• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright (C) 2011 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "stack.h"
18 
19 #include "arch/context.h"
20 #include "base/hex_dump.h"
21 #include "mirror/art_method-inl.h"
22 #include "mirror/class-inl.h"
23 #include "mirror/object.h"
24 #include "mirror/object-inl.h"
25 #include "mirror/object_array-inl.h"
26 #include "quick/quick_method_frame_info.h"
27 #include "runtime.h"
28 #include "thread.h"
29 #include "thread_list.h"
30 #include "throw_location.h"
31 #include "verify_object-inl.h"
32 #include "vmap_table.h"
33 
34 namespace art {
35 
GetThisObject() const36 mirror::Object* ShadowFrame::GetThisObject() const {
37   mirror::ArtMethod* m = GetMethod();
38   if (m->IsStatic()) {
39     return NULL;
40   } else if (m->IsNative()) {
41     return GetVRegReference(0);
42   } else {
43     const DexFile::CodeItem* code_item = m->GetCodeItem();
44     CHECK(code_item != NULL) << PrettyMethod(m);
45     uint16_t reg = code_item->registers_size_ - code_item->ins_size_;
46     return GetVRegReference(reg);
47   }
48 }
49 
GetThisObject(uint16_t num_ins) const50 mirror::Object* ShadowFrame::GetThisObject(uint16_t num_ins) const {
51   mirror::ArtMethod* m = GetMethod();
52   if (m->IsStatic()) {
53     return NULL;
54   } else {
55     return GetVRegReference(NumberOfVRegs() - num_ins);
56   }
57 }
58 
GetCurrentLocationForThrow() const59 ThrowLocation ShadowFrame::GetCurrentLocationForThrow() const {
60   return ThrowLocation(GetThisObject(), GetMethod(), GetDexPC());
61 }
62 
NumJniShadowFrameReferences() const63 size_t ManagedStack::NumJniShadowFrameReferences() const {
64   size_t count = 0;
65   for (const ManagedStack* current_fragment = this; current_fragment != NULL;
66        current_fragment = current_fragment->GetLink()) {
67     for (ShadowFrame* current_frame = current_fragment->top_shadow_frame_; current_frame != NULL;
68          current_frame = current_frame->GetLink()) {
69       if (current_frame->GetMethod()->IsNative()) {
70         // The JNI ShadowFrame only contains references. (For indirect reference.)
71         count += current_frame->NumberOfVRegs();
72       }
73     }
74   }
75   return count;
76 }
77 
ShadowFramesContain(StackReference<mirror::Object> * shadow_frame_entry) const78 bool ManagedStack::ShadowFramesContain(StackReference<mirror::Object>* shadow_frame_entry) const {
79   for (const ManagedStack* current_fragment = this; current_fragment != NULL;
80        current_fragment = current_fragment->GetLink()) {
81     for (ShadowFrame* current_frame = current_fragment->top_shadow_frame_; current_frame != NULL;
82          current_frame = current_frame->GetLink()) {
83       if (current_frame->Contains(shadow_frame_entry)) {
84         return true;
85       }
86     }
87   }
88   return false;
89 }
90 
StackVisitor(Thread * thread,Context * context)91 StackVisitor::StackVisitor(Thread* thread, Context* context)
92     : thread_(thread), cur_shadow_frame_(NULL),
93       cur_quick_frame_(NULL), cur_quick_frame_pc_(0), num_frames_(0), cur_depth_(0),
94       context_(context) {
95   DCHECK(thread == Thread::Current() || thread->IsSuspended()) << *thread;
96 }
97 
StackVisitor(Thread * thread,Context * context,size_t num_frames)98 StackVisitor::StackVisitor(Thread* thread, Context* context, size_t num_frames)
99     : thread_(thread), cur_shadow_frame_(NULL),
100       cur_quick_frame_(NULL), cur_quick_frame_pc_(0), num_frames_(num_frames), cur_depth_(0),
101       context_(context) {
102   DCHECK(thread == Thread::Current() || thread->IsSuspended()) << *thread;
103 }
104 
GetDexPc(bool abort_on_failure) const105 uint32_t StackVisitor::GetDexPc(bool abort_on_failure) const {
106   if (cur_shadow_frame_ != NULL) {
107     return cur_shadow_frame_->GetDexPC();
108   } else if (cur_quick_frame_ != NULL) {
109     return GetMethod()->ToDexPc(cur_quick_frame_pc_, abort_on_failure);
110   } else {
111     return 0;
112   }
113 }
114 
GetThisObject() const115 mirror::Object* StackVisitor::GetThisObject() const {
116   mirror::ArtMethod* m = GetMethod();
117   if (m->IsStatic()) {
118     return NULL;
119   } else if (m->IsNative()) {
120     if (cur_quick_frame_ != NULL) {
121       HandleScope* hs = reinterpret_cast<HandleScope*>(
122           reinterpret_cast<char*>(cur_quick_frame_) + m->GetHandleScopeOffsetInBytes());
123       return hs->GetReference(0);
124     } else {
125       return cur_shadow_frame_->GetVRegReference(0);
126     }
127   } else {
128     const DexFile::CodeItem* code_item = m->GetCodeItem();
129     if (code_item == NULL) {
130       UNIMPLEMENTED(ERROR) << "Failed to determine this object of abstract or proxy method: "
131           << PrettyMethod(m);
132       return nullptr;
133     } else {
134       uint16_t reg = code_item->registers_size_ - code_item->ins_size_;
135       return reinterpret_cast<mirror::Object*>(GetVReg(m, reg, kReferenceVReg));
136     }
137   }
138 }
139 
GetNativePcOffset() const140 size_t StackVisitor::GetNativePcOffset() const {
141   DCHECK(!IsShadowFrame());
142   return GetMethod()->NativePcOffset(cur_quick_frame_pc_);
143 }
144 
GetVReg(mirror::ArtMethod * m,uint16_t vreg,VRegKind kind,uint32_t * val) const145 bool StackVisitor::GetVReg(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind,
146                            uint32_t* val) const {
147   if (cur_quick_frame_ != nullptr) {
148     DCHECK(context_ != nullptr);  // You can't reliably read registers without a context.
149     DCHECK(m == GetMethod());
150     const void* code_pointer = m->GetQuickOatCodePointer();
151     DCHECK(code_pointer != nullptr);
152     const VmapTable vmap_table(m->GetVmapTable(code_pointer));
153     QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
154     uint32_t vmap_offset;
155     // TODO: IsInContext stops before spotting floating point registers.
156     if (vmap_table.IsInContext(vreg, kind, &vmap_offset)) {
157       bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
158       uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
159       uint32_t reg = vmap_table.ComputeRegister(spill_mask, vmap_offset, kind);
160       uintptr_t ptr_val;
161       bool success = is_float ? GetFPR(reg, &ptr_val) : GetGPR(reg, &ptr_val);
162       if (!success) {
163         return false;
164       }
165       bool target64 = Is64BitInstructionSet(kRuntimeISA);
166       if (target64) {
167         bool wide_lo = (kind == kLongLoVReg) || (kind == kDoubleLoVReg);
168         bool wide_hi = (kind == kLongHiVReg) || (kind == kDoubleHiVReg);
169         int64_t value_long = static_cast<int64_t>(ptr_val);
170         if (wide_lo) {
171           ptr_val = static_cast<uintptr_t>(value_long & 0xFFFFFFFF);
172         } else if (wide_hi) {
173           ptr_val = static_cast<uintptr_t>(value_long >> 32);
174         }
175       }
176       *val = ptr_val;
177       return true;
178     } else {
179       const DexFile::CodeItem* code_item = m->GetCodeItem();
180       DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be NULL or how would we compile
181                                                         // its instructions?
182       *val = *GetVRegAddr(cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
183                           frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
184       return true;
185     }
186   } else {
187     *val = cur_shadow_frame_->GetVReg(vreg);
188     return true;
189   }
190 }
191 
GetVRegPair(mirror::ArtMethod * m,uint16_t vreg,VRegKind kind_lo,VRegKind kind_hi,uint64_t * val) const192 bool StackVisitor::GetVRegPair(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind_lo,
193                                VRegKind kind_hi, uint64_t* val) const {
194   if (kind_lo == kLongLoVReg) {
195     DCHECK_EQ(kind_hi, kLongHiVReg);
196   } else if (kind_lo == kDoubleLoVReg) {
197     DCHECK_EQ(kind_hi, kDoubleHiVReg);
198   } else {
199     LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
200   }
201   if (cur_quick_frame_ != nullptr) {
202     DCHECK(context_ != nullptr);  // You can't reliably read registers without a context.
203     DCHECK(m == GetMethod());
204     const void* code_pointer = m->GetQuickOatCodePointer();
205     DCHECK(code_pointer != nullptr);
206     const VmapTable vmap_table(m->GetVmapTable(code_pointer));
207     QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
208     uint32_t vmap_offset_lo, vmap_offset_hi;
209     // TODO: IsInContext stops before spotting floating point registers.
210     if (vmap_table.IsInContext(vreg, kind_lo, &vmap_offset_lo) &&
211         vmap_table.IsInContext(vreg + 1, kind_hi, &vmap_offset_hi)) {
212       bool is_float = (kind_lo == kDoubleLoVReg);
213       uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
214       uint32_t reg_lo = vmap_table.ComputeRegister(spill_mask, vmap_offset_lo, kind_lo);
215       uint32_t reg_hi = vmap_table.ComputeRegister(spill_mask, vmap_offset_hi, kind_hi);
216       uintptr_t ptr_val_lo, ptr_val_hi;
217       bool success = is_float ? GetFPR(reg_lo, &ptr_val_lo) : GetGPR(reg_lo, &ptr_val_lo);
218       success &= is_float ? GetFPR(reg_hi, &ptr_val_hi) : GetGPR(reg_hi, &ptr_val_hi);
219       if (!success) {
220         return false;
221       }
222       bool target64 = Is64BitInstructionSet(kRuntimeISA);
223       if (target64) {
224         int64_t value_long_lo = static_cast<int64_t>(ptr_val_lo);
225         int64_t value_long_hi = static_cast<int64_t>(ptr_val_hi);
226         ptr_val_lo = static_cast<uintptr_t>(value_long_lo & 0xFFFFFFFF);
227         ptr_val_hi = static_cast<uintptr_t>(value_long_hi >> 32);
228       }
229       *val = (static_cast<uint64_t>(ptr_val_hi) << 32) | static_cast<uint32_t>(ptr_val_lo);
230       return true;
231     } else {
232       const DexFile::CodeItem* code_item = m->GetCodeItem();
233       DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be NULL or how would we compile
234                                                         // its instructions?
235       uint32_t* addr = GetVRegAddr(cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
236                                    frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
237       *val = *reinterpret_cast<uint64_t*>(addr);
238       return true;
239     }
240   } else {
241     *val = cur_shadow_frame_->GetVRegLong(vreg);
242     return true;
243   }
244 }
245 
SetVReg(mirror::ArtMethod * m,uint16_t vreg,uint32_t new_value,VRegKind kind)246 bool StackVisitor::SetVReg(mirror::ArtMethod* m, uint16_t vreg, uint32_t new_value,
247                            VRegKind kind) {
248   if (cur_quick_frame_ != nullptr) {
249     DCHECK(context_ != nullptr);  // You can't reliably write registers without a context.
250     DCHECK(m == GetMethod());
251     const void* code_pointer = m->GetQuickOatCodePointer();
252     DCHECK(code_pointer != nullptr);
253     const VmapTable vmap_table(m->GetVmapTable(code_pointer));
254     QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
255     uint32_t vmap_offset;
256     // TODO: IsInContext stops before spotting floating point registers.
257     if (vmap_table.IsInContext(vreg, kind, &vmap_offset)) {
258       bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
259       uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
260       const uint32_t reg = vmap_table.ComputeRegister(spill_mask, vmap_offset, kind);
261       bool target64 = Is64BitInstructionSet(kRuntimeISA);
262       // Deal with 32 or 64-bit wide registers in a way that builds on all targets.
263       if (target64) {
264         bool wide_lo = (kind == kLongLoVReg) || (kind == kDoubleLoVReg);
265         bool wide_hi = (kind == kLongHiVReg) || (kind == kDoubleHiVReg);
266         if (wide_lo || wide_hi) {
267           uintptr_t old_reg_val;
268           bool success = is_float ? GetFPR(reg, &old_reg_val) : GetGPR(reg, &old_reg_val);
269           if (!success) {
270             return false;
271           }
272           uint64_t new_vreg_portion = static_cast<uint64_t>(new_value);
273           uint64_t old_reg_val_as_wide = static_cast<uint64_t>(old_reg_val);
274           uint64_t mask = 0xffffffff;
275           if (wide_lo) {
276             mask = mask << 32;
277           } else {
278             new_vreg_portion = new_vreg_portion << 32;
279           }
280           new_value = static_cast<uintptr_t>((old_reg_val_as_wide & mask) | new_vreg_portion);
281         }
282       }
283       if (is_float) {
284         return SetFPR(reg, new_value);
285       } else {
286         return SetGPR(reg, new_value);
287       }
288     } else {
289       const DexFile::CodeItem* code_item = m->GetCodeItem();
290       DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be NULL or how would we compile
291                                                         // its instructions?
292       uint32_t* addr = GetVRegAddr(cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
293                                    frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
294       *addr = new_value;
295       return true;
296     }
297   } else {
298     cur_shadow_frame_->SetVReg(vreg, new_value);
299     return true;
300   }
301 }
302 
SetVRegPair(mirror::ArtMethod * m,uint16_t vreg,uint64_t new_value,VRegKind kind_lo,VRegKind kind_hi)303 bool StackVisitor::SetVRegPair(mirror::ArtMethod* m, uint16_t vreg, uint64_t new_value,
304                                VRegKind kind_lo, VRegKind kind_hi) {
305   if (kind_lo == kLongLoVReg) {
306     DCHECK_EQ(kind_hi, kLongHiVReg);
307   } else if (kind_lo == kDoubleLoVReg) {
308     DCHECK_EQ(kind_hi, kDoubleHiVReg);
309   } else {
310     LOG(FATAL) << "Expected long or double: kind_lo=" << kind_lo << ", kind_hi=" << kind_hi;
311   }
312   if (cur_quick_frame_ != nullptr) {
313     DCHECK(context_ != nullptr);  // You can't reliably write registers without a context.
314     DCHECK(m == GetMethod());
315     const void* code_pointer = m->GetQuickOatCodePointer();
316     DCHECK(code_pointer != nullptr);
317     const VmapTable vmap_table(m->GetVmapTable(code_pointer));
318     QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
319     uint32_t vmap_offset_lo, vmap_offset_hi;
320     // TODO: IsInContext stops before spotting floating point registers.
321     if (vmap_table.IsInContext(vreg, kind_lo, &vmap_offset_lo) &&
322         vmap_table.IsInContext(vreg + 1, kind_hi, &vmap_offset_hi)) {
323       bool is_float = (kind_lo == kDoubleLoVReg);
324       uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
325       uint32_t reg_lo = vmap_table.ComputeRegister(spill_mask, vmap_offset_lo, kind_lo);
326       uint32_t reg_hi = vmap_table.ComputeRegister(spill_mask, vmap_offset_hi, kind_hi);
327       uintptr_t new_value_lo = static_cast<uintptr_t>(new_value & 0xFFFFFFFF);
328       uintptr_t new_value_hi = static_cast<uintptr_t>(new_value >> 32);
329       bool target64 = Is64BitInstructionSet(kRuntimeISA);
330       // Deal with 32 or 64-bit wide registers in a way that builds on all targets.
331       if (target64) {
332         uintptr_t old_reg_val_lo, old_reg_val_hi;
333         bool success = is_float ? GetFPR(reg_lo, &old_reg_val_lo) : GetGPR(reg_lo, &old_reg_val_lo);
334         success &= is_float ? GetFPR(reg_hi, &old_reg_val_hi) : GetGPR(reg_hi, &old_reg_val_hi);
335         if (!success) {
336           return false;
337         }
338         uint64_t new_vreg_portion_lo = static_cast<uint64_t>(new_value_lo);
339         uint64_t new_vreg_portion_hi = static_cast<uint64_t>(new_value_hi) << 32;
340         uint64_t old_reg_val_lo_as_wide = static_cast<uint64_t>(old_reg_val_lo);
341         uint64_t old_reg_val_hi_as_wide = static_cast<uint64_t>(old_reg_val_hi);
342         uint64_t mask_lo = static_cast<uint64_t>(0xffffffff) << 32;
343         uint64_t mask_hi = 0xffffffff;
344         new_value_lo = static_cast<uintptr_t>((old_reg_val_lo_as_wide & mask_lo) | new_vreg_portion_lo);
345         new_value_hi = static_cast<uintptr_t>((old_reg_val_hi_as_wide & mask_hi) | new_vreg_portion_hi);
346       }
347       bool success = is_float ? SetFPR(reg_lo, new_value_lo) : SetGPR(reg_lo, new_value_lo);
348       success &= is_float ? SetFPR(reg_hi, new_value_hi) : SetGPR(reg_hi, new_value_hi);
349       return success;
350     } else {
351       const DexFile::CodeItem* code_item = m->GetCodeItem();
352       DCHECK(code_item != nullptr) << PrettyMethod(m);  // Can't be NULL or how would we compile
353                                                         // its instructions?
354       uint32_t* addr = GetVRegAddr(cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
355                                    frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
356       *reinterpret_cast<uint64_t*>(addr) = new_value;
357       return true;
358     }
359   } else {
360     cur_shadow_frame_->SetVRegLong(vreg, new_value);
361     return true;
362   }
363 }
364 
GetGPRAddress(uint32_t reg) const365 uintptr_t* StackVisitor::GetGPRAddress(uint32_t reg) const {
366   DCHECK(cur_quick_frame_ != NULL) << "This is a quick frame routine";
367   return context_->GetGPRAddress(reg);
368 }
369 
GetGPR(uint32_t reg,uintptr_t * val) const370 bool StackVisitor::GetGPR(uint32_t reg, uintptr_t* val) const {
371   DCHECK(cur_quick_frame_ != NULL) << "This is a quick frame routine";
372   return context_->GetGPR(reg, val);
373 }
374 
SetGPR(uint32_t reg,uintptr_t value)375 bool StackVisitor::SetGPR(uint32_t reg, uintptr_t value) {
376   DCHECK(cur_quick_frame_ != NULL) << "This is a quick frame routine";
377   return context_->SetGPR(reg, value);
378 }
379 
GetFPR(uint32_t reg,uintptr_t * val) const380 bool StackVisitor::GetFPR(uint32_t reg, uintptr_t* val) const {
381   DCHECK(cur_quick_frame_ != NULL) << "This is a quick frame routine";
382   return context_->GetFPR(reg, val);
383 }
384 
SetFPR(uint32_t reg,uintptr_t value)385 bool StackVisitor::SetFPR(uint32_t reg, uintptr_t value) {
386   DCHECK(cur_quick_frame_ != NULL) << "This is a quick frame routine";
387   return context_->SetFPR(reg, value);
388 }
389 
GetReturnPc() const390 uintptr_t StackVisitor::GetReturnPc() const {
391   byte* sp = reinterpret_cast<byte*>(GetCurrentQuickFrame());
392   DCHECK(sp != NULL);
393   byte* pc_addr = sp + GetMethod()->GetReturnPcOffsetInBytes();
394   return *reinterpret_cast<uintptr_t*>(pc_addr);
395 }
396 
SetReturnPc(uintptr_t new_ret_pc)397 void StackVisitor::SetReturnPc(uintptr_t new_ret_pc) {
398   byte* sp = reinterpret_cast<byte*>(GetCurrentQuickFrame());
399   CHECK(sp != NULL);
400   byte* pc_addr = sp + GetMethod()->GetReturnPcOffsetInBytes();
401   *reinterpret_cast<uintptr_t*>(pc_addr) = new_ret_pc;
402 }
403 
ComputeNumFrames(Thread * thread)404 size_t StackVisitor::ComputeNumFrames(Thread* thread) {
405   struct NumFramesVisitor : public StackVisitor {
406     explicit NumFramesVisitor(Thread* thread)
407         : StackVisitor(thread, NULL), frames(0) {}
408 
409     bool VisitFrame() OVERRIDE {
410       frames++;
411       return true;
412     }
413 
414     size_t frames;
415   };
416   NumFramesVisitor visitor(thread);
417   visitor.WalkStack(true);
418   return visitor.frames;
419 }
420 
GetNextMethodAndDexPc(mirror::ArtMethod ** next_method,uint32_t * next_dex_pc)421 bool StackVisitor::GetNextMethodAndDexPc(mirror::ArtMethod** next_method, uint32_t* next_dex_pc) {
422   struct HasMoreFramesVisitor : public StackVisitor {
423     explicit HasMoreFramesVisitor(Thread* thread, size_t num_frames, size_t frame_height)
424         : StackVisitor(thread, nullptr, num_frames), frame_height_(frame_height),
425           found_frame_(false), has_more_frames_(false), next_method_(nullptr), next_dex_pc_(0) {
426     }
427 
428     bool VisitFrame() OVERRIDE SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
429       if (found_frame_) {
430         mirror::ArtMethod* method = GetMethod();
431         if (method != nullptr && !method->IsRuntimeMethod()) {
432           has_more_frames_ = true;
433           next_method_ = method;
434           next_dex_pc_ = GetDexPc();
435           return false;  // End stack walk once next method is found.
436         }
437       } else if (GetFrameHeight() == frame_height_) {
438         found_frame_ = true;
439       }
440       return true;
441     }
442 
443     size_t frame_height_;
444     bool found_frame_;
445     bool has_more_frames_;
446     mirror::ArtMethod* next_method_;
447     uint32_t next_dex_pc_;
448   };
449   HasMoreFramesVisitor visitor(thread_, GetNumFrames(), GetFrameHeight());
450   visitor.WalkStack(true);
451   *next_method = visitor.next_method_;
452   *next_dex_pc = visitor.next_dex_pc_;
453   return visitor.has_more_frames_;
454 }
455 
DescribeStack(Thread * thread)456 void StackVisitor::DescribeStack(Thread* thread) {
457   struct DescribeStackVisitor : public StackVisitor {
458     explicit DescribeStackVisitor(Thread* thread)
459         : StackVisitor(thread, NULL) {}
460 
461     bool VisitFrame() OVERRIDE SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
462       LOG(INFO) << "Frame Id=" << GetFrameId() << " " << DescribeLocation();
463       return true;
464     }
465   };
466   DescribeStackVisitor visitor(thread);
467   visitor.WalkStack(true);
468 }
469 
DescribeLocation() const470 std::string StackVisitor::DescribeLocation() const {
471   std::string result("Visiting method '");
472   mirror::ArtMethod* m = GetMethod();
473   if (m == NULL) {
474     return "upcall";
475   }
476   result += PrettyMethod(m);
477   result += StringPrintf("' at dex PC 0x%04x", GetDexPc());
478   if (!IsShadowFrame()) {
479     result += StringPrintf(" (native PC %p)", reinterpret_cast<void*>(GetCurrentQuickFramePc()));
480   }
481   return result;
482 }
483 
GetInstrumentationStackFrame(Thread * thread,uint32_t depth)484 static instrumentation::InstrumentationStackFrame& GetInstrumentationStackFrame(Thread* thread,
485                                                                                 uint32_t depth) {
486   CHECK_LT(depth, thread->GetInstrumentationStack()->size());
487   return thread->GetInstrumentationStack()->at(depth);
488 }
489 
SanityCheckFrame() const490 void StackVisitor::SanityCheckFrame() const {
491   if (kIsDebugBuild) {
492     mirror::ArtMethod* method = GetMethod();
493     CHECK_EQ(method->GetClass(), mirror::ArtMethod::GetJavaLangReflectArtMethod());
494     if (cur_quick_frame_ != nullptr) {
495       method->AssertPcIsWithinQuickCode(cur_quick_frame_pc_);
496       // Frame sanity.
497       size_t frame_size = method->GetFrameSizeInBytes();
498       CHECK_NE(frame_size, 0u);
499       // A rough guess at an upper size we expect to see for a frame.
500       // 256 registers
501       // 2 words HandleScope overhead
502       // 3+3 register spills
503       // TODO: this seems architecture specific for the case of JNI frames.
504       // TODO: 083-compiler-regressions ManyFloatArgs shows this estimate is wrong.
505       // const size_t kMaxExpectedFrameSize = (256 + 2 + 3 + 3) * sizeof(word);
506       const size_t kMaxExpectedFrameSize = 2 * KB;
507       CHECK_LE(frame_size, kMaxExpectedFrameSize);
508       size_t return_pc_offset = method->GetReturnPcOffsetInBytes();
509       CHECK_LT(return_pc_offset, frame_size);
510     }
511   }
512 }
513 
WalkStack(bool include_transitions)514 void StackVisitor::WalkStack(bool include_transitions) {
515   DCHECK(thread_ == Thread::Current() || thread_->IsSuspended());
516   CHECK_EQ(cur_depth_, 0U);
517   bool exit_stubs_installed = Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled();
518   uint32_t instrumentation_stack_depth = 0;
519 
520   for (const ManagedStack* current_fragment = thread_->GetManagedStack(); current_fragment != NULL;
521        current_fragment = current_fragment->GetLink()) {
522     cur_shadow_frame_ = current_fragment->GetTopShadowFrame();
523     cur_quick_frame_ = current_fragment->GetTopQuickFrame();
524     cur_quick_frame_pc_ = current_fragment->GetTopQuickFramePc();
525 
526     if (cur_quick_frame_ != NULL) {  // Handle quick stack frames.
527       // Can't be both a shadow and a quick fragment.
528       DCHECK(current_fragment->GetTopShadowFrame() == NULL);
529       mirror::ArtMethod* method = cur_quick_frame_->AsMirrorPtr();
530       while (method != NULL) {
531         SanityCheckFrame();
532         bool should_continue = VisitFrame();
533         if (UNLIKELY(!should_continue)) {
534           return;
535         }
536 
537         if (context_ != NULL) {
538           context_->FillCalleeSaves(*this);
539         }
540         size_t frame_size = method->GetFrameSizeInBytes();
541         // Compute PC for next stack frame from return PC.
542         size_t return_pc_offset = method->GetReturnPcOffsetInBytes(frame_size);
543         byte* return_pc_addr = reinterpret_cast<byte*>(cur_quick_frame_) + return_pc_offset;
544         uintptr_t return_pc = *reinterpret_cast<uintptr_t*>(return_pc_addr);
545         if (UNLIKELY(exit_stubs_installed)) {
546           // While profiling, the return pc is restored from the side stack, except when walking
547           // the stack for an exception where the side stack will be unwound in VisitFrame.
548           if (GetQuickInstrumentationExitPc() == return_pc) {
549             const instrumentation::InstrumentationStackFrame& instrumentation_frame =
550                 GetInstrumentationStackFrame(thread_, instrumentation_stack_depth);
551             instrumentation_stack_depth++;
552             if (GetMethod() == Runtime::Current()->GetCalleeSaveMethod(Runtime::kSaveAll)) {
553               // Skip runtime save all callee frames which are used to deliver exceptions.
554             } else if (instrumentation_frame.interpreter_entry_) {
555               mirror::ArtMethod* callee = Runtime::Current()->GetCalleeSaveMethod(Runtime::kRefsAndArgs);
556               CHECK_EQ(GetMethod(), callee) << "Expected: " << PrettyMethod(callee) << " Found: "
557                                             << PrettyMethod(GetMethod());
558             } else if (instrumentation_frame.method_ != GetMethod()) {
559               LOG(FATAL)  << "Expected: " << PrettyMethod(instrumentation_frame.method_)
560                           << " Found: " << PrettyMethod(GetMethod());
561             }
562             if (num_frames_ != 0) {
563               // Check agreement of frame Ids only if num_frames_ is computed to avoid infinite
564               // recursion.
565               CHECK(instrumentation_frame.frame_id_ == GetFrameId())
566                     << "Expected: " << instrumentation_frame.frame_id_
567                     << " Found: " << GetFrameId();
568             }
569             return_pc = instrumentation_frame.return_pc_;
570           }
571         }
572         cur_quick_frame_pc_ = return_pc;
573         byte* next_frame = reinterpret_cast<byte*>(cur_quick_frame_) + frame_size;
574         cur_quick_frame_ = reinterpret_cast<StackReference<mirror::ArtMethod>*>(next_frame);
575         cur_depth_++;
576         method = cur_quick_frame_->AsMirrorPtr();
577       }
578     } else if (cur_shadow_frame_ != NULL) {
579       do {
580         SanityCheckFrame();
581         bool should_continue = VisitFrame();
582         if (UNLIKELY(!should_continue)) {
583           return;
584         }
585         cur_depth_++;
586         cur_shadow_frame_ = cur_shadow_frame_->GetLink();
587       } while (cur_shadow_frame_ != NULL);
588     }
589     if (include_transitions) {
590       bool should_continue = VisitFrame();
591       if (!should_continue) {
592         return;
593       }
594     }
595     cur_depth_++;
596   }
597   if (num_frames_ != 0) {
598     CHECK_EQ(cur_depth_, num_frames_);
599   }
600 }
601 
602 }  // namespace art
603