1 /*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <elf.h>
18 #include <errno.h>
19 #include <signal.h>
20 #include <string.h>
21 #include <sys/mman.h>
22 #include <sys/ptrace.h>
23 #include <sys/types.h>
24 #include <unistd.h>
25
26 #include <atomic>
27 #include <memory>
28 #include <thread>
29 #include <vector>
30
31 #include <android-base/file.h>
32 #include <android-base/test_utils.h>
33 #include <gtest/gtest.h>
34
35 #include <unwindstack/Elf.h>
36 #include <unwindstack/MapInfo.h>
37 #include <unwindstack/Maps.h>
38 #include <unwindstack/Memory.h>
39
40 #include "ElfFake.h"
41 #include "ElfTestUtils.h"
42 #include "MemoryFake.h"
43
44 namespace unwindstack {
45
46 class MapInfoGetLoadBiasTest : public ::testing::Test {
47 protected:
SetUp()48 void SetUp() override {
49 memory_ = new MemoryFake;
50 process_memory_.reset(memory_);
51 elf_ = new ElfFake(new MemoryFake);
52 elf_container_.reset(elf_);
53 map_info_.reset(new MapInfo(0x1000, 0x20000, 0, PROT_READ | PROT_WRITE, ""));
54 }
55
56 void MultipleThreadTest(uint64_t expected_load_bias);
57
58 std::shared_ptr<Memory> process_memory_;
59 MemoryFake* memory_;
60 ElfFake* elf_;
61 std::unique_ptr<ElfFake> elf_container_;
62 std::unique_ptr<MapInfo> map_info_;
63 };
64
TEST_F(MapInfoGetLoadBiasTest,no_elf_and_no_valid_elf_in_memory)65 TEST_F(MapInfoGetLoadBiasTest, no_elf_and_no_valid_elf_in_memory) {
66 MapInfo info(0x1000, 0x2000, 0, PROT_READ, "");
67
68 EXPECT_EQ(0U, info.GetLoadBias(process_memory_));
69 }
70
TEST_F(MapInfoGetLoadBiasTest,load_bias_cached_from_elf)71 TEST_F(MapInfoGetLoadBiasTest, load_bias_cached_from_elf) {
72 map_info_->elf.reset(elf_container_.release());
73
74 elf_->FakeSetLoadBias(0);
75 EXPECT_EQ(0U, map_info_->GetLoadBias(process_memory_));
76
77 elf_->FakeSetLoadBias(0x1000);
78 EXPECT_EQ(0U, map_info_->GetLoadBias(process_memory_));
79 }
80
TEST_F(MapInfoGetLoadBiasTest,elf_exists)81 TEST_F(MapInfoGetLoadBiasTest, elf_exists) {
82 map_info_->elf.reset(elf_container_.release());
83
84 elf_->FakeSetLoadBias(0);
85 EXPECT_EQ(0U, map_info_->GetLoadBias(process_memory_));
86
87 map_info_->load_bias = static_cast<uint64_t>(-1);
88 elf_->FakeSetLoadBias(0x1000);
89 EXPECT_EQ(0x1000U, map_info_->GetLoadBias(process_memory_));
90 }
91
MultipleThreadTest(uint64_t expected_load_bias)92 void MapInfoGetLoadBiasTest::MultipleThreadTest(uint64_t expected_load_bias) {
93 static constexpr size_t kNumConcurrentThreads = 100;
94
95 uint64_t load_bias_values[kNumConcurrentThreads];
96 std::vector<std::thread*> threads;
97
98 std::atomic_bool wait;
99 wait = true;
100 // Create all of the threads and have them do the GetLoadBias at the same time
101 // to make it likely that a race will occur.
102 for (size_t i = 0; i < kNumConcurrentThreads; i++) {
103 std::thread* thread = new std::thread([i, this, &wait, &load_bias_values]() {
104 while (wait)
105 ;
106 load_bias_values[i] = map_info_->GetLoadBias(process_memory_);
107 });
108 threads.push_back(thread);
109 }
110
111 // Set them all going and wait for the threads to finish.
112 wait = false;
113 for (auto thread : threads) {
114 thread->join();
115 delete thread;
116 }
117
118 // Now verify that all of the elf files are exactly the same and valid.
119 for (size_t i = 0; i < kNumConcurrentThreads; i++) {
120 EXPECT_EQ(expected_load_bias, load_bias_values[i]) << "Thread " << i << " mismatched.";
121 }
122 }
123
TEST_F(MapInfoGetLoadBiasTest,multiple_thread_elf_exists)124 TEST_F(MapInfoGetLoadBiasTest, multiple_thread_elf_exists) {
125 map_info_->elf.reset(elf_container_.release());
126 elf_->FakeSetLoadBias(0x1000);
127
128 MultipleThreadTest(0x1000);
129 }
130
InitElfData(MemoryFake * memory,uint64_t offset)131 static void InitElfData(MemoryFake* memory, uint64_t offset) {
132 Elf32_Ehdr ehdr;
133 TestInitEhdr(&ehdr, ELFCLASS32, EM_ARM);
134 ehdr.e_phoff = 0x5000;
135 ehdr.e_phnum = 2;
136 ehdr.e_phentsize = sizeof(Elf32_Phdr);
137 memory->SetMemory(offset, &ehdr, sizeof(ehdr));
138
139 Elf32_Phdr phdr;
140 memset(&phdr, 0, sizeof(phdr));
141 phdr.p_type = PT_NULL;
142 memory->SetMemory(offset + 0x5000, &phdr, sizeof(phdr));
143 phdr.p_type = PT_LOAD;
144 phdr.p_offset = 0;
145 phdr.p_vaddr = 0xe000;
146 memory->SetMemory(offset + 0x5000 + sizeof(phdr), &phdr, sizeof(phdr));
147 }
148
TEST_F(MapInfoGetLoadBiasTest,elf_exists_in_memory)149 TEST_F(MapInfoGetLoadBiasTest, elf_exists_in_memory) {
150 InitElfData(memory_, map_info_->start);
151
152 EXPECT_EQ(0xe000U, map_info_->GetLoadBias(process_memory_));
153 }
154
TEST_F(MapInfoGetLoadBiasTest,elf_exists_in_memory_cached)155 TEST_F(MapInfoGetLoadBiasTest, elf_exists_in_memory_cached) {
156 InitElfData(memory_, map_info_->start);
157
158 EXPECT_EQ(0xe000U, map_info_->GetLoadBias(process_memory_));
159
160 memory_->Clear();
161 EXPECT_EQ(0xe000U, map_info_->GetLoadBias(process_memory_));
162 }
163
TEST_F(MapInfoGetLoadBiasTest,multiple_thread_elf_exists_in_memory)164 TEST_F(MapInfoGetLoadBiasTest, multiple_thread_elf_exists_in_memory) {
165 InitElfData(memory_, map_info_->start);
166
167 MultipleThreadTest(0xe000);
168 }
169
170 } // namespace unwindstack
171