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 | |
Ian Rogers | debeb3a | 2014-01-23 16:54:52 -0800 | [diff] [blame] | 19 | #include <inttypes.h> |
Christopher Ferris | 943af7d | 2014-01-16 12:41:46 -0800 | [diff] [blame] | 20 | #include <backtrace/BacktraceMap.h> |
Elliott Hughes | ecd3a6f | 2012-06-06 18:16:37 -0700 | [diff] [blame] | 21 | |
Christopher Ferris | caf22ac | 2014-01-27 18:32:14 -0800 | [diff] [blame] | 22 | #include "UniquePtr.h" |
Elliott Hughes | e222ee0 | 2012-12-13 14:41:43 -0800 | [diff] [blame] | 23 | #include "base/stringprintf.h" |
| 24 | #include "ScopedFd.h" |
| 25 | #include "utils.h" |
| 26 | |
Elliott Hughes | 6c9c06d | 2011-11-07 16:43:47 -0800 | [diff] [blame] | 27 | #define USE_ASHMEM 1 |
| 28 | |
| 29 | #ifdef USE_ASHMEM |
| 30 | #include <cutils/ashmem.h> |
| 31 | #endif |
| 32 | |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 33 | namespace art { |
| 34 | |
Christopher Ferris | 943af7d | 2014-01-16 12:41:46 -0800 | [diff] [blame] | 35 | static std::ostream& operator<<( |
| 36 | std::ostream& os, |
| 37 | std::pair<BacktraceMap::const_iterator, BacktraceMap::const_iterator> iters) { |
| 38 | for (BacktraceMap::const_iterator it = iters.first; it != iters.second; ++it) { |
| 39 | os << StringPrintf("0x%08x-0x%08x %c%c%c %s\n", |
| 40 | static_cast<uint32_t>(it->start), |
| 41 | static_cast<uint32_t>(it->end), |
| 42 | (it->flags & PROT_READ) ? 'r' : '-', |
| 43 | (it->flags & PROT_WRITE) ? 'w' : '-', |
| 44 | (it->flags & PROT_EXEC) ? 'x' : '-', it->name.c_str()); |
Elliott Hughes | ecd3a6f | 2012-06-06 18:16:37 -0700 | [diff] [blame] | 45 | } |
| 46 | return os; |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 47 | } |
| 48 | |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 49 | #if defined(__LP64__) && !defined(__x86_64__) |
Andreas Gampe | 71a3eba | 2014-03-17 12:57:08 -0700 | [diff] [blame^] | 50 | uintptr_t MemMap::next_mem_pos_ = kPageSize * 2; // first page to check for low-mem extent |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 51 | #endif |
| 52 | |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 53 | static bool CheckMapRequest(byte* expected_ptr, void* actual_ptr, size_t byte_count, |
| 54 | std::ostringstream* error_msg) { |
| 55 | // Handled first by caller for more specific error messages. |
| 56 | CHECK(actual_ptr != MAP_FAILED); |
| 57 | |
| 58 | if (expected_ptr == nullptr) { |
| 59 | return true; |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 60 | } |
Elliott Hughes | ecd3a6f | 2012-06-06 18:16:37 -0700 | [diff] [blame] | 61 | |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 62 | if (expected_ptr == actual_ptr) { |
| 63 | return true; |
| 64 | } |
| 65 | |
| 66 | // We asked for an address but didn't get what we wanted, all paths below here should fail. |
| 67 | int result = munmap(actual_ptr, byte_count); |
| 68 | if (result == -1) { |
| 69 | PLOG(WARNING) << StringPrintf("munmap(%p, %zd) failed", actual_ptr, byte_count); |
| 70 | } |
| 71 | |
| 72 | uintptr_t actual = reinterpret_cast<uintptr_t>(actual_ptr); |
| 73 | uintptr_t expected = reinterpret_cast<uintptr_t>(expected_ptr); |
| 74 | uintptr_t limit = expected + byte_count; |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 75 | |
Christopher Ferris | caf22ac | 2014-01-27 18:32:14 -0800 | [diff] [blame] | 76 | UniquePtr<BacktraceMap> map(BacktraceMap::Create(getpid())); |
| 77 | if (!map->Build()) { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 78 | *error_msg << StringPrintf("Failed to build process map to determine why mmap returned " |
| 79 | "0x%08" PRIxPTR " instead of 0x%08" PRIxPTR, actual, expected); |
| 80 | |
| 81 | return false; |
Christopher Ferris | 943af7d | 2014-01-16 12:41:46 -0800 | [diff] [blame] | 82 | } |
Christopher Ferris | caf22ac | 2014-01-27 18:32:14 -0800 | [diff] [blame] | 83 | for (BacktraceMap::const_iterator it = map->begin(); it != map->end(); ++it) { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 84 | if ((expected >= it->start && expected < it->end) // start of new within old |
| 85 | || (limit > it->start && limit < it->end) // end of new within old |
| 86 | || (expected <= it->start && limit > it->end)) { // start/end of new includes all of old |
| 87 | *error_msg |
| 88 | << StringPrintf("Requested region 0x%08" PRIxPTR "-0x%08" PRIxPTR " overlaps with " |
| 89 | "existing map 0x%08" PRIxPTR "-0x%08" PRIxPTR " (%s)\n", |
| 90 | expected, limit, |
| 91 | static_cast<uintptr_t>(it->start), static_cast<uintptr_t>(it->end), |
| 92 | it->name.c_str()) |
| 93 | << std::make_pair(it, map->end()); |
| 94 | return false; |
| 95 | } |
Elliott Hughes | 96970cd | 2012-03-13 15:46:31 -0700 | [diff] [blame] | 96 | } |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 97 | *error_msg << StringPrintf("Failed to mmap at expected address, mapped at " |
| 98 | "0x%08" PRIxPTR " instead of 0x%08" PRIxPTR, actual, expected); |
| 99 | return false; |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 100 | } |
| 101 | |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 102 | 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] | 103 | bool low_4gb, std::string* error_msg) { |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 104 | if (byte_count == 0) { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 105 | return new MemMap(name, nullptr, 0, nullptr, 0, prot); |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 106 | } |
Elliott Hughes | ecd3a6f | 2012-06-06 18:16:37 -0700 | [diff] [blame] | 107 | size_t page_aligned_byte_count = RoundUp(byte_count, kPageSize); |
Elliott Hughes | 6c9c06d | 2011-11-07 16:43:47 -0800 | [diff] [blame] | 108 | |
| 109 | #ifdef USE_ASHMEM |
Ian Rogers | a40307e | 2013-02-22 11:32:44 -0800 | [diff] [blame] | 110 | // android_os_Debug.cpp read_mapinfo assumes all ashmem regions associated with the VM are |
| 111 | // prefixed "dalvik-". |
| 112 | std::string debug_friendly_name("dalvik-"); |
| 113 | debug_friendly_name += name; |
| 114 | ScopedFd fd(ashmem_create_region(debug_friendly_name.c_str(), page_aligned_byte_count)); |
Elliott Hughes | 6c9c06d | 2011-11-07 16:43:47 -0800 | [diff] [blame] | 115 | if (fd.get() == -1) { |
Ian Rogers | 8d31bbd | 2013-10-13 10:44:14 -0700 | [diff] [blame] | 116 | *error_msg = StringPrintf("ashmem_create_region failed for '%s': %s", name, strerror(errno)); |
| 117 | return nullptr; |
Elliott Hughes | 6c9c06d | 2011-11-07 16:43:47 -0800 | [diff] [blame] | 118 | } |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 119 | int flags = MAP_PRIVATE; |
Elliott Hughes | 6c9c06d | 2011-11-07 16:43:47 -0800 | [diff] [blame] | 120 | #else |
| 121 | ScopedFd fd(-1); |
| 122 | int flags = MAP_PRIVATE | MAP_ANONYMOUS; |
| 123 | #endif |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 124 | |
| 125 | // TODO: |
| 126 | // A page allocator would be a useful abstraction here, as |
| 127 | // 1) It is doubtful that MAP_32BIT on x86_64 is doing the right job for us |
| 128 | // 2) The linear scheme, even with simple saving of the last known position, is very crude |
| 129 | #if defined(__LP64__) && !defined(__x86_64__) |
| 130 | // MAP_32BIT only available on x86_64. |
| 131 | void* actual = MAP_FAILED; |
| 132 | std::string strerr; |
| 133 | if (low_4gb && expected == nullptr) { |
| 134 | flags |= MAP_FIXED; |
| 135 | |
Andreas Gampe | 71a3eba | 2014-03-17 12:57:08 -0700 | [diff] [blame^] | 136 | for (uintptr_t ptr = next_mem_pos_; ptr < 4 * GB; ptr += kPageSize) { |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 137 | uintptr_t tail_ptr; |
| 138 | |
| 139 | // Check pages are free. |
| 140 | bool safe = true; |
| 141 | for (tail_ptr = ptr; tail_ptr < ptr + page_aligned_byte_count; tail_ptr += kPageSize) { |
| 142 | if (msync(reinterpret_cast<void*>(tail_ptr), kPageSize, 0) == 0) { |
| 143 | safe = false; |
| 144 | break; |
| 145 | } else { |
| 146 | DCHECK_EQ(errno, ENOMEM); |
| 147 | } |
| 148 | } |
| 149 | |
| 150 | next_mem_pos_ = tail_ptr; // update early, as we break out when we found and mapped a region |
| 151 | |
| 152 | if (safe == true) { |
| 153 | actual = mmap(reinterpret_cast<void*>(ptr), page_aligned_byte_count, prot, flags, fd.get(), |
| 154 | 0); |
| 155 | if (actual != MAP_FAILED) { |
| 156 | break; |
| 157 | } |
| 158 | } else { |
| 159 | // Skip over last page. |
| 160 | ptr = tail_ptr; |
| 161 | } |
| 162 | } |
| 163 | |
| 164 | if (actual == MAP_FAILED) { |
| 165 | strerr = "Could not find contiguous low-memory space."; |
| 166 | } |
| 167 | } else { |
| 168 | actual = mmap(expected, page_aligned_byte_count, prot, flags, fd.get(), 0); |
| 169 | strerr = strerror(errno); |
| 170 | } |
| 171 | |
| 172 | #else |
| 173 | #ifdef __x86_64__ |
Ian Rogers | ef7d42f | 2014-01-06 12:55:46 -0800 | [diff] [blame] | 174 | if (low_4gb) { |
| 175 | flags |= MAP_32BIT; |
| 176 | } |
| 177 | #endif |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 178 | |
| 179 | void* actual = mmap(expected, page_aligned_byte_count, prot, flags, fd.get(), 0); |
| 180 | std::string strerr(strerror(errno)); |
Stuart Monteith | 8dba5aa | 2014-03-12 12:44:01 +0000 | [diff] [blame] | 181 | #endif |
| 182 | |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 183 | if (actual == MAP_FAILED) { |
jeffhao | 8161c03 | 2012-10-31 15:50:00 -0700 | [diff] [blame] | 184 | std::string maps; |
| 185 | ReadFileToString("/proc/self/maps", &maps); |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 186 | *error_msg = StringPrintf("Failed anonymous mmap(%p, %zd, 0x%x, 0x%x, %d, 0): %s\n%s", |
| 187 | expected, page_aligned_byte_count, prot, flags, fd.get(), |
| 188 | strerr.c_str(), maps.c_str()); |
Ian Rogers | 8d31bbd | 2013-10-13 10:44:14 -0700 | [diff] [blame] | 189 | return nullptr; |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 190 | } |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 191 | std::ostringstream check_map_request_error_msg; |
| 192 | if (!CheckMapRequest(expected, actual, page_aligned_byte_count, &check_map_request_error_msg)) { |
| 193 | *error_msg = check_map_request_error_msg.str(); |
| 194 | return nullptr; |
| 195 | } |
| 196 | return new MemMap(name, reinterpret_cast<byte*>(actual), byte_count, actual, |
| 197 | page_aligned_byte_count, prot); |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 198 | } |
| 199 | |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 200 | 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] | 201 | off_t start, bool reuse, const char* filename, |
| 202 | std::string* error_msg) { |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 203 | CHECK_NE(0, prot); |
| 204 | CHECK_NE(0, flags & (MAP_SHARED | MAP_PRIVATE)); |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 205 | if (reuse) { |
| 206 | // reuse means it is okay that it overlaps an existing page mapping. |
| 207 | // Only use this if you actually made the page reservation yourself. |
| 208 | CHECK(expected != nullptr); |
| 209 | flags |= MAP_FIXED; |
| 210 | } else { |
| 211 | CHECK_EQ(0, flags & MAP_FIXED); |
| 212 | } |
| 213 | |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 214 | if (byte_count == 0) { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 215 | return new MemMap(filename, nullptr, 0, nullptr, 0, prot); |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 216 | } |
Ian Rogers | f8adc60 | 2013-04-18 17:06:19 -0700 | [diff] [blame] | 217 | // Adjust 'offset' to be page-aligned as required by mmap. |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 218 | int page_offset = start % kPageSize; |
| 219 | off_t page_aligned_offset = start - page_offset; |
Ian Rogers | f8adc60 | 2013-04-18 17:06:19 -0700 | [diff] [blame] | 220 | // 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] | 221 | size_t page_aligned_byte_count = RoundUp(byte_count + page_offset, kPageSize); |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 222 | // The 'expected' is modified (if specified, ie non-null) to be page aligned to the file but not |
| 223 | // necessarily to virtual memory. mmap will page align 'expected' for us. |
| 224 | byte* page_aligned_expected = (expected == nullptr) ? nullptr : (expected - page_offset); |
| 225 | |
| 226 | byte* actual = reinterpret_cast<byte*>(mmap(page_aligned_expected, |
Elliott Hughes | ecd3a6f | 2012-06-06 18:16:37 -0700 | [diff] [blame] | 227 | page_aligned_byte_count, |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 228 | prot, |
| 229 | flags, |
| 230 | fd, |
| 231 | page_aligned_offset)); |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 232 | std::string strerr(strerror(errno)); |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 233 | if (actual == MAP_FAILED) { |
jeffhao | 8161c03 | 2012-10-31 15:50:00 -0700 | [diff] [blame] | 234 | std::string maps; |
| 235 | ReadFileToString("/proc/self/maps", &maps); |
Mathieu Chartier | c7cb190 | 2014-03-05 14:41:03 -0800 | [diff] [blame] | 236 | *error_msg = StringPrintf("mmap(%p, %zd, 0x%x, 0x%x, %d, %" PRId64 |
| 237 | ") of file '%s' failed: %s\n%s", |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 238 | page_aligned_expected, page_aligned_byte_count, prot, flags, fd, |
Mathieu Chartier | 3b6f0fa | 2013-11-13 13:26:07 -0800 | [diff] [blame] | 239 | static_cast<int64_t>(page_aligned_offset), filename, strerr.c_str(), |
| 240 | maps.c_str()); |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 241 | return nullptr; |
| 242 | } |
| 243 | std::ostringstream check_map_request_error_msg; |
| 244 | if (!CheckMapRequest(expected, actual, page_aligned_byte_count, &check_map_request_error_msg)) { |
| 245 | *error_msg = check_map_request_error_msg.str(); |
| 246 | return nullptr; |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 247 | } |
Brian Carlstrom | 0d6adac | 2014-02-05 17:39:16 -0800 | [diff] [blame] | 248 | 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] | 249 | prot); |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 250 | } |
| 251 | |
| 252 | MemMap::~MemMap() { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 253 | if (base_begin_ == nullptr && base_size_ == 0) { |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 254 | return; |
| 255 | } |
Ian Rogers | 30fab40 | 2012-01-23 15:43:46 -0800 | [diff] [blame] | 256 | int result = munmap(base_begin_, base_size_); |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 257 | if (result == -1) { |
| 258 | PLOG(FATAL) << "munmap failed"; |
| 259 | } |
| 260 | } |
| 261 | |
Mathieu Chartier | 1c23e1e | 2012-10-12 14:14:11 -0700 | [diff] [blame] | 262 | MemMap::MemMap(const std::string& name, byte* begin, size_t size, void* base_begin, |
| 263 | size_t base_size, int prot) |
| 264 | : name_(name), begin_(begin), size_(size), base_begin_(base_begin), base_size_(base_size), |
| 265 | prot_(prot) { |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 266 | if (size_ == 0) { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 267 | CHECK(begin_ == nullptr); |
| 268 | CHECK(base_begin_ == nullptr); |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 269 | CHECK_EQ(base_size_, 0U); |
| 270 | } else { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 271 | CHECK(begin_ != nullptr); |
| 272 | CHECK(base_begin_ != nullptr); |
Brian Carlstrom | 9004cb6 | 2013-07-26 15:48:31 -0700 | [diff] [blame] | 273 | CHECK_NE(base_size_, 0U); |
| 274 | } |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 275 | }; |
| 276 | |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 277 | MemMap* MemMap::RemapAtEnd(byte* new_end, const char* tail_name, int tail_prot, |
| 278 | std::string* error_msg) { |
Mathieu Chartier | cc236d7 | 2012-07-20 10:29:05 -0700 | [diff] [blame] | 279 | DCHECK_GE(new_end, Begin()); |
| 280 | DCHECK_LE(new_end, End()); |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 281 | DCHECK_LE(begin_ + size_, reinterpret_cast<byte*>(base_begin_) + base_size_); |
| 282 | DCHECK(IsAligned<kPageSize>(begin_)); |
| 283 | DCHECK(IsAligned<kPageSize>(base_begin_)); |
| 284 | DCHECK(IsAligned<kPageSize>(reinterpret_cast<byte*>(base_begin_) + base_size_)); |
| 285 | DCHECK(IsAligned<kPageSize>(new_end)); |
| 286 | byte* old_end = begin_ + size_; |
| 287 | byte* old_base_end = reinterpret_cast<byte*>(base_begin_) + base_size_; |
| 288 | byte* new_base_end = new_end; |
| 289 | DCHECK_LE(new_base_end, old_base_end); |
| 290 | if (new_base_end == old_base_end) { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 291 | return new MemMap(tail_name, nullptr, 0, nullptr, 0, tail_prot); |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 292 | } |
| 293 | size_ = new_end - reinterpret_cast<byte*>(begin_); |
| 294 | base_size_ = new_base_end - reinterpret_cast<byte*>(base_begin_); |
| 295 | DCHECK_LE(begin_ + size_, reinterpret_cast<byte*>(base_begin_) + base_size_); |
| 296 | size_t tail_size = old_end - new_end; |
| 297 | byte* tail_base_begin = new_base_end; |
| 298 | size_t tail_base_size = old_base_end - new_base_end; |
| 299 | DCHECK_EQ(tail_base_begin + tail_base_size, old_base_end); |
| 300 | DCHECK(IsAligned<kPageSize>(tail_base_size)); |
| 301 | |
| 302 | #ifdef USE_ASHMEM |
| 303 | // android_os_Debug.cpp read_mapinfo assumes all ashmem regions associated with the VM are |
| 304 | // prefixed "dalvik-". |
| 305 | std::string debug_friendly_name("dalvik-"); |
| 306 | debug_friendly_name += tail_name; |
| 307 | 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] | 308 | int flags = MAP_PRIVATE | MAP_FIXED; |
Hiroshi Yamauchi | fd7e7f1 | 2013-10-22 14:17:48 -0700 | [diff] [blame] | 309 | if (fd.get() == -1) { |
| 310 | *error_msg = StringPrintf("ashmem_create_region failed for '%s': %s", |
| 311 | tail_name, strerror(errno)); |
| 312 | return nullptr; |
| 313 | } |
| 314 | #else |
| 315 | ScopedFd fd(-1); |
| 316 | int flags = MAP_PRIVATE | MAP_ANONYMOUS; |
| 317 | #endif |
| 318 | |
| 319 | // Unmap/map the tail region. |
| 320 | int result = munmap(tail_base_begin, tail_base_size); |
| 321 | if (result == -1) { |
| 322 | std::string maps; |
| 323 | ReadFileToString("/proc/self/maps", &maps); |
| 324 | *error_msg = StringPrintf("munmap(%p, %zd) failed for '%s'\n%s", |
| 325 | tail_base_begin, tail_base_size, name_.c_str(), |
| 326 | maps.c_str()); |
| 327 | return nullptr; |
| 328 | } |
| 329 | // Don't cause memory allocation between the munmap and the mmap |
| 330 | // calls. Otherwise, libc (or something else) might take this memory |
| 331 | // region. Note this isn't perfect as there's no way to prevent |
| 332 | // other threads to try to take this memory region here. |
| 333 | byte* actual = reinterpret_cast<byte*>(mmap(tail_base_begin, tail_base_size, tail_prot, |
| 334 | flags, fd.get(), 0)); |
| 335 | if (actual == MAP_FAILED) { |
| 336 | std::string maps; |
| 337 | ReadFileToString("/proc/self/maps", &maps); |
Mathieu Chartier | c7cb190 | 2014-03-05 14:41:03 -0800 | [diff] [blame] | 338 | *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] | 339 | tail_base_begin, tail_base_size, tail_prot, flags, fd.get(), |
| 340 | maps.c_str()); |
| 341 | return nullptr; |
| 342 | } |
| 343 | 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] | 344 | } |
Logan Chien | d88fa26 | 2012-06-06 15:23:32 +0800 | [diff] [blame] | 345 | |
| 346 | bool MemMap::Protect(int prot) { |
Hiroshi Yamauchi | 4fb5df8 | 2014-03-13 15:10:27 -0700 | [diff] [blame] | 347 | if (base_begin_ == nullptr && base_size_ == 0) { |
Ian Rogers | 1c849e5 | 2012-06-28 14:00:33 -0700 | [diff] [blame] | 348 | prot_ = prot; |
Logan Chien | d88fa26 | 2012-06-06 15:23:32 +0800 | [diff] [blame] | 349 | return true; |
| 350 | } |
| 351 | |
| 352 | if (mprotect(base_begin_, base_size_, prot) == 0) { |
Ian Rogers | 1c849e5 | 2012-06-28 14:00:33 -0700 | [diff] [blame] | 353 | prot_ = prot; |
Logan Chien | d88fa26 | 2012-06-06 15:23:32 +0800 | [diff] [blame] | 354 | return true; |
| 355 | } |
| 356 | |
Shih-wei Liao | a060ed9 | 2012-06-07 09:25:28 -0700 | [diff] [blame] | 357 | PLOG(ERROR) << "mprotect(" << reinterpret_cast<void*>(base_begin_) << ", " << base_size_ << ", " |
| 358 | << prot << ") failed"; |
Logan Chien | d88fa26 | 2012-06-06 15:23:32 +0800 | [diff] [blame] | 359 | return false; |
| 360 | } |
| 361 | |
Brian Carlstrom | 0d6adac | 2014-02-05 17:39:16 -0800 | [diff] [blame] | 362 | std::ostream& operator<<(std::ostream& os, const MemMap& mem_map) { |
Mathieu Chartier | c7cb190 | 2014-03-05 14:41:03 -0800 | [diff] [blame] | 363 | os << StringPrintf("[MemMap: %s prot=0x%x %p-%p]", |
Brian Carlstrom | 0d6adac | 2014-02-05 17:39:16 -0800 | [diff] [blame] | 364 | mem_map.GetName().c_str(), mem_map.GetProtect(), |
| 365 | mem_map.BaseBegin(), mem_map.BaseEnd()); |
| 366 | return os; |
| 367 | } |
| 368 | |
Brian Carlstrom | 27ec961 | 2011-09-19 20:20:38 -0700 | [diff] [blame] | 369 | } // namespace art |