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30 // Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>
31 
32 // stackwalker_arm_unittest.cc: Unit tests for StackwalkerARM 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_arm.h"
49 #include "processor/windows_frame_info.h"
50 
51 using google_breakpad::BasicSourceLineResolver;
52 using google_breakpad::CallStack;
53 using google_breakpad::CodeModule;
54 using google_breakpad::StackFrameSymbolizer;
55 using google_breakpad::StackFrame;
56 using google_breakpad::StackFrameARM;
57 using google_breakpad::Stackwalker;
58 using google_breakpad::StackwalkerARM;
59 using google_breakpad::SystemInfo;
60 using google_breakpad::WindowsFrameInfo;
61 using google_breakpad::test_assembler::kLittleEndian;
62 using google_breakpad::test_assembler::Label;
63 using google_breakpad::test_assembler::Section;
64 using std::vector;
65 using testing::_;
66 using testing::AnyNumber;
67 using testing::Return;
68 using testing::SetArgumentPointee;
69 using testing::Test;
70 
71 class StackwalkerARMFixture {
72  public:
StackwalkerARMFixture()73   StackwalkerARMFixture()
74     : stack_section(kLittleEndian),
75       // Give the two modules reasonable standard locations and names
76       // for tests to play with.
77       module1(0x40000000, 0x10000, "module1", "version1"),
78       module2(0x50000000, 0x10000, "module2", "version2") {
79     // Identify the system as a Linux system.
80     system_info.os = "Linux";
81     system_info.os_short = "linux";
82     system_info.os_version = "Lugubrious Labrador";
83     system_info.cpu = "arm";
84     system_info.cpu_info = "";
85 
86     // Put distinctive values in the raw CPU context.
87     BrandContext(&raw_context);
88 
89     // Create some modules with some stock debugging information.
90     modules.Add(&module1);
91     modules.Add(&module2);
92 
93     // By default, none of the modules have symbol info; call
94     // SetModuleSymbols to override this.
95     EXPECT_CALL(supplier, GetCStringSymbolData(_, _, _, _, _))
96       .WillRepeatedly(Return(MockSymbolSupplier::NOT_FOUND));
97 
98     // Avoid GMOCK WARNING "Uninteresting mock function call - returning
99     // directly" for FreeSymbolData().
100     EXPECT_CALL(supplier, FreeSymbolData(_)).Times(AnyNumber());
101 
102     // Reset max_frames_scanned since it's static.
103     Stackwalker::set_max_frames_scanned(1024);
104   }
105 
106   // Set the Breakpad symbol information that supplier should return for
107   // MODULE to INFO.
SetModuleSymbols(MockCodeModule * module,const string & info)108   void SetModuleSymbols(MockCodeModule *module, const string &info) {
109     size_t buffer_size;
110     char *buffer = supplier.CopySymbolDataAndOwnTheCopy(info, &buffer_size);
111     EXPECT_CALL(supplier, GetCStringSymbolData(module, &system_info, _, _, _))
112       .WillRepeatedly(DoAll(SetArgumentPointee<3>(buffer),
113                             SetArgumentPointee<4>(buffer_size),
114                             Return(MockSymbolSupplier::FOUND)));
115   }
116 
117   // Populate stack_region with the contents of stack_section. Use
118   // stack_section.start() as the region's starting address.
RegionFromSection()119   void RegionFromSection() {
120     string contents;
121     ASSERT_TRUE(stack_section.GetContents(&contents));
122     stack_region.Init(stack_section.start().Value(), contents);
123   }
124 
125   // Fill RAW_CONTEXT with pseudo-random data, for round-trip checking.
BrandContext(MDRawContextARM * raw_context)126   void BrandContext(MDRawContextARM *raw_context) {
127     uint8_t x = 173;
128     for (size_t i = 0; i < sizeof(*raw_context); i++)
129       reinterpret_cast<uint8_t *>(raw_context)[i] = (x += 17);
130   }
131 
132   SystemInfo system_info;
133   MDRawContextARM raw_context;
134   Section stack_section;
135   MockMemoryRegion stack_region;
136   MockCodeModule module1;
137   MockCodeModule module2;
138   MockCodeModules modules;
139   MockSymbolSupplier supplier;
140   BasicSourceLineResolver resolver;
141   CallStack call_stack;
142   const vector<StackFrame *> *frames;
143 };
144 
145 class SanityCheck: public StackwalkerARMFixture, public Test { };
146 
TEST_F(SanityCheck,NoResolver)147 TEST_F(SanityCheck, NoResolver) {
148   // Since we have no call frame information, and all unwinding
149   // requires call frame information, the stack walk will end after
150   // the first frame.
151   StackFrameSymbolizer frame_symbolizer(NULL, NULL);
152   StackwalkerARM walker(&system_info, &raw_context, -1, &stack_region, &modules,
153                         &frame_symbolizer);
154   // This should succeed even without a resolver or supplier.
155   vector<const CodeModule*> modules_without_symbols;
156   vector<const CodeModule*> modules_with_corrupt_symbols;
157   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols,
158                           &modules_with_corrupt_symbols));
159   ASSERT_EQ(0U, modules_without_symbols.size());
160   ASSERT_EQ(0U, modules_with_corrupt_symbols.size());
161   frames = call_stack.frames();
162   ASSERT_EQ(1U, frames->size());
163   StackFrameARM *frame = static_cast<StackFrameARM *>(frames->at(0));
164   // Check that the values from the original raw context made it
165   // through to the context in the stack frame.
166   EXPECT_EQ(0, memcmp(&raw_context, &frame->context, sizeof(raw_context)));
167 }
168 
169 class GetContextFrame: public StackwalkerARMFixture, public Test { };
170 
TEST_F(GetContextFrame,Simple)171 TEST_F(GetContextFrame, Simple) {
172   // Since we have no call frame information, and all unwinding
173   // requires call frame information, the stack walk will end after
174   // the first frame.
175   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);
176   StackwalkerARM walker(&system_info, &raw_context, -1, &stack_region, &modules,
177                         &frame_symbolizer);
178   vector<const CodeModule*> modules_without_symbols;
179   vector<const CodeModule*> modules_with_corrupt_symbols;
180   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols,
181                           &modules_with_corrupt_symbols));
182   ASSERT_EQ(0U, modules_without_symbols.size());
183   ASSERT_EQ(0U, modules_with_corrupt_symbols.size());
184   frames = call_stack.frames();
185   ASSERT_EQ(1U, frames->size());
186   StackFrameARM *frame = static_cast<StackFrameARM *>(frames->at(0));
187   // Check that the values from the original raw context made it
188   // through to the context in the stack frame.
189   EXPECT_EQ(0, memcmp(&raw_context, &frame->context, sizeof(raw_context)));
190 }
191 
192 // The stackwalker should be able to produce the context frame even
193 // without stack memory present.
TEST_F(GetContextFrame,NoStackMemory)194 TEST_F(GetContextFrame, NoStackMemory) {
195   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);
196   StackwalkerARM walker(&system_info, &raw_context, -1, NULL, &modules,
197                         &frame_symbolizer);
198   vector<const CodeModule*> modules_without_symbols;
199   vector<const CodeModule*> modules_with_corrupt_symbols;
200   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols,
201                           &modules_with_corrupt_symbols));
202   ASSERT_EQ(0U, modules_without_symbols.size());
203   ASSERT_EQ(0U, modules_with_corrupt_symbols.size());
204   frames = call_stack.frames();
205   ASSERT_EQ(1U, frames->size());
206   StackFrameARM *frame = static_cast<StackFrameARM *>(frames->at(0));
207   // Check that the values from the original raw context made it
208   // through to the context in the stack frame.
209   EXPECT_EQ(0, memcmp(&raw_context, &frame->context, sizeof(raw_context)));
210 }
211 
212 class GetCallerFrame: public StackwalkerARMFixture, public Test { };
213 
TEST_F(GetCallerFrame,ScanWithoutSymbols)214 TEST_F(GetCallerFrame, ScanWithoutSymbols) {
215   // When the stack walker resorts to scanning the stack,
216   // only addresses located within loaded modules are
217   // considered valid return addresses.
218   // Force scanning through three frames to ensure that the
219   // stack pointer is set properly in scan-recovered frames.
220   stack_section.start() = 0x80000000;
221   uint32_t return_address1 = 0x50000100;
222   uint32_t return_address2 = 0x50000900;
223   Label frame1_sp, frame2_sp;
224   stack_section
225     // frame 0
226     .Append(16, 0)                      // space
227 
228     .D32(0x40090000)                    // junk that's not
229     .D32(0x60000000)                    // a return address
230 
231     .D32(return_address1)               // actual return address
232     // frame 1
233     .Mark(&frame1_sp)
234     .Append(16, 0)                      // space
235 
236     .D32(0xF0000000)                    // more junk
237     .D32(0x0000000D)
238 
239     .D32(return_address2)               // actual return address
240     // frame 2
241     .Mark(&frame2_sp)
242     .Append(32, 0);                     // end of stack
243   RegionFromSection();
244 
245   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40005510;
246   raw_context.iregs[MD_CONTEXT_ARM_REG_SP] = stack_section.start().Value();
247 
248   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);
249   StackwalkerARM walker(&system_info, &raw_context, -1, &stack_region, &modules,
250                         &frame_symbolizer);
251   vector<const CodeModule*> modules_without_symbols;
252   vector<const CodeModule*> modules_with_corrupt_symbols;
253   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols,
254                           &modules_with_corrupt_symbols));
255   ASSERT_EQ(2U, modules_without_symbols.size());
256   ASSERT_EQ("module1", modules_without_symbols[0]->debug_file());
257   ASSERT_EQ("module2", modules_without_symbols[1]->debug_file());
258   ASSERT_EQ(0U, modules_with_corrupt_symbols.size());
259   frames = call_stack.frames();
260   ASSERT_EQ(3U, frames->size());
261 
262   StackFrameARM *frame0 = static_cast<StackFrameARM *>(frames->at(0));
263   EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust);
264   ASSERT_EQ(StackFrameARM::CONTEXT_VALID_ALL, frame0->context_validity);
265   EXPECT_EQ(0, memcmp(&raw_context, &frame0->context, sizeof(raw_context)));
266 
267   StackFrameARM *frame1 = static_cast<StackFrameARM *>(frames->at(1));
268   EXPECT_EQ(StackFrame::FRAME_TRUST_SCAN, frame1->trust);
269   ASSERT_EQ((StackFrameARM::CONTEXT_VALID_PC |
270              StackFrameARM::CONTEXT_VALID_SP),
271             frame1->context_validity);
272   EXPECT_EQ(return_address1, frame1->context.iregs[MD_CONTEXT_ARM_REG_PC]);
273   EXPECT_EQ(frame1_sp.Value(), frame1->context.iregs[MD_CONTEXT_ARM_REG_SP]);
274 
275   StackFrameARM *frame2 = static_cast<StackFrameARM *>(frames->at(2));
276   EXPECT_EQ(StackFrame::FRAME_TRUST_SCAN, frame2->trust);
277   ASSERT_EQ((StackFrameARM::CONTEXT_VALID_PC |
278              StackFrameARM::CONTEXT_VALID_SP),
279             frame2->context_validity);
280   EXPECT_EQ(return_address2, frame2->context.iregs[MD_CONTEXT_ARM_REG_PC]);
281   EXPECT_EQ(frame2_sp.Value(), frame2->context.iregs[MD_CONTEXT_ARM_REG_SP]);
282 }
283 
TEST_F(GetCallerFrame,ScanWithFunctionSymbols)284 TEST_F(GetCallerFrame, ScanWithFunctionSymbols) {
285   // During stack scanning, if a potential return address
286   // is located within a loaded module that has symbols,
287   // it is only considered a valid return address if it
288   // lies within a function's bounds.
289   stack_section.start() = 0x80000000;
290   uint32_t return_address = 0x50000200;
291   Label frame1_sp;
292 
293   stack_section
294     // frame 0
295     .Append(16, 0)                      // space
296 
297     .D32(0x40090000)                    // junk that's not
298     .D32(0x60000000)                    // a return address
299 
300     .D32(0x40001000)                    // a couple of plausible addresses
301     .D32(0x5000F000)                    // that are not within functions
302 
303     .D32(return_address)                // actual return address
304     // frame 1
305     .Mark(&frame1_sp)
306     .Append(32, 0);                     // end of stack
307   RegionFromSection();
308 
309   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40000200;
310   raw_context.iregs[MD_CONTEXT_ARM_REG_SP] = stack_section.start().Value();
311 
312   SetModuleSymbols(&module1,
313                    // The youngest frame's function.
314                    "FUNC 100 400 10 monotreme\n");
315   SetModuleSymbols(&module2,
316                    // The calling frame's function.
317                    "FUNC 100 400 10 marsupial\n");
318 
319   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);
320   StackwalkerARM walker(&system_info, &raw_context, -1, &stack_region, &modules,
321                         &frame_symbolizer);
322   vector<const CodeModule*> modules_without_symbols;
323   vector<const CodeModule*> modules_with_corrupt_symbols;
324   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols,
325                           &modules_with_corrupt_symbols));
326   ASSERT_EQ(0U, modules_without_symbols.size());
327   ASSERT_EQ(0U, modules_with_corrupt_symbols.size());
328   frames = call_stack.frames();
329   ASSERT_EQ(2U, frames->size());
330 
331   StackFrameARM *frame0 = static_cast<StackFrameARM *>(frames->at(0));
332   EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust);
333   ASSERT_EQ(StackFrameARM::CONTEXT_VALID_ALL, frame0->context_validity);
334   EXPECT_EQ(0, memcmp(&raw_context, &frame0->context, sizeof(raw_context)));
335   EXPECT_EQ("monotreme", frame0->function_name);
336   EXPECT_EQ(0x40000100U, frame0->function_base);
337 
338   StackFrameARM *frame1 = static_cast<StackFrameARM *>(frames->at(1));
339   EXPECT_EQ(StackFrame::FRAME_TRUST_SCAN, frame1->trust);
340   ASSERT_EQ((StackFrameARM::CONTEXT_VALID_PC |
341              StackFrameARM::CONTEXT_VALID_SP),
342             frame1->context_validity);
343   EXPECT_EQ(return_address, frame1->context.iregs[MD_CONTEXT_ARM_REG_PC]);
344   EXPECT_EQ(frame1_sp.Value(), frame1->context.iregs[MD_CONTEXT_ARM_REG_SP]);
345   EXPECT_EQ("marsupial", frame1->function_name);
346   EXPECT_EQ(0x50000100U, frame1->function_base);
347 }
348 
TEST_F(GetCallerFrame,ScanFirstFrame)349 TEST_F(GetCallerFrame, ScanFirstFrame) {
350   // If the stackwalker resorts to stack scanning, it will scan much
351   // farther to find the caller of the context frame.
352   stack_section.start() = 0x80000000;
353   uint32_t return_address1 = 0x50000100;
354   uint32_t return_address2 = 0x50000900;
355   Label frame1_sp, frame2_sp;
356   stack_section
357     // frame 0
358     .Append(32, 0)                      // space
359 
360     .D32(0x40090000)                    // junk that's not
361     .D32(0x60000000)                    // a return address
362 
363     .Append(96, 0)                      // more space
364 
365     .D32(return_address1)               // actual return address
366     // frame 1
367     .Mark(&frame1_sp)
368     .Append(32, 0)                      // space
369 
370     .D32(0xF0000000)                    // more junk
371     .D32(0x0000000D)
372 
373     .Append(96, 0)                      // more space
374 
375     .D32(return_address2)               // actual return address
376                                         // (won't be found)
377     // frame 2
378     .Mark(&frame2_sp)
379     .Append(32, 0);                     // end of stack
380   RegionFromSection();
381 
382   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40005510;
383   raw_context.iregs[MD_CONTEXT_ARM_REG_SP] = stack_section.start().Value();
384 
385   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);
386   StackwalkerARM walker(&system_info, &raw_context, -1, &stack_region, &modules,
387                         &frame_symbolizer);
388   vector<const CodeModule*> modules_without_symbols;
389   vector<const CodeModule*> modules_with_corrupt_symbols;
390   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols,
391                           &modules_with_corrupt_symbols));
392   ASSERT_EQ(2U, modules_without_symbols.size());
393   ASSERT_EQ("module1", modules_without_symbols[0]->debug_file());
394   ASSERT_EQ("module2", modules_without_symbols[1]->debug_file());
395   ASSERT_EQ(0U, modules_with_corrupt_symbols.size());
396   frames = call_stack.frames();
397   ASSERT_EQ(2U, frames->size());
398 
399   StackFrameARM *frame0 = static_cast<StackFrameARM *>(frames->at(0));
400   EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust);
401   ASSERT_EQ(StackFrameARM::CONTEXT_VALID_ALL, frame0->context_validity);
402   EXPECT_EQ(0, memcmp(&raw_context, &frame0->context, sizeof(raw_context)));
403 
404   StackFrameARM *frame1 = static_cast<StackFrameARM *>(frames->at(1));
405   EXPECT_EQ(StackFrame::FRAME_TRUST_SCAN, frame1->trust);
406   ASSERT_EQ((StackFrameARM::CONTEXT_VALID_PC |
407              StackFrameARM::CONTEXT_VALID_SP),
408             frame1->context_validity);
409   EXPECT_EQ(return_address1, frame1->context.iregs[MD_CONTEXT_ARM_REG_PC]);
410   EXPECT_EQ(frame1_sp.Value(), frame1->context.iregs[MD_CONTEXT_ARM_REG_SP]);
411 }
412 
413 // Test that set_max_frames_scanned prevents using stack scanning
414 // to find caller frames.
TEST_F(GetCallerFrame,ScanningNotAllowed)415 TEST_F(GetCallerFrame, ScanningNotAllowed) {
416   // When the stack walker resorts to scanning the stack,
417   // only addresses located within loaded modules are
418   // considered valid return addresses.
419   stack_section.start() = 0x80000000;
420   uint32_t return_address1 = 0x50000100;
421   uint32_t return_address2 = 0x50000900;
422   Label frame1_sp, frame2_sp;
423   stack_section
424     // frame 0
425     .Append(16, 0)                      // space
426 
427     .D32(0x40090000)                    // junk that's not
428     .D32(0x60000000)                    // a return address
429 
430     .D32(return_address1)               // actual return address
431     // frame 1
432     .Mark(&frame1_sp)
433     .Append(16, 0)                      // space
434 
435     .D32(0xF0000000)                    // more junk
436     .D32(0x0000000D)
437 
438     .D32(return_address2)               // actual return address
439     // frame 2
440     .Mark(&frame2_sp)
441     .Append(32, 0);                     // end of stack
442   RegionFromSection();
443 
444   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40005510;
445   raw_context.iregs[MD_CONTEXT_ARM_REG_SP] = stack_section.start().Value();
446 
447   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);
448   StackwalkerARM walker(&system_info, &raw_context, -1, &stack_region, &modules,
449                         &frame_symbolizer);
450   Stackwalker::set_max_frames_scanned(0);
451 
452   vector<const CodeModule*> modules_without_symbols;
453   vector<const CodeModule*> modules_with_corrupt_symbols;
454   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols,
455                           &modules_with_corrupt_symbols));
456   ASSERT_EQ(1U, modules_without_symbols.size());
457   ASSERT_EQ("module1", modules_without_symbols[0]->debug_file());
458   ASSERT_EQ(0U, modules_with_corrupt_symbols.size());
459   frames = call_stack.frames();
460   ASSERT_EQ(1U, frames->size());
461 
462   StackFrameARM *frame0 = static_cast<StackFrameARM *>(frames->at(0));
463   EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust);
464   ASSERT_EQ(StackFrameARM::CONTEXT_VALID_ALL, frame0->context_validity);
465   EXPECT_EQ(0, memcmp(&raw_context, &frame0->context, sizeof(raw_context)));
466 }
467 
468 struct CFIFixture: public StackwalkerARMFixture {
CFIFixtureCFIFixture469   CFIFixture() {
470     // Provide a bunch of STACK CFI records; we'll walk to the caller
471     // from every point in this series, expecting to find the same set
472     // of register values.
473     SetModuleSymbols(&module1,
474                      // The youngest frame's function.
475                      "FUNC 4000 1000 10 enchiridion\n"
476                      // Initially, nothing has been pushed on the stack,
477                      // and the return address is still in the link register.
478                      "STACK CFI INIT 4000 100 .cfa: sp .ra: lr\n"
479                      // Push r4, the frame pointer, and the link register.
480                      "STACK CFI 4001 .cfa: sp 12 + r4: .cfa 12 - ^"
481                      " r11: .cfa 8 - ^ .ra: .cfa 4 - ^\n"
482                      // Save r4..r7 in r0..r3: verify that we populate
483                      // the youngest frame with all the values we have.
484                      "STACK CFI 4002 r4: r0 r5: r1 r6: r2 r7: r3\n"
485                      // Restore r4..r7. Save the non-callee-saves register r1.
486                      "STACK CFI 4003 .cfa: sp 16 + r1: .cfa 16 - ^"
487                      " r4: r4 r5: r5 r6: r6 r7: r7\n"
488                      // Move the .cfa back four bytes, to point at the return
489                      // address, and restore the sp explicitly.
490                      "STACK CFI 4005 .cfa: sp 12 + r1: .cfa 12 - ^"
491                      " r11: .cfa 4 - ^ .ra: .cfa ^ sp: .cfa 4 +\n"
492                      // Recover the PC explicitly from a new stack slot;
493                      // provide garbage for the .ra.
494                      "STACK CFI 4006 .cfa: sp 16 + pc: .cfa 16 - ^\n"
495 
496                      // The calling function.
497                      "FUNC 5000 1000 10 epictetus\n"
498                      // Mark it as end of stack.
499                      "STACK CFI INIT 5000 1000 .cfa: 0 .ra: 0\n"
500 
501                      // A function whose CFI makes the stack pointer
502                      // go backwards.
503                      "FUNC 6000 1000 20 palinal\n"
504                      "STACK CFI INIT 6000 1000 .cfa: sp 4 - .ra: lr\n"
505 
506                      // A function with CFI expressions that can't be
507                      // evaluated.
508                      "FUNC 7000 1000 20 rhetorical\n"
509                      "STACK CFI INIT 7000 1000 .cfa: moot .ra: ambiguous\n");
510 
511     // Provide some distinctive values for the caller's registers.
512     expected.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40005510;
513     expected.iregs[MD_CONTEXT_ARM_REG_SP] = 0x80000000;
514     expected.iregs[4] = 0xb5d55e68;
515     expected.iregs[5] = 0xebd134f3;
516     expected.iregs[6] = 0xa31e74bc;
517     expected.iregs[7] = 0x2dcb16b3;
518     expected.iregs[8] = 0x2ada2137;
519     expected.iregs[9] = 0xbbbb557d;
520     expected.iregs[10] = 0x48bf8ca7;
521     expected.iregs[MD_CONTEXT_ARM_REG_FP] = 0x8112e110;
522 
523     // Expect CFI to recover all callee-saves registers. Since CFI is the
524     // only stack frame construction technique we have, aside from the
525     // context frame itself, there's no way for us to have a set of valid
526     // registers smaller than this.
527     expected_validity = (StackFrameARM::CONTEXT_VALID_PC |
528                          StackFrameARM::CONTEXT_VALID_SP |
529                          StackFrameARM::CONTEXT_VALID_R4 |
530                          StackFrameARM::CONTEXT_VALID_R5 |
531                          StackFrameARM::CONTEXT_VALID_R6 |
532                          StackFrameARM::CONTEXT_VALID_R7 |
533                          StackFrameARM::CONTEXT_VALID_R8 |
534                          StackFrameARM::CONTEXT_VALID_R9 |
535                          StackFrameARM::CONTEXT_VALID_R10 |
536                          StackFrameARM::CONTEXT_VALID_FP);
537 
538     // By default, context frames provide all registers, as normal.
539     context_frame_validity = StackFrameARM::CONTEXT_VALID_ALL;
540 
541     // By default, registers are unchanged.
542     raw_context = expected;
543   }
544 
545   // Walk the stack, using stack_section as the contents of the stack
546   // and raw_context as the current register values. (Set the stack
547   // pointer to the stack's starting address.) Expect two stack
548   // frames; in the older frame, expect the callee-saves registers to
549   // have values matching those in 'expected'.
CheckWalkCFIFixture550   void CheckWalk() {
551     RegionFromSection();
552     raw_context.iregs[MD_CONTEXT_ARM_REG_SP] = stack_section.start().Value();
553 
554     StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);
555     StackwalkerARM walker(&system_info, &raw_context, -1, &stack_region,
556                           &modules, &frame_symbolizer);
557     walker.SetContextFrameValidity(context_frame_validity);
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     StackFrameARM *frame0 = static_cast<StackFrameARM *>(frames->at(0));
568     EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust);
569     ASSERT_EQ(context_frame_validity, frame0->context_validity);
570     EXPECT_EQ("enchiridion", frame0->function_name);
571     EXPECT_EQ(0x40004000U, frame0->function_base);
572 
573     StackFrameARM *frame1 = static_cast<StackFrameARM *>(frames->at(1));
574     EXPECT_EQ(StackFrame::FRAME_TRUST_CFI, frame1->trust);
575     ASSERT_EQ(expected_validity, frame1->context_validity);
576     if (expected_validity & StackFrameARM::CONTEXT_VALID_R1)
577       EXPECT_EQ(expected.iregs[1], frame1->context.iregs[1]);
578     if (expected_validity & StackFrameARM::CONTEXT_VALID_R4)
579       EXPECT_EQ(expected.iregs[4], frame1->context.iregs[4]);
580     if (expected_validity & StackFrameARM::CONTEXT_VALID_R5)
581       EXPECT_EQ(expected.iregs[5], frame1->context.iregs[5]);
582     if (expected_validity & StackFrameARM::CONTEXT_VALID_R6)
583       EXPECT_EQ(expected.iregs[6], frame1->context.iregs[6]);
584     if (expected_validity & StackFrameARM::CONTEXT_VALID_R7)
585       EXPECT_EQ(expected.iregs[7], frame1->context.iregs[7]);
586     if (expected_validity & StackFrameARM::CONTEXT_VALID_R8)
587       EXPECT_EQ(expected.iregs[8], frame1->context.iregs[8]);
588     if (expected_validity & StackFrameARM::CONTEXT_VALID_R9)
589       EXPECT_EQ(expected.iregs[9], frame1->context.iregs[9]);
590     if (expected_validity & StackFrameARM::CONTEXT_VALID_R10)
591       EXPECT_EQ(expected.iregs[10], frame1->context.iregs[10]);
592     if (expected_validity & StackFrameARM::CONTEXT_VALID_FP)
593       EXPECT_EQ(expected.iregs[MD_CONTEXT_ARM_REG_FP],
594                 frame1->context.iregs[MD_CONTEXT_ARM_REG_FP]);
595 
596     // We would never have gotten a frame in the first place if the SP
597     // and PC weren't valid or ->instruction weren't set.
598     EXPECT_EQ(expected.iregs[MD_CONTEXT_ARM_REG_SP],
599               frame1->context.iregs[MD_CONTEXT_ARM_REG_SP]);
600     EXPECT_EQ(expected.iregs[MD_CONTEXT_ARM_REG_PC],
601               frame1->context.iregs[MD_CONTEXT_ARM_REG_PC]);
602     EXPECT_EQ(expected.iregs[MD_CONTEXT_ARM_REG_PC],
603               frame1->instruction + 2);
604     EXPECT_EQ("epictetus", frame1->function_name);
605   }
606 
607   // The values we expect to find for the caller's registers.
608   MDRawContextARM expected;
609 
610   // The validity mask for expected.
611   int expected_validity;
612 
613   // The validity mask to impose on the context frame.
614   int context_frame_validity;
615 };
616 
617 class CFI: public CFIFixture, public Test { };
618 
TEST_F(CFI,At4000)619 TEST_F(CFI, At4000) {
620   stack_section.start() = expected.iregs[MD_CONTEXT_ARM_REG_SP];
621   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40004000;
622   raw_context.iregs[MD_CONTEXT_ARM_REG_LR] = 0x40005510;
623   CheckWalk();
624 }
625 
TEST_F(CFI,At4001)626 TEST_F(CFI, At4001) {
627   Label frame1_sp = expected.iregs[MD_CONTEXT_ARM_REG_SP];
628   stack_section
629     .D32(0xb5d55e68)            // saved r4
630     .D32(0x8112e110)            // saved fp
631     .D32(0x40005510)            // return address
632     .Mark(&frame1_sp);          // This effectively sets stack_section.start().
633   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40004001;
634   raw_context.iregs[4] = 0x635adc9f;                     // distinct callee r4
635   raw_context.iregs[MD_CONTEXT_ARM_REG_FP] = 0xbe145fc4; // distinct callee fp
636   CheckWalk();
637 }
638 
639 // As above, but unwind from a context that has only the PC and SP.
TEST_F(CFI,At4001LimitedValidity)640 TEST_F(CFI, At4001LimitedValidity) {
641   context_frame_validity =
642     StackFrameARM::CONTEXT_VALID_PC | StackFrameARM::CONTEXT_VALID_SP;
643   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40004001;
644   raw_context.iregs[MD_CONTEXT_ARM_REG_FP] = 0xbe145fc4; // distinct callee fp
645   Label frame1_sp = expected.iregs[MD_CONTEXT_ARM_REG_SP];
646   stack_section
647     .D32(0xb5d55e68)            // saved r4
648     .D32(0x8112e110)            // saved fp
649     .D32(0x40005510)            // return address
650     .Mark(&frame1_sp);          // This effectively sets stack_section.start().
651   expected_validity = (StackFrameARM::CONTEXT_VALID_PC
652                        | StackFrameARM::CONTEXT_VALID_SP
653                        | StackFrameARM::CONTEXT_VALID_FP
654                        | StackFrameARM::CONTEXT_VALID_R4);
655   CheckWalk();
656 }
657 
TEST_F(CFI,At4002)658 TEST_F(CFI, At4002) {
659   Label frame1_sp = expected.iregs[MD_CONTEXT_ARM_REG_SP];
660   stack_section
661     .D32(0xfb81ff3d)            // no longer saved r4
662     .D32(0x8112e110)            // saved fp
663     .D32(0x40005510)            // return address
664     .Mark(&frame1_sp);          // This effectively sets stack_section.start().
665   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40004002;
666   raw_context.iregs[0] = 0xb5d55e68;  // saved r4
667   raw_context.iregs[1] = 0xebd134f3;  // saved r5
668   raw_context.iregs[2] = 0xa31e74bc;  // saved r6
669   raw_context.iregs[3] = 0x2dcb16b3;  // saved r7
670   raw_context.iregs[4] = 0xfdd35466;  // distinct callee r4
671   raw_context.iregs[5] = 0xf18c946c;  // distinct callee r5
672   raw_context.iregs[6] = 0xac2079e8;  // distinct callee r6
673   raw_context.iregs[7] = 0xa449829f;  // distinct callee r7
674   raw_context.iregs[MD_CONTEXT_ARM_REG_FP] = 0xbe145fc4; // distinct callee fp
675   CheckWalk();
676 }
677 
TEST_F(CFI,At4003)678 TEST_F(CFI, At4003) {
679   Label frame1_sp = expected.iregs[MD_CONTEXT_ARM_REG_SP];
680   stack_section
681     .D32(0x48c8dd5a)            // saved r1 (even though it's not callee-saves)
682     .D32(0xcb78040e)            // no longer saved r4
683     .D32(0x8112e110)            // saved fp
684     .D32(0x40005510)            // return address
685     .Mark(&frame1_sp);          // This effectively sets stack_section.start().
686   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40004003;
687   raw_context.iregs[1] = 0xfb756319;                     // distinct callee r1
688   raw_context.iregs[MD_CONTEXT_ARM_REG_FP] = 0x0a2857ea; // distinct callee fp
689   expected.iregs[1] = 0x48c8dd5a;    // caller's r1
690   expected_validity |= StackFrameARM::CONTEXT_VALID_R1;
691   CheckWalk();
692 }
693 
694 // We have no new rule at module offset 0x4004, so the results here should
695 // be the same as those at module offset 0x4003.
TEST_F(CFI,At4004)696 TEST_F(CFI, At4004) {
697   Label frame1_sp = expected.iregs[MD_CONTEXT_ARM_REG_SP];
698   stack_section
699     .D32(0x48c8dd5a)            // saved r1 (even though it's not callee-saves)
700     .D32(0xcb78040e)            // no longer saved r4
701     .D32(0x8112e110)            // saved fp
702     .D32(0x40005510)            // return address
703     .Mark(&frame1_sp);          // This effectively sets stack_section.start().
704   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40004004;
705   raw_context.iregs[1] = 0xfb756319; // distinct callee r1
706   expected.iregs[1] = 0x48c8dd5a; // caller's r1
707   expected_validity |= StackFrameARM::CONTEXT_VALID_R1;
708   CheckWalk();
709 }
710 
711 // Here we move the .cfa, but provide an explicit rule to recover the SP,
712 // so again there should be no change in the registers recovered.
TEST_F(CFI,At4005)713 TEST_F(CFI, At4005) {
714   Label frame1_sp = expected.iregs[MD_CONTEXT_ARM_REG_SP];
715   stack_section
716     .D32(0x48c8dd5a)            // saved r1 (even though it's not callee-saves)
717     .D32(0xf013f841)            // no longer saved r4
718     .D32(0x8112e110)            // saved fp
719     .D32(0x40005510)            // return address
720     .Mark(&frame1_sp);          // This effectively sets stack_section.start().
721   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40004005;
722   raw_context.iregs[1] = 0xfb756319; // distinct callee r1
723   expected.iregs[1] = 0x48c8dd5a; // caller's r1
724   expected_validity |= StackFrameARM::CONTEXT_VALID_R1;
725   CheckWalk();
726 }
727 
728 // Here we provide an explicit rule for the PC, and have the saved .ra be
729 // bogus.
TEST_F(CFI,At4006)730 TEST_F(CFI, At4006) {
731   Label frame1_sp = expected.iregs[MD_CONTEXT_ARM_REG_SP];
732   stack_section
733     .D32(0x40005510)            // saved pc
734     .D32(0x48c8dd5a)            // saved r1 (even though it's not callee-saves)
735     .D32(0xf013f841)            // no longer saved r4
736     .D32(0x8112e110)            // saved fp
737     .D32(0xf8d15783)            // .ra rule recovers this, which is garbage
738     .Mark(&frame1_sp);          // This effectively sets stack_section.start().
739   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40004006;
740   raw_context.iregs[1] = 0xfb756319; // callee's r1, different from caller's
741   expected.iregs[1] = 0x48c8dd5a; // caller's r1
742   expected_validity |= StackFrameARM::CONTEXT_VALID_R1;
743   CheckWalk();
744 }
745 
746 // Check that we reject rules that would cause the stack pointer to
747 // move in the wrong direction.
TEST_F(CFI,RejectBackwards)748 TEST_F(CFI, RejectBackwards) {
749   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40006000;
750   raw_context.iregs[MD_CONTEXT_ARM_REG_SP] = 0x80000000;
751   raw_context.iregs[MD_CONTEXT_ARM_REG_LR] = 0x40005510;
752   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);
753   StackwalkerARM walker(&system_info, &raw_context, -1, &stack_region, &modules,
754                         &frame_symbolizer);
755   vector<const CodeModule*> modules_without_symbols;
756   vector<const CodeModule*> modules_with_corrupt_symbols;
757   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols,
758                           &modules_with_corrupt_symbols));
759   ASSERT_EQ(0U, modules_without_symbols.size());
760   ASSERT_EQ(0U, modules_with_corrupt_symbols.size());
761   frames = call_stack.frames();
762   ASSERT_EQ(1U, frames->size());
763 }
764 
765 // Check that we reject rules whose expressions' evaluation fails.
TEST_F(CFI,RejectBadExpressions)766 TEST_F(CFI, RejectBadExpressions) {
767   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40007000;
768   raw_context.iregs[MD_CONTEXT_ARM_REG_SP] = 0x80000000;
769   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);
770   StackwalkerARM walker(&system_info, &raw_context, -1, &stack_region, &modules,
771                         &frame_symbolizer);
772   vector<const CodeModule*> modules_without_symbols;
773   vector<const CodeModule*> modules_with_corrupt_symbols;
774   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols,
775                           &modules_with_corrupt_symbols));
776   ASSERT_EQ(0U, modules_without_symbols.size());
777   ASSERT_EQ(0U, modules_with_corrupt_symbols.size());
778   frames = call_stack.frames();
779   ASSERT_EQ(1U, frames->size());
780 }
781 
782 class StackwalkerARMFixtureIOS : public StackwalkerARMFixture {
783  public:
StackwalkerARMFixtureIOS()784   StackwalkerARMFixtureIOS() {
785     system_info.os = "iOS";
786     system_info.os_short = "ios";
787   }
788 };
789 
790 class GetFramesByFramePointer: public StackwalkerARMFixtureIOS, public Test { };
791 
TEST_F(GetFramesByFramePointer,OnlyFramePointer)792 TEST_F(GetFramesByFramePointer, OnlyFramePointer) {
793   stack_section.start() = 0x80000000;
794   uint32_t return_address1 = 0x50000100;
795   uint32_t return_address2 = 0x50000900;
796   Label frame1_sp, frame2_sp;
797   Label frame1_fp, frame2_fp;
798   stack_section
799     // frame 0
800     .Append(32, 0)           // Whatever values on the stack.
801     .D32(0x0000000D)         // junk that's not
802     .D32(0xF0000000)         // a return address.
803 
804     .Mark(&frame1_fp)        // Next fp will point to the next value.
805     .D32(frame2_fp)          // Save current frame pointer.
806     .D32(return_address2)    // Save current link register.
807     .Mark(&frame1_sp)
808 
809     // frame 1
810     .Append(32, 0)           // Whatever values on the stack.
811     .D32(0x0000000D)         // junk that's not
812     .D32(0xF0000000)         // a return address.
813 
814     .Mark(&frame2_fp)
815     .D32(0)
816     .D32(0)
817     .Mark(&frame2_sp)
818 
819     // frame 2
820     .Append(32, 0)           // Whatever values on the stack.
821     .D32(0x0000000D)         // junk that's not
822     .D32(0xF0000000);        // a return address.
823   RegionFromSection();
824 
825 
826   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x40005510;
827   raw_context.iregs[MD_CONTEXT_ARM_REG_LR] = return_address1;
828   raw_context.iregs[MD_CONTEXT_ARM_REG_IOS_FP] = frame1_fp.Value();
829   raw_context.iregs[MD_CONTEXT_ARM_REG_SP] = stack_section.start().Value();
830 
831   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);
832   StackwalkerARM walker(&system_info, &raw_context, MD_CONTEXT_ARM_REG_IOS_FP,
833                         &stack_region, &modules, &frame_symbolizer);
834 
835   vector<const CodeModule*> modules_without_symbols;
836   vector<const CodeModule*> modules_with_corrupt_symbols;
837   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols,
838                           &modules_with_corrupt_symbols));
839   ASSERT_EQ(2U, modules_without_symbols.size());
840   ASSERT_EQ("module1", modules_without_symbols[0]->debug_file());
841   ASSERT_EQ("module2", modules_without_symbols[1]->debug_file());
842   ASSERT_EQ(0U, modules_with_corrupt_symbols.size());
843   frames = call_stack.frames();
844   ASSERT_EQ(3U, frames->size());
845 
846   StackFrameARM *frame0 = static_cast<StackFrameARM *>(frames->at(0));
847   EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust);
848   ASSERT_EQ(StackFrameARM::CONTEXT_VALID_ALL, frame0->context_validity);
849   EXPECT_EQ(0, memcmp(&raw_context, &frame0->context, sizeof(raw_context)));
850 
851   StackFrameARM *frame1 = static_cast<StackFrameARM *>(frames->at(1));
852   EXPECT_EQ(StackFrame::FRAME_TRUST_FP, frame1->trust);
853   ASSERT_EQ((StackFrameARM::CONTEXT_VALID_PC |
854              StackFrameARM::CONTEXT_VALID_LR |
855              StackFrameARM::RegisterValidFlag(MD_CONTEXT_ARM_REG_IOS_FP) |
856              StackFrameARM::CONTEXT_VALID_SP),
857             frame1->context_validity);
858   EXPECT_EQ(return_address1, frame1->context.iregs[MD_CONTEXT_ARM_REG_PC]);
859   EXPECT_EQ(return_address2, frame1->context.iregs[MD_CONTEXT_ARM_REG_LR]);
860   EXPECT_EQ(frame1_sp.Value(), frame1->context.iregs[MD_CONTEXT_ARM_REG_SP]);
861   EXPECT_EQ(frame2_fp.Value(),
862             frame1->context.iregs[MD_CONTEXT_ARM_REG_IOS_FP]);
863 
864   StackFrameARM *frame2 = static_cast<StackFrameARM *>(frames->at(2));
865   EXPECT_EQ(StackFrame::FRAME_TRUST_FP, frame2->trust);
866   ASSERT_EQ((StackFrameARM::CONTEXT_VALID_PC |
867              StackFrameARM::CONTEXT_VALID_LR |
868              StackFrameARM::RegisterValidFlag(MD_CONTEXT_ARM_REG_IOS_FP) |
869              StackFrameARM::CONTEXT_VALID_SP),
870             frame2->context_validity);
871   EXPECT_EQ(return_address2, frame2->context.iregs[MD_CONTEXT_ARM_REG_PC]);
872   EXPECT_EQ(0U, frame2->context.iregs[MD_CONTEXT_ARM_REG_LR]);
873   EXPECT_EQ(frame2_sp.Value(), frame2->context.iregs[MD_CONTEXT_ARM_REG_SP]);
874   EXPECT_EQ(0U, frame2->context.iregs[MD_CONTEXT_ARM_REG_IOS_FP]);
875 }
876 
TEST_F(GetFramesByFramePointer,FramePointerAndCFI)877 TEST_F(GetFramesByFramePointer, FramePointerAndCFI) {
878   // Provide the standatd STACK CFI records that is obtained when exmining an
879   // executable produced by XCode.
880   SetModuleSymbols(&module1,
881                      // Adding a function in CFI.
882                      "FUNC 4000 1000 10 enchiridion\n"
883 
884                      "STACK CFI INIT 4000 100 .cfa: sp 0 + .ra: lr\n"
885                      "STACK CFI 4001 .cfa: sp 8 + .ra: .cfa -4 + ^"
886                      " r7: .cfa -8 + ^\n"
887                      "STACK CFI 4002 .cfa: r7 8 +\n"
888                   );
889 
890   stack_section.start() = 0x80000000;
891   uint32_t return_address1 = 0x40004010;
892   uint32_t return_address2 = 0x50000900;
893   Label frame1_sp, frame2_sp;
894   Label frame1_fp, frame2_fp;
895   stack_section
896     // frame 0
897     .Append(32, 0)           // Whatever values on the stack.
898     .D32(0x0000000D)         // junk that's not
899     .D32(0xF0000000)         // a return address.
900 
901     .Mark(&frame1_fp)        // Next fp will point to the next value.
902     .D32(frame2_fp)          // Save current frame pointer.
903     .D32(return_address2)    // Save current link register.
904     .Mark(&frame1_sp)
905 
906     // frame 1
907     .Append(32, 0)           // Whatever values on the stack.
908     .D32(0x0000000D)         // junk that's not
909     .D32(0xF0000000)         // a return address.
910 
911     .Mark(&frame2_fp)
912     .D32(0)
913     .D32(0)
914     .Mark(&frame2_sp)
915 
916     // frame 2
917     .Append(32, 0)           // Whatever values on the stack.
918     .D32(0x0000000D)         // junk that's not
919     .D32(0xF0000000);        // a return address.
920   RegionFromSection();
921 
922 
923   raw_context.iregs[MD_CONTEXT_ARM_REG_PC] = 0x50000400;
924   raw_context.iregs[MD_CONTEXT_ARM_REG_LR] = return_address1;
925   raw_context.iregs[MD_CONTEXT_ARM_REG_IOS_FP] = frame1_fp.Value();
926   raw_context.iregs[MD_CONTEXT_ARM_REG_SP] = stack_section.start().Value();
927 
928   StackFrameSymbolizer frame_symbolizer(&supplier, &resolver);
929   StackwalkerARM walker(&system_info, &raw_context, MD_CONTEXT_ARM_REG_IOS_FP,
930                         &stack_region, &modules, &frame_symbolizer);
931 
932   vector<const CodeModule*> modules_without_symbols;
933   vector<const CodeModule*> modules_with_corrupt_symbols;
934   ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols,
935                           &modules_with_corrupt_symbols));
936   ASSERT_EQ(1U, modules_without_symbols.size());
937   ASSERT_EQ("module2", modules_without_symbols[0]->debug_file());
938   ASSERT_EQ(0U, modules_with_corrupt_symbols.size());
939   frames = call_stack.frames();
940   ASSERT_EQ(3U, frames->size());
941 
942   StackFrameARM *frame0 = static_cast<StackFrameARM *>(frames->at(0));
943   EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust);
944   ASSERT_EQ(StackFrameARM::CONTEXT_VALID_ALL, frame0->context_validity);
945   EXPECT_EQ(0, memcmp(&raw_context, &frame0->context, sizeof(raw_context)));
946 
947   StackFrameARM *frame1 = static_cast<StackFrameARM *>(frames->at(1));
948   EXPECT_EQ(StackFrame::FRAME_TRUST_FP, frame1->trust);
949   ASSERT_EQ((StackFrameARM::CONTEXT_VALID_PC |
950              StackFrameARM::CONTEXT_VALID_LR |
951              StackFrameARM::RegisterValidFlag(MD_CONTEXT_ARM_REG_IOS_FP) |
952              StackFrameARM::CONTEXT_VALID_SP),
953             frame1->context_validity);
954   EXPECT_EQ(return_address1, frame1->context.iregs[MD_CONTEXT_ARM_REG_PC]);
955   EXPECT_EQ(return_address2, frame1->context.iregs[MD_CONTEXT_ARM_REG_LR]);
956   EXPECT_EQ(frame1_sp.Value(), frame1->context.iregs[MD_CONTEXT_ARM_REG_SP]);
957   EXPECT_EQ(frame2_fp.Value(),
958             frame1->context.iregs[MD_CONTEXT_ARM_REG_IOS_FP]);
959   EXPECT_EQ("enchiridion", frame1->function_name);
960   EXPECT_EQ(0x40004000U, frame1->function_base);
961 
962 
963   StackFrameARM *frame2 = static_cast<StackFrameARM *>(frames->at(2));
964   EXPECT_EQ(StackFrame::FRAME_TRUST_CFI, frame2->trust);
965   ASSERT_EQ((StackFrameARM::CONTEXT_VALID_PC |
966              StackFrameARM::CONTEXT_VALID_LR |
967              StackFrameARM::RegisterValidFlag(MD_CONTEXT_ARM_REG_IOS_FP) |
968              StackFrameARM::CONTEXT_VALID_SP),
969             frame2->context_validity);
970   EXPECT_EQ(return_address2, frame2->context.iregs[MD_CONTEXT_ARM_REG_PC]);
971   EXPECT_EQ(0U, frame2->context.iregs[MD_CONTEXT_ARM_REG_LR]);
972   EXPECT_EQ(frame2_sp.Value(), frame2->context.iregs[MD_CONTEXT_ARM_REG_SP]);
973   EXPECT_EQ(0U, frame2->context.iregs[MD_CONTEXT_ARM_REG_IOS_FP]);
974 }
975