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// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/40284755): Remove this and spanify to fix the errors.
#pragma allow_unsafe_buffers
#endif
#include "base/debug/elf_reader.h"
#include <dlfcn.h>
#include <cstdint>
#include <optional>
#include <string_view>
#include "base/debug/test_elf_image_builder.h"
#include "base/files/memory_mapped_file.h"
#include "base/native_library.h"
#include "base/strings/string_util.h"
#include "build/build_config.h"
#include "testing/gtest/include/gtest/gtest.h"
extern char __executable_start;
namespace base::debug {
namespace {
constexpr uint8_t kBuildIdBytes[] = {0xab, 0xcd, 0x12, 0x34};
constexpr const char kBuildIdHexString[] = "ABCD1234";
constexpr const char kBuildIdHexStringLower[] = "ABCD1234";
std::string ParamInfoToString(
const ::testing::TestParamInfo<base::TestElfImageBuilder::MappingType>&
param_info) {
switch (param_info.param) {
case TestElfImageBuilder::RELOCATABLE:
return "Relocatable";
case TestElfImageBuilder::RELOCATABLE_WITH_BIAS:
return "RelocatableWithBias";
case TestElfImageBuilder::NON_RELOCATABLE:
return "NonRelocatable";
}
}
} // namespace
using ElfReaderTest =
::testing::TestWithParam<TestElfImageBuilder::MappingType>;
TEST_P(ElfReaderTest, ReadElfBuildIdUppercase) {
TestElfImage image =
TestElfImageBuilder(GetParam())
.AddLoadSegment(PF_R | PF_X, /* size = */ 2000)
.AddNoteSegment(NT_GNU_BUILD_ID, "GNU", kBuildIdBytes)
.Build();
ElfBuildIdBuffer build_id;
size_t build_id_size = ReadElfBuildId(image.elf_start(), true, build_id);
EXPECT_EQ(8u, build_id_size);
EXPECT_EQ(kBuildIdHexString, std::string_view(&build_id[0], build_id_size));
}
TEST_P(ElfReaderTest, ReadElfBuildIdLowercase) {
TestElfImage image =
TestElfImageBuilder(GetParam())
.AddLoadSegment(PF_R | PF_X, /* size = */ 2000)
.AddNoteSegment(NT_GNU_BUILD_ID, "GNU", kBuildIdBytes)
.Build();
ElfBuildIdBuffer build_id;
size_t build_id_size = ReadElfBuildId(image.elf_start(), false, build_id);
EXPECT_EQ(8u, build_id_size);
EXPECT_EQ(ToLowerASCII(kBuildIdHexStringLower),
std::string_view(&build_id[0], build_id_size));
}
TEST_P(ElfReaderTest, ReadElfBuildIdMultipleNotes) {
constexpr uint8_t kOtherNoteBytes[] = {0xef, 0x56};
TestElfImage image =
TestElfImageBuilder(GetParam())
.AddLoadSegment(PF_R | PF_X, /* size = */ 2000)
.AddNoteSegment(NT_GNU_BUILD_ID + 1, "ABC", kOtherNoteBytes)
.AddNoteSegment(NT_GNU_BUILD_ID, "GNU", kBuildIdBytes)
.Build();
ElfBuildIdBuffer build_id;
size_t build_id_size = ReadElfBuildId(image.elf_start(), true, build_id);
EXPECT_EQ(8u, build_id_size);
EXPECT_EQ(kBuildIdHexString, std::string_view(&build_id[0], build_id_size));
}
TEST_P(ElfReaderTest, ReadElfBuildIdWrongName) {
TestElfImage image =
TestElfImageBuilder(GetParam())
.AddLoadSegment(PF_R | PF_X, /* size = */ 2000)
.AddNoteSegment(NT_GNU_BUILD_ID, "ABC", kBuildIdBytes)
.Build();
ElfBuildIdBuffer build_id;
size_t build_id_size = ReadElfBuildId(image.elf_start(), true, build_id);
EXPECT_EQ(0u, build_id_size);
}
TEST_P(ElfReaderTest, ReadElfBuildIdWrongType) {
TestElfImage image =
TestElfImageBuilder(GetParam())
.AddLoadSegment(PF_R | PF_X, /* size = */ 2000)
.AddNoteSegment(NT_GNU_BUILD_ID + 1, "GNU", kBuildIdBytes)
.Build();
ElfBuildIdBuffer build_id;
size_t build_id_size = ReadElfBuildId(image.elf_start(), true, build_id);
EXPECT_EQ(0u, build_id_size);
}
TEST_P(ElfReaderTest, ReadElfBuildIdNoBuildId) {
TestElfImage image = TestElfImageBuilder(GetParam())
.AddLoadSegment(PF_R | PF_X, /* size = */ 2000)
.Build();
ElfBuildIdBuffer build_id;
size_t build_id_size = ReadElfBuildId(image.elf_start(), true, build_id);
EXPECT_EQ(0u, build_id_size);
}
TEST_P(ElfReaderTest, ReadElfLibraryName) {
TestElfImage image = TestElfImageBuilder(GetParam())
.AddLoadSegment(PF_R | PF_X, /* size = */ 2000)
.AddSoName("mysoname")
.Build();
std::optional<std::string_view> library_name =
ReadElfLibraryName(image.elf_start());
ASSERT_NE(std::nullopt, library_name);
EXPECT_EQ("mysoname", *library_name);
}
TEST_P(ElfReaderTest, ReadElfLibraryNameNoSoName) {
TestElfImage image = TestElfImageBuilder(GetParam())
.AddLoadSegment(PF_R | PF_X, /* size = */ 2000)
.Build();
std::optional<std::string_view> library_name =
ReadElfLibraryName(image.elf_start());
EXPECT_EQ(std::nullopt, library_name);
}
TEST_P(ElfReaderTest, GetRelocationOffset) {
TestElfImage image = TestElfImageBuilder(GetParam())
.AddLoadSegment(PF_R | PF_X, /* size = */ 2000)
.Build();
switch (GetParam()) {
case TestElfImageBuilder::RELOCATABLE:
EXPECT_EQ(reinterpret_cast<size_t>(image.elf_start()),
GetRelocationOffset(image.elf_start()));
break;
case TestElfImageBuilder::RELOCATABLE_WITH_BIAS:
EXPECT_EQ(reinterpret_cast<size_t>(image.elf_start()) -
TestElfImageBuilder::kLoadBias,
GetRelocationOffset(image.elf_start()));
break;
case TestElfImageBuilder::NON_RELOCATABLE:
EXPECT_EQ(0u, GetRelocationOffset(image.elf_start()));
break;
}
}
INSTANTIATE_TEST_SUITE_P(
MappingTypes,
ElfReaderTest,
::testing::Values(TestElfImageBuilder::RELOCATABLE,
TestElfImageBuilder::RELOCATABLE_WITH_BIAS,
TestElfImageBuilder::NON_RELOCATABLE),
&ParamInfoToString);
TEST(ElfReaderTestWithCurrentElfImage, ReadElfBuildId) {
ElfBuildIdBuffer build_id;
size_t build_id_size = ReadElfBuildId(&__executable_start, true, build_id);
ASSERT_NE(build_id_size, 0u);
#if defined(OFFICIAL_BUILD)
constexpr size_t kExpectedBuildIdStringLength = 40; // SHA1 hash in hex.
#else
constexpr size_t kExpectedBuildIdStringLength = 16; // 64-bit int in hex.
#endif
EXPECT_EQ(kExpectedBuildIdStringLength, build_id_size);
for (size_t i = 0; i < build_id_size; ++i) {
char c = build_id[i];
EXPECT_TRUE(IsHexDigit(c));
EXPECT_FALSE(IsAsciiLower(c));
}
}
TEST(ElfReaderTestWithCurrentImage, ReadElfBuildId) {
#if BUILDFLAG(IS_ANDROID)
// On Android the library loader memory maps the full so file.
const char kLibraryName[] = "libbase_unittests__library";
const void* addr = &__executable_start;
#else
const char kLibraryName[] = MALLOC_WRAPPER_LIB;
// On Linux the executable does not contain soname and is not mapped till
// dynamic segment. So, use malloc wrapper so file on which the test already
// depends on.
// Find any symbol in the loaded file.
//
NativeLibraryLoadError error;
NativeLibrary library =
LoadNativeLibrary(base::FilePath(kLibraryName), &error);
void* init_addr =
GetFunctionPointerFromNativeLibrary(library, "MallocWrapper");
// Use this symbol to get full path to the loaded library.
Dl_info info;
int res = dladdr(init_addr, &info);
ASSERT_NE(0, res);
const void* addr = info.dli_fbase;
#endif
auto name = ReadElfLibraryName(addr);
ASSERT_TRUE(name);
EXPECT_NE(std::string::npos, name->find(kLibraryName))
<< "Library name " << *name << " doesn't contain expected "
<< kLibraryName;
#if !BUILDFLAG(IS_ANDROID)
UnloadNativeLibrary(library);
#endif
}
} // namespace base::debug
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