Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2008 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 | |
Brian Carlstrom | fc0e321 | 2013-07-17 14:40:12 -0700 | [diff] [blame] | 17 | #ifndef ART_RUNTIME_MEM_MAP_H_ |
| 18 | #define ART_RUNTIME_MEM_MAP_H_ |
Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 19 | |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 20 | #include "base/mutex.h" |
| 21 | |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame] | 22 | #include <string> |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 23 | #include <map> |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame] | 24 | |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 25 | #include <stddef.h> |
Elliott Hughes | a168c83 | 2012-06-12 15:34:20 -0700 | [diff] [blame] | 26 | #include <sys/mman.h> // For the PROT_* and MAP_* constants. |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 27 | #include <sys/types.h> |
Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 28 | |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 29 | #include "globals.h" |
Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 30 | |
| 31 | namespace art { |
| 32 | |
Ian Rogers | c5f1773 | 2014-06-05 20:48:42 -0700 | [diff] [blame] | 33 | #ifdef __linux__ |
| 34 | static constexpr bool kMadviseZeroes = true; |
| 35 | #else |
| 36 | static constexpr bool kMadviseZeroes = false; |
| 37 | #endif |
| 38 | |
Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 39 | // Used to keep track of mmap segments. |
Andreas Gampe | d8f26db | 2014-05-19 17:01:13 -0700 | [diff] [blame] | 40 | // |
| 41 | // On 64b systems not supporting MAP_32BIT, the implementation of MemMap will do a linear scan |
| 42 | // for free pages. For security, the start of this scan should be randomized. This requires a |
| 43 | // dynamic initializer. |
| 44 | // For this to work, it is paramount that there are no other static initializers that access MemMap. |
| 45 | // Otherwise, calls might see uninitialized values. |
Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 46 | class MemMap { |
| 47 | public: |
Elliott Hughes | ecd3a6f | 2012-06-06 18:16:37 -0700 | [diff] [blame] | 48 | // Request an anonymous region of length 'byte_count' and a requested base address. |
Elliott Hughes | 6c9c06d | 2011-11-07 16:43:47 -0800 | [diff] [blame] | 49 | // Use NULL as the requested base address if you don't care. |
| 50 | // |
| 51 | // The word "anonymous" in this context means "not backed by a file". The supplied |
| 52 | // 'ashmem_name' will be used -- on systems that support it -- to give the mapping |
| 53 | // a name. |
Brian Carlstrom | 4a289ed | 2011-08-16 17:17:49 -0700 | [diff] [blame] | 54 | // |
| 55 | // On success, returns returns a MemMap instance. On failure, returns a NULL; |
Ian Rogers | 8d31bbd | 2013-10-13 10:44:14 -0700 | [diff] [blame] | 56 | static MemMap* MapAnonymous(const char* ashmem_name, byte* addr, size_t byte_count, int prot, |
Ian Rogers | ef7d42f | 2014-01-06 12:55:46 -0800 | [diff] [blame] | 57 | bool low_4gb, std::string* error_msg); |
Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 58 | |
| 59 | // Map part of a file, taking care of non-page aligned offsets. The |
| 60 | // "start" offset is absolute, not relative. |
| 61 | // |
| 62 | // On success, returns returns a MemMap instance. On failure, returns a NULL; |
Ian Rogers | 8d31bbd | 2013-10-13 10:44:14 -0700 | [diff] [blame] | 63 | static MemMap* MapFile(size_t byte_count, int prot, int flags, int fd, off_t start, |
| 64 | const char* filename, std::string* error_msg) { |
| 65 | return MapFileAtAddress(NULL, byte_count, prot, flags, fd, start, false, filename, error_msg); |
Brian Carlstrom | 4a289ed | 2011-08-16 17:17:49 -0700 | [diff] [blame] | 66 | } |
| 67 | |
| 68 | // Map part of a file, taking care of non-page aligned offsets. The |
| 69 | // "start" offset is absolute, not relative. This version allows |
| 70 | // requesting a specific address for the base of the mapping. |
| 71 | // |
| 72 | // On success, returns returns a MemMap instance. On failure, returns a NULL; |
Ian Rogers | 8d31bbd | 2013-10-13 10:44:14 -0700 | [diff] [blame] | 73 | static MemMap* MapFileAtAddress(byte* addr, size_t byte_count, int prot, int flags, int fd, |
| 74 | off_t start, bool reuse, const char* filename, |
| 75 | std::string* error_msg); |
Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 76 | |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 77 | // Releases the memory mapping |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 78 | ~MemMap() LOCKS_EXCLUDED(Locks::mem_maps_lock_); |
Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 79 | |
Brian Carlstrom | 0d6adac | 2014-02-05 17:39:16 -0800 | [diff] [blame] | 80 | const std::string& GetName() const { |
| 81 | return name_; |
| 82 | } |
| 83 | |
Logan Chien | d88fa26 | 2012-06-06 15:23:32 +0800 | [diff] [blame] | 84 | bool Protect(int prot); |
| 85 | |
Ian Rogers | c5f1773 | 2014-06-05 20:48:42 -0700 | [diff] [blame] | 86 | void MadviseDontNeedAndZero(); |
| 87 | |
Ian Rogers | 1c849e5 | 2012-06-28 14:00:33 -0700 | [diff] [blame] | 88 | int GetProtect() const { |
| 89 | return prot_; |
| 90 | } |
| 91 | |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 92 | byte* Begin() const { |
| 93 | return begin_; |
Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 94 | } |
| 95 | |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 96 | size_t Size() const { |
| 97 | return size_; |
Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 98 | } |
| 99 | |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 100 | byte* End() const { |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame] | 101 | return Begin() + Size(); |
| 102 | } |
| 103 | |
Brian Carlstrom | 0d6adac | 2014-02-05 17:39:16 -0800 | [diff] [blame] | 104 | void* BaseBegin() const { |
| 105 | return base_begin_; |
| 106 | } |
| 107 | |
| 108 | size_t BaseSize() const { |
| 109 | return base_size_; |
| 110 | } |
| 111 | |
| 112 | void* BaseEnd() const { |
| 113 | return reinterpret_cast<byte*>(BaseBegin()) + BaseSize(); |
| 114 | } |
| 115 | |
Mathieu Chartier | 2fde533 | 2012-09-14 14:51:54 -0700 | [diff] [blame] | 116 | bool HasAddress(const void* addr) const { |
| 117 | return Begin() <= addr && addr < End(); |
Brian Carlstrom | b765be0 | 2011-08-17 23:54:10 -0700 | [diff] [blame] | 118 | } |
| 119 | |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 120 | // Unmap the pages at end and remap them to create another memory map. |
| 121 | MemMap* RemapAtEnd(byte* new_end, const char* tail_name, int tail_prot, |
| 122 | std::string* error_msg); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 123 | |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 124 | static bool CheckNoGaps(MemMap* begin_map, MemMap* end_map) |
| 125 | LOCKS_EXCLUDED(Locks::mem_maps_lock_); |
| 126 | static void DumpMaps(std::ostream& os) |
| 127 | LOCKS_EXCLUDED(Locks::mem_maps_lock_); |
| 128 | |
Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 129 | private: |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame] | 130 | MemMap(const std::string& name, byte* begin, size_t size, void* base_begin, size_t base_size, |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 131 | int prot) LOCKS_EXCLUDED(Locks::mem_maps_lock_); |
| 132 | |
| 133 | static void DumpMaps(std::ostream& os, const std::multimap<void*, MemMap*>& mem_maps) |
| 134 | LOCKS_EXCLUDED(Locks::mem_maps_lock_); |
| 135 | static void DumpMapsLocked(std::ostream& os, const std::multimap<void*, MemMap*>& mem_maps) |
| 136 | EXCLUSIVE_LOCKS_REQUIRED(Locks::mem_maps_lock_); |
| 137 | static bool HasMemMap(MemMap* map) |
| 138 | EXCLUSIVE_LOCKS_REQUIRED(Locks::mem_maps_lock_); |
| 139 | static MemMap* GetLargestMemMapAt(void* address) |
| 140 | EXCLUSIVE_LOCKS_REQUIRED(Locks::mem_maps_lock_); |
Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 141 | |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame] | 142 | std::string name_; |
Ian Rogers | 1c849e5 | 2012-06-28 14:00:33 -0700 | [diff] [blame] | 143 | byte* const begin_; // Start of data. |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 144 | size_t size_; // Length of data. |
Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 145 | |
Ian Rogers | 1c849e5 | 2012-06-28 14:00:33 -0700 | [diff] [blame] | 146 | void* const base_begin_; // Page-aligned base address. |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 147 | size_t base_size_; // Length of mapping. May be changed by RemapAtEnd (ie Zygote). |
Ian Rogers | 1c849e5 | 2012-06-28 14:00:33 -0700 | [diff] [blame] | 148 | int prot_; // Protection of the map. |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 149 | |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 150 | #if defined(__LP64__) && !defined(__x86_64__) |
| 151 | static uintptr_t next_mem_pos_; // next memory location to check for low_4g extent |
| 152 | #endif |
| 153 | |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 154 | // All the non-empty MemMaps. Use a multimap as we do a reserve-and-divide (eg ElfMap::Load()). |
| 155 | static std::multimap<void*, MemMap*> maps_ GUARDED_BY(Locks::mem_maps_lock_); |
| 156 | |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 157 | friend class MemMapTest; // To allow access to base_begin_ and base_size_. |
Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 158 | }; |
Brian Carlstrom | 0d6adac | 2014-02-05 17:39:16 -0800 | [diff] [blame] | 159 | std::ostream& operator<<(std::ostream& os, const MemMap& mem_map); |
Brian Carlstrom | db4d540 | 2011-08-09 12:18:28 -0700 | [diff] [blame] | 160 | |
| 161 | } // namespace art |
| 162 | |
Brian Carlstrom | fc0e321 | 2013-07-17 14:40:12 -0700 | [diff] [blame] | 163 | #endif // ART_RUNTIME_MEM_MAP_H_ |