| // Copyright 2018 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "components/zucchini/reloc_elf.h" |
| |
| #include <stdint.h> |
| |
| #include <algorithm> |
| #include <memory> |
| #include <vector> |
| |
| #include "base/numerics/safe_conversions.h" |
| #include "components/zucchini/address_translator.h" |
| #include "components/zucchini/algorithm.h" |
| #include "components/zucchini/image_utils.h" |
| #include "components/zucchini/test_utils.h" |
| #include "components/zucchini/type_elf.h" |
| #include "testing/gtest/include/gtest/gtest.h" |
| |
| namespace zucchini { |
| |
| namespace { |
| |
| template <class Elf_Shdr> |
| SectionDimensionsElf MakeSectionDimensions(const BufferRegion& region, |
| offset_t entry_size) { |
| using sh_offset_t = decltype(Elf_Shdr::sh_offset); |
| using sh_size_t = decltype(Elf_Shdr::sh_size); |
| using sh_entsize_t = decltype(Elf_Shdr::sh_entsize); |
| return SectionDimensionsElf{Elf_Shdr{ |
| 0, // sh_name |
| 0, // sh_type |
| 0, // sh_flags |
| 0, // sh_addr |
| // sh_offset |
| base::checked_cast<sh_offset_t>(region.offset), |
| // sh_size |
| base::checked_cast<sh_size_t>(region.size), |
| 0, // sh_link |
| 0, // sh_info |
| 0, // sh_addralign |
| // sh_entsize |
| base::checked_cast<sh_entsize_t>(entry_size), |
| }}; |
| } |
| |
| } // namespace |
| |
| TEST(RelocElfTest, ReadWrite32) { |
| // Set up mock image: Size = 0x3000, .reloc at 0x600. RVA is 0x40000 + offset. |
| constexpr rva_t kBaseRva = 0x40000; |
| std::vector<uint8_t> image_data(0x3000, 0xFF); |
| // "C0 10 04 00 08 00 00 00" represents |
| // (r_sym, r_type, r_offset) = (0x000000, 0x08, 0x000410C0). |
| // r_type = 0x08 = R_386_RELATIVE, and under this r_offset is an RVA |
| // 0x000410C0. Zucchini does not care about r_sym. |
| std::vector<uint8_t> reloc_data1 = ParseHexString( |
| "C0 10 04 00 08 00 00 00 " // R_386_RELATIVE. |
| "F8 10 04 00 08 AB CD EF " // R_386_RELATIVE. |
| "00 10 04 00 00 AB CD EF " // R_386_NONE. |
| "00 10 04 00 07 AB CD EF"); // R_386_JMP_SLOT. |
| BufferRegion reloc_region1 = {0x600, reloc_data1.size()}; |
| std::copy(reloc_data1.begin(), reloc_data1.end(), |
| image_data.begin() + reloc_region1.lo()); |
| |
| std::vector<uint8_t> reloc_data2 = ParseHexString( |
| "BC 20 04 00 08 00 00 00 " // R_386_RELATIVE. |
| "A0 20 04 00 08 AB CD EF"); // R_386_RELATIVE. |
| BufferRegion reloc_region2 = {0x620, reloc_data2.size()}; |
| std::copy(reloc_data2.begin(), reloc_data2.end(), |
| image_data.begin() + reloc_region2.lo()); |
| |
| ConstBufferView image = {image_data.data(), image_data.size()}; |
| offset_t image_size = base::checked_cast<offset_t>(image_data.size()); |
| |
| AddressTranslator translator; |
| translator.Initialize({{0, image_size, kBaseRva, image_size}}); |
| |
| std::vector<SectionDimensionsElf> section_dimensions{ |
| MakeSectionDimensions<elf::Elf32_Shdr>(reloc_region1, 8), |
| MakeSectionDimensions<elf::Elf32_Shdr>(reloc_region2, 8)}; |
| |
| // Make RelocReaderElf. |
| auto reader = std::make_unique<RelocReaderElf>( |
| image, kBit32, section_dimensions, elf::R_386_RELATIVE, 0, image_size, |
| translator); |
| |
| // Read all references and check. |
| std::vector<Reference> refs; |
| for (base::Optional<Reference> ref = reader->GetNext(); ref.has_value(); |
| ref = reader->GetNext()) { |
| refs.push_back(ref.value()); |
| } |
| // Only R_386_RELATIVE references are extracted. Targets are translated from |
| // address (e.g., 0x000420BC) to offset (e.g., 0x20BC). |
| std::vector<Reference> exp_refs{ |
| {0x600, 0x10C0}, {0x608, 0x10F8}, {0x620, 0x20BC}, {0x628, 0x20A0}}; |
| EXPECT_EQ(exp_refs, refs); |
| |
| // Write reference, extract bytes and check. |
| MutableBufferView mutable_image(&image_data[0], image_data.size()); |
| auto writer = |
| std::make_unique<RelocWriterElf>(mutable_image, kBit32, translator); |
| |
| writer->PutNext({0x608, 0x1F83}); |
| std::vector<uint8_t> exp_reloc_data1 = ParseHexString( |
| "C0 10 04 00 08 00 00 00 " // R_386_RELATIVE. |
| "83 1F 04 00 08 AB CD EF " // R_386_RELATIVE (address modified). |
| "00 10 04 00 00 AB CD EF " // R_386_NONE. |
| "00 10 04 00 07 AB CD EF"); // R_386_JMP_SLOT. |
| EXPECT_EQ(exp_reloc_data1, |
| Sub(image_data, reloc_region1.lo(), reloc_region1.hi())); |
| |
| writer->PutNext({0x628, 0x2950}); |
| std::vector<uint8_t> exp_reloc_data2 = ParseHexString( |
| "BC 20 04 00 08 00 00 00 " // R_386_RELATIVE. |
| "50 29 04 00 08 AB CD EF"); // R_386_RELATIVE (address modified). |
| EXPECT_EQ(exp_reloc_data2, |
| Sub(image_data, reloc_region2.lo(), reloc_region2.hi())); |
| } |
| |
| } // namespace zucchini |