stack.cc revision cf4035a4c41ccfcc3e89a0cee25f5218a11b0705 
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 "base/hex_dump.h"
20#include "mirror/art_method-inl.h"
21#include "mirror/class-inl.h"
22#include "mirror/object.h"
23#include "mirror/object-inl.h"
24#include "mirror/object_array-inl.h"
25#include "object_utils.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
34namespace art {
35
36mirror::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 = MethodHelper(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
50mirror::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
59ThrowLocation ShadowFrame::GetCurrentLocationForThrow() const {
60  return ThrowLocation(GetThisObject(), GetMethod(), GetDexPC());
61}
62
63size_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
78bool 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
91StackVisitor::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
98uint32_t StackVisitor::GetDexPc(bool abort_on_failure) const {
99  if (cur_shadow_frame_ != NULL) {
100    return cur_shadow_frame_->GetDexPC();
101  } else if (cur_quick_frame_ != NULL) {
102    return GetMethod()->ToDexPc(cur_quick_frame_pc_, abort_on_failure);
103  } else {
104    return 0;
105  }
106}
107
108mirror::Object* StackVisitor::GetThisObject() const {
109  mirror::ArtMethod* m = GetMethod();
110  if (m->IsStatic()) {
111    return NULL;
112  } else if (m->IsNative()) {
113    if (cur_quick_frame_ != NULL) {
114      HandleScope* hs = reinterpret_cast<HandleScope*>(
115          reinterpret_cast<char*>(cur_quick_frame_) + m->GetHandleScopeOffsetInBytes());
116      return hs->GetReference(0);
117    } else {
118      return cur_shadow_frame_->GetVRegReference(0);
119    }
120  } else {
121    const DexFile::CodeItem* code_item = MethodHelper(m).GetCodeItem();
122    if (code_item == NULL) {
123      UNIMPLEMENTED(ERROR) << "Failed to determine this object of abstract or proxy method: "
124          << PrettyMethod(m);
125      return nullptr;
126    } else {
127      uint16_t reg = code_item->registers_size_ - code_item->ins_size_;
128      return reinterpret_cast<mirror::Object*>(GetVReg(m, reg, kReferenceVReg));
129    }
130  }
131}
132
133size_t StackVisitor::GetNativePcOffset() const {
134  DCHECK(!IsShadowFrame());
135  return GetMethod()->NativePcOffset(cur_quick_frame_pc_);
136}
137
138uint32_t StackVisitor::GetVReg(mirror::ArtMethod* m, uint16_t vreg, VRegKind kind) const {
139  if (cur_quick_frame_ != NULL) {
140    DCHECK(context_ != NULL);  // You can't reliably read registers without a context.
141    DCHECK(m == GetMethod());
142    const void* code_pointer = m->GetQuickOatCodePointer();
143    DCHECK(code_pointer != nullptr);
144    const VmapTable vmap_table(m->GetVmapTable(code_pointer));
145    QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
146    uint32_t vmap_offset;
147    // TODO: IsInContext stops before spotting floating point registers.
148    if (vmap_table.IsInContext(vreg, kind, &vmap_offset)) {
149      bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
150      uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
151      return GetGPR(vmap_table.ComputeRegister(spill_mask, vmap_offset, kind));
152    } else {
153      const DexFile::CodeItem* code_item = MethodHelper(m).GetCodeItem();
154      DCHECK(code_item != NULL) << PrettyMethod(m);  // Can't be NULL or how would we compile its instructions?
155      return *GetVRegAddr(cur_quick_frame_, code_item, frame_info.CoreSpillMask(),
156                          frame_info.FpSpillMask(), frame_info.FrameSizeInBytes(), vreg);
157    }
158  } else {
159    return cur_shadow_frame_->GetVReg(vreg);
160  }
161}
162
163void StackVisitor::SetVReg(mirror::ArtMethod* m, uint16_t vreg, uint32_t new_value,
164                           VRegKind kind) {
165  if (cur_quick_frame_ != NULL) {
166    DCHECK(context_ != NULL);  // You can't reliably write registers without a context.
167    DCHECK(m == GetMethod());
168    const void* code_pointer = m->GetQuickOatCodePointer();
169    DCHECK(code_pointer != nullptr);
170    const VmapTable vmap_table(m->GetVmapTable(code_pointer));
171    QuickMethodFrameInfo frame_info = m->GetQuickFrameInfo(code_pointer);
172    uint32_t vmap_offset;
173    // TODO: IsInContext stops before spotting floating point registers.
174    if (vmap_table.IsInContext(vreg, kind, &vmap_offset)) {
175      bool is_float = (kind == kFloatVReg) || (kind == kDoubleLoVReg) || (kind == kDoubleHiVReg);
176      uint32_t spill_mask = is_float ? frame_info.FpSpillMask() : frame_info.CoreSpillMask();
177      const uint32_t reg = vmap_table.ComputeRegister(spill_mask, vmap_offset, kReferenceVReg);
178      SetGPR(reg, new_value);
179    } else {
180      const DexFile::CodeItem* code_item = MethodHelper(m).GetCodeItem();
181      DCHECK(code_item != NULL) << PrettyMethod(m);  // Can't be NULL or how would we compile its instructions?
182      int offset = GetVRegOffset(code_item, frame_info.CoreSpillMask(), frame_info.FpSpillMask(),
183                                 frame_info.FrameSizeInBytes(), vreg, kRuntimeISA);
184      byte* vreg_addr = reinterpret_cast<byte*>(GetCurrentQuickFrame()) + offset;
185      *reinterpret_cast<uint32_t*>(vreg_addr) = new_value;
186    }
187  } else {
188    return cur_shadow_frame_->SetVReg(vreg, new_value);
189  }
190}
191
192uintptr_t* StackVisitor::GetGPRAddress(uint32_t reg) const {
193  DCHECK(cur_quick_frame_ != NULL) << "This is a quick frame routine";
194  return context_->GetGPRAddress(reg);
195}
196
197uintptr_t StackVisitor::GetGPR(uint32_t reg) const {
198  DCHECK(cur_quick_frame_ != NULL) << "This is a quick frame routine";
199  return context_->GetGPR(reg);
200}
201
202void StackVisitor::SetGPR(uint32_t reg, uintptr_t value) {
203  DCHECK(cur_quick_frame_ != NULL) << "This is a quick frame routine";
204  context_->SetGPR(reg, value);
205}
206
207uintptr_t StackVisitor::GetReturnPc() const {
208  byte* sp = reinterpret_cast<byte*>(GetCurrentQuickFrame());
209  DCHECK(sp != NULL);
210  byte* pc_addr = sp + GetMethod()->GetReturnPcOffsetInBytes();
211  return *reinterpret_cast<uintptr_t*>(pc_addr);
212}
213
214void StackVisitor::SetReturnPc(uintptr_t new_ret_pc) {
215  byte* sp = reinterpret_cast<byte*>(GetCurrentQuickFrame());
216  CHECK(sp != NULL);
217  byte* pc_addr = sp + GetMethod()->GetReturnPcOffsetInBytes();
218  *reinterpret_cast<uintptr_t*>(pc_addr) = new_ret_pc;
219}
220
221size_t StackVisitor::ComputeNumFrames(Thread* thread) {
222  struct NumFramesVisitor : public StackVisitor {
223    explicit NumFramesVisitor(Thread* thread)
224        : StackVisitor(thread, NULL), frames(0) {}
225
226    virtual bool VisitFrame() {
227      frames++;
228      return true;
229    }
230
231    size_t frames;
232  };
233  NumFramesVisitor visitor(thread);
234  visitor.WalkStack(true);
235  return visitor.frames;
236}
237
238void StackVisitor::DescribeStack(Thread* thread) {
239  struct DescribeStackVisitor : public StackVisitor {
240    explicit DescribeStackVisitor(Thread* thread)
241        : StackVisitor(thread, NULL) {}
242
243    virtual bool VisitFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
244      LOG(INFO) << "Frame Id=" << GetFrameId() << " " << DescribeLocation();
245      return true;
246    }
247  };
248  DescribeStackVisitor visitor(thread);
249  visitor.WalkStack(true);
250}
251
252std::string StackVisitor::DescribeLocation() const {
253  std::string result("Visiting method '");
254  mirror::ArtMethod* m = GetMethod();
255  if (m == NULL) {
256    return "upcall";
257  }
258  result += PrettyMethod(m);
259  result += StringPrintf("' at dex PC 0x%04x", GetDexPc());
260  if (!IsShadowFrame()) {
261    result += StringPrintf(" (native PC %p)", reinterpret_cast<void*>(GetCurrentQuickFramePc()));
262  }
263  return result;
264}
265
266instrumentation::InstrumentationStackFrame& StackVisitor::GetInstrumentationStackFrame(uint32_t depth) const {
267  CHECK_LT(depth, thread_->GetInstrumentationStack()->size());
268  return thread_->GetInstrumentationStack()->at(depth);
269}
270
271void StackVisitor::SanityCheckFrame() const {
272  if (kIsDebugBuild) {
273    mirror::ArtMethod* method = GetMethod();
274    CHECK_EQ(method->GetClass(), mirror::ArtMethod::GetJavaLangReflectArtMethod());
275    if (cur_quick_frame_ != nullptr) {
276      method->AssertPcIsWithinQuickCode(cur_quick_frame_pc_);
277      // Frame sanity.
278      size_t frame_size = method->GetFrameSizeInBytes();
279      CHECK_NE(frame_size, 0u);
280      // A rough guess at an upper size we expect to see for a frame.
281      // 256 registers
282      // 2 words HandleScope overhead
283      // 3+3 register spills
284      // TODO: this seems architecture specific for the case of JNI frames.
285      // TODO: 083-compiler-regressions ManyFloatArgs shows this estimate is wrong.
286      // const size_t kMaxExpectedFrameSize = (256 + 2 + 3 + 3) * sizeof(word);
287      const size_t kMaxExpectedFrameSize = 2 * KB;
288      CHECK_LE(frame_size, kMaxExpectedFrameSize);
289      size_t return_pc_offset = method->GetReturnPcOffsetInBytes();
290      CHECK_LT(return_pc_offset, frame_size);
291    }
292  }
293}
294
295void StackVisitor::WalkStack(bool include_transitions) {
296  DCHECK(thread_ == Thread::Current() || thread_->IsSuspended());
297  CHECK_EQ(cur_depth_, 0U);
298  bool exit_stubs_installed = Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled();
299  uint32_t instrumentation_stack_depth = 0;
300
301  for (const ManagedStack* current_fragment = thread_->GetManagedStack(); current_fragment != NULL;
302       current_fragment = current_fragment->GetLink()) {
303    cur_shadow_frame_ = current_fragment->GetTopShadowFrame();
304    cur_quick_frame_ = current_fragment->GetTopQuickFrame();
305    cur_quick_frame_pc_ = current_fragment->GetTopQuickFramePc();
306
307    if (cur_quick_frame_ != NULL) {  // Handle quick stack frames.
308      // Can't be both a shadow and a quick fragment.
309      DCHECK(current_fragment->GetTopShadowFrame() == NULL);
310      mirror::ArtMethod* method = cur_quick_frame_->AsMirrorPtr();
311      while (method != NULL) {
312        SanityCheckFrame();
313        bool should_continue = VisitFrame();
314        if (UNLIKELY(!should_continue)) {
315          return;
316        }
317
318        if (context_ != NULL) {
319          context_->FillCalleeSaves(*this);
320        }
321        size_t frame_size = method->GetFrameSizeInBytes();
322        // Compute PC for next stack frame from return PC.
323        size_t return_pc_offset = method->GetReturnPcOffsetInBytes(frame_size);
324        byte* return_pc_addr = reinterpret_cast<byte*>(cur_quick_frame_) + return_pc_offset;
325        uintptr_t return_pc = *reinterpret_cast<uintptr_t*>(return_pc_addr);
326        if (UNLIKELY(exit_stubs_installed)) {
327          // While profiling, the return pc is restored from the side stack, except when walking
328          // the stack for an exception where the side stack will be unwound in VisitFrame.
329          if (GetQuickInstrumentationExitPc() == return_pc) {
330            const instrumentation::InstrumentationStackFrame& instrumentation_frame =
331                GetInstrumentationStackFrame(instrumentation_stack_depth);
332            instrumentation_stack_depth++;
333            if (GetMethod() == Runtime::Current()->GetCalleeSaveMethod(Runtime::kSaveAll)) {
334              // Skip runtime save all callee frames which are used to deliver exceptions.
335            } else if (instrumentation_frame.interpreter_entry_) {
336              mirror::ArtMethod* callee = Runtime::Current()->GetCalleeSaveMethod(Runtime::kRefsAndArgs);
337              CHECK_EQ(GetMethod(), callee) << "Expected: " << PrettyMethod(callee) << " Found: "
338                                            << PrettyMethod(GetMethod());
339            } else if (instrumentation_frame.method_ != GetMethod()) {
340              LOG(FATAL)  << "Expected: " << PrettyMethod(instrumentation_frame.method_)
341                          << " Found: " << PrettyMethod(GetMethod());
342            }
343            if (num_frames_ != 0) {
344              // Check agreement of frame Ids only if num_frames_ is computed to avoid infinite
345              // recursion.
346              CHECK(instrumentation_frame.frame_id_ == GetFrameId())
347                    << "Expected: " << instrumentation_frame.frame_id_
348                    << " Found: " << GetFrameId();
349            }
350            return_pc = instrumentation_frame.return_pc_;
351          }
352        }
353        cur_quick_frame_pc_ = return_pc;
354        byte* next_frame = reinterpret_cast<byte*>(cur_quick_frame_) + frame_size;
355        cur_quick_frame_ = reinterpret_cast<StackReference<mirror::ArtMethod>*>(next_frame);
356        cur_depth_++;
357        method = cur_quick_frame_->AsMirrorPtr();
358      }
359    } else if (cur_shadow_frame_ != NULL) {
360      do {
361        SanityCheckFrame();
362        bool should_continue = VisitFrame();
363        if (UNLIKELY(!should_continue)) {
364          return;
365        }
366        cur_depth_++;
367        cur_shadow_frame_ = cur_shadow_frame_->GetLink();
368      } while (cur_shadow_frame_ != NULL);
369    }
370    if (include_transitions) {
371      bool should_continue = VisitFrame();
372      if (!should_continue) {
373        return;
374      }
375    }
376    cur_depth_++;
377  }
378  if (num_frames_ != 0) {
379    CHECK_EQ(cur_depth_, num_frames_);
380  }
381}
382
383}  // namespace art
384