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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 "image.h"
18 
19 #include <lz4.h>
20 #include <sstream>
21 
22 #include "base/bit_utils.h"
23 #include "base/length_prefixed_array.h"
24 #include "base/utils.h"
25 #include "mirror/object-inl.h"
26 #include "mirror/object_array-inl.h"
27 #include "mirror/object_array.h"
28 
29 namespace art {
30 
31 const uint8_t ImageHeader::kImageMagic[] = { 'a', 'r', 't', '\n' };
32 // Last change: kAccNterpInvokeFastPathFlag in method modifiers.
33 const uint8_t ImageHeader::kImageVersion[] = { '0', '9', '9', '\0' };
34 
ImageHeader(uint32_t image_reservation_size,uint32_t component_count,uint32_t image_begin,uint32_t image_size,ImageSection * sections,uint32_t image_roots,uint32_t oat_checksum,uint32_t oat_file_begin,uint32_t oat_data_begin,uint32_t oat_data_end,uint32_t oat_file_end,uint32_t boot_image_begin,uint32_t boot_image_size,uint32_t boot_image_component_count,uint32_t boot_image_checksum,uint32_t pointer_size)35 ImageHeader::ImageHeader(uint32_t image_reservation_size,
36                          uint32_t component_count,
37                          uint32_t image_begin,
38                          uint32_t image_size,
39                          ImageSection* sections,
40                          uint32_t image_roots,
41                          uint32_t oat_checksum,
42                          uint32_t oat_file_begin,
43                          uint32_t oat_data_begin,
44                          uint32_t oat_data_end,
45                          uint32_t oat_file_end,
46                          uint32_t boot_image_begin,
47                          uint32_t boot_image_size,
48                          uint32_t boot_image_component_count,
49                          uint32_t boot_image_checksum,
50                          uint32_t pointer_size)
51   : image_reservation_size_(image_reservation_size),
52     component_count_(component_count),
53     image_begin_(image_begin),
54     image_size_(image_size),
55     image_checksum_(0u),
56     oat_checksum_(oat_checksum),
57     oat_file_begin_(oat_file_begin),
58     oat_data_begin_(oat_data_begin),
59     oat_data_end_(oat_data_end),
60     oat_file_end_(oat_file_end),
61     boot_image_begin_(boot_image_begin),
62     boot_image_size_(boot_image_size),
63     boot_image_component_count_(boot_image_component_count),
64     boot_image_checksum_(boot_image_checksum),
65     image_roots_(image_roots),
66     pointer_size_(pointer_size) {
67   CHECK_EQ(image_begin, RoundUp(image_begin, kPageSize));
68   CHECK_EQ(oat_file_begin, RoundUp(oat_file_begin, kPageSize));
69   CHECK_EQ(oat_data_begin, RoundUp(oat_data_begin, kPageSize));
70   CHECK_LT(image_roots, oat_file_begin);
71   CHECK_LE(oat_file_begin, oat_data_begin);
72   CHECK_LT(oat_data_begin, oat_data_end);
73   CHECK_LE(oat_data_end, oat_file_end);
74   CHECK(ValidPointerSize(pointer_size_)) << pointer_size_;
75   memcpy(magic_, kImageMagic, sizeof(kImageMagic));
76   memcpy(version_, kImageVersion, sizeof(kImageVersion));
77   std::copy_n(sections, kSectionCount, sections_);
78 }
79 
RelocateImageReferences(int64_t delta)80 void ImageHeader::RelocateImageReferences(int64_t delta) {
81   CHECK_ALIGNED(delta, kPageSize) << "relocation delta must be page aligned";
82   oat_file_begin_ += delta;
83   oat_data_begin_ += delta;
84   oat_data_end_ += delta;
85   oat_file_end_ += delta;
86   image_begin_ += delta;
87   image_roots_ += delta;
88 }
89 
RelocateBootImageReferences(int64_t delta)90 void ImageHeader::RelocateBootImageReferences(int64_t delta) {
91   CHECK_ALIGNED(delta, kPageSize) << "relocation delta must be page aligned";
92   DCHECK_EQ(boot_image_begin_ != 0u, boot_image_size_ != 0u);
93   if (boot_image_begin_ != 0u) {
94     boot_image_begin_ += delta;
95   }
96   for (size_t i = 0; i < kImageMethodsCount; ++i) {
97     image_methods_[i] += delta;
98   }
99 }
100 
IsAppImage() const101 bool ImageHeader::IsAppImage() const {
102   // Unlike boot image and boot image extensions which include address space for
103   // oat files in their reservation size, app images are loaded separately from oat
104   // files and their reservation size is the image size rounded up to full page.
105   return image_reservation_size_ == RoundUp(image_size_, kPageSize);
106 }
107 
GetImageSpaceCount() const108 uint32_t ImageHeader::GetImageSpaceCount() const {
109   DCHECK(!IsAppImage());
110   DCHECK_NE(component_count_, 0u);  // Must be the header for the first component.
111   // For images compiled with --single-image, there is only one oat file. To detect
112   // that, check whether the reservation ends at the end of the first oat file.
113   return (image_begin_ + image_reservation_size_ == oat_file_end_) ? 1u : component_count_;
114 }
115 
IsValid() const116 bool ImageHeader::IsValid() const {
117   if (memcmp(magic_, kImageMagic, sizeof(kImageMagic)) != 0) {
118     return false;
119   }
120   if (memcmp(version_, kImageVersion, sizeof(kImageVersion)) != 0) {
121     return false;
122   }
123   if (!IsAligned<kPageSize>(image_reservation_size_)) {
124     return false;
125   }
126   // Unsigned so wraparound is well defined.
127   if (image_begin_ >= image_begin_ + image_size_) {
128     return false;
129   }
130   if (oat_file_begin_ > oat_file_end_) {
131     return false;
132   }
133   if (oat_data_begin_ > oat_data_end_) {
134     return false;
135   }
136   if (oat_file_begin_ >= oat_data_begin_) {
137     return false;
138   }
139   return true;
140 }
141 
GetMagic() const142 const char* ImageHeader::GetMagic() const {
143   CHECK(IsValid());
144   return reinterpret_cast<const char*>(magic_);
145 }
146 
GetImageMethod(ImageMethod index) const147 ArtMethod* ImageHeader::GetImageMethod(ImageMethod index) const {
148   CHECK_LT(static_cast<size_t>(index), kImageMethodsCount);
149   return reinterpret_cast<ArtMethod*>(image_methods_[index]);
150 }
151 
operator <<(std::ostream & os,const ImageSection & section)152 std::ostream& operator<<(std::ostream& os, const ImageSection& section) {
153   return os << "size=" << section.Size() << " range=" << section.Offset() << "-" << section.End();
154 }
155 
VisitObjects(ObjectVisitor * visitor,uint8_t * base,PointerSize pointer_size) const156 void ImageHeader::VisitObjects(ObjectVisitor* visitor,
157                                uint8_t* base,
158                                PointerSize pointer_size) const {
159   DCHECK_EQ(pointer_size, GetPointerSize());
160   const ImageSection& objects = GetObjectsSection();
161   static const size_t kStartPos = RoundUp(sizeof(ImageHeader), kObjectAlignment);
162   for (size_t pos = kStartPos; pos < objects.Size(); ) {
163     mirror::Object* object = reinterpret_cast<mirror::Object*>(base + objects.Offset() + pos);
164     visitor->Visit(object);
165     pos += RoundUp(object->SizeOf(), kObjectAlignment);
166   }
167 }
168 
GetPointerSize() const169 PointerSize ImageHeader::GetPointerSize() const {
170   return ConvertToPointerSize(pointer_size_);
171 }
172 
Decompress(uint8_t * out_ptr,const uint8_t * in_ptr,std::string * error_msg) const173 bool ImageHeader::Block::Decompress(uint8_t* out_ptr,
174                                     const uint8_t* in_ptr,
175                                     std::string* error_msg) const {
176   switch (storage_mode_) {
177     case kStorageModeUncompressed: {
178       CHECK_EQ(image_size_, data_size_);
179       memcpy(out_ptr + image_offset_, in_ptr + data_offset_, data_size_);
180       break;
181     }
182     case kStorageModeLZ4:
183     case kStorageModeLZ4HC: {
184       // LZ4HC and LZ4 have same internal format, both use LZ4_decompress.
185       const size_t decompressed_size = LZ4_decompress_safe(
186           reinterpret_cast<const char*>(in_ptr) + data_offset_,
187           reinterpret_cast<char*>(out_ptr) + image_offset_,
188           data_size_,
189           image_size_);
190       CHECK_EQ(decompressed_size, image_size_);
191       break;
192     }
193     default: {
194       if (error_msg != nullptr) {
195         *error_msg = (std::ostringstream() << "Invalid image format " << storage_mode_).str();
196       }
197       return false;
198     }
199   }
200   return true;
201 }
202 
GetImageSectionName(ImageSections index)203 const char* ImageHeader::GetImageSectionName(ImageSections index) {
204   switch (index) {
205     case kSectionObjects: return "Objects";
206     case kSectionArtFields: return "ArtFields";
207     case kSectionArtMethods: return "ArtMethods";
208     case kSectionRuntimeMethods: return "RuntimeMethods";
209     case kSectionImTables: return "ImTables";
210     case kSectionIMTConflictTables: return "IMTConflictTables";
211     case kSectionInternedStrings: return "InternedStrings";
212     case kSectionClassTable: return "ClassTable";
213     case kSectionStringReferenceOffsets: return "StringReferenceOffsets";
214     case kSectionMetadata: return "Metadata";
215     case kSectionImageBitmap: return "ImageBitmap";
216     case kSectionCount: return nullptr;
217   }
218 }
219 
220 }  // namespace art
221