libsanitizer/sanitizer_common/sanitizer_posix.cc

   1 //===-- sanitizer_posix.cc ------------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is shared between AddressSanitizer and ThreadSanitizer
   9 // run-time libraries and implements POSIX-specific functions from
  10 // sanitizer_posix.h.
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "sanitizer_platform.h"
  14
  15 #if SANITIZER_POSIX
  16
  17 #include "sanitizer_common.h"
  18 #include "sanitizer_libc.h"
  19 #include "sanitizer_posix.h"
  20 #include "sanitizer_procmaps.h"
  21 #include "sanitizer_stacktrace.h"
  22
  23 #include <fcntl.h>
  24 #include <signal.h>
  25 #include <sys/mman.h>
  26
  27 #if SANITIZER_LINUX
  28 #include <sys/utsname.h>
  29 #endif
  30
  31 #if SANITIZER_LINUX && !SANITIZER_ANDROID
  32 #include <sys/personality.h>
  33 #endif
  34
  35 #if SANITIZER_FREEBSD
  36 // The MAP_NORESERVE define has been removed in FreeBSD 11.x, and even before
  37 // that, it was never implemented.  So just define it to zero.
  38 #undef  MAP_NORESERVE
  39 #define MAP_NORESERVE 0
  40 #endif
  41
  42 namespace __sanitizer {
  43
  44 // ------------- sanitizer_common.h
  45 uptr GetMmapGranularity() {
  46   return GetPageSize();
  47 }
  48
  49 #if SANITIZER_WORDSIZE == 32
  50 // Take care of unusable kernel area in top gigabyte.
  51 static uptr GetKernelAreaSize() {
  52 #if SANITIZER_LINUX && !SANITIZER_X32
  53   const uptr gbyte = 1UL << 30;
  54
  55   // Firstly check if there are writable segments
  56   // mapped to top gigabyte (e.g. stack).
  57   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
  58   uptr end, prot;
  59   while (proc_maps.Next(/*start*/nullptr, &end,
  60                         /*offset*/nullptr, /*filename*/nullptr,
  61                         /*filename_size*/0, &prot)) {
  62     if ((end >= 3 * gbyte)
  63         && (prot & MemoryMappingLayout::kProtectionWrite) != 0)
  64       return 0;
  65   }
  66
  67 #if !SANITIZER_ANDROID
  68   // Even if nothing is mapped, top Gb may still be accessible
  69   // if we are running on 64-bit kernel.
  70   // Uname may report misleading results if personality type
  71   // is modified (e.g. under schroot) so check this as well.
  72   struct utsname uname_info;
  73   int pers = personality(0xffffffffUL);
  74   if (!(pers & PER_MASK)
  75       && uname(&uname_info) == 0
  76       && internal_strstr(uname_info.machine, "64"))
  77     return 0;
  78 #endif  // SANITIZER_ANDROID
  79
  80   // Top gigabyte is reserved for kernel.
  81   return gbyte;
  82 #else
  83   return 0;
  84 #endif  // SANITIZER_LINUX && !SANITIZER_X32
  85 }
  86 #endif  // SANITIZER_WORDSIZE == 32
  87
  88 uptr GetMaxVirtualAddress() {
  89 #if SANITIZER_WORDSIZE == 64
  90 # if defined(__powerpc64__) || defined(__aarch64__)
  91   // On PowerPC64 we have two different address space layouts: 44- and 46-bit.
  92   // We somehow need to figure out which one we are using now and choose
  93   // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
  94   // Note that with 'ulimit -s unlimited' the stack is moved away from the top
  95   // of the address space, so simply checking the stack address is not enough.
  96   // This should (does) work for both PowerPC64 Endian modes.
  97   // Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit.
  98   return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
  99 # elif defined(__mips64)
 100   return (1ULL << 40) - 1;  // 0x000000ffffffffffUL;
 101 # else
 102   return (1ULL << 47) - 1;  // 0x00007fffffffffffUL;
 103 # endif
 104 #else  // SANITIZER_WORDSIZE == 32
 105   uptr res = (1ULL << 32) - 1;  // 0xffffffff;
 106   if (!common_flags()->full_address_space)
 107     res -= GetKernelAreaSize();
 108   CHECK_LT(reinterpret_cast<uptr>(&res), res);
 109   return res;
 110 #endif  // SANITIZER_WORDSIZE
 111 }
 112
 113 void *MmapOrDie(uptr size, const char *mem_type) {
 114   size = RoundUpTo(size, GetPageSizeCached());
 115   uptr res = internal_mmap(nullptr, size,
 116                            PROT_READ | PROT_WRITE,
 117                            MAP_PRIVATE | MAP_ANON, -1, 0);
 118   int reserrno;
 119   if (internal_iserror(res, &reserrno))
 120     ReportMmapFailureAndDie(size, mem_type, "allocate", reserrno);
 121   IncreaseTotalMmap(size);
 122   return (void *)res;
 123 }
 124
 125 void UnmapOrDie(void *addr, uptr size) {
 126   if (!addr || !size) return;
 127   uptr res = internal_munmap(addr, size);
 128   if (internal_iserror(res)) {
 129     Report("ERROR: %s failed to deallocate 0x%zx (%zd) bytes at address %p\n",
 130            SanitizerToolName, size, size, addr);
 131     CHECK("unable to unmap" && 0);
 132   }
 133   DecreaseTotalMmap(size);
 134 }
 135
 136 void *MmapNoReserveOrDie(uptr size, const char *mem_type) {
 137   uptr PageSize = GetPageSizeCached();
 138   uptr p = internal_mmap(nullptr,
 139                          RoundUpTo(size, PageSize),
 140                          PROT_READ | PROT_WRITE,
 141                          MAP_PRIVATE | MAP_ANON | MAP_NORESERVE,
 142                          -1, 0);
 143   int reserrno;
 144   if (internal_iserror(p, &reserrno))
 145     ReportMmapFailureAndDie(size, mem_type, "allocate noreserve", reserrno);
 146   IncreaseTotalMmap(size);
 147   return (void *)p;
 148 }
 149
 150 void *MmapFixedOrDie(uptr fixed_addr, uptr size) {
 151   uptr PageSize = GetPageSizeCached();
 152   uptr p = internal_mmap((void*)(fixed_addr & ~(PageSize - 1)),
 153       RoundUpTo(size, PageSize),
 154       PROT_READ | PROT_WRITE,
 155       MAP_PRIVATE | MAP_ANON | MAP_FIXED,
 156       -1, 0);
 157   int reserrno;
 158   if (internal_iserror(p, &reserrno)) {
 159     char mem_type[30];
 160     internal_snprintf(mem_type, sizeof(mem_type), "memory at address 0x%zx",
 161                       fixed_addr);
 162     ReportMmapFailureAndDie(size, mem_type, "allocate", reserrno);
 163   }
 164   IncreaseTotalMmap(size);
 165   return (void *)p;
 166 }
 167
 168 bool MprotectNoAccess(uptr addr, uptr size) {
 169   return 0 == internal_mprotect((void*)addr, size, PROT_NONE);
 170 }
 171
 172 fd_t OpenFile(const char *filename, FileAccessMode mode, error_t *errno_p) {
 173   int flags;
 174   switch (mode) {
 175     case RdOnly: flags = O_RDONLY; break;
 176     case WrOnly: flags = O_WRONLY | O_CREAT; break;
 177     case RdWr: flags = O_RDWR | O_CREAT; break;
 178   }
 179   fd_t res = internal_open(filename, flags, 0660);
 180   if (internal_iserror(res, errno_p))
 181     return kInvalidFd;
 182   return res;
 183 }
 184
 185 void CloseFile(fd_t fd) {
 186   internal_close(fd);
 187 }
 188
 189 bool ReadFromFile(fd_t fd, void *buff, uptr buff_size, uptr *bytes_read,
 190                   error_t *error_p) {
 191   uptr res = internal_read(fd, buff, buff_size);
 192   if (internal_iserror(res, error_p))
 193     return false;
 194   if (bytes_read)
 195     *bytes_read = res;
 196   return true;
 197 }
 198
 199 bool WriteToFile(fd_t fd, const void *buff, uptr buff_size, uptr *bytes_written,
 200                  error_t *error_p) {
 201   uptr res = internal_write(fd, buff, buff_size);
 202   if (internal_iserror(res, error_p))
 203     return false;
 204   if (bytes_written)
 205     *bytes_written = res;
 206   return true;
 207 }
 208
 209 bool RenameFile(const char *oldpath, const char *newpath, error_t *error_p) {
 210   uptr res = internal_rename(oldpath, newpath);
 211   return !internal_iserror(res, error_p);
 212 }
 213
 214 void *MapFileToMemory(const char *file_name, uptr *buff_size) {
 215   fd_t fd = OpenFile(file_name, RdOnly);
 216   CHECK(fd != kInvalidFd);
 217   uptr fsize = internal_filesize(fd);
 218   CHECK_NE(fsize, (uptr)-1);
 219   CHECK_GT(fsize, 0);
 220   *buff_size = RoundUpTo(fsize, GetPageSizeCached());
 221   uptr map = internal_mmap(nullptr, *buff_size, PROT_READ, MAP_PRIVATE, fd, 0);
 222   return internal_iserror(map) ? nullptr : (void *)map;
 223 }
 224
 225 void *MapWritableFileToMemory(void *addr, uptr size, fd_t fd, OFF_T offset) {
 226   uptr flags = MAP_SHARED;
 227   if (addr) flags |= MAP_FIXED;
 228   uptr p = internal_mmap(addr, size, PROT_READ | PROT_WRITE, flags, fd, offset);
 229   int mmap_errno = 0;
 230   if (internal_iserror(p, &mmap_errno)) {
 231     Printf("could not map writable file (%d, %lld, %zu): %zd, errno: %d\n",
 232            fd, (long long)offset, size, p, mmap_errno);
 233     return nullptr;
 234   }
 235   return (void *)p;
 236 }
 237
 238 static inline bool IntervalsAreSeparate(uptr start1, uptr end1,
 239                                         uptr start2, uptr end2) {
 240   CHECK(start1 <= end1);
 241   CHECK(start2 <= end2);
 242   return (end1 < start2) || (end2 < start1);
 243 }
 244
 245 // FIXME: this is thread-unsafe, but should not cause problems most of the time.
 246 // When the shadow is mapped only a single thread usually exists (plus maybe
 247 // several worker threads on Mac, which aren't expected to map big chunks of
 248 // memory).
 249 bool MemoryRangeIsAvailable(uptr range_start, uptr range_end) {
 250   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
 251   uptr start, end;
 252   while (proc_maps.Next(&start, &end,
 253                         /*offset*/nullptr, /*filename*/nullptr,
 254                         /*filename_size*/0, /*protection*/nullptr)) {
 255     if (start == end) continue;  // Empty range.
 256     CHECK_NE(0, end);
 257     if (!IntervalsAreSeparate(start, end - 1, range_start, range_end))
 258       return false;
 259   }
 260   return true;
 261 }
 262
 263 void DumpProcessMap() {
 264   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
 265   uptr start, end;
 266   const sptr kBufSize = 4095;
 267   char *filename = (char*)MmapOrDie(kBufSize, __func__);
 268   Report("Process memory map follows:\n");
 269   while (proc_maps.Next(&start, &end, /* file_offset */nullptr,
 270                         filename, kBufSize, /* protection */nullptr)) {
 271     Printf("\t%p-%p\t%s\n", (void*)start, (void*)end, filename);
 272   }
 273   Report("End of process memory map.\n");
 274   UnmapOrDie(filename, kBufSize);
 275 }
 276
 277 const char *GetPwd() {
 278   return GetEnv("PWD");
 279 }
 280
 281 bool IsPathSeparator(const char c) {
 282   return c == '/';
 283 }
 284
 285 bool IsAbsolutePath(const char *path) {
 286   return path != nullptr && IsPathSeparator(path[0]);
 287 }
 288
 289 void ReportFile::Write(const char *buffer, uptr length) {
 290   SpinMutexLock l(mu);
 291   static const char *kWriteError =
 292       "ReportFile::Write() can't output requested buffer!\n";
 293   ReopenIfNecessary();
 294   if (length != internal_write(fd, buffer, length)) {
 295     internal_write(fd, kWriteError, internal_strlen(kWriteError));
 296     Die();
 297   }
 298 }
 299
 300 bool GetCodeRangeForFile(const char *module, uptr *start, uptr *end) {
 301   uptr s, e, off, prot;
 302   InternalScopedString buff(kMaxPathLength);
 303   MemoryMappingLayout proc_maps(/*cache_enabled*/false);
 304   while (proc_maps.Next(&s, &e, &off, buff.data(), buff.size(), &prot)) {
 305     if ((prot & MemoryMappingLayout::kProtectionExecute) != 0
 306         && internal_strcmp(module, buff.data()) == 0) {
 307       *start = s;
 308       *end = e;
 309       return true;
 310     }
 311   }
 312   return false;
 313 }
 314
 315 SignalContext SignalContext::Create(void *siginfo, void *context) {
 316   uptr addr = (uptr)((siginfo_t*)siginfo)->si_addr;
 317   uptr pc, sp, bp;
 318   GetPcSpBp(context, &pc, &sp, &bp);
 319   return SignalContext(context, addr, pc, sp, bp);
 320 }
 321
 322 // This function check is the built VMA matches the runtime one for
 323 // architectures with multiple VMA size.
 324 void CheckVMASize() {
 325 #ifdef __aarch64__
 326   static const unsigned kBuiltVMA = SANITIZER_AARCH64_VMA;
 327   unsigned maxRuntimeVMA =
 328     (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1);
 329   if (kBuiltVMA != maxRuntimeVMA) {
 330     Printf("WARNING: %s runtime VMA is not the one built for.\n",
 331       SanitizerToolName);
 332     Printf("\tBuilt VMA:   %u bits\n", kBuiltVMA);
 333     Printf("\tRuntime VMA: %u bits\n", maxRuntimeVMA);
 334   }
 335 #endif
 336 }
 337
 338 } // namespace __sanitizer
 339
 340 #endif // SANITIZER_POSIX