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 "mirror/object_array.h"
20 #include "mirror/object_array-inl.h"
21 #include "mirror/object-inl.h"
22 #include "utils.h"
23 
24 namespace art {
25 
26 const byte ImageHeader::kImageMagic[] = { 'a', 'r', 't', '\n' };
27 const byte ImageHeader::kImageVersion[] = { '0', '1', '2', '\0' };
28 
ImageHeader(uint32_t image_begin,uint32_t image_size,uint32_t image_bitmap_offset,uint32_t image_bitmap_size,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,bool compile_pic)29 ImageHeader::ImageHeader(uint32_t image_begin,
30                          uint32_t image_size,
31                          uint32_t image_bitmap_offset,
32                          uint32_t image_bitmap_size,
33                          uint32_t image_roots,
34                          uint32_t oat_checksum,
35                          uint32_t oat_file_begin,
36                          uint32_t oat_data_begin,
37                          uint32_t oat_data_end,
38                          uint32_t oat_file_end,
39                          bool compile_pic)
40   : image_begin_(image_begin),
41     image_size_(image_size),
42     image_bitmap_offset_(image_bitmap_offset),
43     image_bitmap_size_(image_bitmap_size),
44     oat_checksum_(oat_checksum),
45     oat_file_begin_(oat_file_begin),
46     oat_data_begin_(oat_data_begin),
47     oat_data_end_(oat_data_end),
48     oat_file_end_(oat_file_end),
49     patch_delta_(0),
50     image_roots_(image_roots),
51     compile_pic_(compile_pic) {
52   CHECK_EQ(image_begin, RoundUp(image_begin, kPageSize));
53   CHECK_EQ(oat_file_begin, RoundUp(oat_file_begin, kPageSize));
54   CHECK_EQ(oat_data_begin, RoundUp(oat_data_begin, kPageSize));
55   CHECK_LT(image_begin, image_roots);
56   CHECK_LT(image_roots, oat_file_begin);
57   CHECK_LE(oat_file_begin, oat_data_begin);
58   CHECK_LT(oat_data_begin, oat_data_end);
59   CHECK_LE(oat_data_end, oat_file_end);
60   memcpy(magic_, kImageMagic, sizeof(kImageMagic));
61   memcpy(version_, kImageVersion, sizeof(kImageVersion));
62 }
63 
RelocateImage(off_t delta)64 void ImageHeader::RelocateImage(off_t delta) {
65   CHECK_ALIGNED(delta, kPageSize) << " patch delta must be page aligned";
66   image_begin_ += delta;
67   oat_file_begin_ += delta;
68   oat_data_begin_ += delta;
69   oat_data_end_ += delta;
70   oat_file_end_ += delta;
71   image_roots_ += delta;
72   patch_delta_ += delta;
73 }
74 
IsValid() const75 bool ImageHeader::IsValid() const {
76   if (memcmp(magic_, kImageMagic, sizeof(kImageMagic)) != 0) {
77     return false;
78   }
79   if (memcmp(version_, kImageVersion, sizeof(kImageVersion)) != 0) {
80     return false;
81   }
82   // Unsigned so wraparound is well defined.
83   if (image_begin_ >= image_begin_ + image_size_) {
84     return false;
85   }
86   if (oat_file_begin_ > oat_file_end_) {
87     return false;
88   }
89   if (oat_data_begin_ > oat_data_end_) {
90     return false;
91   }
92   if (oat_file_begin_ >= oat_data_begin_) {
93     return false;
94   }
95   if (image_roots_ <= image_begin_ || oat_file_begin_ <= image_roots_) {
96     return false;
97   }
98   if (!IsAligned<kPageSize>(patch_delta_)) {
99     return false;
100   }
101   return true;
102 }
103 
GetMagic() const104 const char* ImageHeader::GetMagic() const {
105   CHECK(IsValid());
106   return reinterpret_cast<const char*>(magic_);
107 }
108 
GetImageRoot(ImageRoot image_root) const109 mirror::Object* ImageHeader::GetImageRoot(ImageRoot image_root) const {
110   return GetImageRoots()->Get(image_root);
111 }
112 
GetImageRoots() const113 mirror::ObjectArray<mirror::Object>* ImageHeader::GetImageRoots() const {
114   return reinterpret_cast<mirror::ObjectArray<mirror::Object>*>(image_roots_);
115 }
116 
117 }  // namespace art
118