Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -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 | |
| 17 | #include "mem_map.h" |
| 18 | |
Evgenii Stepanov | 1e13374 | 2015-05-20 12:30:59 -0700 | [diff] [blame] | 19 | #include "base/memory_tool.h" |
Christopher Ferris | 943af7d | 2014-01-16 12:41:46 -0800 | [diff] [blame] | 20 | #include <backtrace/BacktraceMap.h> |
Ian Rogers | c7dd295 | 2014-10-21 23:31:19 -0700 | [diff] [blame] | 21 | #include <inttypes.h> |
Josh Gao | 0389cd5 | 2015-09-16 16:27:00 -0700 | [diff] [blame] | 22 | #include <stdlib.h> |
Ian Rogers | c7dd295 | 2014-10-21 23:31:19 -0700 | [diff] [blame] | 23 | |
Ian Rogers | 700a402 | 2014-05-19 16:49:03 -0700 | [diff] [blame] | 24 | #include <memory> |
Ian Rogers | c7dd295 | 2014-10-21 23:31:19 -0700 | [diff] [blame] | 25 | #include <sstream> |
Elliott Hughes | ecd3a6f | 2012-06-06 18:16:37 -0700 | [diff] [blame] | 26 | |
Elliott Hughes | e222ee0 | 2012-12-13 14:41:43 -0800 | [diff] [blame] | 27 | #include "base/stringprintf.h" |
Andreas Gampe | 43e10b0 | 2016-07-15 17:17:34 -0700 | [diff] [blame] | 28 | #include "base/unix_file/fd_file.h" |
| 29 | #include "os.h" |
Ian Rogers | c7dd295 | 2014-10-21 23:31:19 -0700 | [diff] [blame] | 30 | #include "thread-inl.h" |
Elliott Hughes | e222ee0 | 2012-12-13 14:41:43 -0800 | [diff] [blame] | 31 | #include "utils.h" |
| 32 | |
Elliott Hughes | 6c9c06d | 2011-11-07 16:43:47 -0800 | [diff] [blame] | 33 | #include <cutils/ashmem.h> |
Nicolas Geoffray | a25dce9 | 2016-01-12 16:41:10 +0000 | [diff] [blame] | 34 | |
Ian Rogers | 997f0f9 | 2014-06-21 22:58:05 -0700 | [diff] [blame] | 35 | #ifndef ANDROID_OS |
| 36 | #include <sys/resource.h> |
| 37 | #endif |
Elliott Hughes | 6c9c06d | 2011-11-07 16:43:47 -0800 | [diff] [blame] | 38 | |
Ian Rogers | d6b6865 | 2014-06-23 14:07:03 -0700 | [diff] [blame] | 39 | #ifndef MAP_ANONYMOUS |
| 40 | #define MAP_ANONYMOUS MAP_ANON |
| 41 | #endif |
| 42 | |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 43 | namespace art { |
| 44 | |
Christopher Ferris | 943af7d | 2014-01-16 12:41:46 -0800 | [diff] [blame] | 45 | static std::ostream& operator<<( |
| 46 | std::ostream& os, |
| 47 | std::pair<BacktraceMap::const_iterator, BacktraceMap::const_iterator> iters) { |
| 48 | for (BacktraceMap::const_iterator it = iters.first; it != iters.second; ++it) { |
| 49 | os << StringPrintf("0x%08x-0x%08x %c%c%c %s\n", |
| 50 | static_cast<uint32_t>(it->start), |
| 51 | static_cast<uint32_t>(it->end), |
| 52 | (it->flags & PROT_READ) ? 'r' : '-', |
| 53 | (it->flags & PROT_WRITE) ? 'w' : '-', |
| 54 | (it->flags & PROT_EXEC) ? 'x' : '-', it->name.c_str()); |
Elliott Hughes | ecd3a6f | 2012-06-06 18:16:37 -0700 | [diff] [blame] | 55 | } |
| 56 | return os; |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 57 | } |
| 58 | |
Mathieu Chartier | bad0267 | 2014-08-25 13:08:22 -0700 | [diff] [blame] | 59 | std::ostream& operator<<(std::ostream& os, const MemMap::Maps& mem_maps) { |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 60 | os << "MemMap:" << std::endl; |
| 61 | for (auto it = mem_maps.begin(); it != mem_maps.end(); ++it) { |
| 62 | void* base = it->first; |
| 63 | MemMap* map = it->second; |
| 64 | CHECK_EQ(base, map->BaseBegin()); |
| 65 | os << *map << std::endl; |
| 66 | } |
| 67 | return os; |
| 68 | } |
| 69 | |
Mathieu Chartier | 6e88ef6 | 2014-10-14 15:01:24 -0700 | [diff] [blame] | 70 | MemMap::Maps* MemMap::maps_ = nullptr; |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 71 | |
Ian Rogers | c3ccc10 | 2014-06-25 11:52:14 -0700 | [diff] [blame] | 72 | #if USE_ART_LOW_4G_ALLOCATOR |
Andreas Gampe | d8f26db | 2014-05-19 17:01:13 -0700 | [diff] [blame] | 73 | // Handling mem_map in 32b address range for 64b architectures that do not support MAP_32BIT. |
| 74 | |
| 75 | // The regular start of memory allocations. The first 64KB is protected by SELinux. |
Andreas Gampe | 6bd621a | 2014-05-16 17:28:58 -0700 | [diff] [blame] | 76 | static constexpr uintptr_t LOW_MEM_START = 64 * KB; |
Andreas Gampe | 7104cbf | 2014-03-21 11:44:43 -0700 | [diff] [blame] | 77 | |
Andreas Gampe | d8f26db | 2014-05-19 17:01:13 -0700 | [diff] [blame] | 78 | // Generate random starting position. |
| 79 | // To not interfere with image position, take the image's address and only place it below. Current |
| 80 | // formula (sketch): |
| 81 | // |
| 82 | // ART_BASE_ADDR = 0001XXXXXXXXXXXXXXX |
| 83 | // ---------------------------------------- |
| 84 | // = 0000111111111111111 |
| 85 | // & ~(kPageSize - 1) =~0000000000000001111 |
| 86 | // ---------------------------------------- |
| 87 | // mask = 0000111111111110000 |
| 88 | // & random data = YYYYYYYYYYYYYYYYYYY |
| 89 | // ----------------------------------- |
| 90 | // tmp = 0000YYYYYYYYYYY0000 |
| 91 | // + LOW_MEM_START = 0000000000001000000 |
| 92 | // -------------------------------------- |
| 93 | // start |
| 94 | // |
Josh Gao | 0389cd5 | 2015-09-16 16:27:00 -0700 | [diff] [blame] | 95 | // arc4random as an entropy source is exposed in Bionic, but not in glibc. When we |
Andreas Gampe | d8f26db | 2014-05-19 17:01:13 -0700 | [diff] [blame] | 96 | // do not have Bionic, simply start with LOW_MEM_START. |
| 97 | |
| 98 | // Function is standalone so it can be tested somewhat in mem_map_test.cc. |
| 99 | #ifdef __BIONIC__ |
| 100 | uintptr_t CreateStartPos(uint64_t input) { |
| 101 | CHECK_NE(0, ART_BASE_ADDRESS); |
| 102 | |
| 103 | // Start with all bits below highest bit in ART_BASE_ADDRESS. |
| 104 | constexpr size_t leading_zeros = CLZ(static_cast<uint32_t>(ART_BASE_ADDRESS)); |
| 105 | constexpr uintptr_t mask_ones = (1 << (31 - leading_zeros)) - 1; |
| 106 | |
| 107 | // Lowest (usually 12) bits are not used, as aligned by page size. |
| 108 | constexpr uintptr_t mask = mask_ones & ~(kPageSize - 1); |
| 109 | |
| 110 | // Mask input data. |
| 111 | return (input & mask) + LOW_MEM_START; |
| 112 | } |
| 113 | #endif |
| 114 | |
| 115 | static uintptr_t GenerateNextMemPos() { |
| 116 | #ifdef __BIONIC__ |
Josh Gao | 0389cd5 | 2015-09-16 16:27:00 -0700 | [diff] [blame] | 117 | uint64_t random_data; |
| 118 | arc4random_buf(&random_data, sizeof(random_data)); |
| 119 | return CreateStartPos(random_data); |
Andreas Gampe | d8f26db | 2014-05-19 17:01:13 -0700 | [diff] [blame] | 120 | #else |
Josh Gao | 0389cd5 | 2015-09-16 16:27:00 -0700 | [diff] [blame] | 121 | // No arc4random on host, see above. |
Andreas Gampe | d8f26db | 2014-05-19 17:01:13 -0700 | [diff] [blame] | 122 | return LOW_MEM_START; |
| 123 | #endif |
| 124 | } |
| 125 | |
| 126 | // Initialize linear scan to random position. |
| 127 | uintptr_t MemMap::next_mem_pos_ = GenerateNextMemPos(); |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 128 | #endif |
| 129 | |
Mathieu Chartier | 24a0fc8 | 2015-10-13 16:38:52 -0700 | [diff] [blame] | 130 | // Return true if the address range is contained in a single memory map by either reading |
| 131 | // the maps_ variable or the /proc/self/map entry. |
Mathieu Chartier | e58991b | 2015-10-13 07:59:34 -0700 | [diff] [blame] | 132 | bool MemMap::ContainedWithinExistingMap(uint8_t* ptr, size_t size, std::string* error_msg) { |
Vladimir Marko | 5c42c29 | 2015-02-25 12:02:49 +0000 | [diff] [blame] | 133 | uintptr_t begin = reinterpret_cast<uintptr_t>(ptr); |
| 134 | uintptr_t end = begin + size; |
Mathieu Chartier | e58991b | 2015-10-13 07:59:34 -0700 | [diff] [blame] | 135 | |
Mathieu Chartier | 24a0fc8 | 2015-10-13 16:38:52 -0700 | [diff] [blame] | 136 | // There is a suspicion that BacktraceMap::Create is occasionally missing maps. TODO: Investigate |
| 137 | // further. |
Mathieu Chartier | e58991b | 2015-10-13 07:59:34 -0700 | [diff] [blame] | 138 | { |
| 139 | MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_); |
Mathieu Chartier | 24a0fc8 | 2015-10-13 16:38:52 -0700 | [diff] [blame] | 140 | for (auto& pair : *maps_) { |
Mathieu Chartier | e58991b | 2015-10-13 07:59:34 -0700 | [diff] [blame] | 141 | MemMap* const map = pair.second; |
| 142 | if (begin >= reinterpret_cast<uintptr_t>(map->Begin()) && |
| 143 | end <= reinterpret_cast<uintptr_t>(map->End())) { |
| 144 | return true; |
| 145 | } |
| 146 | } |
| 147 | } |
| 148 | |
Jim_Guo | a62a588 | 2014-04-28 11:11:57 +0800 | [diff] [blame] | 149 | std::unique_ptr<BacktraceMap> map(BacktraceMap::Create(getpid(), true)); |
Mathieu Chartier | ebe2dfc | 2015-11-24 13:47:52 -0800 | [diff] [blame] | 150 | if (map == nullptr) { |
| 151 | if (error_msg != nullptr) { |
| 152 | *error_msg = StringPrintf("Failed to build process map"); |
| 153 | } |
Jim_Guo | a62a588 | 2014-04-28 11:11:57 +0800 | [diff] [blame] | 154 | return false; |
| 155 | } |
Christopher Ferris | 56f8b56 | 2016-06-16 23:19:36 -0700 | [diff] [blame] | 156 | |
| 157 | ScopedBacktraceMapIteratorLock lock(map.get()); |
Jim_Guo | a62a588 | 2014-04-28 11:11:57 +0800 | [diff] [blame] | 158 | for (BacktraceMap::const_iterator it = map->begin(); it != map->end(); ++it) { |
| 159 | if ((begin >= it->start && begin < it->end) // start of new within old |
| 160 | && (end > it->start && end <= it->end)) { // end of new within old |
| 161 | return true; |
| 162 | } |
| 163 | } |
Mathieu Chartier | ebe2dfc | 2015-11-24 13:47:52 -0800 | [diff] [blame] | 164 | if (error_msg != nullptr) { |
| 165 | PrintFileToLog("/proc/self/maps", LogSeverity::ERROR); |
| 166 | *error_msg = StringPrintf("Requested region 0x%08" PRIxPTR "-0x%08" PRIxPTR " does not overlap " |
| 167 | "any existing map. See process maps in the log.", begin, end); |
| 168 | } |
Jim_Guo | a62a588 | 2014-04-28 11:11:57 +0800 | [diff] [blame] | 169 | return false; |
| 170 | } |
| 171 | |
| 172 | // Return true if the address range does not conflict with any /proc/self/maps entry. |
| 173 | static bool CheckNonOverlapping(uintptr_t begin, |
| 174 | uintptr_t end, |
| 175 | std::string* error_msg) { |
| 176 | std::unique_ptr<BacktraceMap> map(BacktraceMap::Create(getpid(), true)); |
Christopher Ferris | 836572a | 2014-08-05 15:43:13 -0700 | [diff] [blame] | 177 | if (map.get() == nullptr) { |
Jim_Guo | a62a588 | 2014-04-28 11:11:57 +0800 | [diff] [blame] | 178 | *error_msg = StringPrintf("Failed to build process map"); |
| 179 | return false; |
| 180 | } |
Christopher Ferris | 56f8b56 | 2016-06-16 23:19:36 -0700 | [diff] [blame] | 181 | ScopedBacktraceMapIteratorLock(map.get()); |
Jim_Guo | a62a588 | 2014-04-28 11:11:57 +0800 | [diff] [blame] | 182 | for (BacktraceMap::const_iterator it = map->begin(); it != map->end(); ++it) { |
| 183 | if ((begin >= it->start && begin < it->end) // start of new within old |
| 184 | || (end > it->start && end < it->end) // end of new within old |
| 185 | || (begin <= it->start && end > it->end)) { // start/end of new includes all of old |
| 186 | std::ostringstream map_info; |
| 187 | map_info << std::make_pair(it, map->end()); |
| 188 | *error_msg = StringPrintf("Requested region 0x%08" PRIxPTR "-0x%08" PRIxPTR " overlaps with " |
| 189 | "existing map 0x%08" PRIxPTR "-0x%08" PRIxPTR " (%s)\n%s", |
| 190 | begin, end, |
| 191 | static_cast<uintptr_t>(it->start), static_cast<uintptr_t>(it->end), |
| 192 | it->name.c_str(), |
| 193 | map_info.str().c_str()); |
| 194 | return false; |
| 195 | } |
| 196 | } |
| 197 | return true; |
| 198 | } |
| 199 | |
| 200 | // CheckMapRequest to validate a non-MAP_FAILED mmap result based on |
| 201 | // the expected value, calling munmap if validation fails, giving the |
| 202 | // reason in error_msg. |
| 203 | // |
Mathieu Chartier | 2cebb24 | 2015-04-21 16:50:40 -0700 | [diff] [blame] | 204 | // If the expected_ptr is null, nothing is checked beyond the fact |
Jim_Guo | a62a588 | 2014-04-28 11:11:57 +0800 | [diff] [blame] | 205 | // that the actual_ptr is not MAP_FAILED. However, if expected_ptr is |
| 206 | // non-null, we check that pointer is the actual_ptr == expected_ptr, |
| 207 | // and if not, report in error_msg what the conflict mapping was if |
| 208 | // found, or a generic error in other cases. |
Ian Rogers | 1373595 | 2014-10-08 12:43:28 -0700 | [diff] [blame] | 209 | static bool CheckMapRequest(uint8_t* expected_ptr, void* actual_ptr, size_t byte_count, |
Jim_Guo | a62a588 | 2014-04-28 11:11:57 +0800 | [diff] [blame] | 210 | std::string* error_msg) { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 211 | // Handled first by caller for more specific error messages. |
| 212 | CHECK(actual_ptr != MAP_FAILED); |
| 213 | |
| 214 | if (expected_ptr == nullptr) { |
| 215 | return true; |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 216 | } |
Elliott Hughes | ecd3a6f | 2012-06-06 18:16:37 -0700 | [diff] [blame] | 217 | |
Jim_Guo | a62a588 | 2014-04-28 11:11:57 +0800 | [diff] [blame] | 218 | uintptr_t actual = reinterpret_cast<uintptr_t>(actual_ptr); |
| 219 | uintptr_t expected = reinterpret_cast<uintptr_t>(expected_ptr); |
| 220 | uintptr_t limit = expected + byte_count; |
| 221 | |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 222 | if (expected_ptr == actual_ptr) { |
| 223 | return true; |
| 224 | } |
| 225 | |
| 226 | // We asked for an address but didn't get what we wanted, all paths below here should fail. |
| 227 | int result = munmap(actual_ptr, byte_count); |
| 228 | if (result == -1) { |
| 229 | PLOG(WARNING) << StringPrintf("munmap(%p, %zd) failed", actual_ptr, byte_count); |
| 230 | } |
| 231 | |
Mathieu Chartier | ebe2dfc | 2015-11-24 13:47:52 -0800 | [diff] [blame] | 232 | if (error_msg != nullptr) { |
Mathieu Chartier | 83723ae | 2016-02-24 10:09:23 -0800 | [diff] [blame] | 233 | // We call this here so that we can try and generate a full error |
| 234 | // message with the overlapping mapping. There's no guarantee that |
| 235 | // that there will be an overlap though, since |
| 236 | // - The kernel is not *required* to honor expected_ptr unless MAP_FIXED is |
| 237 | // true, even if there is no overlap |
| 238 | // - There might have been an overlap at the point of mmap, but the |
| 239 | // overlapping region has since been unmapped. |
| 240 | std::string error_detail; |
| 241 | CheckNonOverlapping(expected, limit, &error_detail); |
Mathieu Chartier | ebe2dfc | 2015-11-24 13:47:52 -0800 | [diff] [blame] | 242 | std::ostringstream os; |
| 243 | os << StringPrintf("Failed to mmap at expected address, mapped at " |
| 244 | "0x%08" PRIxPTR " instead of 0x%08" PRIxPTR, |
| 245 | actual, expected); |
| 246 | if (!error_detail.empty()) { |
| 247 | os << " : " << error_detail; |
| 248 | } |
| 249 | *error_msg = os.str(); |
Christopher Ferris | 943af7d | 2014-01-16 12:41:46 -0800 | [diff] [blame] | 250 | } |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 251 | return false; |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 252 | } |
| 253 | |
Mathieu Chartier | 38c8221 | 2015-06-04 16:22:41 -0700 | [diff] [blame] | 254 | #if USE_ART_LOW_4G_ALLOCATOR |
Mathieu Chartier | 42bddce | 2015-11-09 15:16:56 -0800 | [diff] [blame] | 255 | static inline void* TryMemMapLow4GB(void* ptr, |
| 256 | size_t page_aligned_byte_count, |
| 257 | int prot, |
| 258 | int flags, |
| 259 | int fd, |
| 260 | off_t offset) { |
| 261 | void* actual = mmap(ptr, page_aligned_byte_count, prot, flags, fd, offset); |
Mathieu Chartier | 38c8221 | 2015-06-04 16:22:41 -0700 | [diff] [blame] | 262 | if (actual != MAP_FAILED) { |
| 263 | // Since we didn't use MAP_FIXED the kernel may have mapped it somewhere not in the low |
| 264 | // 4GB. If this is the case, unmap and retry. |
| 265 | if (reinterpret_cast<uintptr_t>(actual) + page_aligned_byte_count >= 4 * GB) { |
| 266 | munmap(actual, page_aligned_byte_count); |
| 267 | actual = MAP_FAILED; |
| 268 | } |
| 269 | } |
| 270 | return actual; |
| 271 | } |
| 272 | #endif |
| 273 | |
Mathieu Chartier | 42bddce | 2015-11-09 15:16:56 -0800 | [diff] [blame] | 274 | MemMap* MemMap::MapAnonymous(const char* name, |
| 275 | uint8_t* expected_ptr, |
| 276 | size_t byte_count, |
| 277 | int prot, |
| 278 | bool low_4gb, |
| 279 | bool reuse, |
Nicolas Geoffray | a25dce9 | 2016-01-12 16:41:10 +0000 | [diff] [blame] | 280 | std::string* error_msg, |
| 281 | bool use_ashmem) { |
Ian Rogers | 6a3c1fc | 2014-10-31 00:33:20 -0700 | [diff] [blame] | 282 | #ifndef __LP64__ |
| 283 | UNUSED(low_4gb); |
| 284 | #endif |
Nicolas Geoffray | 58a73d2 | 2016-11-29 21:49:43 +0000 | [diff] [blame] | 285 | use_ashmem = use_ashmem && !kIsTargetLinux; |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 286 | if (byte_count == 0) { |
Jim_Guo | a62a588 | 2014-04-28 11:11:57 +0800 | [diff] [blame] | 287 | return new MemMap(name, nullptr, 0, nullptr, 0, prot, false); |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 288 | } |
Elliott Hughes | ecd3a6f | 2012-06-06 18:16:37 -0700 | [diff] [blame] | 289 | size_t page_aligned_byte_count = RoundUp(byte_count, kPageSize); |
Elliott Hughes | 6c9c06d | 2011-11-07 16:43:47 -0800 | [diff] [blame] | 290 | |
Elliott Hughes | 6c9c06d | 2011-11-07 16:43:47 -0800 | [diff] [blame] | 291 | int flags = MAP_PRIVATE | MAP_ANONYMOUS; |
Vladimir Marko | 5c42c29 | 2015-02-25 12:02:49 +0000 | [diff] [blame] | 292 | if (reuse) { |
| 293 | // reuse means it is okay that it overlaps an existing page mapping. |
| 294 | // Only use this if you actually made the page reservation yourself. |
| 295 | CHECK(expected_ptr != nullptr); |
| 296 | |
Vladimir Marko | b550582 | 2015-05-08 11:10:16 +0100 | [diff] [blame] | 297 | DCHECK(ContainedWithinExistingMap(expected_ptr, byte_count, error_msg)) << *error_msg; |
Vladimir Marko | 5c42c29 | 2015-02-25 12:02:49 +0000 | [diff] [blame] | 298 | flags |= MAP_FIXED; |
| 299 | } |
| 300 | |
Andreas Gampe | 43e10b0 | 2016-07-15 17:17:34 -0700 | [diff] [blame] | 301 | File fd; |
Ian Rogers | 997f0f9 | 2014-06-21 22:58:05 -0700 | [diff] [blame] | 302 | |
Nicolas Geoffray | a25dce9 | 2016-01-12 16:41:10 +0000 | [diff] [blame] | 303 | if (use_ashmem) { |
| 304 | if (!kIsTargetBuild) { |
Bilyan Borisov | 3071f80 | 2016-03-31 17:15:53 +0100 | [diff] [blame] | 305 | // When not on Android (either host or assuming a linux target) ashmem is faked using |
| 306 | // files in /tmp. Ensure that such files won't fail due to ulimit restrictions. If they |
| 307 | // will then use a regular mmap. |
Nicolas Geoffray | a25dce9 | 2016-01-12 16:41:10 +0000 | [diff] [blame] | 308 | struct rlimit rlimit_fsize; |
| 309 | CHECK_EQ(getrlimit(RLIMIT_FSIZE, &rlimit_fsize), 0); |
| 310 | use_ashmem = (rlimit_fsize.rlim_cur == RLIM_INFINITY) || |
| 311 | (page_aligned_byte_count < rlimit_fsize.rlim_cur); |
| 312 | } |
| 313 | } |
| 314 | |
Ian Rogers | 997f0f9 | 2014-06-21 22:58:05 -0700 | [diff] [blame] | 315 | if (use_ashmem) { |
| 316 | // android_os_Debug.cpp read_mapinfo assumes all ashmem regions associated with the VM are |
| 317 | // prefixed "dalvik-". |
| 318 | std::string debug_friendly_name("dalvik-"); |
| 319 | debug_friendly_name += name; |
Andreas Gampe | 43e10b0 | 2016-07-15 17:17:34 -0700 | [diff] [blame] | 320 | fd.Reset(ashmem_create_region(debug_friendly_name.c_str(), page_aligned_byte_count), |
| 321 | /* check_usage */ false); |
Richard Uhler | a5c61bf | 2016-10-24 15:54:44 +0100 | [diff] [blame] | 322 | |
Andreas Gampe | 43e10b0 | 2016-07-15 17:17:34 -0700 | [diff] [blame] | 323 | if (fd.Fd() == -1) { |
Richard Uhler | a5c61bf | 2016-10-24 15:54:44 +0100 | [diff] [blame] | 324 | // We failed to create the ashmem region. Print a warning, but continue |
| 325 | // anyway by creating a true anonymous mmap with an fd of -1. It is |
| 326 | // better to use an unlabelled anonymous map than to fail to create a |
| 327 | // map at all. |
| 328 | PLOG(WARNING) << "ashmem_create_region failed for '" << name << "'"; |
| 329 | } else { |
| 330 | // We succeeded in creating the ashmem region. Use the created ashmem |
| 331 | // region as backing for the mmap. |
| 332 | flags &= ~MAP_ANONYMOUS; |
Ian Rogers | 997f0f9 | 2014-06-21 22:58:05 -0700 | [diff] [blame] | 333 | } |
Ian Rogers | 997f0f9 | 2014-06-21 22:58:05 -0700 | [diff] [blame] | 334 | } |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 335 | |
Brian Carlstrom | aa94cf3 | 2014-03-23 23:47:25 -0700 | [diff] [blame] | 336 | // We need to store and potentially set an error number for pretty printing of errors |
| 337 | int saved_errno = 0; |
| 338 | |
Mathieu Chartier | 42bddce | 2015-11-09 15:16:56 -0800 | [diff] [blame] | 339 | void* actual = MapInternal(expected_ptr, |
| 340 | page_aligned_byte_count, |
| 341 | prot, |
| 342 | flags, |
Andreas Gampe | 43e10b0 | 2016-07-15 17:17:34 -0700 | [diff] [blame] | 343 | fd.Fd(), |
Mathieu Chartier | 42bddce | 2015-11-09 15:16:56 -0800 | [diff] [blame] | 344 | 0, |
| 345 | low_4gb); |
Brian Carlstrom | aa94cf3 | 2014-03-23 23:47:25 -0700 | [diff] [blame] | 346 | saved_errno = errno; |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 347 | |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 348 | if (actual == MAP_FAILED) { |
Mathieu Chartier | 83723ae | 2016-02-24 10:09:23 -0800 | [diff] [blame] | 349 | if (error_msg != nullptr) { |
Andreas Gampe | 7fa5578 | 2016-06-15 17:45:01 -0700 | [diff] [blame] | 350 | if (kIsDebugBuild || VLOG_IS_ON(oat)) { |
| 351 | PrintFileToLog("/proc/self/maps", LogSeverity::WARNING); |
| 352 | } |
Brian Carlstrom | aa94cf3 | 2014-03-23 23:47:25 -0700 | [diff] [blame] | 353 | |
Mathieu Chartier | 83723ae | 2016-02-24 10:09:23 -0800 | [diff] [blame] | 354 | *error_msg = StringPrintf("Failed anonymous mmap(%p, %zd, 0x%x, 0x%x, %d, 0): %s. " |
| 355 | "See process maps in the log.", |
| 356 | expected_ptr, |
| 357 | page_aligned_byte_count, |
| 358 | prot, |
| 359 | flags, |
Andreas Gampe | 43e10b0 | 2016-07-15 17:17:34 -0700 | [diff] [blame] | 360 | fd.Fd(), |
Mathieu Chartier | 83723ae | 2016-02-24 10:09:23 -0800 | [diff] [blame] | 361 | strerror(saved_errno)); |
| 362 | } |
Ian Rogers | 8d31bbd | 2013-10-13 10:44:14 -0700 | [diff] [blame] | 363 | return nullptr; |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 364 | } |
Jim_Guo | a62a588 | 2014-04-28 11:11:57 +0800 | [diff] [blame] | 365 | if (!CheckMapRequest(expected_ptr, actual, page_aligned_byte_count, error_msg)) { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 366 | return nullptr; |
| 367 | } |
Ian Rogers | 1373595 | 2014-10-08 12:43:28 -0700 | [diff] [blame] | 368 | return new MemMap(name, reinterpret_cast<uint8_t*>(actual), byte_count, actual, |
Mathieu Chartier | 01d4b50 | 2015-06-12 17:32:31 -0700 | [diff] [blame] | 369 | page_aligned_byte_count, prot, reuse); |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 370 | } |
| 371 | |
David Srbecky | 1baabf0 | 2015-06-16 17:12:34 +0000 | [diff] [blame] | 372 | MemMap* MemMap::MapDummy(const char* name, uint8_t* addr, size_t byte_count) { |
| 373 | if (byte_count == 0) { |
| 374 | return new MemMap(name, nullptr, 0, nullptr, 0, 0, false); |
| 375 | } |
| 376 | const size_t page_aligned_byte_count = RoundUp(byte_count, kPageSize); |
| 377 | return new MemMap(name, addr, byte_count, addr, page_aligned_byte_count, 0, true /* reuse */); |
| 378 | } |
| 379 | |
Mathieu Chartier | 42bddce | 2015-11-09 15:16:56 -0800 | [diff] [blame] | 380 | MemMap* MemMap::MapFileAtAddress(uint8_t* expected_ptr, |
| 381 | size_t byte_count, |
| 382 | int prot, |
| 383 | int flags, |
| 384 | int fd, |
| 385 | off_t start, |
| 386 | bool low_4gb, |
| 387 | bool reuse, |
| 388 | const char* filename, |
Ian Rogers | 8d31bbd | 2013-10-13 10:44:14 -0700 | [diff] [blame] | 389 | std::string* error_msg) { |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 390 | CHECK_NE(0, prot); |
| 391 | CHECK_NE(0, flags & (MAP_SHARED | MAP_PRIVATE)); |
Narayan Kamath | b89c3da | 2014-08-21 17:38:09 +0100 | [diff] [blame] | 392 | |
| 393 | // Note that we do not allow MAP_FIXED unless reuse == true, i.e we |
| 394 | // expect his mapping to be contained within an existing map. |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 395 | if (reuse) { |
| 396 | // reuse means it is okay that it overlaps an existing page mapping. |
| 397 | // Only use this if you actually made the page reservation yourself. |
Jim_Guo | a62a588 | 2014-04-28 11:11:57 +0800 | [diff] [blame] | 398 | CHECK(expected_ptr != nullptr); |
Narayan Kamath | b89c3da | 2014-08-21 17:38:09 +0100 | [diff] [blame] | 399 | |
Mathieu Chartier | ebe2dfc | 2015-11-24 13:47:52 -0800 | [diff] [blame] | 400 | DCHECK(ContainedWithinExistingMap(expected_ptr, byte_count, error_msg)) |
| 401 | << ((error_msg != nullptr) ? *error_msg : std::string()); |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 402 | flags |= MAP_FIXED; |
| 403 | } else { |
| 404 | CHECK_EQ(0, flags & MAP_FIXED); |
Narayan Kamath | b89c3da | 2014-08-21 17:38:09 +0100 | [diff] [blame] | 405 | // Don't bother checking for an overlapping region here. We'll |
| 406 | // check this if required after the fact inside CheckMapRequest. |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 407 | } |
| 408 | |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 409 | if (byte_count == 0) { |
Jim_Guo | a62a588 | 2014-04-28 11:11:57 +0800 | [diff] [blame] | 410 | return new MemMap(filename, nullptr, 0, nullptr, 0, prot, false); |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 411 | } |
Ian Rogers | f8adc60 | 2013-04-18 17:06:19 -0700 | [diff] [blame] | 412 | // Adjust 'offset' to be page-aligned as required by mmap. |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 413 | int page_offset = start % kPageSize; |
| 414 | off_t page_aligned_offset = start - page_offset; |
Ian Rogers | f8adc60 | 2013-04-18 17:06:19 -0700 | [diff] [blame] | 415 | // Adjust 'byte_count' to be page-aligned as we will map this anyway. |
Elliott Hughes | ecd3a6f | 2012-06-06 18:16:37 -0700 | [diff] [blame] | 416 | size_t page_aligned_byte_count = RoundUp(byte_count + page_offset, kPageSize); |
Jim_Guo | a62a588 | 2014-04-28 11:11:57 +0800 | [diff] [blame] | 417 | // The 'expected_ptr' is modified (if specified, ie non-null) to be page aligned to the file but |
| 418 | // not necessarily to virtual memory. mmap will page align 'expected' for us. |
Mathieu Chartier | 2cebb24 | 2015-04-21 16:50:40 -0700 | [diff] [blame] | 419 | uint8_t* page_aligned_expected = |
| 420 | (expected_ptr == nullptr) ? nullptr : (expected_ptr - page_offset); |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 421 | |
Evgenii Stepanov | 1e13374 | 2015-05-20 12:30:59 -0700 | [diff] [blame] | 422 | size_t redzone_size = 0; |
| 423 | if (RUNNING_ON_MEMORY_TOOL && kMemoryToolAddsRedzones && expected_ptr == nullptr) { |
| 424 | redzone_size = kPageSize; |
| 425 | page_aligned_byte_count += redzone_size; |
| 426 | } |
| 427 | |
Mathieu Chartier | 42bddce | 2015-11-09 15:16:56 -0800 | [diff] [blame] | 428 | uint8_t* actual = reinterpret_cast<uint8_t*>(MapInternal(page_aligned_expected, |
| 429 | page_aligned_byte_count, |
| 430 | prot, |
| 431 | flags, |
| 432 | fd, |
| 433 | page_aligned_offset, |
| 434 | low_4gb)); |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 435 | if (actual == MAP_FAILED) { |
Mathieu Chartier | ebe2dfc | 2015-11-24 13:47:52 -0800 | [diff] [blame] | 436 | if (error_msg != nullptr) { |
| 437 | auto saved_errno = errno; |
Brian Carlstrom | aa94cf3 | 2014-03-23 23:47:25 -0700 | [diff] [blame] | 438 | |
Andreas Gampe | 7ec0904 | 2016-04-01 17:20:49 -0700 | [diff] [blame] | 439 | if (kIsDebugBuild || VLOG_IS_ON(oat)) { |
| 440 | PrintFileToLog("/proc/self/maps", LogSeverity::WARNING); |
| 441 | } |
Brian Carlstrom | aa94cf3 | 2014-03-23 23:47:25 -0700 | [diff] [blame] | 442 | |
Mathieu Chartier | ebe2dfc | 2015-11-24 13:47:52 -0800 | [diff] [blame] | 443 | *error_msg = StringPrintf("mmap(%p, %zd, 0x%x, 0x%x, %d, %" PRId64 |
| 444 | ") of file '%s' failed: %s. See process maps in the log.", |
| 445 | page_aligned_expected, page_aligned_byte_count, prot, flags, fd, |
| 446 | static_cast<int64_t>(page_aligned_offset), filename, |
| 447 | strerror(saved_errno)); |
| 448 | } |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 449 | return nullptr; |
| 450 | } |
Jim_Guo | a62a588 | 2014-04-28 11:11:57 +0800 | [diff] [blame] | 451 | if (!CheckMapRequest(expected_ptr, actual, page_aligned_byte_count, error_msg)) { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 452 | return nullptr; |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 453 | } |
Evgenii Stepanov | 1e13374 | 2015-05-20 12:30:59 -0700 | [diff] [blame] | 454 | if (redzone_size != 0) { |
| 455 | const uint8_t *real_start = actual + page_offset; |
| 456 | const uint8_t *real_end = actual + page_offset + byte_count; |
| 457 | const uint8_t *mapping_end = actual + page_aligned_byte_count; |
| 458 | |
| 459 | MEMORY_TOOL_MAKE_NOACCESS(actual, real_start - actual); |
| 460 | MEMORY_TOOL_MAKE_NOACCESS(real_end, mapping_end - real_end); |
| 461 | page_aligned_byte_count -= redzone_size; |
| 462 | } |
| 463 | |
Brian Carlstrom | 0d6adac | 2014-02-05 17:39:16 -0800 | [diff] [blame] | 464 | return new MemMap(filename, actual + page_offset, byte_count, actual, page_aligned_byte_count, |
Evgenii Stepanov | 1e13374 | 2015-05-20 12:30:59 -0700 | [diff] [blame] | 465 | prot, reuse, redzone_size); |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 466 | } |
| 467 | |
| 468 | MemMap::~MemMap() { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 469 | if (base_begin_ == nullptr && base_size_ == 0) { |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 470 | return; |
| 471 | } |
Evgenii Stepanov | 1e13374 | 2015-05-20 12:30:59 -0700 | [diff] [blame] | 472 | |
| 473 | // Unlike Valgrind, AddressSanitizer requires that all manually poisoned memory is unpoisoned |
| 474 | // before it is returned to the system. |
| 475 | if (redzone_size_ != 0) { |
| 476 | MEMORY_TOOL_MAKE_UNDEFINED( |
| 477 | reinterpret_cast<char*>(base_begin_) + base_size_ - redzone_size_, |
| 478 | redzone_size_); |
| 479 | } |
| 480 | |
Jim_Guo | a62a588 | 2014-04-28 11:11:57 +0800 | [diff] [blame] | 481 | if (!reuse_) { |
Evgenii Stepanov | 1e13374 | 2015-05-20 12:30:59 -0700 | [diff] [blame] | 482 | MEMORY_TOOL_MAKE_UNDEFINED(base_begin_, base_size_); |
Jim_Guo | a62a588 | 2014-04-28 11:11:57 +0800 | [diff] [blame] | 483 | int result = munmap(base_begin_, base_size_); |
| 484 | if (result == -1) { |
| 485 | PLOG(FATAL) << "munmap failed"; |
| 486 | } |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 487 | } |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 488 | |
| 489 | // Remove it from maps_. |
| 490 | MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_); |
| 491 | bool found = false; |
Mathieu Chartier | 6e88ef6 | 2014-10-14 15:01:24 -0700 | [diff] [blame] | 492 | DCHECK(maps_ != nullptr); |
| 493 | for (auto it = maps_->lower_bound(base_begin_), end = maps_->end(); |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 494 | it != end && it->first == base_begin_; ++it) { |
| 495 | if (it->second == this) { |
| 496 | found = true; |
Mathieu Chartier | 6e88ef6 | 2014-10-14 15:01:24 -0700 | [diff] [blame] | 497 | maps_->erase(it); |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 498 | break; |
| 499 | } |
| 500 | } |
| 501 | CHECK(found) << "MemMap not found"; |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 502 | } |
| 503 | |
Ian Rogers | 1373595 | 2014-10-08 12:43:28 -0700 | [diff] [blame] | 504 | MemMap::MemMap(const std::string& name, uint8_t* begin, size_t size, void* base_begin, |
Evgenii Stepanov | 1e13374 | 2015-05-20 12:30:59 -0700 | [diff] [blame] | 505 | size_t base_size, int prot, bool reuse, size_t redzone_size) |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame] | 506 | : name_(name), begin_(begin), size_(size), base_begin_(base_begin), base_size_(base_size), |
Evgenii Stepanov | 1e13374 | 2015-05-20 12:30:59 -0700 | [diff] [blame] | 507 | prot_(prot), reuse_(reuse), redzone_size_(redzone_size) { |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 508 | if (size_ == 0) { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 509 | CHECK(begin_ == nullptr); |
| 510 | CHECK(base_begin_ == nullptr); |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 511 | CHECK_EQ(base_size_, 0U); |
| 512 | } else { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 513 | CHECK(begin_ != nullptr); |
| 514 | CHECK(base_begin_ != nullptr); |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 515 | CHECK_NE(base_size_, 0U); |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 516 | |
| 517 | // Add it to maps_. |
| 518 | MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_); |
Mathieu Chartier | 6e88ef6 | 2014-10-14 15:01:24 -0700 | [diff] [blame] | 519 | DCHECK(maps_ != nullptr); |
| 520 | maps_->insert(std::make_pair(base_begin_, this)); |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 521 | } |
Andreas Gampe | c8ccf68 | 2014-09-29 20:07:43 -0700 | [diff] [blame] | 522 | } |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 523 | |
Ian Rogers | 1373595 | 2014-10-08 12:43:28 -0700 | [diff] [blame] | 524 | MemMap* MemMap::RemapAtEnd(uint8_t* new_end, const char* tail_name, int tail_prot, |
Nicolas Geoffray | a25dce9 | 2016-01-12 16:41:10 +0000 | [diff] [blame] | 525 | std::string* error_msg, bool use_ashmem) { |
Nicolas Geoffray | 58a73d2 | 2016-11-29 21:49:43 +0000 | [diff] [blame] | 526 | use_ashmem = use_ashmem && !kIsTargetLinux; |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 527 | DCHECK_GE(new_end, Begin()); |
| 528 | DCHECK_LE(new_end, End()); |
Ian Rogers | 1373595 | 2014-10-08 12:43:28 -0700 | [diff] [blame] | 529 | DCHECK_LE(begin_ + size_, reinterpret_cast<uint8_t*>(base_begin_) + base_size_); |
Roland Levillain | 14d9057 | 2015-07-16 10:52:26 +0100 | [diff] [blame] | 530 | DCHECK_ALIGNED(begin_, kPageSize); |
| 531 | DCHECK_ALIGNED(base_begin_, kPageSize); |
| 532 | DCHECK_ALIGNED(reinterpret_cast<uint8_t*>(base_begin_) + base_size_, kPageSize); |
| 533 | DCHECK_ALIGNED(new_end, kPageSize); |
Ian Rogers | 1373595 | 2014-10-08 12:43:28 -0700 | [diff] [blame] | 534 | uint8_t* old_end = begin_ + size_; |
| 535 | uint8_t* old_base_end = reinterpret_cast<uint8_t*>(base_begin_) + base_size_; |
| 536 | uint8_t* new_base_end = new_end; |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 537 | DCHECK_LE(new_base_end, old_base_end); |
| 538 | if (new_base_end == old_base_end) { |
Jim_Guo | a62a588 | 2014-04-28 11:11:57 +0800 | [diff] [blame] | 539 | return new MemMap(tail_name, nullptr, 0, nullptr, 0, tail_prot, false); |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 540 | } |
Ian Rogers | 1373595 | 2014-10-08 12:43:28 -0700 | [diff] [blame] | 541 | size_ = new_end - reinterpret_cast<uint8_t*>(begin_); |
| 542 | base_size_ = new_base_end - reinterpret_cast<uint8_t*>(base_begin_); |
| 543 | DCHECK_LE(begin_ + size_, reinterpret_cast<uint8_t*>(base_begin_) + base_size_); |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 544 | size_t tail_size = old_end - new_end; |
Ian Rogers | 1373595 | 2014-10-08 12:43:28 -0700 | [diff] [blame] | 545 | uint8_t* tail_base_begin = new_base_end; |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 546 | size_t tail_base_size = old_base_end - new_base_end; |
| 547 | DCHECK_EQ(tail_base_begin + tail_base_size, old_base_end); |
Roland Levillain | 14d9057 | 2015-07-16 10:52:26 +0100 | [diff] [blame] | 548 | DCHECK_ALIGNED(tail_base_size, kPageSize); |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 549 | |
Nicolas Geoffray | a25dce9 | 2016-01-12 16:41:10 +0000 | [diff] [blame] | 550 | int int_fd = -1; |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 551 | int flags = MAP_PRIVATE | MAP_ANONYMOUS; |
Nicolas Geoffray | a25dce9 | 2016-01-12 16:41:10 +0000 | [diff] [blame] | 552 | if (use_ashmem) { |
| 553 | // android_os_Debug.cpp read_mapinfo assumes all ashmem regions associated with the VM are |
| 554 | // prefixed "dalvik-". |
| 555 | std::string debug_friendly_name("dalvik-"); |
| 556 | debug_friendly_name += tail_name; |
| 557 | int_fd = ashmem_create_region(debug_friendly_name.c_str(), tail_base_size); |
| 558 | flags = MAP_PRIVATE | MAP_FIXED; |
| 559 | if (int_fd == -1) { |
| 560 | *error_msg = StringPrintf("ashmem_create_region failed for '%s': %s", |
| 561 | tail_name, strerror(errno)); |
| 562 | return nullptr; |
| 563 | } |
| 564 | } |
Andreas Gampe | 43e10b0 | 2016-07-15 17:17:34 -0700 | [diff] [blame] | 565 | File fd(int_fd, /* check_usage */ false); |
Evgenii Stepanov | 1e13374 | 2015-05-20 12:30:59 -0700 | [diff] [blame] | 566 | |
| 567 | MEMORY_TOOL_MAKE_UNDEFINED(tail_base_begin, tail_base_size); |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 568 | // Unmap/map the tail region. |
| 569 | int result = munmap(tail_base_begin, tail_base_size); |
| 570 | if (result == -1) { |
Andreas Gampe | a6dfdae | 2015-02-24 15:50:19 -0800 | [diff] [blame] | 571 | PrintFileToLog("/proc/self/maps", LogSeverity::WARNING); |
| 572 | *error_msg = StringPrintf("munmap(%p, %zd) failed for '%s'. See process maps in the log.", |
| 573 | tail_base_begin, tail_base_size, name_.c_str()); |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 574 | return nullptr; |
| 575 | } |
| 576 | // Don't cause memory allocation between the munmap and the mmap |
| 577 | // calls. Otherwise, libc (or something else) might take this memory |
| 578 | // region. Note this isn't perfect as there's no way to prevent |
| 579 | // other threads to try to take this memory region here. |
Ian Rogers | 1373595 | 2014-10-08 12:43:28 -0700 | [diff] [blame] | 580 | uint8_t* actual = reinterpret_cast<uint8_t*>(mmap(tail_base_begin, tail_base_size, tail_prot, |
Andreas Gampe | 43e10b0 | 2016-07-15 17:17:34 -0700 | [diff] [blame] | 581 | flags, fd.Fd(), 0)); |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 582 | if (actual == MAP_FAILED) { |
Andreas Gampe | a6dfdae | 2015-02-24 15:50:19 -0800 | [diff] [blame] | 583 | PrintFileToLog("/proc/self/maps", LogSeverity::WARNING); |
| 584 | *error_msg = StringPrintf("anonymous mmap(%p, %zd, 0x%x, 0x%x, %d, 0) failed. See process " |
| 585 | "maps in the log.", tail_base_begin, tail_base_size, tail_prot, flags, |
Andreas Gampe | 43e10b0 | 2016-07-15 17:17:34 -0700 | [diff] [blame] | 586 | fd.Fd()); |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 587 | return nullptr; |
| 588 | } |
Jim_Guo | a62a588 | 2014-04-28 11:11:57 +0800 | [diff] [blame] | 589 | return new MemMap(tail_name, actual, tail_size, actual, tail_base_size, tail_prot, false); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 590 | } |
Logan Chien | d88fa26 | 2012-06-06 15:23:32 +0800 | [diff] [blame] | 591 | |
Ian Rogers | c5f1773 | 2014-06-05 20:48:42 -0700 | [diff] [blame] | 592 | void MemMap::MadviseDontNeedAndZero() { |
| 593 | if (base_begin_ != nullptr || base_size_ != 0) { |
| 594 | if (!kMadviseZeroes) { |
| 595 | memset(base_begin_, 0, base_size_); |
| 596 | } |
| 597 | int result = madvise(base_begin_, base_size_, MADV_DONTNEED); |
| 598 | if (result == -1) { |
| 599 | PLOG(WARNING) << "madvise failed"; |
| 600 | } |
| 601 | } |
| 602 | } |
| 603 | |
Vladimir Marko | 9bdf108 | 2016-01-21 12:15:52 +0000 | [diff] [blame] | 604 | bool MemMap::Sync() { |
Hiroshi Yamauchi | 29ab360 | 2016-03-08 15:17:21 -0800 | [diff] [blame] | 605 | bool result; |
| 606 | if (redzone_size_ != 0) { |
| 607 | // To avoid valgrind errors, temporarily lift the lower-end noaccess protection before passing |
| 608 | // it to msync() as it only accepts page-aligned base address, and exclude the higher-end |
| 609 | // noaccess protection from the msync range. b/27552451. |
| 610 | uint8_t* base_begin = reinterpret_cast<uint8_t*>(base_begin_); |
| 611 | MEMORY_TOOL_MAKE_DEFINED(base_begin, begin_ - base_begin); |
| 612 | result = msync(BaseBegin(), End() - base_begin, MS_SYNC) == 0; |
| 613 | MEMORY_TOOL_MAKE_NOACCESS(base_begin, begin_ - base_begin); |
| 614 | } else { |
| 615 | result = msync(BaseBegin(), BaseSize(), MS_SYNC) == 0; |
| 616 | } |
| 617 | return result; |
Vladimir Marko | 9bdf108 | 2016-01-21 12:15:52 +0000 | [diff] [blame] | 618 | } |
| 619 | |
Logan Chien | d88fa26 | 2012-06-06 15:23:32 +0800 | [diff] [blame] | 620 | bool MemMap::Protect(int prot) { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 621 | if (base_begin_ == nullptr && base_size_ == 0) { |
Ian Rogers | 1c849e5 | 2012-06-28 14:00:33 -0700 | [diff] [blame] | 622 | prot_ = prot; |
Logan Chien | d88fa26 | 2012-06-06 15:23:32 +0800 | [diff] [blame] | 623 | return true; |
| 624 | } |
| 625 | |
| 626 | if (mprotect(base_begin_, base_size_, prot) == 0) { |
Ian Rogers | 1c849e5 | 2012-06-28 14:00:33 -0700 | [diff] [blame] | 627 | prot_ = prot; |
Logan Chien | d88fa26 | 2012-06-06 15:23:32 +0800 | [diff] [blame] | 628 | return true; |
| 629 | } |
| 630 | |
Shih-wei Liao | a060ed9 | 2012-06-07 09:25:28 -0700 | [diff] [blame] | 631 | PLOG(ERROR) << "mprotect(" << reinterpret_cast<void*>(base_begin_) << ", " << base_size_ << ", " |
| 632 | << prot << ") failed"; |
Logan Chien | d88fa26 | 2012-06-06 15:23:32 +0800 | [diff] [blame] | 633 | return false; |
| 634 | } |
| 635 | |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 636 | bool MemMap::CheckNoGaps(MemMap* begin_map, MemMap* end_map) { |
| 637 | MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_); |
| 638 | CHECK(begin_map != nullptr); |
| 639 | CHECK(end_map != nullptr); |
| 640 | CHECK(HasMemMap(begin_map)); |
| 641 | CHECK(HasMemMap(end_map)); |
| 642 | CHECK_LE(begin_map->BaseBegin(), end_map->BaseBegin()); |
| 643 | MemMap* map = begin_map; |
| 644 | while (map->BaseBegin() != end_map->BaseBegin()) { |
| 645 | MemMap* next_map = GetLargestMemMapAt(map->BaseEnd()); |
| 646 | if (next_map == nullptr) { |
| 647 | // Found a gap. |
| 648 | return false; |
| 649 | } |
| 650 | map = next_map; |
| 651 | } |
| 652 | return true; |
| 653 | } |
| 654 | |
Vladimir Marko | 17a924a | 2015-05-08 15:17:32 +0100 | [diff] [blame] | 655 | void MemMap::DumpMaps(std::ostream& os, bool terse) { |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 656 | MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_); |
Vladimir Marko | 17a924a | 2015-05-08 15:17:32 +0100 | [diff] [blame] | 657 | DumpMapsLocked(os, terse); |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 658 | } |
| 659 | |
Vladimir Marko | 17a924a | 2015-05-08 15:17:32 +0100 | [diff] [blame] | 660 | void MemMap::DumpMapsLocked(std::ostream& os, bool terse) { |
| 661 | const auto& mem_maps = *maps_; |
| 662 | if (!terse) { |
| 663 | os << mem_maps; |
| 664 | return; |
| 665 | } |
| 666 | |
| 667 | // Terse output example: |
| 668 | // [MemMap: 0x409be000+0x20P~0x11dP+0x20P~0x61cP+0x20P prot=0x3 LinearAlloc] |
| 669 | // [MemMap: 0x451d6000+0x6bP(3) prot=0x3 large object space allocation] |
| 670 | // The details: |
| 671 | // "+0x20P" means 0x20 pages taken by a single mapping, |
| 672 | // "~0x11dP" means a gap of 0x11d pages, |
| 673 | // "+0x6bP(3)" means 3 mappings one after another, together taking 0x6b pages. |
| 674 | os << "MemMap:" << std::endl; |
| 675 | for (auto it = mem_maps.begin(), maps_end = mem_maps.end(); it != maps_end;) { |
| 676 | MemMap* map = it->second; |
| 677 | void* base = it->first; |
| 678 | CHECK_EQ(base, map->BaseBegin()); |
| 679 | os << "[MemMap: " << base; |
| 680 | ++it; |
| 681 | // Merge consecutive maps with the same protect flags and name. |
| 682 | constexpr size_t kMaxGaps = 9; |
| 683 | size_t num_gaps = 0; |
| 684 | size_t num = 1u; |
| 685 | size_t size = map->BaseSize(); |
Roland Levillain | 14d9057 | 2015-07-16 10:52:26 +0100 | [diff] [blame] | 686 | CHECK_ALIGNED(size, kPageSize); |
Vladimir Marko | 17a924a | 2015-05-08 15:17:32 +0100 | [diff] [blame] | 687 | void* end = map->BaseEnd(); |
| 688 | while (it != maps_end && |
| 689 | it->second->GetProtect() == map->GetProtect() && |
| 690 | it->second->GetName() == map->GetName() && |
| 691 | (it->second->BaseBegin() == end || num_gaps < kMaxGaps)) { |
| 692 | if (it->second->BaseBegin() != end) { |
| 693 | ++num_gaps; |
| 694 | os << "+0x" << std::hex << (size / kPageSize) << "P"; |
| 695 | if (num != 1u) { |
| 696 | os << "(" << std::dec << num << ")"; |
| 697 | } |
| 698 | size_t gap = |
| 699 | reinterpret_cast<uintptr_t>(it->second->BaseBegin()) - reinterpret_cast<uintptr_t>(end); |
Roland Levillain | 14d9057 | 2015-07-16 10:52:26 +0100 | [diff] [blame] | 700 | CHECK_ALIGNED(gap, kPageSize); |
Vladimir Marko | 17a924a | 2015-05-08 15:17:32 +0100 | [diff] [blame] | 701 | os << "~0x" << std::hex << (gap / kPageSize) << "P"; |
| 702 | num = 0u; |
| 703 | size = 0u; |
| 704 | } |
Roland Levillain | 14d9057 | 2015-07-16 10:52:26 +0100 | [diff] [blame] | 705 | CHECK_ALIGNED(it->second->BaseSize(), kPageSize); |
Vladimir Marko | 17a924a | 2015-05-08 15:17:32 +0100 | [diff] [blame] | 706 | ++num; |
| 707 | size += it->second->BaseSize(); |
| 708 | end = it->second->BaseEnd(); |
| 709 | ++it; |
| 710 | } |
| 711 | os << "+0x" << std::hex << (size / kPageSize) << "P"; |
| 712 | if (num != 1u) { |
| 713 | os << "(" << std::dec << num << ")"; |
| 714 | } |
| 715 | os << " prot=0x" << std::hex << map->GetProtect() << " " << map->GetName() << "]" << std::endl; |
| 716 | } |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 717 | } |
| 718 | |
| 719 | bool MemMap::HasMemMap(MemMap* map) { |
| 720 | void* base_begin = map->BaseBegin(); |
Mathieu Chartier | 6e88ef6 | 2014-10-14 15:01:24 -0700 | [diff] [blame] | 721 | for (auto it = maps_->lower_bound(base_begin), end = maps_->end(); |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 722 | it != end && it->first == base_begin; ++it) { |
| 723 | if (it->second == map) { |
| 724 | return true; |
| 725 | } |
| 726 | } |
| 727 | return false; |
| 728 | } |
| 729 | |
| 730 | MemMap* MemMap::GetLargestMemMapAt(void* address) { |
| 731 | size_t largest_size = 0; |
| 732 | MemMap* largest_map = nullptr; |
Mathieu Chartier | 6e88ef6 | 2014-10-14 15:01:24 -0700 | [diff] [blame] | 733 | DCHECK(maps_ != nullptr); |
| 734 | for (auto it = maps_->lower_bound(address), end = maps_->end(); |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 735 | it != end && it->first == address; ++it) { |
| 736 | MemMap* map = it->second; |
| 737 | CHECK(map != nullptr); |
| 738 | if (largest_size < map->BaseSize()) { |
| 739 | largest_size = map->BaseSize(); |
| 740 | largest_map = map; |
| 741 | } |
| 742 | } |
| 743 | return largest_map; |
| 744 | } |
| 745 | |
Mathieu Chartier | 6e88ef6 | 2014-10-14 15:01:24 -0700 | [diff] [blame] | 746 | void MemMap::Init() { |
| 747 | MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_); |
| 748 | if (maps_ == nullptr) { |
| 749 | // dex2oat calls MemMap::Init twice since its needed before the runtime is created. |
| 750 | maps_ = new Maps; |
| 751 | } |
| 752 | } |
| 753 | |
| 754 | void MemMap::Shutdown() { |
| 755 | MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_); |
| 756 | delete maps_; |
| 757 | maps_ = nullptr; |
| 758 | } |
| 759 | |
Mathieu Chartier | 379d09f | 2015-01-08 11:28:13 -0800 | [diff] [blame] | 760 | void MemMap::SetSize(size_t new_size) { |
| 761 | if (new_size == base_size_) { |
| 762 | return; |
| 763 | } |
| 764 | CHECK_ALIGNED(new_size, kPageSize); |
| 765 | CHECK_EQ(base_size_, size_) << "Unsupported"; |
| 766 | CHECK_LE(new_size, base_size_); |
Evgenii Stepanov | 1e13374 | 2015-05-20 12:30:59 -0700 | [diff] [blame] | 767 | MEMORY_TOOL_MAKE_UNDEFINED( |
| 768 | reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(BaseBegin()) + |
| 769 | new_size), |
| 770 | base_size_ - new_size); |
Mathieu Chartier | 379d09f | 2015-01-08 11:28:13 -0800 | [diff] [blame] | 771 | CHECK_EQ(munmap(reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(BaseBegin()) + new_size), |
| 772 | base_size_ - new_size), 0) << new_size << " " << base_size_; |
| 773 | base_size_ = new_size; |
| 774 | size_ = new_size; |
| 775 | } |
| 776 | |
Mathieu Chartier | 42bddce | 2015-11-09 15:16:56 -0800 | [diff] [blame] | 777 | void* MemMap::MapInternal(void* addr, |
| 778 | size_t length, |
| 779 | int prot, |
| 780 | int flags, |
| 781 | int fd, |
| 782 | off_t offset, |
| 783 | bool low_4gb) { |
| 784 | #ifdef __LP64__ |
Mathieu Chartier | 42bddce | 2015-11-09 15:16:56 -0800 | [diff] [blame] | 785 | // When requesting low_4g memory and having an expectation, the requested range should fit into |
| 786 | // 4GB. |
| 787 | if (low_4gb && ( |
| 788 | // Start out of bounds. |
| 789 | (reinterpret_cast<uintptr_t>(addr) >> 32) != 0 || |
| 790 | // End out of bounds. For simplicity, this will fail for the last page of memory. |
| 791 | ((reinterpret_cast<uintptr_t>(addr) + length) >> 32) != 0)) { |
| 792 | LOG(ERROR) << "The requested address space (" << addr << ", " |
| 793 | << reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(addr) + length) |
| 794 | << ") cannot fit in low_4gb"; |
| 795 | return MAP_FAILED; |
| 796 | } |
| 797 | #else |
| 798 | UNUSED(low_4gb); |
| 799 | #endif |
| 800 | DCHECK_ALIGNED(length, kPageSize); |
| 801 | if (low_4gb) { |
| 802 | DCHECK_EQ(flags & MAP_FIXED, 0); |
| 803 | } |
| 804 | // TODO: |
| 805 | // A page allocator would be a useful abstraction here, as |
| 806 | // 1) It is doubtful that MAP_32BIT on x86_64 is doing the right job for us |
| 807 | void* actual = MAP_FAILED; |
| 808 | #if USE_ART_LOW_4G_ALLOCATOR |
| 809 | // MAP_32BIT only available on x86_64. |
| 810 | if (low_4gb && addr == nullptr) { |
| 811 | bool first_run = true; |
| 812 | |
| 813 | MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_); |
| 814 | for (uintptr_t ptr = next_mem_pos_; ptr < 4 * GB; ptr += kPageSize) { |
| 815 | // Use maps_ as an optimization to skip over large maps. |
| 816 | // Find the first map which is address > ptr. |
| 817 | auto it = maps_->upper_bound(reinterpret_cast<void*>(ptr)); |
| 818 | if (it != maps_->begin()) { |
| 819 | auto before_it = it; |
| 820 | --before_it; |
| 821 | // Start at the end of the map before the upper bound. |
| 822 | ptr = std::max(ptr, reinterpret_cast<uintptr_t>(before_it->second->BaseEnd())); |
| 823 | CHECK_ALIGNED(ptr, kPageSize); |
| 824 | } |
| 825 | while (it != maps_->end()) { |
| 826 | // How much space do we have until the next map? |
| 827 | size_t delta = reinterpret_cast<uintptr_t>(it->first) - ptr; |
| 828 | // If the space may be sufficient, break out of the loop. |
| 829 | if (delta >= length) { |
| 830 | break; |
| 831 | } |
| 832 | // Otherwise, skip to the end of the map. |
| 833 | ptr = reinterpret_cast<uintptr_t>(it->second->BaseEnd()); |
| 834 | CHECK_ALIGNED(ptr, kPageSize); |
| 835 | ++it; |
| 836 | } |
| 837 | |
| 838 | // Try to see if we get lucky with this address since none of the ART maps overlap. |
| 839 | actual = TryMemMapLow4GB(reinterpret_cast<void*>(ptr), length, prot, flags, fd, offset); |
| 840 | if (actual != MAP_FAILED) { |
| 841 | next_mem_pos_ = reinterpret_cast<uintptr_t>(actual) + length; |
| 842 | return actual; |
| 843 | } |
| 844 | |
| 845 | if (4U * GB - ptr < length) { |
| 846 | // Not enough memory until 4GB. |
| 847 | if (first_run) { |
| 848 | // Try another time from the bottom; |
| 849 | ptr = LOW_MEM_START - kPageSize; |
| 850 | first_run = false; |
| 851 | continue; |
| 852 | } else { |
| 853 | // Second try failed. |
| 854 | break; |
| 855 | } |
| 856 | } |
| 857 | |
| 858 | uintptr_t tail_ptr; |
| 859 | |
| 860 | // Check pages are free. |
| 861 | bool safe = true; |
| 862 | for (tail_ptr = ptr; tail_ptr < ptr + length; tail_ptr += kPageSize) { |
| 863 | if (msync(reinterpret_cast<void*>(tail_ptr), kPageSize, 0) == 0) { |
| 864 | safe = false; |
| 865 | break; |
| 866 | } else { |
| 867 | DCHECK_EQ(errno, ENOMEM); |
| 868 | } |
| 869 | } |
| 870 | |
| 871 | next_mem_pos_ = tail_ptr; // update early, as we break out when we found and mapped a region |
| 872 | |
| 873 | if (safe == true) { |
| 874 | actual = TryMemMapLow4GB(reinterpret_cast<void*>(ptr), length, prot, flags, fd, offset); |
| 875 | if (actual != MAP_FAILED) { |
| 876 | return actual; |
| 877 | } |
| 878 | } else { |
| 879 | // Skip over last page. |
| 880 | ptr = tail_ptr; |
| 881 | } |
| 882 | } |
| 883 | |
| 884 | if (actual == MAP_FAILED) { |
| 885 | LOG(ERROR) << "Could not find contiguous low-memory space."; |
| 886 | errno = ENOMEM; |
| 887 | } |
| 888 | } else { |
| 889 | actual = mmap(addr, length, prot, flags, fd, offset); |
| 890 | } |
| 891 | |
| 892 | #else |
| 893 | #if defined(__LP64__) |
| 894 | if (low_4gb && addr == nullptr) { |
| 895 | flags |= MAP_32BIT; |
| 896 | } |
| 897 | #endif |
| 898 | actual = mmap(addr, length, prot, flags, fd, offset); |
| 899 | #endif |
| 900 | return actual; |
| 901 | } |
| 902 | |
Brian Carlstrom | 0d6adac | 2014-02-05 17:39:16 -0800 | [diff] [blame] | 903 | std::ostream& operator<<(std::ostream& os, const MemMap& mem_map) { |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 904 | os << StringPrintf("[MemMap: %p-%p prot=0x%x %s]", |
| 905 | mem_map.BaseBegin(), mem_map.BaseEnd(), mem_map.GetProtect(), |
| 906 | mem_map.GetName().c_str()); |
Brian Carlstrom | 0d6adac | 2014-02-05 17:39:16 -0800 | [diff] [blame] | 907 | return os; |
| 908 | } |
| 909 | |
Hiroshi Yamauchi | 6edb9ae | 2016-02-08 14:18:21 -0800 | [diff] [blame] | 910 | void MemMap::TryReadable() { |
| 911 | if (base_begin_ == nullptr && base_size_ == 0) { |
| 912 | return; |
| 913 | } |
| 914 | CHECK_NE(prot_ & PROT_READ, 0); |
| 915 | volatile uint8_t* begin = reinterpret_cast<volatile uint8_t*>(base_begin_); |
| 916 | volatile uint8_t* end = begin + base_size_; |
| 917 | DCHECK(IsAligned<kPageSize>(begin)); |
| 918 | DCHECK(IsAligned<kPageSize>(end)); |
| 919 | // Read the first byte of each page. Use volatile to prevent the compiler from optimizing away the |
| 920 | // reads. |
| 921 | for (volatile uint8_t* ptr = begin; ptr < end; ptr += kPageSize) { |
| 922 | // This read could fault if protection wasn't set correctly. |
| 923 | uint8_t value = *ptr; |
| 924 | UNUSED(value); |
| 925 | } |
| 926 | } |
| 927 | |
Mathieu Chartier | 6e6078a | 2016-10-24 15:45:41 -0700 | [diff] [blame] | 928 | void ZeroAndReleasePages(void* address, size_t length) { |
| 929 | uint8_t* const mem_begin = reinterpret_cast<uint8_t*>(address); |
| 930 | uint8_t* const mem_end = mem_begin + length; |
| 931 | uint8_t* const page_begin = AlignUp(mem_begin, kPageSize); |
| 932 | uint8_t* const page_end = AlignDown(mem_end, kPageSize); |
| 933 | if (!kMadviseZeroes || page_begin >= page_end) { |
| 934 | // No possible area to madvise. |
| 935 | std::fill(mem_begin, mem_end, 0); |
| 936 | } else { |
| 937 | // Spans one or more pages. |
| 938 | DCHECK_LE(mem_begin, page_begin); |
| 939 | DCHECK_LE(page_begin, page_end); |
| 940 | DCHECK_LE(page_end, mem_end); |
| 941 | std::fill(mem_begin, page_begin, 0); |
| 942 | CHECK_NE(madvise(page_begin, page_end - page_begin, MADV_DONTNEED), -1) << "madvise failed"; |
| 943 | std::fill(page_end, mem_end, 0); |
| 944 | } |
| 945 | } |
| 946 | |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 947 | } // namespace art |