src/breakpad/src/processor/stackwalker_amd64_unittest.cc

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  29
  30 // Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>
  31
  32 // stackwalker_amd64_unittest.cc: Unit tests for StackwalkerAMD64 class.
  33
  34 #include <string.h>
  35 #include <string>
  36 #include <vector>
  37
  38 #include "breakpad_googletest_includes.h"
  39 #include "common/test_assembler.h"
  40 #include "common/using_std_string.h"
  41 #include "google_breakpad/common/minidump_format.h"
  42 #include "google_breakpad/processor/basic_source_line_resolver.h"
  43 #include "google_breakpad/processor/call_stack.h"
  44 #include "google_breakpad/processor/code_module.h"
  45 #include "google_breakpad/processor/source_line_resolver_interface.h"
  46 #include "google_breakpad/processor/stack_frame_cpu.h"
  47 #include "processor/stackwalker_unittest_utils.h"
  48 #include "processor/stackwalker_amd64.h"
  49
  50 using google_breakpad::BasicSourceLineResolver;
  51 using google_breakpad::CallStack;
  52 using google_breakpad::CodeModule;
  53 using google_breakpad::StackFrameSymbolizer;
  54 using google_breakpad::StackFrame;
  55 using google_breakpad::StackFrameAMD64;
  56 using google_breakpad::Stackwalker;
  57 using google_breakpad::StackwalkerAMD64;
  58 using google_breakpad::SystemInfo;
  59 using google_breakpad::test_assembler::kLittleEndian;
  60 using google_breakpad::test_assembler::Label;
  61 using google_breakpad::test_assembler::Section;
  62 using std::vector;
  63 using testing::_;
  64 using testing::AnyNumber;
  65 using testing::Return;
  66 using testing::SetArgumentPointee;
  67 using testing::Test;
  68
  69 class StackwalkerAMD64Fixture {
  70  public:
  71   StackwalkerAMD64Fixture()
  72     : stack_section(kLittleEndian),
  73       // Give the two modules reasonable standard locations and names
  74       // for tests to play with.
  75       module1(0x40000000c0000000ULL, 0x10000, "module1", "version1"),
  76       module2(0x50000000b0000000ULL, 0x10000, "module2", "version2") {
  77     // Identify the system as a Linux system.
  78     system_info.os = "Linux";
  79     system_info.os_short = "linux";
  80     system_info.os_version = "Horrendous Hippo";
  81     system_info.cpu = "x86";
  82     system_info.cpu_info = "";
  83
  84     // Put distinctive values in the raw CPU context.
  85     BrandContext(&raw_context);
  86
  87     // Create some modules with some stock debugging information.
  88     modules.Add(&module1);
  89     modules.Add(&module2);
  90
  91     // By default, none of the modules have symbol info; call
  92     // SetModuleSymbols to override this.
  93     EXPECT_CALL(supplier, GetCStringSymbolData(_, _, _, _, _))
  94       .WillRepeatedly(Return(MockSymbolSupplier::NOT_FOUND));
  95
  96     // Avoid GMOCK WARNING "Uninteresting mock function call - returning
  97     // directly" for FreeSymbolData().
  98     EXPECT_CALL(supplier, FreeSymbolData(_)).Times(AnyNumber());
  99
 100     // Reset max_frames_scanned since it's static.
 101     Stackwalker::set_max_frames_scanned(1024);
 102   }
 103
 104   // Set the Breakpad symbol information that supplier should return for
 105   // MODULE to INFO.
 106   void SetModuleSymbols(MockCodeModule *module, const string &info) {
 107     size_t buffer_size;
 108     char *buffer = supplier.CopySymbolDataAndOwnTheCopy(info, &buffer_size);
 109     EXPECT_CALL(supplier, GetCStringSymbolData(module, &system_info, _, _, _))
 110       .WillRepeatedly(DoAll(SetArgumentPointee<3>(buffer),
 111                             SetArgumentPointee<4>(buffer_size),
 112                             Return(MockSymbolSupplier::FOUND)));
 113   }
 114
 115   // Populate stack_region with the contents of stack_section. Use
 116   // stack_section.start() as the region's starting address.
 117   void RegionFromSection() {
 118     string contents;
 119     ASSERT_TRUE(stack_section.GetContents(&contents));
 120     stack_region.Init(stack_section.start().Value(), contents);
 121   }
 122
 123   // Fill RAW_CONTEXT with pseudo-random data, for round-trip checking.
 124   void BrandContext(MDRawContextAMD64 *raw_context) {
 125     uint8_t x = 173;
 126     for (size_t i = 0; i < sizeof(*raw_context); i++)
 127       reinterpret_cast<uint8_t *>(raw_context)[i] = (x += 17);
 128   }
 129
 130   SystemInfo system_info;
 131   MDRawContextAMD64 raw_context;
 132   Section stack_section;
 133   MockMemoryRegion stack_region;
 134   MockCodeModule module1;
 135   MockCodeModule module2;
 136   MockCodeModules modules;
 137   MockSymbolSupplier supplier;
 138   BasicSourceLineResolver resolver;
 139   CallStack call_stack;
 140   const vector<StackFrame *> *frames;
 141 };
 142
 143 class GetContextFrame: public StackwalkerAMD64Fixture, public Test { };
 144
 145 class SanityCheck: public StackwalkerAMD64Fixture, public Test { };
 146
 147 TEST_F(SanityCheck, NoResolver) {
 148   // There should be no references to the stack in this walk: we don't
 149   // provide any call frame information, so trying to reconstruct the
 150   // context frame's caller should fail. So there's no need for us to
 151   // provide stack contents.
 152   raw_context.rip = 0x40000000c0000200ULL;
 153   raw_context.rbp = 0x8000000080000000ULL;
 154
 155   StackFrameSymbolizer frame_symbolizer(NULL, NULL);
 156   StackwalkerAMD64 walker(&system_info, &raw_context, &stack_region, &modules,
 157                           &frame_symbolizer);
 158   // This should succeed even without a resolver or supplier.
 159   vector<const CodeModule*> modules_without_symbols;
 160   vector<const CodeModule*> modules_with_corrupt_symbols;
 161   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols,
 162                           &modules_with_corrupt_symbols));
 163   ASSERT_EQ(1U, modules_without_symbols.size());
 164   ASSERT_EQ("module1", modules_without_symbols[0]->debug_file());
 165   ASSERT_EQ(0U, modules_with_corrupt_symbols.size());
 166   frames = call_stack.frames();
 167   ASSERT_GE(1U, frames->size());
 168   StackFrameAMD64 *frame = static_cast<StackFrameAMD64 *>(frames->at(0));
 169   // Check that the values from the original raw context made it
 170   // through to the context in the stack frame.
 171   EXPECT_EQ(0, memcmp(&raw_context, &frame->context, sizeof(raw_context)));
 172 }
 173
 174 TEST_F(GetContextFrame, Simple) {
 175   // There should be no references to the stack in this walk: we don't
 176   // provide any call frame information, so trying to reconstruct the
 177   // context frame's caller should fail. So there's no need for us to
 178   // provide stack contents.
 179   raw_context.rip = 0x40000000c0000200ULL;
 180   raw_context.rbp = 0x8000000080000000ULL;
 181
 182   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);
 183   StackwalkerAMD64 walker(&system_info, &raw_context, &stack_region, &modules,
 184                           &frame_symbolizer);
 185   vector<const CodeModule*> modules_without_symbols;
 186   vector<const CodeModule*> modules_with_corrupt_symbols;
 187   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols,
 188                           &modules_with_corrupt_symbols));
 189   ASSERT_EQ(1U, modules_without_symbols.size());
 190   ASSERT_EQ("module1", modules_without_symbols[0]->debug_file());
 191   ASSERT_EQ(0U, modules_with_corrupt_symbols.size());
 192   frames = call_stack.frames();
 193   ASSERT_GE(1U, frames->size());
 194   StackFrameAMD64 *frame = static_cast<StackFrameAMD64 *>(frames->at(0));
 195   // Check that the values from the original raw context made it
 196   // through to the context in the stack frame.
 197   EXPECT_EQ(0, memcmp(&raw_context, &frame->context, sizeof(raw_context)));
 198 }
 199
 200 // The stackwalker should be able to produce the context frame even
 201 // without stack memory present.
 202 TEST_F(GetContextFrame, NoStackMemory) {
 203   raw_context.rip = 0x40000000c0000200ULL;
 204   raw_context.rbp = 0x8000000080000000ULL;
 205
 206   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);
 207   StackwalkerAMD64 walker(&system_info, &raw_context, NULL, &modules,
 208                           &frame_symbolizer);
 209   vector<const CodeModule*> modules_without_symbols;
 210   vector<const CodeModule*> modules_with_corrupt_symbols;
 211   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols,
 212                           &modules_with_corrupt_symbols));
 213   ASSERT_EQ(1U, modules_without_symbols.size());
 214   ASSERT_EQ("module1", modules_without_symbols[0]->debug_file());
 215   ASSERT_EQ(0U, modules_with_corrupt_symbols.size());
 216   frames = call_stack.frames();
 217   ASSERT_GE(1U, frames->size());
 218   StackFrameAMD64 *frame = static_cast<StackFrameAMD64 *>(frames->at(0));
 219   // Check that the values from the original raw context made it
 220   // through to the context in the stack frame.
 221   EXPECT_EQ(0, memcmp(&raw_context, &frame->context, sizeof(raw_context)));
 222 }
 223
 224 class GetCallerFrame: public StackwalkerAMD64Fixture, public Test { };
 225
 226 TEST_F(GetCallerFrame, ScanWithoutSymbols) {
 227   // When the stack walker resorts to scanning the stack,
 228   // only addresses located within loaded modules are
 229   // considered valid return addresses.
 230   // Force scanning through three frames to ensure that the
 231   // stack pointer is set properly in scan-recovered frames.
 232   stack_section.start() = 0x8000000080000000ULL;
 233   uint64_t return_address1 = 0x50000000b0000100ULL;
 234   uint64_t return_address2 = 0x50000000b0000900ULL;
 235   Label frame1_sp, frame2_sp, frame1_rbp;
 236   stack_section
 237     // frame 0
 238     .Append(16, 0)                      // space
 239
 240     .D64(0x40000000b0000000ULL)         // junk that's not
 241     .D64(0x50000000d0000000ULL)         // a return address
 242
 243     .D64(return_address1)               // actual return address
 244     // frame 1
 245     .Mark(&frame1_sp)
 246     .Append(16, 0)                      // space
 247
 248     .D64(0x40000000b0000000ULL)         // more junk
 249     .D64(0x50000000d0000000ULL)
 250
 251     .Mark(&frame1_rbp)
 252     .D64(stack_section.start())         // This is in the right place to be
 253                                         // a saved rbp, but it's bogus, so
 254                                         // we shouldn't report it.
 255
 256     .D64(return_address2)               // actual return address
 257     // frame 2
 258     .Mark(&frame2_sp)
 259     .Append(32, 0);                     // end of stack
 260
 261   RegionFromSection();
 262
 263   raw_context.rip = 0x40000000c0000200ULL;
 264   raw_context.rbp = frame1_rbp.Value();
 265   raw_context.rsp = stack_section.start().Value();
 266
 267   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);
 268   StackwalkerAMD64 walker(&system_info, &raw_context, &stack_region, &modules,
 269                           &frame_symbolizer);
 270   vector<const CodeModule*> modules_without_symbols;
 271   vector<const CodeModule*> modules_with_corrupt_symbols;
 272   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols,
 273                           &modules_with_corrupt_symbols));
 274   ASSERT_EQ(2U, modules_without_symbols.size());
 275   ASSERT_EQ("module1", modules_without_symbols[0]->debug_file());
 276   ASSERT_EQ("module2", modules_without_symbols[1]->debug_file());
 277   ASSERT_EQ(0U, modules_with_corrupt_symbols.size());
 278   frames = call_stack.frames();
 279   ASSERT_EQ(3U, frames->size());
 280
 281   StackFrameAMD64 *frame0 = static_cast<StackFrameAMD64 *>(frames->at(0));
 282   EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust);
 283   ASSERT_EQ(StackFrameAMD64::CONTEXT_VALID_ALL, frame0->context_validity);
 284   EXPECT_EQ(0, memcmp(&raw_context, &frame0->context, sizeof(raw_context)));
 285
 286   StackFrameAMD64 *frame1 = static_cast<StackFrameAMD64 *>(frames->at(1));
 287   EXPECT_EQ(StackFrame::FRAME_TRUST_SCAN, frame1->trust);
 288   ASSERT_EQ((StackFrameAMD64::CONTEXT_VALID_RIP |
 289              StackFrameAMD64::CONTEXT_VALID_RSP |
 290              StackFrameAMD64::CONTEXT_VALID_RBP),
 291             frame1->context_validity);
 292   EXPECT_EQ(return_address1, frame1->context.rip);
 293   EXPECT_EQ(frame1_sp.Value(), frame1->context.rsp);
 294   EXPECT_EQ(frame1_rbp.Value(), frame1->context.rbp);
 295
 296   StackFrameAMD64 *frame2 = static_cast<StackFrameAMD64 *>(frames->at(2));
 297   EXPECT_EQ(StackFrame::FRAME_TRUST_SCAN, frame2->trust);
 298   ASSERT_EQ((StackFrameAMD64::CONTEXT_VALID_RIP |
 299              StackFrameAMD64::CONTEXT_VALID_RSP),
 300             frame2->context_validity);
 301   EXPECT_EQ(return_address2, frame2->context.rip);
 302   EXPECT_EQ(frame2_sp.Value(), frame2->context.rsp);
 303 }
 304
 305 TEST_F(GetCallerFrame, ScanWithFunctionSymbols) {
 306   // During stack scanning, if a potential return address
 307   // is located within a loaded module that has symbols,
 308   // it is only considered a valid return address if it
 309   // lies within a function's bounds.
 310   stack_section.start() = 0x8000000080000000ULL;
 311   uint64_t return_address = 0x50000000b0000110ULL;
 312   Label frame1_sp, frame1_rbp;
 313
 314   stack_section
 315     // frame 0
 316     .Append(16, 0)                      // space
 317
 318     .D64(0x40000000b0000000ULL)         // junk that's not
 319     .D64(0x50000000b0000000ULL)         // a return address
 320
 321     .D64(0x40000000c0001000ULL)         // a couple of plausible addresses
 322     .D64(0x50000000b000aaaaULL)         // that are not within functions
 323
 324     .D64(return_address)                // actual return address
 325     // frame 1
 326     .Mark(&frame1_sp)
 327     .Append(32, 0)                      // end of stack
 328     .Mark(&frame1_rbp);
 329   RegionFromSection();
 330
 331   raw_context.rip = 0x40000000c0000200ULL;
 332   raw_context.rbp = frame1_rbp.Value();
 333   raw_context.rsp = stack_section.start().Value();
 334
 335   SetModuleSymbols(&module1,
 336                    // The youngest frame's function.
 337                    "FUNC 100 400 10 platypus\n");
 338   SetModuleSymbols(&module2,
 339                    // The calling frame's function.
 340                    "FUNC 100 400 10 echidna\n");
 341
 342   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);
 343   StackwalkerAMD64 walker(&system_info, &raw_context, &stack_region, &modules,
 344                           &frame_symbolizer);
 345   vector<const CodeModule*> modules_without_symbols;
 346   vector<const CodeModule*> modules_with_corrupt_symbols;
 347   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols,
 348                           &modules_with_corrupt_symbols));
 349   ASSERT_EQ(0U, modules_without_symbols.size());
 350   ASSERT_EQ(0U, modules_with_corrupt_symbols.size());
 351   frames = call_stack.frames();
 352   ASSERT_EQ(2U, frames->size());
 353
 354   StackFrameAMD64 *frame0 = static_cast<StackFrameAMD64 *>(frames->at(0));
 355   EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust);
 356   ASSERT_EQ(StackFrameAMD64::CONTEXT_VALID_ALL, frame0->context_validity);
 357   EXPECT_EQ("platypus", frame0->function_name);
 358   EXPECT_EQ(0x40000000c0000100ULL, frame0->function_base);
 359
 360   StackFrameAMD64 *frame1 = static_cast<StackFrameAMD64 *>(frames->at(1));
 361   EXPECT_EQ(StackFrame::FRAME_TRUST_SCAN, frame1->trust);
 362   ASSERT_EQ((StackFrameAMD64::CONTEXT_VALID_RIP |
 363              StackFrameAMD64::CONTEXT_VALID_RSP |
 364              StackFrameAMD64::CONTEXT_VALID_RBP),
 365             frame1->context_validity);
 366   EXPECT_EQ(return_address, frame1->context.rip);
 367   EXPECT_EQ(frame1_sp.Value(), frame1->context.rsp);
 368   EXPECT_EQ(frame1_rbp.Value(), frame1->context.rbp);
 369   EXPECT_EQ("echidna", frame1->function_name);
 370   EXPECT_EQ(0x50000000b0000100ULL, frame1->function_base);
 371 }
 372
 373 // Test that set_max_frames_scanned prevents using stack scanning
 374 // to find caller frames.
 375 TEST_F(GetCallerFrame, ScanningNotAllowed) {
 376   // When the stack walker resorts to scanning the stack,
 377   // only addresses located within loaded modules are
 378   // considered valid return addresses.
 379   stack_section.start() = 0x8000000080000000ULL;
 380   uint64_t return_address1 = 0x50000000b0000100ULL;
 381   uint64_t return_address2 = 0x50000000b0000900ULL;
 382   Label frame1_sp, frame2_sp, frame1_rbp;
 383   stack_section
 384     // frame 0
 385     .Append(16, 0)                      // space
 386
 387     .D64(0x40000000b0000000ULL)         // junk that's not
 388     .D64(0x50000000d0000000ULL)         // a return address
 389
 390     .D64(return_address1)               // actual return address
 391     // frame 1
 392     .Mark(&frame1_sp)
 393     .Append(16, 0)                      // space
 394
 395     .D64(0x40000000b0000000ULL)         // more junk
 396     .D64(0x50000000d0000000ULL)
 397
 398     .Mark(&frame1_rbp)
 399     .D64(stack_section.start())         // This is in the right place to be
 400                                         // a saved rbp, but it's bogus, so
 401                                         // we shouldn't report it.
 402
 403     .D64(return_address2)               // actual return address
 404     // frame 2
 405     .Mark(&frame2_sp)
 406     .Append(32, 0);                     // end of stack
 407
 408   RegionFromSection();
 409
 410   raw_context.rip = 0x40000000c0000200ULL;
 411   raw_context.rbp = frame1_rbp.Value();
 412   raw_context.rsp = stack_section.start().Value();
 413
 414   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);
 415   StackwalkerAMD64 walker(&system_info, &raw_context, &stack_region, &modules,
 416                           &frame_symbolizer);
 417   Stackwalker::set_max_frames_scanned(0);
 418
 419   vector<const CodeModule*> modules_without_symbols;
 420   vector<const CodeModule*> modules_with_corrupt_symbols;
 421   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols,
 422                           &modules_with_corrupt_symbols));
 423   ASSERT_EQ(1U, modules_without_symbols.size());
 424   ASSERT_EQ("module1", modules_without_symbols[0]->debug_file());
 425   ASSERT_EQ(0U, modules_with_corrupt_symbols.size());
 426   frames = call_stack.frames();
 427   ASSERT_EQ(1U, frames->size());
 428
 429   StackFrameAMD64 *frame0 = static_cast<StackFrameAMD64 *>(frames->at(0));
 430   EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust);
 431   ASSERT_EQ(StackFrameAMD64::CONTEXT_VALID_ALL, frame0->context_validity);
 432   EXPECT_EQ(0, memcmp(&raw_context, &frame0->context, sizeof(raw_context)));
 433 }
 434
 435 TEST_F(GetCallerFrame, CallerPushedRBP) {
 436   // Functions typically push their %rbp upon entry and set %rbp pointing
 437   // there.  If stackwalking finds a plausible address for the next frame's
 438   // %rbp directly below the return address, assume that it is indeed the
 439   // next frame's %rbp.
 440   stack_section.start() = 0x8000000080000000ULL;
 441   uint64_t return_address = 0x50000000b0000110ULL;
 442   Label frame0_rbp, frame1_sp, frame1_rbp;
 443
 444   stack_section
 445     // frame 0
 446     .Append(16, 0)                      // space
 447
 448     .D64(0x40000000b0000000ULL)         // junk that's not
 449     .D64(0x50000000b0000000ULL)         // a return address
 450
 451     .D64(0x40000000c0001000ULL)         // a couple of plausible addresses
 452     .D64(0x50000000b000aaaaULL)         // that are not within functions
 453
 454     .Mark(&frame0_rbp)
 455     .D64(frame1_rbp)                    // caller-pushed %rbp
 456     .D64(return_address)                // actual return address
 457     // frame 1
 458     .Mark(&frame1_sp)
 459     .Append(32, 0)                      // body of frame1
 460     .Mark(&frame1_rbp);                 // end of stack
 461   RegionFromSection();
 462
 463   raw_context.rip = 0x40000000c0000200ULL;
 464   raw_context.rbp = frame0_rbp.Value();
 465   raw_context.rsp = stack_section.start().Value();
 466
 467   SetModuleSymbols(&module1,
 468                    // The youngest frame's function.
 469                    "FUNC 100 400 10 sasquatch\n");
 470   SetModuleSymbols(&module2,
 471                    // The calling frame's function.
 472                    "FUNC 100 400 10 yeti\n");
 473
 474   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);
 475   StackwalkerAMD64 walker(&system_info, &raw_context, &stack_region, &modules,
 476                           &frame_symbolizer);
 477   vector<const CodeModule*> modules_without_symbols;
 478   vector<const CodeModule*> modules_with_corrupt_symbols;
 479   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols,
 480                           &modules_with_corrupt_symbols));
 481   ASSERT_EQ(0U, modules_without_symbols.size());
 482   ASSERT_EQ(0U, modules_with_corrupt_symbols.size());
 483   frames = call_stack.frames();
 484   ASSERT_EQ(2U, frames->size());
 485
 486   StackFrameAMD64 *frame0 = static_cast<StackFrameAMD64 *>(frames->at(0));
 487   EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust);
 488   ASSERT_EQ(StackFrameAMD64::CONTEXT_VALID_ALL, frame0->context_validity);
 489   EXPECT_EQ(frame0_rbp.Value(), frame0->context.rbp);
 490   EXPECT_EQ("sasquatch", frame0->function_name);
 491   EXPECT_EQ(0x40000000c0000100ULL, frame0->function_base);
 492
 493   StackFrameAMD64 *frame1 = static_cast<StackFrameAMD64 *>(frames->at(1));
 494   EXPECT_EQ(StackFrame::FRAME_TRUST_FP, frame1->trust);
 495   ASSERT_EQ((StackFrameAMD64::CONTEXT_VALID_RIP |
 496              StackFrameAMD64::CONTEXT_VALID_RSP |
 497              StackFrameAMD64::CONTEXT_VALID_RBP),
 498             frame1->context_validity);
 499   EXPECT_EQ(return_address, frame1->context.rip);
 500   EXPECT_EQ(frame1_sp.Value(), frame1->context.rsp);
 501   EXPECT_EQ(frame1_rbp.Value(), frame1->context.rbp);
 502   EXPECT_EQ("yeti", frame1->function_name);
 503   EXPECT_EQ(0x50000000b0000100ULL, frame1->function_base);
 504 }
 505
 506 struct CFIFixture: public StackwalkerAMD64Fixture {
 507   CFIFixture() {
 508     // Provide a bunch of STACK CFI records; we'll walk to the caller
 509     // from every point in this series, expecting to find the same set
 510     // of register values.
 511     SetModuleSymbols(&module1,
 512                      // The youngest frame's function.
 513                      "FUNC 4000 1000 10 enchiridion\n"
 514                      // Initially, just a return address.
 515                      "STACK CFI INIT 4000 100 .cfa: $rsp 8 + .ra: .cfa 8 - ^\n"
 516                      // Push %rbx.
 517                      "STACK CFI 4001 .cfa: $rsp 16 + $rbx: .cfa 16 - ^\n"
 518                      // Save %r12 in %rbx.  Weird, but permitted.
 519                      "STACK CFI 4002 $r12: $rbx\n"
 520                      // Allocate frame space, and save %r13.
 521                      "STACK CFI 4003 .cfa: $rsp 40 + $r13: .cfa 32 - ^\n"
 522                      // Put the return address in %r13.
 523                      "STACK CFI 4005 .ra: $r13\n"
 524                      // Save %rbp, and use it as a frame pointer.
 525                      "STACK CFI 4006 .cfa: $rbp 16 + $rbp: .cfa 24 - ^\n"
 526
 527                      // The calling function.
 528                      "FUNC 5000 1000 10 epictetus\n"
 529                      // Mark it as end of stack.
 530                      "STACK CFI INIT 5000 1000 .cfa: $rsp .ra 0\n");
 531
 532     // Provide some distinctive values for the caller's registers.
 533     expected.rsp = 0x8000000080000000ULL;
 534     expected.rip = 0x40000000c0005510ULL;
 535     expected.rbp = 0x68995b1de4700266ULL;
 536     expected.rbx = 0x5a5beeb38de23be8ULL;
 537     expected.r12 = 0xed1b02e8cc0fc79cULL;
 538     expected.r13 = 0x1d20ad8acacbe930ULL;
 539     expected.r14 = 0xe94cffc2f7adaa28ULL;
 540     expected.r15 = 0xb638d17d8da413b5ULL;
 541
 542     // By default, registers are unchanged.
 543     raw_context = expected;
 544   }
 545
 546   // Walk the stack, using stack_section as the contents of the stack
 547   // and raw_context as the current register values. (Set
 548   // raw_context.rsp to the stack's starting address.) Expect two
 549   // stack frames; in the older frame, expect the callee-saves
 550   // registers to have values matching those in 'expected'.
 551   void CheckWalk() {
 552     RegionFromSection();
 553     raw_context.rsp = stack_section.start().Value();
 554
 555     StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);
 556     StackwalkerAMD64 walker(&system_info, &raw_context, &stack_region, &modules,
 557                             &frame_symbolizer);
 558     vector<const CodeModule*> modules_without_symbols;
 559     vector<const CodeModule*> modules_with_corrupt_symbols;
 560     ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols,
 561                             &modules_with_corrupt_symbols));
 562     ASSERT_EQ(0U, modules_without_symbols.size());
 563     ASSERT_EQ(0U, modules_with_corrupt_symbols.size());
 564     frames = call_stack.frames();
 565     ASSERT_EQ(2U, frames->size());
 566
 567     StackFrameAMD64 *frame0 = static_cast<StackFrameAMD64 *>(frames->at(0));
 568     EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust);
 569     ASSERT_EQ(StackFrameAMD64::CONTEXT_VALID_ALL, frame0->context_validity);
 570     EXPECT_EQ("enchiridion", frame0->function_name);
 571     EXPECT_EQ(0x40000000c0004000ULL, frame0->function_base);
 572
 573     StackFrameAMD64 *frame1 = static_cast<StackFrameAMD64 *>(frames->at(1));
 574     EXPECT_EQ(StackFrame::FRAME_TRUST_CFI, frame1->trust);
 575     ASSERT_EQ((StackFrameAMD64::CONTEXT_VALID_RIP |
 576                StackFrameAMD64::CONTEXT_VALID_RSP |
 577                StackFrameAMD64::CONTEXT_VALID_RBP |
 578                StackFrameAMD64::CONTEXT_VALID_RBX |
 579                StackFrameAMD64::CONTEXT_VALID_R12 |
 580                StackFrameAMD64::CONTEXT_VALID_R13 |
 581                StackFrameAMD64::CONTEXT_VALID_R14 |
 582                StackFrameAMD64::CONTEXT_VALID_R15),
 583               frame1->context_validity);
 584     EXPECT_EQ(expected.rip, frame1->context.rip);
 585     EXPECT_EQ(expected.rsp, frame1->context.rsp);
 586     EXPECT_EQ(expected.rbp, frame1->context.rbp);
 587     EXPECT_EQ(expected.rbx, frame1->context.rbx);
 588     EXPECT_EQ(expected.r12, frame1->context.r12);
 589     EXPECT_EQ(expected.r13, frame1->context.r13);
 590     EXPECT_EQ(expected.r14, frame1->context.r14);
 591     EXPECT_EQ(expected.r15, frame1->context.r15);
 592     EXPECT_EQ("epictetus", frame1->function_name);
 593   }
 594
 595   // The values we expect to find for the caller's registers.
 596   MDRawContextAMD64 expected;
 597 };
 598
 599 class CFI: public CFIFixture, public Test { };
 600
 601 TEST_F(CFI, At4000) {
 602   Label frame1_rsp = expected.rsp;
 603   stack_section
 604     .D64(0x40000000c0005510ULL) // return address
 605     .Mark(&frame1_rsp);         // This effectively sets stack_section.start().
 606   raw_context.rip = 0x40000000c0004000ULL;
 607   CheckWalk();
 608 }
 609
 610 TEST_F(CFI, At4001) {
 611   Label frame1_rsp = expected.rsp;
 612   stack_section
 613     .D64(0x5a5beeb38de23be8ULL) // saved %rbx
 614     .D64(0x40000000c0005510ULL) // return address
 615     .Mark(&frame1_rsp);         // This effectively sets stack_section.start().
 616   raw_context.rip = 0x40000000c0004001ULL;
 617   raw_context.rbx = 0xbe0487d2f9eafe29ULL; // callee's (distinct) %rbx value
 618   CheckWalk();
 619 }
 620
 621 TEST_F(CFI, At4002) {
 622   Label frame1_rsp = expected.rsp;
 623   stack_section
 624     .D64(0x5a5beeb38de23be8ULL) // saved %rbx
 625     .D64(0x40000000c0005510ULL) // return address
 626     .Mark(&frame1_rsp);         // This effectively sets stack_section.start().
 627   raw_context.rip = 0x40000000c0004002ULL;
 628   raw_context.rbx = 0xed1b02e8cc0fc79cULL; // saved %r12
 629   raw_context.r12 = 0xb0118de918a4bceaULL; // callee's (distinct) %r12 value
 630   CheckWalk();
 631 }
 632
 633 TEST_F(CFI, At4003) {
 634   Label frame1_rsp = expected.rsp;
 635   stack_section
 636     .D64(0x0e023828dffd4d81ULL) // garbage
 637     .D64(0x1d20ad8acacbe930ULL) // saved %r13
 638     .D64(0x319e68b49e3ace0fULL) // garbage
 639     .D64(0x5a5beeb38de23be8ULL) // saved %rbx
 640     .D64(0x40000000c0005510ULL) // return address
 641     .Mark(&frame1_rsp);         // This effectively sets stack_section.start().
 642   raw_context.rip = 0x40000000c0004003ULL;
 643   raw_context.rbx = 0xed1b02e8cc0fc79cULL; // saved %r12
 644   raw_context.r12 = 0x89d04fa804c87a43ULL; // callee's (distinct) %r12
 645   raw_context.r13 = 0x5118e02cbdb24b03ULL; // callee's (distinct) %r13
 646   CheckWalk();
 647 }
 648
 649 // The results here should be the same as those at module offset 0x4003.
 650 TEST_F(CFI, At4004) {
 651   Label frame1_rsp = expected.rsp;
 652   stack_section
 653     .D64(0x0e023828dffd4d81ULL) // garbage
 654     .D64(0x1d20ad8acacbe930ULL) // saved %r13
 655     .D64(0x319e68b49e3ace0fULL) // garbage
 656     .D64(0x5a5beeb38de23be8ULL) // saved %rbx
 657     .D64(0x40000000c0005510ULL) // return address
 658     .Mark(&frame1_rsp);         // This effectively sets stack_section.start().
 659   raw_context.rip = 0x40000000c0004004ULL;
 660   raw_context.rbx = 0xed1b02e8cc0fc79cULL; // saved %r12
 661   raw_context.r12 = 0x89d04fa804c87a43ULL; // callee's (distinct) %r12
 662   raw_context.r13 = 0x5118e02cbdb24b03ULL; // callee's (distinct) %r13
 663   CheckWalk();
 664 }
 665
 666 TEST_F(CFI, At4005) {
 667   Label frame1_rsp = expected.rsp;
 668   stack_section
 669     .D64(0x4b516dd035745953ULL) // garbage
 670     .D64(0x1d20ad8acacbe930ULL) // saved %r13
 671     .D64(0xa6d445e16ae3d872ULL) // garbage
 672     .D64(0x5a5beeb38de23be8ULL) // saved %rbx
 673     .D64(0xaa95fa054aedfbaeULL) // garbage
 674     .Mark(&frame1_rsp);         // This effectively sets stack_section.start().
 675   raw_context.rip = 0x40000000c0004005ULL;
 676   raw_context.rbx = 0xed1b02e8cc0fc79cULL; // saved %r12
 677   raw_context.r12 = 0x46b1b8868891b34aULL; // callee's %r12
 678   raw_context.r13 = 0x40000000c0005510ULL; // return address
 679   CheckWalk();
 680 }
 681
 682 TEST_F(CFI, At4006) {
 683   Label frame0_rbp;
 684   Label frame1_rsp = expected.rsp;
 685   stack_section
 686     .D64(0x043c6dfceb91aa34ULL) // garbage
 687     .D64(0x1d20ad8acacbe930ULL) // saved %r13
 688     .D64(0x68995b1de4700266ULL) // saved %rbp
 689     .Mark(&frame0_rbp)          // frame pointer points here
 690     .D64(0x5a5beeb38de23be8ULL) // saved %rbx
 691     .D64(0xf015ee516ad89eabULL) // garbage
 692     .Mark(&frame1_rsp);         // This effectively sets stack_section.start().
 693   raw_context.rip = 0x40000000c0004006ULL;
 694   raw_context.rbp = frame0_rbp.Value();
 695   raw_context.rbx = 0xed1b02e8cc0fc79cULL; // saved %r12
 696   raw_context.r12 = 0x26e007b341acfebdULL; // callee's %r12
 697   raw_context.r13 = 0x40000000c0005510ULL; // return address
 698   CheckWalk();
 699 }