aboutsummaryrefslogtreecommitdiff
path: root/src/common/linux/synth_elf_unittest.cc
blob: cd74c28624246a579c9185e0d2c341c920517cf2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
// Copyright (c) 2011 Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// Original author: Ted Mielczarek <ted.mielczarek@gmail.com>

// synth_elf_unittest.cc:
// Unittests for google_breakpad::synth_elf::ELF

#include <elf.h>

#include "breakpad_googletest_includes.h"
#include "common/linux/elfutils.h"
#include "common/linux/synth_elf.h"
#include "common/using_std_string.h"

using google_breakpad::ElfClass32;
using google_breakpad::ElfClass64;
using google_breakpad::synth_elf::ELF;
using google_breakpad::synth_elf::Notes;
using google_breakpad::synth_elf::Section;
using google_breakpad::synth_elf::StringTable;
using google_breakpad::synth_elf::SymbolTable;
using google_breakpad::test_assembler::Endianness;
using google_breakpad::test_assembler::kBigEndian;
using google_breakpad::test_assembler::kLittleEndian;
using google_breakpad::test_assembler::Label;
using ::testing::Test;
using ::testing::Types;

class StringTableTest : public Test {
public:
  StringTableTest() : table(kLittleEndian) {}

  StringTable table;
};

TEST_F(StringTableTest, Empty) {
  EXPECT_EQ(1U, table.Size());
  string contents;
  ASSERT_TRUE(table.GetContents(&contents));
  const char* kExpectedContents = "\0";
  EXPECT_EQ(0, memcmp(kExpectedContents,
                      contents.c_str(),
                      contents.size()));
  ASSERT_TRUE(table.empty_string.IsKnownConstant());
  EXPECT_EQ(0U, table.empty_string.Value());
}

TEST_F(StringTableTest, Basic) {
  const string s1("table fills with strings");
  const string s2("offsets preserved as labels");
  const string s3("verified with tests");
  const char* kExpectedContents = 
    "\0table fills with strings\0"
    "offsets preserved as labels\0"
    "verified with tests\0";
  Label l1(table.Add(s1));
  Label l2(table.Add(s2));
  Label l3(table.Add(s3));
  string contents;
  ASSERT_TRUE(table.GetContents(&contents));
  EXPECT_EQ(0, memcmp(kExpectedContents,
                      contents.c_str(),
                      contents.size()));
  // empty_string is at zero, other strings start at 1.
  ASSERT_TRUE(l1.IsKnownConstant());
  EXPECT_EQ(1U, l1.Value());
  // Each string has an extra byte for a trailing null.
  EXPECT_EQ(1 + s1.length() + 1, l2.Value());
  EXPECT_EQ(1 + s1.length() + 1 + s2.length() + 1, l3.Value());
}

TEST_F(StringTableTest, Duplicates) {
  const string s1("string 1");
  const string s2("string 2");
  const string s3("");
  const char* kExpectedContents = "\0string 1\0string 2\0";
  Label l1(table.Add(s1));
  Label l2(table.Add(s2));
  // Adding strings twice should return the same Label.
  Label l3(table.Add(s3));
  Label l4(table.Add(s2));
  string contents;
  ASSERT_TRUE(table.GetContents(&contents));
  EXPECT_EQ(0, memcmp(kExpectedContents,
                      contents.c_str(),
                      contents.size()));
  EXPECT_EQ(0U, table.empty_string.Value());
  EXPECT_EQ(table.empty_string.Value(), l3.Value());
  EXPECT_EQ(l2.Value(), l4.Value());
}

class SymbolTableTest : public Test {};

TEST_F(SymbolTableTest, Simple32) {
  StringTable table(kLittleEndian);
  SymbolTable syms(kLittleEndian, 4, table);

  const string kFuncName1 = "superfunc";
  const uint32_t kFuncAddr1 = 0x10001000;
  const uint32_t kFuncSize1 = 0x10;
  const string kFuncName2 = "awesomefunc";
  const uint32_t kFuncAddr2 = 0x20002000;
  const uint32_t kFuncSize2 = 0x2f;
  const string kFuncName3 = "megafunc";
  const uint32_t kFuncAddr3 = 0x30003000;
  const uint32_t kFuncSize3 = 0x3c;

  syms.AddSymbol(kFuncName1, kFuncAddr1, kFuncSize1,
                 ELF32_ST_INFO(STB_GLOBAL, STT_FUNC),
                 SHN_UNDEF + 1);
  syms.AddSymbol(kFuncName2, kFuncAddr2, kFuncSize2,
                 ELF32_ST_INFO(STB_LOCAL, STT_FUNC),
                 SHN_UNDEF + 2);
  syms.AddSymbol(kFuncName3, kFuncAddr3, kFuncSize3,
                 ELF32_ST_INFO(STB_LOCAL, STT_FUNC),
                 SHN_UNDEF + 3);

  const char kExpectedStringTable[] = "\0superfunc\0awesomefunc\0megafunc";
  const size_t kExpectedStringTableSize = sizeof(kExpectedStringTable);
  EXPECT_EQ(kExpectedStringTableSize, table.Size());
  string table_contents;
  table.GetContents(&table_contents);
  EXPECT_EQ(0, memcmp(kExpectedStringTable,
                      table_contents.c_str(),
                      table_contents.size()));

  const uint8_t kExpectedSymbolContents[] = {
    // Symbol 1
    0x01, 0x00, 0x00, 0x00, // name
    0x00, 0x10, 0x00, 0x10, // value
    0x10, 0x00, 0x00, 0x00, // size
    ELF32_ST_INFO(STB_GLOBAL, STT_FUNC), // info
    0x00, // other
    0x01, 0x00, // shndx
    // Symbol 2
    0x0B, 0x00, 0x00, 0x00, // name
    0x00, 0x20, 0x00, 0x20, // value
    0x2f, 0x00, 0x00, 0x00, // size
    ELF32_ST_INFO(STB_LOCAL, STT_FUNC), // info
    0x00, // other
    0x02, 0x00, // shndx
    // Symbol 3
    0x17, 0x00, 0x00, 0x00, // name
    0x00, 0x30, 0x00, 0x30, // value
    0x3c, 0x00, 0x00, 0x00, // size
    ELF32_ST_INFO(STB_LOCAL, STT_FUNC), // info
    0x00, // other
    0x03, 0x00, // shndx
  };
  const size_t kExpectedSymbolSize = sizeof(kExpectedSymbolContents);
  EXPECT_EQ(kExpectedSymbolSize, syms.Size());

  string symbol_contents;
  syms.GetContents(&symbol_contents);
  EXPECT_EQ(0, memcmp(kExpectedSymbolContents,
                      symbol_contents.c_str(),
                      symbol_contents.size()));
}

template<typename ElfClass>
class BasicElf : public Test {};

// Doesn't seem worthwhile writing the tests to be endian-independent
// when they're unlikely to ever be run on big-endian systems.
#if defined(__i386__) || defined(__x86_64__)

typedef Types<ElfClass32, ElfClass64> ElfClasses;

TYPED_TEST_SUITE(BasicElf, ElfClasses);

TYPED_TEST(BasicElf, EmptyLE) {
  typedef typename TypeParam::Ehdr Ehdr;
  typedef typename TypeParam::Phdr Phdr;
  typedef typename TypeParam::Shdr Shdr;
  const size_t kStringTableSize = sizeof("\0.shstrtab");
  const size_t kStringTableAlign = 4 - kStringTableSize % 4;
  const size_t kExpectedSize = sizeof(Ehdr) +
    // Two sections, SHT_NULL + the section header string table.
    2 * sizeof(Shdr) +
    kStringTableSize + kStringTableAlign;

  // It doesn't really matter that the machine type is right for the class.
  ELF elf(EM_386, TypeParam::kClass, kLittleEndian);
  elf.Finish();
  EXPECT_EQ(kExpectedSize, elf.Size());

  string contents;
  ASSERT_TRUE(elf.GetContents(&contents));
  ASSERT_EQ(kExpectedSize, contents.size());
  const Ehdr* header =
    reinterpret_cast<const Ehdr*>(contents.data());
  const uint8_t kIdent[] = {
    ELFMAG0, ELFMAG1, ELFMAG2, ELFMAG3,
    TypeParam::kClass, ELFDATA2LSB, EV_CURRENT, ELFOSABI_SYSV,
    0, 0, 0, 0, 0, 0, 0, 0
  };
  EXPECT_EQ(0, memcmp(kIdent, header->e_ident, sizeof(kIdent)));
  EXPECT_EQ(ET_EXEC, header->e_type);
  EXPECT_EQ(EM_386, header->e_machine);
  EXPECT_EQ(static_cast<unsigned int>(EV_CURRENT), header->e_version);
  EXPECT_EQ(0U, header->e_entry);
  EXPECT_EQ(0U, header->e_phoff);
  EXPECT_EQ(sizeof(Ehdr) + kStringTableSize + kStringTableAlign,
            header->e_shoff);
  EXPECT_EQ(0U, header->e_flags);
  EXPECT_EQ(sizeof(Ehdr), header->e_ehsize);
  EXPECT_EQ(sizeof(Phdr), header->e_phentsize);
  EXPECT_EQ(0, header->e_phnum);
  EXPECT_EQ(sizeof(Shdr), header->e_shentsize);
  EXPECT_EQ(2, header->e_shnum);
  EXPECT_EQ(1, header->e_shstrndx);

  const Shdr* shdr =
    reinterpret_cast<const Shdr*>(contents.data() + header->e_shoff);
  EXPECT_EQ(0U, shdr[0].sh_name);
  EXPECT_EQ(static_cast<unsigned int>(SHT_NULL), shdr[0].sh_type);
  EXPECT_EQ(0U, shdr[0].sh_flags);
  EXPECT_EQ(0U, shdr[0].sh_addr);
  EXPECT_EQ(0U, shdr[0].sh_offset);
  EXPECT_EQ(0U, shdr[0].sh_size);
  EXPECT_EQ(0U, shdr[0].sh_link);
  EXPECT_EQ(0U, shdr[0].sh_info);
  EXPECT_EQ(0U, shdr[0].sh_addralign);
  EXPECT_EQ(0U, shdr[0].sh_entsize);

  EXPECT_EQ(1U, shdr[1].sh_name);
  EXPECT_EQ(static_cast<unsigned int>(SHT_STRTAB), shdr[1].sh_type);
  EXPECT_EQ(0U, shdr[1].sh_flags);
  EXPECT_EQ(0U, shdr[1].sh_addr);
  EXPECT_EQ(sizeof(Ehdr), shdr[1].sh_offset);
  EXPECT_EQ(kStringTableSize, shdr[1].sh_size);
  EXPECT_EQ(0U, shdr[1].sh_link);
  EXPECT_EQ(0U, shdr[1].sh_info);
  EXPECT_EQ(0U, shdr[1].sh_addralign);
  EXPECT_EQ(0U, shdr[1].sh_entsize);
}

TYPED_TEST(BasicElf, BasicLE) {
  typedef typename TypeParam::Ehdr Ehdr;
  typedef typename TypeParam::Phdr Phdr;
  typedef typename TypeParam::Shdr Shdr;
  const size_t kStringTableSize = sizeof("\0.text\0.bss\0.shstrtab");
  const size_t kStringTableAlign = 4 - kStringTableSize % 4;
  const size_t kExpectedSize = sizeof(Ehdr) +
    // Four sections, SHT_NULL + the section header string table +
    // 4096 bytes of the size-aligned .text section + one program header.
    sizeof(Phdr) + 4 * sizeof(Shdr) + 4096 +
    kStringTableSize + kStringTableAlign;

  // It doesn't really matter that the machine type is right for the class.
  ELF elf(EM_386, TypeParam::kClass, kLittleEndian);
  Section text(kLittleEndian);
  text.Append(4094, 0);
  int text_idx = elf.AddSection(".text", text, SHT_PROGBITS);
  Section bss(kLittleEndian);
  bss.Append(16, 0);
  int bss_idx = elf.AddSection(".bss", bss, SHT_NOBITS);
  elf.AddSegment(text_idx, bss_idx, PT_LOAD);
  elf.Finish();
  EXPECT_EQ(kExpectedSize, elf.Size());

  string contents;
  ASSERT_TRUE(elf.GetContents(&contents));
  ASSERT_EQ(kExpectedSize, contents.size());
  const Ehdr* header =
    reinterpret_cast<const Ehdr*>(contents.data());
  const uint8_t kIdent[] = {
    ELFMAG0, ELFMAG1, ELFMAG2, ELFMAG3,
    TypeParam::kClass, ELFDATA2LSB, EV_CURRENT, ELFOSABI_SYSV,
    0, 0, 0, 0, 0, 0, 0, 0
  };
  EXPECT_EQ(0, memcmp(kIdent, header->e_ident, sizeof(kIdent)));
  EXPECT_EQ(ET_EXEC, header->e_type);
  EXPECT_EQ(EM_386, header->e_machine);
  EXPECT_EQ(static_cast<unsigned int>(EV_CURRENT), header->e_version);
  EXPECT_EQ(0U, header->e_entry);
  EXPECT_EQ(sizeof(Ehdr), header->e_phoff);
  EXPECT_EQ(sizeof(Ehdr) + sizeof(Phdr) + 4096 + kStringTableSize +
            kStringTableAlign, header->e_shoff);
  EXPECT_EQ(0U, header->e_flags);
  EXPECT_EQ(sizeof(Ehdr), header->e_ehsize);
  EXPECT_EQ(sizeof(Phdr), header->e_phentsize);
  EXPECT_EQ(1, header->e_phnum);
  EXPECT_EQ(sizeof(Shdr), header->e_shentsize);
  EXPECT_EQ(4, header->e_shnum);
  EXPECT_EQ(3, header->e_shstrndx);

  const Shdr* shdr =
    reinterpret_cast<const Shdr*>(contents.data() + header->e_shoff);
  EXPECT_EQ(0U, shdr[0].sh_name);
  EXPECT_EQ(static_cast<unsigned int>(SHT_NULL), shdr[0].sh_type);
  EXPECT_EQ(0U, shdr[0].sh_flags);
  EXPECT_EQ(0U, shdr[0].sh_addr);
  EXPECT_EQ(0U, shdr[0].sh_offset);
  EXPECT_EQ(0U, shdr[0].sh_size);
  EXPECT_EQ(0U, shdr[0].sh_link);
  EXPECT_EQ(0U, shdr[0].sh_info);
  EXPECT_EQ(0U, shdr[0].sh_addralign);
  EXPECT_EQ(0U, shdr[0].sh_entsize);

  EXPECT_EQ(1U, shdr[1].sh_name);
  EXPECT_EQ(static_cast<unsigned int>(SHT_PROGBITS), shdr[1].sh_type);
  EXPECT_EQ(0U, shdr[1].sh_flags);
  EXPECT_EQ(0U, shdr[1].sh_addr);
  EXPECT_EQ(sizeof(Ehdr) + sizeof(Phdr), shdr[1].sh_offset);
  EXPECT_EQ(4094U, shdr[1].sh_size);
  EXPECT_EQ(0U, shdr[1].sh_link);
  EXPECT_EQ(0U, shdr[1].sh_info);
  EXPECT_EQ(0U, shdr[1].sh_addralign);
  EXPECT_EQ(0U, shdr[1].sh_entsize);

  EXPECT_EQ(sizeof("\0.text"), shdr[2].sh_name);
  EXPECT_EQ(static_cast<unsigned int>(SHT_NOBITS), shdr[2].sh_type);
  EXPECT_EQ(0U, shdr[2].sh_flags);
  EXPECT_EQ(0U, shdr[2].sh_addr);
  EXPECT_EQ(0U, shdr[2].sh_offset);
  EXPECT_EQ(16U, shdr[2].sh_size);
  EXPECT_EQ(0U, shdr[2].sh_link);
  EXPECT_EQ(0U, shdr[2].sh_info);
  EXPECT_EQ(0U, shdr[2].sh_addralign);
  EXPECT_EQ(0U, shdr[2].sh_entsize);

  EXPECT_EQ(sizeof("\0.text\0.bss"), shdr[3].sh_name);
  EXPECT_EQ(static_cast<unsigned int>(SHT_STRTAB), shdr[3].sh_type);
  EXPECT_EQ(0U, shdr[3].sh_flags);
  EXPECT_EQ(0U, shdr[3].sh_addr);
  EXPECT_EQ(sizeof(Ehdr) + sizeof(Phdr) + 4096, shdr[3].sh_offset);
  EXPECT_EQ(kStringTableSize, shdr[3].sh_size);
  EXPECT_EQ(0U, shdr[3].sh_link);
  EXPECT_EQ(0U, shdr[3].sh_info);
  EXPECT_EQ(0U, shdr[3].sh_addralign);
  EXPECT_EQ(0U, shdr[3].sh_entsize);

  const Phdr* phdr =
    reinterpret_cast<const Phdr*>(contents.data() + header->e_phoff);
  EXPECT_EQ(static_cast<unsigned int>(PT_LOAD), phdr->p_type);
  EXPECT_EQ(sizeof(Ehdr) + sizeof(Phdr), phdr->p_offset);
  EXPECT_EQ(0U, phdr->p_vaddr);
  EXPECT_EQ(0U, phdr->p_paddr);
  EXPECT_EQ(4096U, phdr->p_filesz);
  EXPECT_EQ(4096U + 16U, phdr->p_memsz);
  EXPECT_EQ(0U, phdr->p_flags);
  EXPECT_EQ(0U, phdr->p_align);
}

class ElfNotesTest : public Test {};

TEST_F(ElfNotesTest, Empty) {
  Notes notes(kLittleEndian);
  string contents;
  ASSERT_TRUE(notes.GetContents(&contents));
  EXPECT_EQ(0U, contents.size());
}

TEST_F(ElfNotesTest, Notes) {
  Notes notes(kLittleEndian);
  notes.AddNote(1, "Linux", reinterpret_cast<const uint8_t *>("\x42\x02\0\0"),
                4);
  notes.AddNote(2, "a", reinterpret_cast<const uint8_t *>("foobar"),
                sizeof("foobar") - 1);

  const uint8_t kExpectedNotesContents[] = {
    // Note 1
    0x06, 0x00, 0x00, 0x00, // name size, including terminating zero
    0x04, 0x00, 0x00, 0x00, // desc size
    0x01, 0x00, 0x00, 0x00, // type
    'L', 'i', 'n', 'u', 'x', 0x00, 0x00, 0x00, // padded "Linux"
    0x42, 0x02, 0x00, 0x00, // desc
    // Note 2
    0x02, 0x00, 0x00, 0x00, // name size
    0x06, 0x00, 0x00, 0x00, // desc size
    0x02, 0x00, 0x00, 0x00, // type
    'a',  0x00, 0x00, 0x00, // padded "a"
    'f', 'o', 'o', 'b', 'a', 'r', 0x00, 0x00, // padded "foobar"
  };
  const size_t kExpectedNotesSize = sizeof(kExpectedNotesContents);
  EXPECT_EQ(kExpectedNotesSize, notes.Size());

  string notes_contents;
  ASSERT_TRUE(notes.GetContents(&notes_contents));
  EXPECT_EQ(0, memcmp(kExpectedNotesContents,
                      notes_contents.data(),
                      notes_contents.size()));
}

#endif  // defined(__i386__) || defined(__x86_64__)