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" |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 18 | #include "thread-inl.h" |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 19 | |
Ian Rogers | debeb3a | 2014-01-23 16:54:52 -0800 | [diff] [blame] | 20 | #include <inttypes.h> |
Christopher Ferris | 943af7d | 2014-01-16 12:41:46 -0800 | [diff] [blame] | 21 | #include <backtrace/BacktraceMap.h> |
Ian Rogers | 700a402 | 2014-05-19 16:49:03 -0700 | [diff] [blame] | 22 | #include <memory> |
Elliott Hughes | ecd3a6f | 2012-06-06 18:16:37 -0700 | [diff] [blame] | 23 | |
Andreas Gampe | d8f26db | 2014-05-19 17:01:13 -0700 | [diff] [blame] | 24 | // See CreateStartPos below. |
| 25 | #ifdef __BIONIC__ |
| 26 | #include <sys/auxv.h> |
| 27 | #endif |
| 28 | |
Elliott Hughes | e222ee0 | 2012-12-13 14:41:43 -0800 | [diff] [blame] | 29 | #include "base/stringprintf.h" |
| 30 | #include "ScopedFd.h" |
| 31 | #include "utils.h" |
| 32 | |
Elliott Hughes | 6c9c06d | 2011-11-07 16:43:47 -0800 | [diff] [blame] | 33 | #define USE_ASHMEM 1 |
| 34 | |
| 35 | #ifdef USE_ASHMEM |
| 36 | #include <cutils/ashmem.h> |
Ian Rogers | 997f0f9 | 2014-06-21 22:58:05 -0700 | [diff] [blame] | 37 | #ifndef ANDROID_OS |
| 38 | #include <sys/resource.h> |
| 39 | #endif |
Elliott Hughes | 6c9c06d | 2011-11-07 16:43:47 -0800 | [diff] [blame] | 40 | #endif |
| 41 | |
Ian Rogers | d6b6865 | 2014-06-23 14:07:03 -0700 | [diff] [blame] | 42 | #ifndef MAP_ANONYMOUS |
| 43 | #define MAP_ANONYMOUS MAP_ANON |
| 44 | #endif |
| 45 | |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 46 | namespace art { |
| 47 | |
Christopher Ferris | 943af7d | 2014-01-16 12:41:46 -0800 | [diff] [blame] | 48 | static std::ostream& operator<<( |
| 49 | std::ostream& os, |
| 50 | std::pair<BacktraceMap::const_iterator, BacktraceMap::const_iterator> iters) { |
| 51 | for (BacktraceMap::const_iterator it = iters.first; it != iters.second; ++it) { |
| 52 | os << StringPrintf("0x%08x-0x%08x %c%c%c %s\n", |
| 53 | static_cast<uint32_t>(it->start), |
| 54 | static_cast<uint32_t>(it->end), |
| 55 | (it->flags & PROT_READ) ? 'r' : '-', |
| 56 | (it->flags & PROT_WRITE) ? 'w' : '-', |
| 57 | (it->flags & PROT_EXEC) ? 'x' : '-', it->name.c_str()); |
Elliott Hughes | ecd3a6f | 2012-06-06 18:16:37 -0700 | [diff] [blame] | 58 | } |
| 59 | return os; |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 60 | } |
| 61 | |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 62 | std::ostream& operator<<(std::ostream& os, const std::multimap<void*, MemMap*>& mem_maps) { |
| 63 | os << "MemMap:" << std::endl; |
| 64 | for (auto it = mem_maps.begin(); it != mem_maps.end(); ++it) { |
| 65 | void* base = it->first; |
| 66 | MemMap* map = it->second; |
| 67 | CHECK_EQ(base, map->BaseBegin()); |
| 68 | os << *map << std::endl; |
| 69 | } |
| 70 | return os; |
| 71 | } |
| 72 | |
| 73 | std::multimap<void*, MemMap*> MemMap::maps_; |
| 74 | |
Ian Rogers | c3ccc10 | 2014-06-25 11:52:14 -0700 | [diff] [blame] | 75 | #if USE_ART_LOW_4G_ALLOCATOR |
Andreas Gampe | d8f26db | 2014-05-19 17:01:13 -0700 | [diff] [blame] | 76 | // Handling mem_map in 32b address range for 64b architectures that do not support MAP_32BIT. |
| 77 | |
| 78 | // 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] | 79 | static constexpr uintptr_t LOW_MEM_START = 64 * KB; |
Andreas Gampe | 7104cbf | 2014-03-21 11:44:43 -0700 | [diff] [blame] | 80 | |
Andreas Gampe | d8f26db | 2014-05-19 17:01:13 -0700 | [diff] [blame] | 81 | // Generate random starting position. |
| 82 | // To not interfere with image position, take the image's address and only place it below. Current |
| 83 | // formula (sketch): |
| 84 | // |
| 85 | // ART_BASE_ADDR = 0001XXXXXXXXXXXXXXX |
| 86 | // ---------------------------------------- |
| 87 | // = 0000111111111111111 |
| 88 | // & ~(kPageSize - 1) =~0000000000000001111 |
| 89 | // ---------------------------------------- |
| 90 | // mask = 0000111111111110000 |
| 91 | // & random data = YYYYYYYYYYYYYYYYYYY |
| 92 | // ----------------------------------- |
| 93 | // tmp = 0000YYYYYYYYYYY0000 |
| 94 | // + LOW_MEM_START = 0000000000001000000 |
| 95 | // -------------------------------------- |
| 96 | // start |
| 97 | // |
| 98 | // getauxval as an entropy source is exposed in Bionic, but not in glibc before 2.16. When we |
| 99 | // do not have Bionic, simply start with LOW_MEM_START. |
| 100 | |
| 101 | // Function is standalone so it can be tested somewhat in mem_map_test.cc. |
| 102 | #ifdef __BIONIC__ |
| 103 | uintptr_t CreateStartPos(uint64_t input) { |
| 104 | CHECK_NE(0, ART_BASE_ADDRESS); |
| 105 | |
| 106 | // Start with all bits below highest bit in ART_BASE_ADDRESS. |
| 107 | constexpr size_t leading_zeros = CLZ(static_cast<uint32_t>(ART_BASE_ADDRESS)); |
| 108 | constexpr uintptr_t mask_ones = (1 << (31 - leading_zeros)) - 1; |
| 109 | |
| 110 | // Lowest (usually 12) bits are not used, as aligned by page size. |
| 111 | constexpr uintptr_t mask = mask_ones & ~(kPageSize - 1); |
| 112 | |
| 113 | // Mask input data. |
| 114 | return (input & mask) + LOW_MEM_START; |
| 115 | } |
| 116 | #endif |
| 117 | |
| 118 | static uintptr_t GenerateNextMemPos() { |
| 119 | #ifdef __BIONIC__ |
| 120 | uint8_t* random_data = reinterpret_cast<uint8_t*>(getauxval(AT_RANDOM)); |
| 121 | // The lower 8B are taken for the stack guard. Use the upper 8B (with mask). |
| 122 | return CreateStartPos(*reinterpret_cast<uintptr_t*>(random_data + 8)); |
| 123 | #else |
| 124 | // No auxv on host, see above. |
| 125 | return LOW_MEM_START; |
| 126 | #endif |
| 127 | } |
| 128 | |
| 129 | // Initialize linear scan to random position. |
| 130 | uintptr_t MemMap::next_mem_pos_ = GenerateNextMemPos(); |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 131 | #endif |
| 132 | |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 133 | static bool CheckMapRequest(byte* expected_ptr, void* actual_ptr, size_t byte_count, |
| 134 | std::ostringstream* error_msg) { |
| 135 | // Handled first by caller for more specific error messages. |
| 136 | CHECK(actual_ptr != MAP_FAILED); |
| 137 | |
| 138 | if (expected_ptr == nullptr) { |
| 139 | return true; |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 140 | } |
Elliott Hughes | ecd3a6f | 2012-06-06 18:16:37 -0700 | [diff] [blame] | 141 | |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 142 | if (expected_ptr == actual_ptr) { |
| 143 | return true; |
| 144 | } |
| 145 | |
| 146 | // We asked for an address but didn't get what we wanted, all paths below here should fail. |
| 147 | int result = munmap(actual_ptr, byte_count); |
| 148 | if (result == -1) { |
| 149 | PLOG(WARNING) << StringPrintf("munmap(%p, %zd) failed", actual_ptr, byte_count); |
| 150 | } |
| 151 | |
| 152 | uintptr_t actual = reinterpret_cast<uintptr_t>(actual_ptr); |
| 153 | uintptr_t expected = reinterpret_cast<uintptr_t>(expected_ptr); |
| 154 | uintptr_t limit = expected + byte_count; |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 155 | |
Ian Rogers | 700a402 | 2014-05-19 16:49:03 -0700 | [diff] [blame] | 156 | std::unique_ptr<BacktraceMap> map(BacktraceMap::Create(getpid())); |
Christopher Ferris | caf22ac | 2014-01-27 18:32:14 -0800 | [diff] [blame] | 157 | if (!map->Build()) { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 158 | *error_msg << StringPrintf("Failed to build process map to determine why mmap returned " |
| 159 | "0x%08" PRIxPTR " instead of 0x%08" PRIxPTR, actual, expected); |
| 160 | |
| 161 | return false; |
Christopher Ferris | 943af7d | 2014-01-16 12:41:46 -0800 | [diff] [blame] | 162 | } |
Christopher Ferris | caf22ac | 2014-01-27 18:32:14 -0800 | [diff] [blame] | 163 | for (BacktraceMap::const_iterator it = map->begin(); it != map->end(); ++it) { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 164 | if ((expected >= it->start && expected < it->end) // start of new within old |
| 165 | || (limit > it->start && limit < it->end) // end of new within old |
| 166 | || (expected <= it->start && limit > it->end)) { // start/end of new includes all of old |
| 167 | *error_msg |
| 168 | << StringPrintf("Requested region 0x%08" PRIxPTR "-0x%08" PRIxPTR " overlaps with " |
| 169 | "existing map 0x%08" PRIxPTR "-0x%08" PRIxPTR " (%s)\n", |
| 170 | expected, limit, |
| 171 | static_cast<uintptr_t>(it->start), static_cast<uintptr_t>(it->end), |
| 172 | it->name.c_str()) |
| 173 | << std::make_pair(it, map->end()); |
| 174 | return false; |
| 175 | } |
Elliott Hughes | 96970cd | 2012-03-13 15:46:31 -0700 | [diff] [blame] | 176 | } |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 177 | *error_msg << StringPrintf("Failed to mmap at expected address, mapped at " |
| 178 | "0x%08" PRIxPTR " instead of 0x%08" PRIxPTR, actual, expected); |
| 179 | return false; |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 180 | } |
| 181 | |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 182 | MemMap* MemMap::MapAnonymous(const char* name, byte* expected, size_t byte_count, int prot, |
Ian Rogers | ef7d42f | 2014-01-06 12:55:46 -0800 | [diff] [blame] | 183 | bool low_4gb, std::string* error_msg) { |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 184 | if (byte_count == 0) { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 185 | return new MemMap(name, nullptr, 0, nullptr, 0, prot); |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 186 | } |
Elliott Hughes | ecd3a6f | 2012-06-06 18:16:37 -0700 | [diff] [blame] | 187 | size_t page_aligned_byte_count = RoundUp(byte_count, kPageSize); |
Elliott Hughes | 6c9c06d | 2011-11-07 16:43:47 -0800 | [diff] [blame] | 188 | |
Elliott Hughes | 6c9c06d | 2011-11-07 16:43:47 -0800 | [diff] [blame] | 189 | int flags = MAP_PRIVATE | MAP_ANONYMOUS; |
Ian Rogers | 997f0f9 | 2014-06-21 22:58:05 -0700 | [diff] [blame] | 190 | ScopedFd fd(-1); |
| 191 | |
| 192 | #ifdef USE_ASHMEM |
| 193 | #ifdef HAVE_ANDROID_OS |
| 194 | const bool use_ashmem = true; |
| 195 | #else |
| 196 | // When not on Android ashmem is faked using files in /tmp. Ensure that such files won't |
| 197 | // fail due to ulimit restrictions. If they will then use a regular mmap. |
| 198 | struct rlimit rlimit_fsize; |
| 199 | CHECK_EQ(getrlimit(RLIMIT_FSIZE, &rlimit_fsize), 0); |
| 200 | const bool use_ashmem = (rlimit_fsize.rlim_cur == RLIM_INFINITY) || |
| 201 | (page_aligned_byte_count < rlimit_fsize.rlim_cur); |
| 202 | #endif |
| 203 | if (use_ashmem) { |
| 204 | // android_os_Debug.cpp read_mapinfo assumes all ashmem regions associated with the VM are |
| 205 | // prefixed "dalvik-". |
| 206 | std::string debug_friendly_name("dalvik-"); |
| 207 | debug_friendly_name += name; |
| 208 | fd.reset(ashmem_create_region(debug_friendly_name.c_str(), page_aligned_byte_count)); |
| 209 | if (fd.get() == -1) { |
| 210 | *error_msg = StringPrintf("ashmem_create_region failed for '%s': %s", name, strerror(errno)); |
| 211 | return nullptr; |
| 212 | } |
| 213 | flags = MAP_PRIVATE; |
| 214 | } |
Elliott Hughes | 6c9c06d | 2011-11-07 16:43:47 -0800 | [diff] [blame] | 215 | #endif |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 216 | |
Brian Carlstrom | aa94cf3 | 2014-03-23 23:47:25 -0700 | [diff] [blame] | 217 | // We need to store and potentially set an error number for pretty printing of errors |
| 218 | int saved_errno = 0; |
| 219 | |
Qiming Shi | 84d49cc | 2014-04-24 15:38:41 +0800 | [diff] [blame] | 220 | #ifdef __LP64__ |
| 221 | // When requesting low_4g memory and having an expectation, the requested range should fit into |
| 222 | // 4GB. |
| 223 | if (low_4gb && ( |
| 224 | // Start out of bounds. |
| 225 | (reinterpret_cast<uintptr_t>(expected) >> 32) != 0 || |
| 226 | // End out of bounds. For simplicity, this will fail for the last page of memory. |
| 227 | (reinterpret_cast<uintptr_t>(expected + page_aligned_byte_count) >> 32) != 0)) { |
| 228 | *error_msg = StringPrintf("The requested address space (%p, %p) cannot fit in low_4gb", |
| 229 | expected, expected + page_aligned_byte_count); |
| 230 | return nullptr; |
| 231 | } |
| 232 | #endif |
| 233 | |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 234 | // TODO: |
| 235 | // A page allocator would be a useful abstraction here, as |
| 236 | // 1) It is doubtful that MAP_32BIT on x86_64 is doing the right job for us |
| 237 | // 2) The linear scheme, even with simple saving of the last known position, is very crude |
Ian Rogers | c3ccc10 | 2014-06-25 11:52:14 -0700 | [diff] [blame] | 238 | #if USE_ART_LOW_4G_ALLOCATOR |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 239 | // MAP_32BIT only available on x86_64. |
| 240 | void* actual = MAP_FAILED; |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 241 | if (low_4gb && expected == nullptr) { |
Andreas Gampe | 7104cbf | 2014-03-21 11:44:43 -0700 | [diff] [blame] | 242 | bool first_run = true; |
| 243 | |
Andreas Gampe | 71a3eba | 2014-03-17 12:57:08 -0700 | [diff] [blame] | 244 | for (uintptr_t ptr = next_mem_pos_; ptr < 4 * GB; ptr += kPageSize) { |
Andreas Gampe | 7104cbf | 2014-03-21 11:44:43 -0700 | [diff] [blame] | 245 | if (4U * GB - ptr < page_aligned_byte_count) { |
| 246 | // Not enough memory until 4GB. |
| 247 | if (first_run) { |
| 248 | // Try another time from the bottom; |
Andreas Gampe | 9de65ff | 2014-03-21 17:25:57 -0700 | [diff] [blame] | 249 | ptr = LOW_MEM_START - kPageSize; |
Andreas Gampe | 7104cbf | 2014-03-21 11:44:43 -0700 | [diff] [blame] | 250 | first_run = false; |
| 251 | continue; |
| 252 | } else { |
| 253 | // Second try failed. |
| 254 | break; |
| 255 | } |
| 256 | } |
| 257 | |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 258 | uintptr_t tail_ptr; |
| 259 | |
| 260 | // Check pages are free. |
| 261 | bool safe = true; |
| 262 | for (tail_ptr = ptr; tail_ptr < ptr + page_aligned_byte_count; tail_ptr += kPageSize) { |
| 263 | if (msync(reinterpret_cast<void*>(tail_ptr), kPageSize, 0) == 0) { |
| 264 | safe = false; |
| 265 | break; |
| 266 | } else { |
| 267 | DCHECK_EQ(errno, ENOMEM); |
| 268 | } |
| 269 | } |
| 270 | |
| 271 | next_mem_pos_ = tail_ptr; // update early, as we break out when we found and mapped a region |
| 272 | |
| 273 | if (safe == true) { |
| 274 | actual = mmap(reinterpret_cast<void*>(ptr), page_aligned_byte_count, prot, flags, fd.get(), |
| 275 | 0); |
| 276 | if (actual != MAP_FAILED) { |
Mathieu Chartier | c355a2a | 2014-05-30 13:02:46 -0700 | [diff] [blame] | 277 | // Since we didn't use MAP_FIXED the kernel may have mapped it somewhere not in the low |
| 278 | // 4GB. If this is the case, unmap and retry. |
| 279 | if (reinterpret_cast<uintptr_t>(actual) + page_aligned_byte_count < 4 * GB) { |
| 280 | break; |
| 281 | } else { |
| 282 | munmap(actual, page_aligned_byte_count); |
| 283 | actual = MAP_FAILED; |
| 284 | } |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 285 | } |
| 286 | } else { |
| 287 | // Skip over last page. |
| 288 | ptr = tail_ptr; |
| 289 | } |
| 290 | } |
| 291 | |
| 292 | if (actual == MAP_FAILED) { |
Brian Carlstrom | aa94cf3 | 2014-03-23 23:47:25 -0700 | [diff] [blame] | 293 | LOG(ERROR) << "Could not find contiguous low-memory space."; |
| 294 | saved_errno = ENOMEM; |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 295 | } |
| 296 | } else { |
| 297 | actual = mmap(expected, page_aligned_byte_count, prot, flags, fd.get(), 0); |
Brian Carlstrom | aa94cf3 | 2014-03-23 23:47:25 -0700 | [diff] [blame] | 298 | saved_errno = errno; |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 299 | } |
| 300 | |
| 301 | #else |
Ian Rogers | c3ccc10 | 2014-06-25 11:52:14 -0700 | [diff] [blame] | 302 | #if defined(__LP64__) |
Qiming Shi | 84d49cc | 2014-04-24 15:38:41 +0800 | [diff] [blame] | 303 | if (low_4gb && expected == nullptr) { |
Ian Rogers | ef7d42f | 2014-01-06 12:55:46 -0800 | [diff] [blame] | 304 | flags |= MAP_32BIT; |
| 305 | } |
| 306 | #endif |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 307 | |
| 308 | void* actual = mmap(expected, page_aligned_byte_count, prot, flags, fd.get(), 0); |
Brian Carlstrom | aa94cf3 | 2014-03-23 23:47:25 -0700 | [diff] [blame] | 309 | saved_errno = errno; |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 310 | #endif |
| 311 | |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 312 | if (actual == MAP_FAILED) { |
jeffhao | 8161c03 | 2012-10-31 15:50:00 -0700 | [diff] [blame] | 313 | std::string maps; |
| 314 | ReadFileToString("/proc/self/maps", &maps); |
Brian Carlstrom | aa94cf3 | 2014-03-23 23:47:25 -0700 | [diff] [blame] | 315 | |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 316 | *error_msg = StringPrintf("Failed anonymous mmap(%p, %zd, 0x%x, 0x%x, %d, 0): %s\n%s", |
| 317 | expected, page_aligned_byte_count, prot, flags, fd.get(), |
Brian Carlstrom | aa94cf3 | 2014-03-23 23:47:25 -0700 | [diff] [blame] | 318 | strerror(saved_errno), maps.c_str()); |
Ian Rogers | 8d31bbd | 2013-10-13 10:44:14 -0700 | [diff] [blame] | 319 | return nullptr; |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 320 | } |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 321 | std::ostringstream check_map_request_error_msg; |
| 322 | if (!CheckMapRequest(expected, actual, page_aligned_byte_count, &check_map_request_error_msg)) { |
| 323 | *error_msg = check_map_request_error_msg.str(); |
| 324 | return nullptr; |
| 325 | } |
| 326 | return new MemMap(name, reinterpret_cast<byte*>(actual), byte_count, actual, |
| 327 | page_aligned_byte_count, prot); |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 328 | } |
| 329 | |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 330 | MemMap* MemMap::MapFileAtAddress(byte* expected, size_t byte_count, int prot, int flags, int fd, |
Ian Rogers | 8d31bbd | 2013-10-13 10:44:14 -0700 | [diff] [blame] | 331 | off_t start, bool reuse, const char* filename, |
| 332 | std::string* error_msg) { |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 333 | CHECK_NE(0, prot); |
| 334 | CHECK_NE(0, flags & (MAP_SHARED | MAP_PRIVATE)); |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 335 | if (reuse) { |
| 336 | // reuse means it is okay that it overlaps an existing page mapping. |
| 337 | // Only use this if you actually made the page reservation yourself. |
| 338 | CHECK(expected != nullptr); |
| 339 | flags |= MAP_FIXED; |
| 340 | } else { |
| 341 | CHECK_EQ(0, flags & MAP_FIXED); |
| 342 | } |
| 343 | |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 344 | if (byte_count == 0) { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 345 | return new MemMap(filename, nullptr, 0, nullptr, 0, prot); |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 346 | } |
Ian Rogers | f8adc60 | 2013-04-18 17:06:19 -0700 | [diff] [blame] | 347 | // Adjust 'offset' to be page-aligned as required by mmap. |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 348 | int page_offset = start % kPageSize; |
| 349 | off_t page_aligned_offset = start - page_offset; |
Ian Rogers | f8adc60 | 2013-04-18 17:06:19 -0700 | [diff] [blame] | 350 | // 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] | 351 | size_t page_aligned_byte_count = RoundUp(byte_count + page_offset, kPageSize); |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 352 | // The 'expected' is modified (if specified, ie non-null) to be page aligned to the file but not |
| 353 | // necessarily to virtual memory. mmap will page align 'expected' for us. |
| 354 | byte* page_aligned_expected = (expected == nullptr) ? nullptr : (expected - page_offset); |
| 355 | |
| 356 | byte* actual = reinterpret_cast<byte*>(mmap(page_aligned_expected, |
Elliott Hughes | ecd3a6f | 2012-06-06 18:16:37 -0700 | [diff] [blame] | 357 | page_aligned_byte_count, |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 358 | prot, |
| 359 | flags, |
| 360 | fd, |
| 361 | page_aligned_offset)); |
| 362 | if (actual == MAP_FAILED) { |
Brian Carlstrom | aa94cf3 | 2014-03-23 23:47:25 -0700 | [diff] [blame] | 363 | auto saved_errno = errno; |
| 364 | |
jeffhao | 8161c03 | 2012-10-31 15:50:00 -0700 | [diff] [blame] | 365 | std::string maps; |
| 366 | ReadFileToString("/proc/self/maps", &maps); |
Brian Carlstrom | aa94cf3 | 2014-03-23 23:47:25 -0700 | [diff] [blame] | 367 | |
Mathieu Chartier | c7cb190 | 2014-03-05 14:41:03 -0800 | [diff] [blame] | 368 | *error_msg = StringPrintf("mmap(%p, %zd, 0x%x, 0x%x, %d, %" PRId64 |
| 369 | ") of file '%s' failed: %s\n%s", |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 370 | page_aligned_expected, page_aligned_byte_count, prot, flags, fd, |
Brian Carlstrom | aa94cf3 | 2014-03-23 23:47:25 -0700 | [diff] [blame] | 371 | static_cast<int64_t>(page_aligned_offset), filename, |
| 372 | strerror(saved_errno), maps.c_str()); |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 373 | return nullptr; |
| 374 | } |
| 375 | std::ostringstream check_map_request_error_msg; |
| 376 | if (!CheckMapRequest(expected, actual, page_aligned_byte_count, &check_map_request_error_msg)) { |
| 377 | *error_msg = check_map_request_error_msg.str(); |
| 378 | return nullptr; |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 379 | } |
Brian Carlstrom | 0d6adac | 2014-02-05 17:39:16 -0800 | [diff] [blame] | 380 | return new MemMap(filename, actual + page_offset, byte_count, actual, page_aligned_byte_count, |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame] | 381 | prot); |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 382 | } |
| 383 | |
| 384 | MemMap::~MemMap() { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 385 | if (base_begin_ == nullptr && base_size_ == 0) { |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 386 | return; |
| 387 | } |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 388 | int result = munmap(base_begin_, base_size_); |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 389 | if (result == -1) { |
| 390 | PLOG(FATAL) << "munmap failed"; |
| 391 | } |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 392 | |
| 393 | // Remove it from maps_. |
| 394 | MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_); |
| 395 | bool found = false; |
| 396 | for (auto it = maps_.lower_bound(base_begin_), end = maps_.end(); |
| 397 | it != end && it->first == base_begin_; ++it) { |
| 398 | if (it->second == this) { |
| 399 | found = true; |
| 400 | maps_.erase(it); |
| 401 | break; |
| 402 | } |
| 403 | } |
| 404 | CHECK(found) << "MemMap not found"; |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 405 | } |
| 406 | |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame] | 407 | MemMap::MemMap(const std::string& name, byte* begin, size_t size, void* base_begin, |
| 408 | size_t base_size, int prot) |
| 409 | : name_(name), begin_(begin), size_(size), base_begin_(base_begin), base_size_(base_size), |
| 410 | prot_(prot) { |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 411 | if (size_ == 0) { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 412 | CHECK(begin_ == nullptr); |
| 413 | CHECK(base_begin_ == nullptr); |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 414 | CHECK_EQ(base_size_, 0U); |
| 415 | } else { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 416 | CHECK(begin_ != nullptr); |
| 417 | CHECK(base_begin_ != nullptr); |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 418 | CHECK_NE(base_size_, 0U); |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 419 | |
| 420 | // Add it to maps_. |
| 421 | MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_); |
| 422 | maps_.insert(std::pair<void*, MemMap*>(base_begin_, this)); |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 423 | } |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 424 | }; |
| 425 | |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 426 | MemMap* MemMap::RemapAtEnd(byte* new_end, const char* tail_name, int tail_prot, |
| 427 | std::string* error_msg) { |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 428 | DCHECK_GE(new_end, Begin()); |
| 429 | DCHECK_LE(new_end, End()); |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 430 | DCHECK_LE(begin_ + size_, reinterpret_cast<byte*>(base_begin_) + base_size_); |
| 431 | DCHECK(IsAligned<kPageSize>(begin_)); |
| 432 | DCHECK(IsAligned<kPageSize>(base_begin_)); |
| 433 | DCHECK(IsAligned<kPageSize>(reinterpret_cast<byte*>(base_begin_) + base_size_)); |
| 434 | DCHECK(IsAligned<kPageSize>(new_end)); |
| 435 | byte* old_end = begin_ + size_; |
| 436 | byte* old_base_end = reinterpret_cast<byte*>(base_begin_) + base_size_; |
| 437 | byte* new_base_end = new_end; |
| 438 | DCHECK_LE(new_base_end, old_base_end); |
| 439 | if (new_base_end == old_base_end) { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 440 | return new MemMap(tail_name, nullptr, 0, nullptr, 0, tail_prot); |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 441 | } |
| 442 | size_ = new_end - reinterpret_cast<byte*>(begin_); |
| 443 | base_size_ = new_base_end - reinterpret_cast<byte*>(base_begin_); |
| 444 | DCHECK_LE(begin_ + size_, reinterpret_cast<byte*>(base_begin_) + base_size_); |
| 445 | size_t tail_size = old_end - new_end; |
| 446 | byte* tail_base_begin = new_base_end; |
| 447 | size_t tail_base_size = old_base_end - new_base_end; |
| 448 | DCHECK_EQ(tail_base_begin + tail_base_size, old_base_end); |
| 449 | DCHECK(IsAligned<kPageSize>(tail_base_size)); |
| 450 | |
| 451 | #ifdef USE_ASHMEM |
| 452 | // android_os_Debug.cpp read_mapinfo assumes all ashmem regions associated with the VM are |
| 453 | // prefixed "dalvik-". |
| 454 | std::string debug_friendly_name("dalvik-"); |
| 455 | debug_friendly_name += tail_name; |
| 456 | ScopedFd fd(ashmem_create_region(debug_friendly_name.c_str(), tail_base_size)); |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 457 | int flags = MAP_PRIVATE | MAP_FIXED; |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 458 | if (fd.get() == -1) { |
| 459 | *error_msg = StringPrintf("ashmem_create_region failed for '%s': %s", |
| 460 | tail_name, strerror(errno)); |
| 461 | return nullptr; |
| 462 | } |
| 463 | #else |
| 464 | ScopedFd fd(-1); |
| 465 | int flags = MAP_PRIVATE | MAP_ANONYMOUS; |
| 466 | #endif |
| 467 | |
| 468 | // Unmap/map the tail region. |
| 469 | int result = munmap(tail_base_begin, tail_base_size); |
| 470 | if (result == -1) { |
| 471 | std::string maps; |
| 472 | ReadFileToString("/proc/self/maps", &maps); |
| 473 | *error_msg = StringPrintf("munmap(%p, %zd) failed for '%s'\n%s", |
| 474 | tail_base_begin, tail_base_size, name_.c_str(), |
| 475 | maps.c_str()); |
| 476 | return nullptr; |
| 477 | } |
| 478 | // Don't cause memory allocation between the munmap and the mmap |
| 479 | // calls. Otherwise, libc (or something else) might take this memory |
| 480 | // region. Note this isn't perfect as there's no way to prevent |
| 481 | // other threads to try to take this memory region here. |
| 482 | byte* actual = reinterpret_cast<byte*>(mmap(tail_base_begin, tail_base_size, tail_prot, |
| 483 | flags, fd.get(), 0)); |
| 484 | if (actual == MAP_FAILED) { |
| 485 | std::string maps; |
| 486 | ReadFileToString("/proc/self/maps", &maps); |
Mathieu Chartier | c7cb190 | 2014-03-05 14:41:03 -0800 | [diff] [blame] | 487 | *error_msg = StringPrintf("anonymous mmap(%p, %zd, 0x%x, 0x%x, %d, 0) failed\n%s", |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 488 | tail_base_begin, tail_base_size, tail_prot, flags, fd.get(), |
| 489 | maps.c_str()); |
| 490 | return nullptr; |
| 491 | } |
| 492 | return new MemMap(tail_name, actual, tail_size, actual, tail_base_size, tail_prot); |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 493 | } |
Logan Chien | d88fa26 | 2012-06-06 15:23:32 +0800 | [diff] [blame] | 494 | |
Ian Rogers | c5f1773 | 2014-06-05 20:48:42 -0700 | [diff] [blame] | 495 | void MemMap::MadviseDontNeedAndZero() { |
| 496 | if (base_begin_ != nullptr || base_size_ != 0) { |
| 497 | if (!kMadviseZeroes) { |
| 498 | memset(base_begin_, 0, base_size_); |
| 499 | } |
| 500 | int result = madvise(base_begin_, base_size_, MADV_DONTNEED); |
| 501 | if (result == -1) { |
| 502 | PLOG(WARNING) << "madvise failed"; |
| 503 | } |
| 504 | } |
| 505 | } |
| 506 | |
Logan Chien | d88fa26 | 2012-06-06 15:23:32 +0800 | [diff] [blame] | 507 | bool MemMap::Protect(int prot) { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 508 | if (base_begin_ == nullptr && base_size_ == 0) { |
Ian Rogers | 1c849e5 | 2012-06-28 14:00:33 -0700 | [diff] [blame] | 509 | prot_ = prot; |
Logan Chien | d88fa26 | 2012-06-06 15:23:32 +0800 | [diff] [blame] | 510 | return true; |
| 511 | } |
| 512 | |
| 513 | if (mprotect(base_begin_, base_size_, prot) == 0) { |
Ian Rogers | 1c849e5 | 2012-06-28 14:00:33 -0700 | [diff] [blame] | 514 | prot_ = prot; |
Logan Chien | d88fa26 | 2012-06-06 15:23:32 +0800 | [diff] [blame] | 515 | return true; |
| 516 | } |
| 517 | |
Shih-wei Liao | a060ed9 | 2012-06-07 09:25:28 -0700 | [diff] [blame] | 518 | PLOG(ERROR) << "mprotect(" << reinterpret_cast<void*>(base_begin_) << ", " << base_size_ << ", " |
| 519 | << prot << ") failed"; |
Logan Chien | d88fa26 | 2012-06-06 15:23:32 +0800 | [diff] [blame] | 520 | return false; |
| 521 | } |
| 522 | |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 523 | bool MemMap::CheckNoGaps(MemMap* begin_map, MemMap* end_map) { |
| 524 | MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_); |
| 525 | CHECK(begin_map != nullptr); |
| 526 | CHECK(end_map != nullptr); |
| 527 | CHECK(HasMemMap(begin_map)); |
| 528 | CHECK(HasMemMap(end_map)); |
| 529 | CHECK_LE(begin_map->BaseBegin(), end_map->BaseBegin()); |
| 530 | MemMap* map = begin_map; |
| 531 | while (map->BaseBegin() != end_map->BaseBegin()) { |
| 532 | MemMap* next_map = GetLargestMemMapAt(map->BaseEnd()); |
| 533 | if (next_map == nullptr) { |
| 534 | // Found a gap. |
| 535 | return false; |
| 536 | } |
| 537 | map = next_map; |
| 538 | } |
| 539 | return true; |
| 540 | } |
| 541 | |
| 542 | void MemMap::DumpMaps(std::ostream& os) { |
| 543 | DumpMaps(os, maps_); |
| 544 | } |
| 545 | |
| 546 | void MemMap::DumpMaps(std::ostream& os, const std::multimap<void*, MemMap*>& mem_maps) { |
| 547 | MutexLock mu(Thread::Current(), *Locks::mem_maps_lock_); |
| 548 | DumpMapsLocked(os, mem_maps); |
| 549 | } |
| 550 | |
| 551 | void MemMap::DumpMapsLocked(std::ostream& os, const std::multimap<void*, MemMap*>& mem_maps) { |
| 552 | os << mem_maps; |
| 553 | } |
| 554 | |
| 555 | bool MemMap::HasMemMap(MemMap* map) { |
| 556 | void* base_begin = map->BaseBegin(); |
| 557 | for (auto it = maps_.lower_bound(base_begin), end = maps_.end(); |
| 558 | it != end && it->first == base_begin; ++it) { |
| 559 | if (it->second == map) { |
| 560 | return true; |
| 561 | } |
| 562 | } |
| 563 | return false; |
| 564 | } |
| 565 | |
| 566 | MemMap* MemMap::GetLargestMemMapAt(void* address) { |
| 567 | size_t largest_size = 0; |
| 568 | MemMap* largest_map = nullptr; |
| 569 | for (auto it = maps_.lower_bound(address), end = maps_.end(); |
| 570 | it != end && it->first == address; ++it) { |
| 571 | MemMap* map = it->second; |
| 572 | CHECK(map != nullptr); |
| 573 | if (largest_size < map->BaseSize()) { |
| 574 | largest_size = map->BaseSize(); |
| 575 | largest_map = map; |
| 576 | } |
| 577 | } |
| 578 | return largest_map; |
| 579 | } |
| 580 | |
Brian Carlstrom | 0d6adac | 2014-02-05 17:39:16 -0800 | [diff] [blame] | 581 | std::ostream& operator<<(std::ostream& os, const MemMap& mem_map) { |
Hiroshi Yamauchi | 3eed93d | 2014-06-04 11:43:59 -0700 | [diff] [blame] | 582 | os << StringPrintf("[MemMap: %p-%p prot=0x%x %s]", |
| 583 | mem_map.BaseBegin(), mem_map.BaseEnd(), mem_map.GetProtect(), |
| 584 | mem_map.GetName().c_str()); |
Brian Carlstrom | 0d6adac | 2014-02-05 17:39:16 -0800 | [diff] [blame] | 585 | return os; |
| 586 | } |
| 587 | |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 588 | } // namespace art |