patchoat.h revision 2f6cdb01f74772c1c521a125776ef57ea3c73d43
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 "arch/instruction_set.h" 21#include "base/macros.h" 22#include "base/mutex.h" 23#include "elf_file.h" 24#include "elf_utils.h" 25#include "gc/accounting/space_bitmap.h" 26#include "gc/heap.h" 27#include "os.h" 28#include "utils.h" 29 30namespace art { 31 32class ImageHeader; 33class OatHeader; 34 35namespace mirror { 36class Object; 37class Reference; 38class Class; 39class ArtMethod; 40} // namespace mirror 41 42class PatchOat { 43 public: 44 // Patch only the oat file 45 static bool Patch(File* oat_in, off_t delta, File* oat_out, TimingLogger* timings, 46 bool output_oat_opened_from_fd, // Was this using --oatput-oat-fd ? 47 bool new_oat_out); // Output oat was a new file created by us? 48 49 // Patch only the image (art file) 50 static bool Patch(const std::string& art_location, off_t delta, File* art_out, InstructionSet isa, 51 TimingLogger* timings); 52 53 // Patch both the image and the oat file 54 static bool Patch(File* oat_in, const std::string& art_location, 55 off_t delta, File* oat_out, File* art_out, InstructionSet isa, 56 TimingLogger* timings, 57 bool output_oat_opened_from_fd, // Was this using --oatput-oat-fd ? 58 bool new_oat_out); // Output oat was a new file created by us? 59 60 private: 61 // Takes ownership only of the ElfFile. All other pointers are only borrowed. 62 PatchOat(ElfFile* oat_file, off_t delta, TimingLogger* timings) 63 : oat_file_(oat_file), image_(nullptr), bitmap_(nullptr), heap_(nullptr), delta_(delta), 64 isa_(kNone), timings_(timings) {} 65 PatchOat(InstructionSet isa, MemMap* image, gc::accounting::ContinuousSpaceBitmap* bitmap, 66 MemMap* heap, off_t delta, TimingLogger* timings) 67 : image_(image), bitmap_(bitmap), heap_(heap), 68 delta_(delta), isa_(isa), timings_(timings) {} 69 PatchOat(InstructionSet isa, ElfFile* oat_file, MemMap* image, 70 gc::accounting::ContinuousSpaceBitmap* bitmap, MemMap* heap, off_t delta, 71 TimingLogger* timings) 72 : oat_file_(oat_file), image_(image), bitmap_(bitmap), heap_(heap), 73 delta_(delta), isa_(isa), timings_(timings) {} 74 ~PatchOat() {} 75 76 // Was the .art image at image_path made with --compile-pic ? 77 static bool IsImagePic(const ImageHeader& image_header, const std::string& image_path); 78 79 enum MaybePic { 80 NOT_PIC, // Code not pic. Patch as usual. 81 PIC, // Code was pic. Create symlink; skip OAT patching. 82 ERROR_OAT_FILE, // Failed to symlink oat file 83 ERROR_FIRST = ERROR_OAT_FILE, 84 }; 85 86 // Was the .oat image at oat_in made with --compile-pic ? 87 static MaybePic IsOatPic(const ElfFile* oat_in); 88 89 // Attempt to replace the file with a symlink 90 // Returns false if it fails 91 static bool ReplaceOatFileWithSymlink(const std::string& input_oat_filename, 92 const std::string& output_oat_filename, 93 bool output_oat_opened_from_fd, 94 bool new_oat_out); // Output oat was newly created? 95 96 static void BitmapCallback(mirror::Object* obj, void* arg) 97 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 98 reinterpret_cast<PatchOat*>(arg)->VisitObject(obj); 99 } 100 101 void VisitObject(mirror::Object* obj) 102 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 103 void FixupMethod(mirror::ArtMethod* object, mirror::ArtMethod* copy) 104 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 105 bool InHeap(mirror::Object*); 106 107 // Patches oat in place, modifying the oat_file given to the constructor. 108 bool PatchElf(); 109 template <typename ElfFileImpl> 110 bool PatchElf(ElfFileImpl* oat_file); 111 template <typename ElfFileImpl> 112 bool PatchOatHeader(ElfFileImpl* oat_file); 113 114 bool PatchImage() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 115 void PatchArtFields(const ImageHeader* image_header) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 116 void PatchDexFileArrays(mirror::ObjectArray<mirror::Object>* img_roots) 117 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); 118 119 bool WriteElf(File* out); 120 bool WriteImage(File* out); 121 122 template <typename T> 123 T* RelocatedCopyOf(T* obj) { 124 if (obj == nullptr) { 125 return nullptr; 126 } 127 DCHECK_GT(reinterpret_cast<uintptr_t>(obj), reinterpret_cast<uintptr_t>(heap_->Begin())); 128 DCHECK_LT(reinterpret_cast<uintptr_t>(obj), reinterpret_cast<uintptr_t>(heap_->End())); 129 uintptr_t heap_off = 130 reinterpret_cast<uintptr_t>(obj) - reinterpret_cast<uintptr_t>(heap_->Begin()); 131 DCHECK_LT(heap_off, image_->Size()); 132 return reinterpret_cast<T*>(image_->Begin() + heap_off); 133 } 134 135 template <typename T> 136 T* RelocatedAddressOfPointer(T* obj) { 137 return obj == nullptr ? nullptr : 138 reinterpret_cast<T*>(reinterpret_cast<uintptr_t>(obj) + delta_); 139 } 140 141 // Look up the oat header from any elf file. 142 static const OatHeader* GetOatHeader(const ElfFile* elf_file); 143 144 // Templatized version to actually look up the oat header 145 template <typename ElfFileImpl> 146 static const OatHeader* GetOatHeader(const ElfFileImpl* elf_file); 147 148 // Walks through the old image and patches the mmap'd copy of it to the new offset. It does not 149 // change the heap. 150 class PatchVisitor { 151 public: 152 PatchVisitor(PatchOat* patcher, mirror::Object* copy) : patcher_(patcher), copy_(copy) {} 153 ~PatchVisitor() {} 154 void operator() (mirror::Object* obj, MemberOffset off, bool b) const 155 EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_); 156 // For reference classes. 157 void operator() (mirror::Class* cls, mirror::Reference* ref) const 158 EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_); 159 private: 160 PatchOat* const patcher_; 161 mirror::Object* const copy_; 162 }; 163 164 // The elf file we are patching. 165 std::unique_ptr<ElfFile> oat_file_; 166 // A mmap of the image we are patching. This is modified. 167 const MemMap* const image_; 168 // The bitmap over the image within the heap we are patching. This is not modified. 169 gc::accounting::ContinuousSpaceBitmap* const bitmap_; 170 // The heap we are patching. This is not modified. 171 const MemMap* const heap_; 172 // The amount we are changing the offset by. 173 const off_t delta_; 174 // Active instruction set, used to know the entrypoint size. 175 const InstructionSet isa_; 176 177 TimingLogger* timings_; 178 179 DISALLOW_IMPLICIT_CONSTRUCTORS(PatchOat); 180}; 181 182} // namespace art 183#endif // ART_PATCHOAT_PATCHOAT_H_ 184