platform_system_core/libunwindstack/tests/MapInfoGetElfTest.cpp
Christopher Ferris bf373edc3c Add caching of build id in MapInfo object.
Change the GetBuildID function to return a std::string.
Added benchmark to check how long it takes to get the build id from
a file versus an elf object.
Added a way to get an elf without passing in a valid process_memory and
added tests for this.

Test: New unit tests.
Change-Id: I3029019767e0181c758d611fe635bc1bf72d6e8e
2019-01-17 20:14:00 -08:00

374 lines
12 KiB
C++

/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <elf.h>
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/ptrace.h>
#include <sys/types.h>
#include <unistd.h>
#include <atomic>
#include <memory>
#include <thread>
#include <vector>
#include <android-base/file.h>
#include <gtest/gtest.h>
#include <unwindstack/Elf.h>
#include <unwindstack/MapInfo.h>
#include <unwindstack/Maps.h>
#include <unwindstack/Memory.h>
#include "ElfTestUtils.h"
#include "MemoryFake.h"
namespace unwindstack {
class MapInfoGetElfTest : public ::testing::Test {
protected:
void SetUp() override {
memory_ = new MemoryFake;
process_memory_.reset(memory_);
}
template <typename Ehdr, typename Shdr>
static void InitElf(uint64_t sh_offset, Ehdr* ehdr, uint8_t class_type, uint8_t machine_type) {
memset(ehdr, 0, sizeof(*ehdr));
memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
ehdr->e_ident[EI_CLASS] = class_type;
ehdr->e_machine = machine_type;
ehdr->e_shoff = sh_offset;
ehdr->e_shentsize = sizeof(Shdr) + 100;
ehdr->e_shnum = 4;
}
const size_t kMapSize = 4096;
std::shared_ptr<Memory> process_memory_;
MemoryFake* memory_;
TemporaryFile elf_;
};
TEST_F(MapInfoGetElfTest, invalid) {
MapInfo info(nullptr, 0x1000, 0x2000, 0, PROT_READ, "");
// The map is empty, but this should still create an invalid elf object.
Elf* elf = info.GetElf(process_memory_, ARCH_ARM);
ASSERT_TRUE(elf != nullptr);
ASSERT_FALSE(elf->valid());
}
TEST_F(MapInfoGetElfTest, valid32) {
MapInfo info(nullptr, 0x3000, 0x4000, 0, PROT_READ, "");
Elf32_Ehdr ehdr;
TestInitEhdr<Elf32_Ehdr>(&ehdr, ELFCLASS32, EM_ARM);
memory_->SetMemory(0x3000, &ehdr, sizeof(ehdr));
Elf* elf = info.GetElf(process_memory_, ARCH_ARM);
ASSERT_TRUE(elf != nullptr);
ASSERT_TRUE(elf->valid());
EXPECT_EQ(static_cast<uint32_t>(EM_ARM), elf->machine_type());
EXPECT_EQ(ELFCLASS32, elf->class_type());
// Now verify that an empty process memory returns an invalid elf object.
info.elf.reset();
elf = info.GetElf(std::shared_ptr<Memory>(), ARCH_ARM);
ASSERT_TRUE(elf != nullptr);
ASSERT_FALSE(elf->valid());
}
TEST_F(MapInfoGetElfTest, valid64) {
MapInfo info(nullptr, 0x8000, 0x9000, 0, PROT_READ, "");
Elf64_Ehdr ehdr;
TestInitEhdr<Elf64_Ehdr>(&ehdr, ELFCLASS64, EM_AARCH64);
memory_->SetMemory(0x8000, &ehdr, sizeof(ehdr));
Elf* elf = info.GetElf(process_memory_, ARCH_ARM64);
ASSERT_TRUE(elf != nullptr);
ASSERT_TRUE(elf->valid());
EXPECT_EQ(static_cast<uint32_t>(EM_AARCH64), elf->machine_type());
EXPECT_EQ(ELFCLASS64, elf->class_type());
}
TEST_F(MapInfoGetElfTest, invalid_arch_mismatch) {
MapInfo info(nullptr, 0x3000, 0x4000, 0, PROT_READ, "");
Elf32_Ehdr ehdr;
TestInitEhdr<Elf32_Ehdr>(&ehdr, ELFCLASS32, EM_ARM);
memory_->SetMemory(0x3000, &ehdr, sizeof(ehdr));
Elf* elf = info.GetElf(process_memory_, ARCH_X86);
ASSERT_TRUE(elf != nullptr);
ASSERT_FALSE(elf->valid());
}
TEST_F(MapInfoGetElfTest, gnu_debugdata_init32) {
MapInfo info(nullptr, 0x2000, 0x3000, 0, PROT_READ, "");
TestInitGnuDebugdata<Elf32_Ehdr, Elf32_Shdr>(ELFCLASS32, EM_ARM, true,
[&](uint64_t offset, const void* ptr, size_t size) {
memory_->SetMemory(0x2000 + offset, ptr, size);
});
Elf* elf = info.GetElf(process_memory_, ARCH_ARM);
ASSERT_TRUE(elf != nullptr);
ASSERT_TRUE(elf->valid());
EXPECT_EQ(static_cast<uint32_t>(EM_ARM), elf->machine_type());
EXPECT_EQ(ELFCLASS32, elf->class_type());
EXPECT_TRUE(elf->gnu_debugdata_interface() != nullptr);
}
TEST_F(MapInfoGetElfTest, gnu_debugdata_init64) {
MapInfo info(nullptr, 0x5000, 0x8000, 0, PROT_READ, "");
TestInitGnuDebugdata<Elf64_Ehdr, Elf64_Shdr>(ELFCLASS64, EM_AARCH64, true,
[&](uint64_t offset, const void* ptr, size_t size) {
memory_->SetMemory(0x5000 + offset, ptr, size);
});
Elf* elf = info.GetElf(process_memory_, ARCH_ARM64);
ASSERT_TRUE(elf != nullptr);
ASSERT_TRUE(elf->valid());
EXPECT_EQ(static_cast<uint32_t>(EM_AARCH64), elf->machine_type());
EXPECT_EQ(ELFCLASS64, elf->class_type());
EXPECT_TRUE(elf->gnu_debugdata_interface() != nullptr);
}
TEST_F(MapInfoGetElfTest, end_le_start) {
MapInfo info(nullptr, 0x1000, 0x1000, 0, PROT_READ, elf_.path);
Elf32_Ehdr ehdr;
TestInitEhdr<Elf32_Ehdr>(&ehdr, ELFCLASS32, EM_ARM);
ASSERT_TRUE(android::base::WriteFully(elf_.fd, &ehdr, sizeof(ehdr)));
Elf* elf = info.GetElf(process_memory_, ARCH_ARM);
ASSERT_TRUE(elf != nullptr);
ASSERT_FALSE(elf->valid());
info.elf.reset();
info.end = 0xfff;
elf = info.GetElf(process_memory_, ARCH_ARM);
ASSERT_TRUE(elf != nullptr);
ASSERT_FALSE(elf->valid());
// Make sure this test is valid.
info.elf.reset();
info.end = 0x2000;
elf = info.GetElf(process_memory_, ARCH_ARM);
ASSERT_TRUE(elf != nullptr);
ASSERT_TRUE(elf->valid());
}
// Verify that if the offset is non-zero but there is no elf at the offset,
// that the full file is used.
TEST_F(MapInfoGetElfTest, file_backed_non_zero_offset_full_file) {
MapInfo info(nullptr, 0x1000, 0x2000, 0x100, PROT_READ, elf_.path);
std::vector<uint8_t> buffer(0x1000);
memset(buffer.data(), 0, buffer.size());
Elf32_Ehdr ehdr;
TestInitEhdr<Elf32_Ehdr>(&ehdr, ELFCLASS32, EM_ARM);
memcpy(buffer.data(), &ehdr, sizeof(ehdr));
ASSERT_TRUE(android::base::WriteFully(elf_.fd, buffer.data(), buffer.size()));
Elf* elf = info.GetElf(process_memory_, ARCH_ARM);
ASSERT_TRUE(elf != nullptr);
ASSERT_TRUE(elf->valid());
ASSERT_TRUE(elf->memory() != nullptr);
ASSERT_EQ(0x100U, info.elf_offset);
// Read the entire file.
memset(buffer.data(), 0, buffer.size());
ASSERT_TRUE(elf->memory()->ReadFully(0, buffer.data(), buffer.size()));
ASSERT_EQ(0, memcmp(buffer.data(), &ehdr, sizeof(ehdr)));
for (size_t i = sizeof(ehdr); i < buffer.size(); i++) {
ASSERT_EQ(0, buffer[i]) << "Failed at byte " << i;
}
ASSERT_FALSE(elf->memory()->ReadFully(buffer.size(), buffer.data(), 1));
}
// Verify that if the offset is non-zero and there is an elf at that
// offset, that only part of the file is used.
TEST_F(MapInfoGetElfTest, file_backed_non_zero_offset_partial_file) {
MapInfo info(nullptr, 0x1000, 0x2000, 0x2000, PROT_READ, elf_.path);
std::vector<uint8_t> buffer(0x4000);
memset(buffer.data(), 0, buffer.size());
Elf32_Ehdr ehdr;
TestInitEhdr<Elf32_Ehdr>(&ehdr, ELFCLASS32, EM_ARM);
memcpy(&buffer[info.offset], &ehdr, sizeof(ehdr));
ASSERT_TRUE(android::base::WriteFully(elf_.fd, buffer.data(), buffer.size()));
Elf* elf = info.GetElf(process_memory_, ARCH_ARM);
ASSERT_TRUE(elf != nullptr);
ASSERT_TRUE(elf->valid());
ASSERT_TRUE(elf->memory() != nullptr);
ASSERT_EQ(0U, info.elf_offset);
// Read the valid part of the file.
ASSERT_TRUE(elf->memory()->ReadFully(0, buffer.data(), 0x1000));
ASSERT_EQ(0, memcmp(buffer.data(), &ehdr, sizeof(ehdr)));
for (size_t i = sizeof(ehdr); i < 0x1000; i++) {
ASSERT_EQ(0, buffer[i]) << "Failed at byte " << i;
}
ASSERT_FALSE(elf->memory()->ReadFully(0x1000, buffer.data(), 1));
}
// Verify that if the offset is non-zero and there is an elf at that
// offset, that only part of the file is used. Further verify that if the
// embedded elf is bigger than the initial map, the new object is larger
// than the original map size. Do this for a 32 bit elf and a 64 bit elf.
TEST_F(MapInfoGetElfTest, file_backed_non_zero_offset_partial_file_whole_elf32) {
MapInfo info(nullptr, 0x5000, 0x6000, 0x1000, PROT_READ, elf_.path);
std::vector<uint8_t> buffer(0x4000);
memset(buffer.data(), 0, buffer.size());
Elf32_Ehdr ehdr;
TestInitEhdr<Elf32_Ehdr>(&ehdr, ELFCLASS32, EM_ARM);
ehdr.e_shoff = 0x2000;
ehdr.e_shentsize = sizeof(Elf32_Shdr) + 100;
ehdr.e_shnum = 4;
memcpy(&buffer[info.offset], &ehdr, sizeof(ehdr));
ASSERT_TRUE(android::base::WriteFully(elf_.fd, buffer.data(), buffer.size()));
Elf* elf = info.GetElf(process_memory_, ARCH_ARM);
ASSERT_TRUE(elf != nullptr);
ASSERT_TRUE(elf->valid());
ASSERT_TRUE(elf->memory() != nullptr);
ASSERT_EQ(0U, info.elf_offset);
// Verify the memory is a valid elf.
memset(buffer.data(), 0, buffer.size());
ASSERT_TRUE(elf->memory()->ReadFully(0, buffer.data(), 0x1000));
ASSERT_EQ(0, memcmp(buffer.data(), &ehdr, sizeof(ehdr)));
// Read past the end of what would normally be the size of the map.
ASSERT_TRUE(elf->memory()->ReadFully(0x1000, buffer.data(), 1));
}
TEST_F(MapInfoGetElfTest, file_backed_non_zero_offset_partial_file_whole_elf64) {
MapInfo info(nullptr, 0x7000, 0x8000, 0x1000, PROT_READ, elf_.path);
std::vector<uint8_t> buffer(0x4000);
memset(buffer.data(), 0, buffer.size());
Elf64_Ehdr ehdr;
TestInitEhdr<Elf64_Ehdr>(&ehdr, ELFCLASS64, EM_AARCH64);
ehdr.e_shoff = 0x2000;
ehdr.e_shentsize = sizeof(Elf64_Shdr) + 100;
ehdr.e_shnum = 4;
memcpy(&buffer[info.offset], &ehdr, sizeof(ehdr));
ASSERT_TRUE(android::base::WriteFully(elf_.fd, buffer.data(), buffer.size()));
Elf* elf = info.GetElf(process_memory_, ARCH_ARM64);
ASSERT_TRUE(elf != nullptr);
ASSERT_TRUE(elf->valid());
ASSERT_TRUE(elf->memory() != nullptr);
ASSERT_EQ(0U, info.elf_offset);
// Verify the memory is a valid elf.
memset(buffer.data(), 0, buffer.size());
ASSERT_TRUE(elf->memory()->ReadFully(0, buffer.data(), 0x1000));
ASSERT_EQ(0, memcmp(buffer.data(), &ehdr, sizeof(ehdr)));
// Read past the end of what would normally be the size of the map.
ASSERT_TRUE(elf->memory()->ReadFully(0x1000, buffer.data(), 1));
}
TEST_F(MapInfoGetElfTest, check_device_maps) {
MapInfo info(nullptr, 0x7000, 0x8000, 0x1000, PROT_READ | MAPS_FLAGS_DEVICE_MAP,
"/dev/something");
// Create valid elf data in process memory for this to verify that only
// the name is causing invalid elf data.
Elf64_Ehdr ehdr;
TestInitEhdr<Elf64_Ehdr>(&ehdr, ELFCLASS64, EM_X86_64);
ehdr.e_shoff = 0x2000;
ehdr.e_shentsize = sizeof(Elf64_Shdr) + 100;
ehdr.e_shnum = 0;
memory_->SetMemory(0x7000, &ehdr, sizeof(ehdr));
Elf* elf = info.GetElf(process_memory_, ARCH_X86_64);
ASSERT_TRUE(elf != nullptr);
ASSERT_FALSE(elf->valid());
// Set the name to nothing to verify that it still fails.
info.elf.reset();
info.name = "";
elf = info.GetElf(process_memory_, ARCH_X86_64);
ASSERT_FALSE(elf->valid());
// Change the flags and verify the elf is valid now.
info.elf.reset();
info.flags = PROT_READ;
elf = info.GetElf(process_memory_, ARCH_X86_64);
ASSERT_TRUE(elf->valid());
}
TEST_F(MapInfoGetElfTest, multiple_thread_get_elf) {
static constexpr size_t kNumConcurrentThreads = 100;
Elf64_Ehdr ehdr;
TestInitEhdr<Elf64_Ehdr>(&ehdr, ELFCLASS64, EM_X86_64);
ehdr.e_shoff = 0x2000;
ehdr.e_shentsize = sizeof(Elf64_Shdr) + 100;
ehdr.e_shnum = 0;
memory_->SetMemory(0x7000, &ehdr, sizeof(ehdr));
Elf* elf_in_threads[kNumConcurrentThreads];
std::vector<std::thread*> threads;
std::atomic_bool wait;
wait = true;
// Create all of the threads and have them do the GetElf at the same time
// to make it likely that a race will occur.
MapInfo info(nullptr, 0x7000, 0x8000, 0x1000, PROT_READ, "");
for (size_t i = 0; i < kNumConcurrentThreads; i++) {
std::thread* thread = new std::thread([i, this, &wait, &info, &elf_in_threads]() {
while (wait)
;
Elf* elf = info.GetElf(process_memory_, ARCH_X86_64);
elf_in_threads[i] = elf;
});
threads.push_back(thread);
}
ASSERT_TRUE(info.elf == nullptr);
// Set them all going and wait for the threads to finish.
wait = false;
for (auto thread : threads) {
thread->join();
delete thread;
}
// Now verify that all of the elf files are exactly the same and valid.
Elf* elf = info.elf.get();
ASSERT_TRUE(elf != nullptr);
EXPECT_TRUE(elf->valid());
for (size_t i = 0; i < kNumConcurrentThreads; i++) {
EXPECT_EQ(elf, elf_in_threads[i]) << "Thread " << i << " mismatched.";
}
}
} // namespace unwindstack