1 // Copyright 2014 the V8 project authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 // Platform specific code for AIX goes here. For the POSIX comaptible parts 6 // the implementation is in platform-posix.cc. 7 8 #include <pthread.h> 9 #include <semaphore.h> 10 #include <signal.h> 11 #include <stdio.h> 12 #include <stdlib.h> 13 #include <sys/resource.h> 14 #include <sys/time.h> 15 #include <sys/ucontext.h> 16 17 #include <errno.h> 18 #include <fcntl.h> // open 19 #include <limits.h> 20 #include <stdarg.h> 21 #include <strings.h> // index 22 #include <sys/mman.h> // mmap & munmap 23 #include <sys/stat.h> // open 24 #include <sys/types.h> // mmap & munmap 25 #include <unistd.h> // getpagesize 26 27 #include <cmath> 28 29 #undef MAP_TYPE 30 31 #include "src/base/macros.h" 32 #include "src/base/platform/platform.h" 33 34 35 namespace v8 { 36 namespace base { 37 38 39 static inline void* mmapHelper(size_t len, int prot, int flags, int fildes, 40 off_t off) { 41 void* addr = OS::GetRandomMmapAddr(); 42 return mmap(addr, len, prot, flags, fildes, off); 43 } 44 45 46 const char* OS::LocalTimezone(double time, TimezoneCache* cache) { 47 if (std::isnan(time)) return ""; 48 time_t tv = static_cast<time_t>(floor(time / msPerSecond)); 49 struct tm tm; 50 struct tm* t = localtime_r(&tv, &tm); 51 if (NULL == t) return ""; 52 return tzname[0]; // The location of the timezone string on AIX. 53 } 54 55 56 double OS::LocalTimeOffset(TimezoneCache* cache) { 57 // On AIX, struct tm does not contain a tm_gmtoff field. 58 time_t utc = time(NULL); 59 DCHECK(utc != -1); 60 struct tm tm; 61 struct tm* loc = localtime_r(&utc, &tm); 62 DCHECK(loc != NULL); 63 return static_cast<double>((mktime(loc) - utc) * msPerSecond); 64 } 65 66 67 void* OS::Allocate(const size_t requested, size_t* allocated, bool executable) { 68 const size_t msize = RoundUp(requested, getpagesize()); 69 int prot = PROT_READ | PROT_WRITE | (executable ? PROT_EXEC : 0); 70 void* mbase = mmapHelper(msize, prot, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 71 72 if (mbase == MAP_FAILED) return NULL; 73 *allocated = msize; 74 return mbase; 75 } 76 77 78 static unsigned StringToLong(char* buffer) { 79 return static_cast<unsigned>(strtol(buffer, NULL, 16)); // NOLINT 80 } 81 82 83 std::vector<OS::SharedLibraryAddress> OS::GetSharedLibraryAddresses() { 84 std::vector<SharedLibraryAddress> result; 85 static const int MAP_LENGTH = 1024; 86 int fd = open("/proc/self/maps", O_RDONLY); 87 if (fd < 0) return result; 88 while (true) { 89 char addr_buffer[11]; 90 addr_buffer[0] = '0'; 91 addr_buffer[1] = 'x'; 92 addr_buffer[10] = 0; 93 ssize_t rc = read(fd, addr_buffer + 2, 8); 94 if (rc < 8) break; 95 unsigned start = StringToLong(addr_buffer); 96 rc = read(fd, addr_buffer + 2, 1); 97 if (rc < 1) break; 98 if (addr_buffer[2] != '-') break; 99 rc = read(fd, addr_buffer + 2, 8); 100 if (rc < 8) break; 101 unsigned end = StringToLong(addr_buffer); 102 char buffer[MAP_LENGTH]; 103 int bytes_read = -1; 104 do { 105 bytes_read++; 106 if (bytes_read >= MAP_LENGTH - 1) break; 107 rc = read(fd, buffer + bytes_read, 1); 108 if (rc < 1) break; 109 } while (buffer[bytes_read] != '\n'); 110 buffer[bytes_read] = 0; 111 // Ignore mappings that are not executable. 112 if (buffer[3] != 'x') continue; 113 char* start_of_path = index(buffer, '/'); 114 // There may be no filename in this line. Skip to next. 115 if (start_of_path == NULL) continue; 116 buffer[bytes_read] = 0; 117 result.push_back(SharedLibraryAddress(start_of_path, start, end)); 118 } 119 close(fd); 120 return result; 121 } 122 123 124 void OS::SignalCodeMovingGC() {} 125 126 127 // Constants used for mmap. 128 static const int kMmapFd = -1; 129 static const int kMmapFdOffset = 0; 130 131 VirtualMemory::VirtualMemory() : address_(NULL), size_(0) {} 132 133 134 VirtualMemory::VirtualMemory(size_t size) 135 : address_(ReserveRegion(size)), size_(size) {} 136 137 138 VirtualMemory::VirtualMemory(size_t size, size_t alignment) 139 : address_(NULL), size_(0) { 140 DCHECK((alignment % OS::AllocateAlignment()) == 0); 141 size_t request_size = 142 RoundUp(size + alignment, static_cast<intptr_t>(OS::AllocateAlignment())); 143 void* reservation = 144 mmapHelper(request_size, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, kMmapFd, 145 kMmapFdOffset); 146 if (reservation == MAP_FAILED) return; 147 148 uint8_t* base = static_cast<uint8_t*>(reservation); 149 uint8_t* aligned_base = RoundUp(base, alignment); 150 DCHECK_LE(base, aligned_base); 151 152 // Unmap extra memory reserved before and after the desired block. 153 if (aligned_base != base) { 154 size_t prefix_size = static_cast<size_t>(aligned_base - base); 155 OS::Free(base, prefix_size); 156 request_size -= prefix_size; 157 } 158 159 size_t aligned_size = RoundUp(size, OS::AllocateAlignment()); 160 DCHECK_LE(aligned_size, request_size); 161 162 if (aligned_size != request_size) { 163 size_t suffix_size = request_size - aligned_size; 164 OS::Free(aligned_base + aligned_size, suffix_size); 165 request_size -= suffix_size; 166 } 167 168 DCHECK(aligned_size == request_size); 169 170 address_ = static_cast<void*>(aligned_base); 171 size_ = aligned_size; 172 } 173 174 175 VirtualMemory::~VirtualMemory() { 176 if (IsReserved()) { 177 bool result = ReleaseRegion(address(), size()); 178 DCHECK(result); 179 USE(result); 180 } 181 } 182 183 184 bool VirtualMemory::IsReserved() { return address_ != NULL; } 185 186 187 void VirtualMemory::Reset() { 188 address_ = NULL; 189 size_ = 0; 190 } 191 192 193 bool VirtualMemory::Commit(void* address, size_t size, bool is_executable) { 194 return CommitRegion(address, size, is_executable); 195 } 196 197 198 bool VirtualMemory::Uncommit(void* address, size_t size) { 199 return UncommitRegion(address, size); 200 } 201 202 203 bool VirtualMemory::Guard(void* address) { 204 OS::Guard(address, OS::CommitPageSize()); 205 return true; 206 } 207 208 209 void* VirtualMemory::ReserveRegion(size_t size) { 210 void* result = mmapHelper(size, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, 211 kMmapFd, kMmapFdOffset); 212 213 if (result == MAP_FAILED) return NULL; 214 215 return result; 216 } 217 218 219 bool VirtualMemory::CommitRegion(void* base, size_t size, bool is_executable) { 220 int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0); 221 222 if (mprotect(base, size, prot) == -1) return false; 223 224 return true; 225 } 226 227 228 bool VirtualMemory::UncommitRegion(void* base, size_t size) { 229 return mprotect(base, size, PROT_NONE) != -1; 230 } 231 232 bool VirtualMemory::ReleasePartialRegion(void* base, size_t size, 233 void* free_start, size_t free_size) { 234 return munmap(free_start, free_size) == 0; 235 } 236 237 238 bool VirtualMemory::ReleaseRegion(void* base, size_t size) { 239 return munmap(base, size) == 0; 240 } 241 242 243 bool VirtualMemory::HasLazyCommits() { return true; } 244 } // namespace base 245 } // namespace v8 246
