courgette/disassembler_elf_32_x86_unittest.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "courgette/disassembler_elf_32_x86.h"
   6
   7 #include <ctype.h>
   8 #include <stddef.h>
   9 #include <stdint.h>
  10
  11 #include <algorithm>
  12 #include <memory>
  13 #include <set>
  14 #include <string>
  15 #include <vector>
  16
  17 #include "base/memory/ptr_util.h"
  18 #include "courgette/assembly_program.h"
  19 #include "courgette/base_test_unittest.h"
  20 #include "courgette/image_utils.h"
  21
  22 namespace courgette {
  23
  24 namespace {
  25
  26 class TestDisassemblerElf32X86 : public DisassemblerElf32X86 {
  27  public:
  28   TestDisassemblerElf32X86(const uint8_t* start, size_t length)
  29       : DisassemblerElf32X86(start, length) {}
  30   ~TestDisassemblerElf32X86() override = default;
  31
  32   void TestSectionHeaderFileOffsetOrder() {
  33     std::vector<FileOffset> file_offsets;
  34     for (Elf32_Half section_id : section_header_file_offset_order_) {
  35       const Elf32_Shdr* section_header = SectionHeader(section_id);
  36       file_offsets.push_back(section_header->sh_offset);
  37     }
  38     EXPECT_EQ(static_cast<size_t>(SectionHeaderCount()), file_offsets.size());
  39     EXPECT_TRUE(std::is_sorted(file_offsets.begin(), file_offsets.end()));
  40   }
  41
  42   void TestSectionName() {
  43     std::set<std::string> name_set;
  44     for (const Elf32_Shdr& section_header : section_header_table_) {
  45       std::string name;
  46       EXPECT_TRUE(SectionName(section_header, &name));
  47       // Ensure |name| is unique and is printable (may be empty though).
  48       EXPECT_EQ(0U, name_set.count(name));
  49       EXPECT_TRUE(std::all_of(name.begin(), name.end(), ::isprint));
  50       name_set.insert(name);
  51     }
  52     // Check for existence of a few common sections.
  53     EXPECT_EQ(1U, name_set.count(".text"));
  54     EXPECT_EQ(1U, name_set.count(".data"));
  55     EXPECT_EQ(1U, name_set.count(".rodata"));
  56     EXPECT_EQ(1U, name_set.count(".bss"));
  57     EXPECT_EQ(1U, name_set.count(".shstrtab"));
  58   }
  59 };
  60
  61 class DisassemblerElf32X86Test : public BaseTest {
  62  public:
  63   void TestExe(const char* file_name,
  64                size_t expected_abs_count,
  65                size_t expected_rel_count) const;
  66 };
  67
  68 void DisassemblerElf32X86Test::TestExe(const char* file_name,
  69                                        size_t expected_abs_count,
  70                                        size_t expected_rel_count) const {
  71   std::string file1 = FileContents(file_name);
  72
  73   auto disassembler = std::make_unique<TestDisassemblerElf32X86>(
  74       reinterpret_cast<const uint8_t*>(file1.c_str()), file1.length());
  75
  76   bool can_parse_header = disassembler->ParseHeader();
  77   EXPECT_TRUE(can_parse_header);
  78   EXPECT_TRUE(disassembler->ok());
  79   EXPECT_EQ(EXE_ELF_32_X86, disassembler->kind());
  80   EXPECT_EQ(0U, disassembler->image_base());
  81
  82   // The length of the disassembled value will be slightly smaller than the
  83   // real file, since trailing debug info is not included
  84   EXPECT_EQ(file1.length(), disassembler->length());
  85
  86   const uint8_t* offset_p = disassembler->FileOffsetToPointer(0);
  87   EXPECT_EQ(reinterpret_cast<const void*>(file1.c_str()),
  88             reinterpret_cast<const void*>(offset_p));
  89   EXPECT_EQ(0x7F, offset_p[0]);
  90   EXPECT_EQ('E', offset_p[1]);
  91   EXPECT_EQ('L', offset_p[2]);
  92   EXPECT_EQ('F', offset_p[3]);
  93
  94   std::unique_ptr<AssemblyProgram> program = disassembler->CreateProgram(false);
  95   EXPECT_TRUE(nullptr != program.get());
  96
  97   const std::vector<RVA>& abs32_list = disassembler->Abs32Locations();
  98
  99   // Flatten the list typed rel32 to a list of rel32 RVAs.
 100   std::vector<RVA> rel32_list;
 101   rel32_list.reserve(disassembler->Rel32Locations().size());
 102   for (auto& typed_rel32 : disassembler->Rel32Locations())
 103     rel32_list.push_back(typed_rel32->rva());
 104
 105   EXPECT_EQ(expected_abs_count, abs32_list.size());
 106   EXPECT_EQ(expected_rel_count, rel32_list.size());
 107
 108   EXPECT_TRUE(std::is_sorted(abs32_list.begin(), abs32_list.end()));
 109   EXPECT_TRUE(std::is_sorted(rel32_list.begin(), rel32_list.end()));
 110
 111   // Verify that rel32 RVAs do not overlap with abs32 RVAs.
 112   // TODO(huangs): Fix this to account for RVA's 4-byte width.
 113   bool found_match = false;
 114   std::vector<RVA>::const_iterator abs32_it = abs32_list.begin();
 115   std::vector<RVA>::const_iterator rel32_it = rel32_list.begin();
 116   while (abs32_it != abs32_list.end() && rel32_it != rel32_list.end()) {
 117     if (*abs32_it < *rel32_it) {
 118       ++abs32_it;
 119     } else if (*abs32_it > *rel32_it) {
 120       ++rel32_it;
 121     } else {
 122       found_match = true;
 123     }
 124   }
 125   EXPECT_FALSE(found_match);
 126
 127   disassembler->TestSectionHeaderFileOffsetOrder();
 128
 129   disassembler->TestSectionName();
 130 }
 131
 132 }  // namespace
 133
 134 TEST_F(DisassemblerElf32X86Test, All) {
 135   TestExe("elf-32-1", 200, 3337);
 136   TestExe("elf-32-high-bss", 0, 4);
 137 }
 138
 139 }  // namespace courgette