Christopher Ferris | 0d7cf3e | 2017-04-19 15:42:19 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2017 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 <sys/types.h> |
| 18 | #include <unistd.h> |
| 19 | |
| 20 | #include <memory> |
| 21 | #include <string> |
| 22 | |
Christopher Ferris | d226a51 | 2017-07-14 10:37:19 -0700 | [diff] [blame] | 23 | #include <unwindstack/Elf.h> |
| 24 | #include <unwindstack/MapInfo.h> |
| 25 | #include <unwindstack/Maps.h> |
| 26 | #include <unwindstack/Memory.h> |
| 27 | |
| 28 | namespace unwindstack { |
Christopher Ferris | 0d7cf3e | 2017-04-19 15:42:19 -0700 | [diff] [blame] | 29 | |
Christopher Ferris | 3f805ac | 2017-08-30 13:15:19 -0700 | [diff] [blame] | 30 | Memory* MapInfo::GetFileMemory() { |
| 31 | std::unique_ptr<MemoryFileAtOffset> memory(new MemoryFileAtOffset); |
| 32 | if (offset == 0) { |
| 33 | if (memory->Init(name, 0)) { |
| 34 | return memory.release(); |
| 35 | } |
| 36 | return nullptr; |
| 37 | } |
| 38 | |
| 39 | // There are two possibilities when the offset is non-zero. |
| 40 | // - There is an elf file embedded in a file. |
| 41 | // - The whole file is an elf file, and the offset needs to be saved. |
| 42 | // |
| 43 | // Map in just the part of the file for the map. If this is not |
| 44 | // a valid elf, then reinit as if the whole file is an elf file. |
| 45 | // If the offset is a valid elf, then determine the size of the map |
| 46 | // and reinit to that size. This is needed because the dynamic linker |
| 47 | // only maps in a portion of the original elf, and never the symbol |
| 48 | // file data. |
| 49 | uint64_t map_size = end - start; |
| 50 | if (!memory->Init(name, offset, map_size)) { |
| 51 | return nullptr; |
| 52 | } |
| 53 | |
| 54 | bool valid; |
| 55 | uint64_t max_size; |
| 56 | Elf::GetInfo(memory.get(), &valid, &max_size); |
| 57 | if (!valid) { |
| 58 | // Init as if the whole file is an elf. |
| 59 | if (memory->Init(name, 0)) { |
| 60 | elf_offset = offset; |
| 61 | return memory.release(); |
| 62 | } |
| 63 | return nullptr; |
| 64 | } |
| 65 | |
| 66 | if (max_size > map_size) { |
| 67 | if (memory->Init(name, offset, max_size)) { |
| 68 | return memory.release(); |
| 69 | } |
| 70 | // Try to reinit using the default map_size. |
| 71 | if (memory->Init(name, offset, map_size)) { |
| 72 | return memory.release(); |
| 73 | } |
| 74 | return nullptr; |
| 75 | } |
| 76 | return memory.release(); |
| 77 | } |
| 78 | |
Christopher Ferris | 0d7cf3e | 2017-04-19 15:42:19 -0700 | [diff] [blame] | 79 | Memory* MapInfo::CreateMemory(pid_t pid) { |
| 80 | if (end <= start) { |
| 81 | return nullptr; |
| 82 | } |
| 83 | |
| 84 | elf_offset = 0; |
| 85 | |
| 86 | // First try and use the file associated with the info. |
| 87 | if (!name.empty()) { |
| 88 | // Fail on device maps. |
| 89 | if (flags & MAPS_FLAGS_DEVICE_MAP) { |
| 90 | return nullptr; |
| 91 | } |
Christopher Ferris | 3f805ac | 2017-08-30 13:15:19 -0700 | [diff] [blame] | 92 | Memory* memory = GetFileMemory(); |
| 93 | if (memory != nullptr) { |
| 94 | return memory; |
Christopher Ferris | 0d7cf3e | 2017-04-19 15:42:19 -0700 | [diff] [blame] | 95 | } |
| 96 | } |
| 97 | |
Christopher Ferris | 3f805ac | 2017-08-30 13:15:19 -0700 | [diff] [blame] | 98 | Memory* memory; |
Christopher Ferris | 0d7cf3e | 2017-04-19 15:42:19 -0700 | [diff] [blame] | 99 | if (pid == getpid()) { |
| 100 | memory = new MemoryLocal(); |
| 101 | } else { |
| 102 | memory = new MemoryRemote(pid); |
| 103 | } |
| 104 | return new MemoryRange(memory, start, end); |
| 105 | } |
| 106 | |
Christopher Ferris | 570b76f | 2017-06-30 17:18:16 -0700 | [diff] [blame] | 107 | Elf* MapInfo::GetElf(pid_t pid, bool init_gnu_debugdata) { |
Christopher Ferris | 0d7cf3e | 2017-04-19 15:42:19 -0700 | [diff] [blame] | 108 | if (elf) { |
| 109 | return elf; |
| 110 | } |
| 111 | |
| 112 | elf = new Elf(CreateMemory(pid)); |
Christopher Ferris | 570b76f | 2017-06-30 17:18:16 -0700 | [diff] [blame] | 113 | if (elf->Init() && init_gnu_debugdata) { |
| 114 | elf->InitGnuDebugdata(); |
| 115 | } |
Christopher Ferris | 0d7cf3e | 2017-04-19 15:42:19 -0700 | [diff] [blame] | 116 | // If the init fails, keep the elf around as an invalid object so we |
| 117 | // don't try to reinit the object. |
| 118 | return elf; |
| 119 | } |
Christopher Ferris | d226a51 | 2017-07-14 10:37:19 -0700 | [diff] [blame] | 120 | |
| 121 | } // namespace unwindstack |