patchoat.h revision c8ccf68b805c92674545f63e0341ba47e8d9701c 
1/*
2 * Copyright (C) 2014 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#ifndef ART_PATCHOAT_PATCHOAT_H_
18#define ART_PATCHOAT_PATCHOAT_H_
19
20#include "base/macros.h"
21#include "base/mutex.h"
22#include "instruction_set.h"
23#include "os.h"
24#include "elf_file.h"
25#include "elf_utils.h"
26#include "gc/accounting/space_bitmap.h"
27#include "gc/heap.h"
28#include "utils.h"
29
30namespace art {
31
32class ImageHeader;
33
34namespace mirror {
35class Object;
36class Reference;
37class Class;
38class ArtMethod;
39}  // namespace mirror
40
41class PatchOat {
42 public:
43  static bool Patch(File* oat_in, off_t delta, File* oat_out, TimingLogger* timings);
44
45  static bool Patch(const std::string& art_location, off_t delta, File* art_out, InstructionSet isa,
46                    TimingLogger* timings);
47
48  static bool Patch(const File* oat_in, const std::string& art_location,
49                    off_t delta, File* oat_out, File* art_out, InstructionSet isa,
50                    TimingLogger* timings);
51
52 private:
53  // Takes ownership only of the ElfFile. All other pointers are only borrowed.
54  PatchOat(ElfFile* oat_file, off_t delta, TimingLogger* timings)
55      : oat_file_(oat_file), delta_(delta), timings_(timings) {}
56  PatchOat(MemMap* image, gc::accounting::ContinuousSpaceBitmap* bitmap,
57           MemMap* heap, off_t delta, TimingLogger* timings)
58      : image_(image), bitmap_(bitmap), heap_(heap),
59        delta_(delta), timings_(timings) {}
60  PatchOat(ElfFile* oat_file, MemMap* image, gc::accounting::ContinuousSpaceBitmap* bitmap,
61           MemMap* heap, off_t delta, TimingLogger* timings)
62      : oat_file_(oat_file), image_(image), bitmap_(bitmap), heap_(heap),
63        delta_(delta), timings_(timings) {}
64  ~PatchOat() {}
65
66  static void BitmapCallback(mirror::Object* obj, void* arg)
67      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
68    reinterpret_cast<PatchOat*>(arg)->VisitObject(obj);
69  }
70
71  void VisitObject(mirror::Object* obj)
72      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
73  void FixupMethod(mirror::ArtMethod* object, mirror::ArtMethod* copy)
74      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
75  bool InHeap(mirror::Object*);
76
77  // Patches oat in place, modifying the oat_file given to the constructor.
78  bool PatchElf();
79  bool PatchTextSection();
80  // Templatized version to actually do the patching with the right sized offsets.
81  template <typename ptr_t> bool PatchTextSection(const Elf32_Shdr& patches_sec);
82  template <typename ptr_t> bool CheckOatFile(const Elf32_Shdr& patches_sec);
83  bool PatchOatHeader();
84  bool PatchSymbols(Elf32_Shdr* section);
85
86  bool PatchImage() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
87
88  bool WriteElf(File* out);
89  bool WriteImage(File* out);
90
91  mirror::Object* RelocatedCopyOf(mirror::Object*);
92  mirror::Object* RelocatedAddressOf(mirror::Object* obj);
93
94  // Walks through the old image and patches the mmap'd copy of it to the new offset. It does not
95  // change the heap.
96  class PatchVisitor {
97  public:
98    PatchVisitor(PatchOat* patcher, mirror::Object* copy) : patcher_(patcher), copy_(copy) {}
99    ~PatchVisitor() {}
100    void operator() (mirror::Object* obj, MemberOffset off, bool b) const
101      EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_);
102    // For reference classes.
103    void operator() (mirror::Class* cls, mirror::Reference* ref) const
104      EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_);
105  private:
106    PatchOat* patcher_;
107    mirror::Object* copy_;
108  };
109
110  // The elf file we are patching.
111  std::unique_ptr<ElfFile> oat_file_;
112  // A mmap of the image we are patching. This is modified.
113  const MemMap* image_;
114  // The heap we are patching. This is not modified.
115  gc::accounting::ContinuousSpaceBitmap* bitmap_;
116  // The heap we are patching. This is not modified.
117  const MemMap* heap_;
118  // The amount we are changing the offset by.
119  off_t delta_;
120  TimingLogger* timings_;
121
122  DISALLOW_IMPLICIT_CONSTRUCTORS(PatchOat);
123};
124
125}  // namespace art
126#endif  // ART_PATCHOAT_PATCHOAT_H_
127