org>
Reviewed-by: Samuel Huang <huangs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#597264}
NOKEYCHECK=True
GitOrigin-RevId: af95efbfe9d3f3ca90c105f7d1c9c13e43fcde8c
---
 disassembler_elf.cc | 59 ++++++++++++++++++++++++++++-------------------------
 1 file changed, 31 insertions(+), 28 deletions(-)

(limited to 'disassembler_elf.cc')

diff --git a/disassembler_elf.cc b/disassembler_elf.cc
index 8107987..0f6d3a0 100644
--- a/disassembler_elf.cc
+++ b/disassembler_elf.cc
@@ -153,23 +153,6 @@ std::unique_ptr<ReferenceWriter> DisassemblerElf<Traits>::MakeWriteRelocs(
   return std::make_unique<RelocWriterElf>(image, Traits::kBitness, translator_);
 }
 
-template <class Traits>
-std::unique_ptr<ReferenceReader> DisassemblerElf<Traits>::MakeReadAbs32(
-    offset_t lo,
-    offset_t hi) {
-  Abs32RvaExtractorWin32 abs_rva_extractor(image_, {Traits::kBitness, 0},
-                                           abs32_locations_, lo, hi);
-  return std::make_unique<Abs32ReaderWin32>(std::move(abs_rva_extractor),
-                                            translator_);
-}
-
-template <class Traits>
-std::unique_ptr<ReferenceWriter> DisassemblerElf<Traits>::MakeWriteAbs32(
-    MutableBufferView image) {
-  return std::make_unique<Abs32WriterWin32>(
-      image, AbsoluteAddress(Traits::kBitness, 0), translator_);
-}
-
 template <class Traits>
 bool DisassemblerElf<Traits>::ParseHeader() {
   BufferSource source(image_);
@@ -303,7 +286,7 @@ void DisassemblerElf<Traits>::ExtractInterestingSectionHeaders() {
 
 template <class Traits>
 void DisassemblerElf<Traits>::GetAbs32FromRelocSections() {
-  constexpr int kAbs32Width = 4;
+  constexpr int kAbs32Width = Traits::kVAWidth;
   DCHECK(abs32_locations_.empty());
   auto relocs = MakeReadRelocs(0, offset_t(size()));
   for (auto ref = relocs->GetNext(); ref; ref = relocs->GetNext()) {
@@ -317,7 +300,7 @@ void DisassemblerElf<Traits>::GetAbs32FromRelocSections() {
 
   // Abs32 reference bodies must not overlap. If found, simply remove them.
   size_t num_removed =
-      RemoveOverlappingAbs32Locations(Traits::kBitness, &abs32_locations_);
+      RemoveOverlappingAbs32Locations(kAbs32Width, &abs32_locations_);
   if (num_removed) {
     LOG(WARNING) << "Warning: Found and removed " << num_removed
                  << " abs32 locations with overlapping bodies.";
@@ -349,15 +332,17 @@ DisassemblerElfIntel<Traits>::~DisassemblerElfIntel() = default;
 template <class Traits>
 std::vector<ReferenceGroup> DisassemblerElfIntel<Traits>::MakeReferenceGroups()
     const {
-  return {{ReferenceTypeTraits{4, TypeTag(kReloc), PoolTag(kReloc)},
-           &DisassemblerElfIntel<Traits>::MakeReadRelocs,
-           &DisassemblerElfIntel<Traits>::MakeWriteRelocs},
-          {ReferenceTypeTraits{4, TypeTag(kAbs32), PoolTag(kAbs32)},
-           &DisassemblerElfIntel<Traits>::MakeReadAbs32,
-           &DisassemblerElfIntel<Traits>::MakeWriteAbs32},
-          {ReferenceTypeTraits{4, TypeTag(kRel32), PoolTag(kRel32)},
-           &DisassemblerElfIntel<Traits>::MakeReadRel32,
-           &DisassemblerElfIntel<Traits>::MakeWriteRel32}};
+  return {
+      {ReferenceTypeTraits{sizeof(Traits::Elf_Rel::r_offset), TypeTag(kReloc),
+                           PoolTag(kReloc)},
+       &DisassemblerElfIntel<Traits>::MakeReadRelocs,
+       &DisassemblerElfIntel<Traits>::MakeWriteRelocs},
+      {ReferenceTypeTraits{Traits::kVAWidth, TypeTag(kAbs32), PoolTag(kAbs32)},
+       &DisassemblerElfIntel<Traits>::MakeReadAbs32,
+       &DisassemblerElfIntel<Traits>::MakeWriteAbs32},
+      {ReferenceTypeTraits{4, TypeTag(kRel32), PoolTag(kRel32)},
+       &DisassemblerElfIntel<Traits>::MakeReadRel32,
+       &DisassemblerElfIntel<Traits>::MakeWriteRel32}};
 }
 
 template <class Traits>
@@ -403,6 +388,24 @@ void DisassemblerElfIntel<Traits>::PostProcessRel32() {
   std::sort(rel32_locations_.begin(), rel32_locations_.end());
 }
 
+template <class Traits>
+std::unique_ptr<ReferenceReader> DisassemblerElfIntel<Traits>::MakeReadAbs32(
+    offset_t lo,
+    offset_t hi) {
+  Abs32RvaExtractorWin32 abs_rva_extractor(this->image_,
+                                           AbsoluteAddress(Traits::kBitness, 0),
+                                           this->abs32_locations_, lo, hi);
+  return std::make_unique<Abs32ReaderWin32>(std::move(abs_rva_extractor),
+                                            this->translator_);
+}
+
+template <class Traits>
+std::unique_ptr<ReferenceWriter> DisassemblerElfIntel<Traits>::MakeWriteAbs32(
+    MutableBufferView image) {
+  return std::make_unique<Abs32WriterWin32>(
+      image, AbsoluteAddress(Traits::kBitness, 0), this->translator_);
+}
+
 template <class Traits>
 std::unique_ptr<ReferenceReader> DisassemblerElfIntel<Traits>::MakeReadRel32(
     offset_t lo,
-- 
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