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 "base/bit_utils.h"
20 #include "mirror/object_array.h"
21 #include "mirror/object_array-inl.h"
22 #include "mirror/object-inl.h"
23 
24 namespace art {
25 
26 const uint8_t ImageHeader::kImageMagic[] = { 'a', 'r', 't', '\n' };
27 const uint8_t ImageHeader::kImageVersion[] = { '0', '1', '7', '\0' };
28 
ImageHeader(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 pointer_size,bool compile_pic)29 ImageHeader::ImageHeader(uint32_t image_begin,
30                          uint32_t image_size,
31                          ImageSection* sections,
32                          uint32_t image_roots,
33                          uint32_t oat_checksum,
34                          uint32_t oat_file_begin,
35                          uint32_t oat_data_begin,
36                          uint32_t oat_data_end,
37                          uint32_t oat_file_end,
38                          uint32_t pointer_size,
39                          bool compile_pic)
40   : image_begin_(image_begin),
41     image_size_(image_size),
42     oat_checksum_(oat_checksum),
43     oat_file_begin_(oat_file_begin),
44     oat_data_begin_(oat_data_begin),
45     oat_data_end_(oat_data_end),
46     oat_file_end_(oat_file_end),
47     patch_delta_(0),
48     image_roots_(image_roots),
49     pointer_size_(pointer_size),
50     compile_pic_(compile_pic) {
51   CHECK_EQ(image_begin, RoundUp(image_begin, kPageSize));
52   CHECK_EQ(oat_file_begin, RoundUp(oat_file_begin, kPageSize));
53   CHECK_EQ(oat_data_begin, RoundUp(oat_data_begin, kPageSize));
54   CHECK_LT(image_begin, image_roots);
55   CHECK_LT(image_roots, oat_file_begin);
56   CHECK_LE(oat_file_begin, oat_data_begin);
57   CHECK_LT(oat_data_begin, oat_data_end);
58   CHECK_LE(oat_data_end, oat_file_end);
59   CHECK(ValidPointerSize(pointer_size_)) << pointer_size_;
60   memcpy(magic_, kImageMagic, sizeof(kImageMagic));
61   memcpy(version_, kImageVersion, sizeof(kImageVersion));
62   std::copy_n(sections, kSectionCount, sections_);
63 }
64 
RelocateImage(off_t delta)65 void ImageHeader::RelocateImage(off_t delta) {
66   CHECK_ALIGNED(delta, kPageSize) << " patch delta must be page aligned";
67   image_begin_ += delta;
68   oat_file_begin_ += delta;
69   oat_data_begin_ += delta;
70   oat_data_end_ += delta;
71   oat_file_end_ += delta;
72   image_roots_ += delta;
73   patch_delta_ += delta;
74   for (size_t i = 0; i < kImageMethodsCount; ++i) {
75     image_methods_[i] += delta;
76   }
77 }
78 
IsValid() const79 bool ImageHeader::IsValid() const {
80   if (memcmp(magic_, kImageMagic, sizeof(kImageMagic)) != 0) {
81     return false;
82   }
83   if (memcmp(version_, kImageVersion, sizeof(kImageVersion)) != 0) {
84     return false;
85   }
86   // Unsigned so wraparound is well defined.
87   if (image_begin_ >= image_begin_ + image_size_) {
88     return false;
89   }
90   if (oat_file_begin_ > oat_file_end_) {
91     return false;
92   }
93   if (oat_data_begin_ > oat_data_end_) {
94     return false;
95   }
96   if (oat_file_begin_ >= oat_data_begin_) {
97     return false;
98   }
99   if (image_roots_ <= image_begin_ || oat_file_begin_ <= image_roots_) {
100     return false;
101   }
102   if (!IsAligned<kPageSize>(patch_delta_)) {
103     return false;
104   }
105   return true;
106 }
107 
GetMagic() const108 const char* ImageHeader::GetMagic() const {
109   CHECK(IsValid());
110   return reinterpret_cast<const char*>(magic_);
111 }
112 
GetImageRoot(ImageRoot image_root) const113 mirror::Object* ImageHeader::GetImageRoot(ImageRoot image_root) const {
114   return GetImageRoots()->Get(image_root);
115 }
116 
GetImageRoots() const117 mirror::ObjectArray<mirror::Object>* ImageHeader::GetImageRoots() const {
118   // Need a read barrier as it's not visited during root scan.
119   // Pass in the address of the local variable to the read barrier
120   // rather than image_roots_ because it won't move (asserted below)
121   // and it's a const member.
122   mirror::ObjectArray<mirror::Object>* image_roots =
123       reinterpret_cast<mirror::ObjectArray<mirror::Object>*>(image_roots_);
124   mirror::ObjectArray<mirror::Object>* result =
125       ReadBarrier::BarrierForRoot<mirror::ObjectArray<mirror::Object>, kWithReadBarrier, true>(
126           &image_roots);
127   DCHECK_EQ(image_roots, result);
128   return result;
129 }
130 
GetImageMethod(ImageMethod index) const131 ArtMethod* ImageHeader::GetImageMethod(ImageMethod index) const {
132   CHECK_LT(static_cast<size_t>(index), kImageMethodsCount);
133   return reinterpret_cast<ArtMethod*>(image_methods_[index]);
134 }
135 
SetImageMethod(ImageMethod index,ArtMethod * method)136 void ImageHeader::SetImageMethod(ImageMethod index, ArtMethod* method) {
137   CHECK_LT(static_cast<size_t>(index), kImageMethodsCount);
138   image_methods_[index] = reinterpret_cast<uint64_t>(method);
139 }
140 
GetImageSection(ImageSections index) const141 const ImageSection& ImageHeader::GetImageSection(ImageSections index) const {
142   CHECK_LT(static_cast<size_t>(index), kSectionCount);
143   return sections_[index];
144 }
145 
operator <<(std::ostream & os,const ImageSection & section)146 std::ostream& operator<<(std::ostream& os, const ImageSection& section) {
147   return os << "size=" << section.Size() << " range=" << section.Offset() << "-" << section.End();
148 }
149 
150 }  // namespace art
151