1 // Copyright 2018 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #ifdef UNSAFE_BUFFERS_BUILD
6 // TODO(crbug.com/40284755): Remove this and use spans.
7 #pragma allow_unsafe_buffers
8 #endif
9
10 #include "base/trace_event/cfi_backtrace_android.h"
11
12 #include "base/files/file_util.h"
13 #include "testing/gtest/include/gtest/gtest.h"
14
15 namespace base {
16 namespace trace_event {
17
18 namespace {
19
GetPC()20 void* GetPC() {
21 return __builtin_return_address(0);
22 }
23
24 } // namespace
25
TEST(CFIBacktraceAndroidTest,TestUnwinding)26 TEST(CFIBacktraceAndroidTest, TestUnwinding) {
27 auto* unwinder = CFIBacktraceAndroid::GetInitializedInstance();
28 EXPECT_TRUE(unwinder->can_unwind_stack_frames());
29 EXPECT_GT(unwinder->executable_start_addr(), 0u);
30 EXPECT_GT(unwinder->executable_end_addr(), unwinder->executable_start_addr());
31 EXPECT_GT(unwinder->cfi_mmap_->length(), 0u);
32
33 const size_t kMaxFrames = 100;
34 const void* frames[kMaxFrames];
35 size_t unwind_count = unwinder->Unwind(frames, kMaxFrames);
36 // Expect at least 2 frames in the result.
37 ASSERT_GT(unwind_count, 2u);
38 EXPECT_LE(unwind_count, kMaxFrames);
39
40 const size_t kMaxCurrentFuncCodeSize = 50;
41 const uintptr_t current_pc = reinterpret_cast<uintptr_t>(GetPC());
42 const uintptr_t actual_frame = reinterpret_cast<uintptr_t>(frames[2]);
43 EXPECT_NEAR(current_pc, actual_frame, kMaxCurrentFuncCodeSize);
44
45 for (size_t i = 0; i < unwind_count; ++i) {
46 EXPECT_GT(reinterpret_cast<uintptr_t>(frames[i]),
47 unwinder->executable_start_addr());
48 EXPECT_LT(reinterpret_cast<uintptr_t>(frames[i]),
49 unwinder->executable_end_addr());
50 }
51 }
52
53 // Flaky: https://bugs.chromium.org/p/chromium/issues/detail?id=829555
TEST(CFIBacktraceAndroidTest,DISABLED_TestFindCFIRow)54 TEST(CFIBacktraceAndroidTest, DISABLED_TestFindCFIRow) {
55 auto* unwinder = CFIBacktraceAndroid::GetInitializedInstance();
56 /* Input is generated from the CFI file:
57 STACK CFI INIT 1000 500
58 STACK CFI 1002 .cfa: sp 272 + .ra: .cfa -4 + ^ r4: .cfa -16 +
59 STACK CFI 1008 .cfa: sp 544 + .r1: .cfa -0 + ^ r4: .cfa -16 + ^
60 STACK CFI 1040 .cfa: sp 816 + .r1: .cfa -0 + ^ r4: .cfa -16 + ^
61 STACK CFI 1050 .cfa: sp 816 + .ra: .cfa -8 + ^ r4: .cfa -16 + ^
62 STACK CFI 1080 .cfa: sp 544 + .r1: .cfa -0 + ^ r4: .cfa -16 + ^
63
64 STACK CFI INIT 2000 22
65 STACK CFI 2004 .cfa: sp 16 + .ra: .cfa -12 + ^ r4: .cfa -16 + ^
66 STACK CFI 2008 .cfa: sp 16 + .ra: .cfa -12 + ^ r4: .cfa -16 + ^
67
68 STACK CFI INIT 2024 100
69 STACK CFI 2030 .cfa: sp 48 + .ra: .cfa -12 + ^ r4: .cfa -16 + ^
70 STACK CFI 2100 .cfa: sp 64 + .r1: .cfa -0 + ^ r4: .cfa -16 + ^
71
72 STACK CFI INIT 2200 10
73 STACK CFI 2204 .cfa: sp 44 + .ra: .cfa -8 + ^ r4: .cfa -16 + ^
74 */
75 uint16_t input[] = {// UNW_INDEX size
76 0x07, 0x0,
77
78 // UNW_INDEX address column (4 byte rows).
79 0x1000, 0x0, 0x1502, 0x0, 0x2000, 0x0, 0x2024, 0x0,
80 0x2126, 0x0, 0x2200, 0x0, 0x2212, 0x0,
81
82 // UNW_INDEX index column (2 byte rows).
83 0x0, 0xffff, 0xb, 0x10, 0xffff, 0x15, 0xffff,
84
85 // UNW_DATA table.
86 0x5, 0x2, 0x111, 0x8, 0x220, 0x40, 0x330, 0x50, 0x332,
87 0x80, 0x220, 0x2, 0x4, 0x13, 0x8, 0x13, 0x2, 0xc, 0x33,
88 0xdc, 0x40, 0x1, 0x4, 0x2e};
89 FilePath temp_path;
90 CreateTemporaryFile(&temp_path);
91 EXPECT_TRUE(WriteFile(temp_path, as_byte_span(input)));
92
93 unwinder->cfi_mmap_.reset(new MemoryMappedFile());
94 ASSERT_TRUE(unwinder->cfi_mmap_->Initialize(temp_path));
95 unwinder->ParseCFITables();
96
97 CFIBacktraceAndroid::CFIRow cfi_row = {0};
98 EXPECT_FALSE(unwinder->FindCFIRowForPC(0x01, &cfi_row));
99 EXPECT_FALSE(unwinder->FindCFIRowForPC(0x100, &cfi_row));
100 EXPECT_FALSE(unwinder->FindCFIRowForPC(0x1502, &cfi_row));
101 EXPECT_FALSE(unwinder->FindCFIRowForPC(0x3000, &cfi_row));
102 EXPECT_FALSE(unwinder->FindCFIRowForPC(0x2024, &cfi_row));
103 EXPECT_FALSE(unwinder->FindCFIRowForPC(0x2212, &cfi_row));
104
105 const CFIBacktraceAndroid::CFIRow kRow1 = {0x110, 0x4};
106 const CFIBacktraceAndroid::CFIRow kRow2 = {0x220, 0x4};
107 const CFIBacktraceAndroid::CFIRow kRow3 = {0x220, 0x8};
108 const CFIBacktraceAndroid::CFIRow kRow4 = {0x30, 0xc};
109 const CFIBacktraceAndroid::CFIRow kRow5 = {0x2c, 0x8};
110 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1002, &cfi_row));
111 EXPECT_EQ(kRow1, cfi_row);
112 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1003, &cfi_row));
113 EXPECT_EQ(kRow1, cfi_row);
114 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1008, &cfi_row));
115 EXPECT_EQ(kRow2, cfi_row);
116 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1009, &cfi_row));
117 EXPECT_EQ(kRow2, cfi_row);
118 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1039, &cfi_row));
119 EXPECT_EQ(kRow2, cfi_row);
120 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1080, &cfi_row));
121 EXPECT_EQ(kRow3, cfi_row);
122 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1100, &cfi_row));
123 EXPECT_EQ(kRow3, cfi_row);
124 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x2050, &cfi_row));
125 EXPECT_EQ(kRow4, cfi_row);
126 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x2208, &cfi_row));
127 EXPECT_EQ(kRow5, cfi_row);
128 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x2210, &cfi_row));
129 EXPECT_EQ(kRow5, cfi_row);
130
131 // Test if cache is used on the future calls to Find, all addresses should
132 // have different hash. Resetting the memory map to make sure it is never
133 // accessed in Find().
134 unwinder->cfi_mmap_.reset(new MemoryMappedFile());
135 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1002, &cfi_row));
136 EXPECT_EQ(kRow1, cfi_row);
137 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1003, &cfi_row));
138 EXPECT_EQ(kRow1, cfi_row);
139 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1008, &cfi_row));
140 EXPECT_EQ(kRow2, cfi_row);
141 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1009, &cfi_row));
142 EXPECT_EQ(kRow2, cfi_row);
143 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1039, &cfi_row));
144 EXPECT_EQ(kRow2, cfi_row);
145 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1080, &cfi_row));
146 EXPECT_EQ(kRow3, cfi_row);
147 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1100, &cfi_row));
148 EXPECT_EQ(kRow3, cfi_row);
149 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x2050, &cfi_row));
150 EXPECT_EQ(kRow4, cfi_row);
151 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x2208, &cfi_row));
152 EXPECT_EQ(kRow5, cfi_row);
153 EXPECT_TRUE(unwinder->FindCFIRowForPC(0x2210, &cfi_row));
154 EXPECT_EQ(kRow5, cfi_row);
155 }
156
TEST(CFIBacktraceAndroidTest,TestCFICache)157 TEST(CFIBacktraceAndroidTest, TestCFICache) {
158 // Use ASSERT macros in this function since they are in loop and using EXPECT
159 // prints too many failures.
160 CFIBacktraceAndroid::CFICache cache;
161 CFIBacktraceAndroid::CFIRow cfi;
162
163 // Empty cache should not find anything.
164 EXPECT_FALSE(cache.Find(1, &cfi));
165
166 // Insert 1 - 2*kLimit
167 for (uintptr_t i = 1; i <= 2 * cache.kLimit; ++i) {
168 CFIBacktraceAndroid::CFIRow val = {static_cast<uint16_t>(4 * i),
169 static_cast<uint16_t>(2 * i)};
170 cache.Add(i, val);
171 ASSERT_TRUE(cache.Find(i, &cfi));
172 ASSERT_EQ(cfi, val);
173
174 // Inserting more than kLimit items evicts |i - cache.kLimit| from cache.
175 if (i >= cache.kLimit)
176 ASSERT_FALSE(cache.Find(i - cache.kLimit, &cfi));
177 }
178 // Cache contains kLimit+1 - 2*kLimit.
179
180 // Check that 1 - kLimit cannot be found.
181 for (uintptr_t i = 1; i <= cache.kLimit; ++i) {
182 ASSERT_FALSE(cache.Find(i, &cfi));
183 }
184
185 // Check if kLimit+1 - 2*kLimit still exists in cache.
186 for (uintptr_t i = cache.kLimit + 1; i <= 2 * cache.kLimit; ++i) {
187 CFIBacktraceAndroid::CFIRow val = {static_cast<uint16_t>(4 * i),
188 static_cast<uint16_t>(2 * i)};
189 ASSERT_TRUE(cache.Find(i, &cfi));
190 ASSERT_EQ(cfi, val);
191 }
192
193 // Insert 2*kLimit+1, will evict kLimit.
194 cfi = {1, 1};
195 cache.Add(2 * cache.kLimit + 1, cfi);
196 EXPECT_TRUE(cache.Find(2 * cache.kLimit + 1, &cfi));
197 EXPECT_FALSE(cache.Find(cache.kLimit + 1, &cfi));
198 // Cache contains kLimit+1 - 2*kLimit.
199 }
200
201 } // namespace trace_event
202 } // namespace base
203