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(__aarch64__) && SANITIZER_IOS && !SANITIZER_IOSSIM
  91   // Ideally, we would derive the upper bound from MACH_VM_MAX_ADDRESS. The
  92   // upper bound can change depending on the device.
  93   return 0x200000000 - 1;
  94 # elif defined(__powerpc64__) || defined(__aarch64__)
  95   // On PowerPC64 we have two different address space layouts: 44- and 46-bit.
  96   // We somehow need to figure out which one we are using now and choose
  97   // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
  98   // Note that with 'ulimit -s unlimited' the stack is moved away from the top
  99   // of the address space, so simply checking the stack address is not enough.
 100   // This should (does) work for both PowerPC64 Endian modes.
 101   // Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit.
 102   return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
 103 # elif defined(__mips64)
 104   return (1ULL << 40) - 1;  // 0x000000ffffffffffUL;
 105 # elif defined(__s390x__)
 106   return (1ULL << 53) - 1;  // 0x001fffffffffffffUL;
 107 # else
 108   return (1ULL << 47) - 1;  // 0x00007fffffffffffUL;
 109 # endif
 110 #else  // SANITIZER_WORDSIZE == 32
 111 # if defined(__s390__)
 112   return (1ULL << 31) - 1;  // 0x7fffffff;
 113 # else
 114   uptr res = (1ULL << 32) - 1;  // 0xffffffff;
 115   if (!common_flags()->full_address_space)
 116     res -= GetKernelAreaSize();
 117   CHECK_LT(reinterpret_cast<uptr>(&res), res);
 118   return res;
 119 # endif
 120 #endif  // SANITIZER_WORDSIZE
 121 }
 122
 123 void *MmapOrDie(uptr size, const char *mem_type, bool raw_report) {
 124   size = RoundUpTo(size, GetPageSizeCached());
 125   uptr res = internal_mmap(nullptr, size,
 126                            PROT_READ | PROT_WRITE,
 127                            MAP_PRIVATE | MAP_ANON, -1, 0);
 128   int reserrno;
 129   if (internal_iserror(res, &reserrno))
 130     ReportMmapFailureAndDie(size, mem_type, "allocate", reserrno, raw_report);
 131   IncreaseTotalMmap(size);
 132   return (void *)res;
 133 }
 134
 135 void UnmapOrDie(void *addr, uptr size) {
 136   if (!addr || !size) return;
 137   uptr res = internal_munmap(addr, size);
 138   if (internal_iserror(res)) {
 139     Report("ERROR: %s failed to deallocate 0x%zx (%zd) bytes at address %p\n",
 140            SanitizerToolName, size, size, addr);
 141     CHECK("unable to unmap" && 0);
 142   }
 143   DecreaseTotalMmap(size);
 144 }
 145
 146 // We want to map a chunk of address space aligned to 'alignment'.
 147 // We do it by maping a bit more and then unmaping redundant pieces.
 148 // We probably can do it with fewer syscalls in some OS-dependent way.
 149 void *MmapAlignedOrDie(uptr size, uptr alignment, const char *mem_type) {
 150   CHECK(IsPowerOfTwo(size));
 151   CHECK(IsPowerOfTwo(alignment));
 152   uptr map_size = size + alignment;
 153   uptr map_res = (uptr)MmapOrDie(map_size, mem_type);
 154   uptr map_end = map_res + map_size;
 155   uptr res = map_res;
 156   if (res & (alignment - 1))  // Not aligned.
 157     res = (map_res + alignment) & ~(alignment - 1);
 158   uptr end = res + size;
 159   if (res != map_res)
 160     UnmapOrDie((void*)map_res, res - map_res);
 161   if (end != map_end)
 162     UnmapOrDie((void*)end, map_end - end);
 163   return (void*)res;
 164 }
 165
 166 void *MmapNoReserveOrDie(uptr size, const char *mem_type) {
 167   uptr PageSize = GetPageSizeCached();
 168   uptr p = internal_mmap(nullptr,
 169                          RoundUpTo(size, PageSize),
 170                          PROT_READ | PROT_WRITE,
 171                          MAP_PRIVATE | MAP_ANON | MAP_NORESERVE,
 172                          -1, 0);
 173   int reserrno;
 174   if (internal_iserror(p, &reserrno))
 175     ReportMmapFailureAndDie(size, mem_type, "allocate noreserve", reserrno);
 176   IncreaseTotalMmap(size);
 177   return (void *)p;
 178 }
 179
 180 void *MmapFixedOrDie(uptr fixed_addr, uptr size) {
 181   uptr PageSize = GetPageSizeCached();
 182   uptr p = internal_mmap((void*)(fixed_addr & ~(PageSize - 1)),
 183       RoundUpTo(size, PageSize),
 184       PROT_READ | PROT_WRITE,
 185       MAP_PRIVATE | MAP_ANON | MAP_FIXED,
 186       -1, 0);
 187   int reserrno;
 188   if (internal_iserror(p, &reserrno)) {
 189     char mem_type[30];
 190     internal_snprintf(mem_type, sizeof(mem_type), "memory at address 0x%zx",
 191                       fixed_addr);
 192     ReportMmapFailureAndDie(size, mem_type, "allocate", reserrno);
 193   }
 194   IncreaseTotalMmap(size);
 195   return (void *)p;
 196 }
 197
 198 bool MprotectNoAccess(uptr addr, uptr size) {
 199   return 0 == internal_mprotect((void*)addr, size, PROT_NONE);
 200 }
 201
 202 bool MprotectReadOnly(uptr addr, uptr size) {
 203   return 0 == internal_mprotect((void *)addr, size, PROT_READ);
 204 }
 205
 206 fd_t OpenFile(const char *filename, FileAccessMode mode, error_t *errno_p) {
 207   int flags;
 208   switch (mode) {
 209     case RdOnly: flags = O_RDONLY; break;
 210     case WrOnly: flags = O_WRONLY | O_CREAT; break;
 211     case RdWr: flags = O_RDWR | O_CREAT; break;
 212   }
 213   fd_t res = internal_open(filename, flags, 0660);
 214   if (internal_iserror(res, errno_p))
 215     return kInvalidFd;
 216   return res;
 217 }
 218
 219 void CloseFile(fd_t fd) {
 220   internal_close(fd);
 221 }
 222
 223 bool ReadFromFile(fd_t fd, void *buff, uptr buff_size, uptr *bytes_read,
 224                   error_t *error_p) {
 225   uptr res = internal_read(fd, buff, buff_size);
 226   if (internal_iserror(res, error_p))
 227     return false;
 228   if (bytes_read)
 229     *bytes_read = res;
 230   return true;
 231 }
 232
 233 bool WriteToFile(fd_t fd, const void *buff, uptr buff_size, uptr *bytes_written,
 234                  error_t *error_p) {
 235   uptr res = internal_write(fd, buff, buff_size);
 236   if (internal_iserror(res, error_p))
 237     return false;
 238   if (bytes_written)
 239     *bytes_written = res;
 240   return true;
 241 }
 242
 243 bool RenameFile(const char *oldpath, const char *newpath, error_t *error_p) {
 244   uptr res = internal_rename(oldpath, newpath);
 245   return !internal_iserror(res, error_p);
 246 }
 247
 248 void *MapFileToMemory(const char *file_name, uptr *buff_size) {
 249   fd_t fd = OpenFile(file_name, RdOnly);
 250   CHECK(fd != kInvalidFd);
 251   uptr fsize = internal_filesize(fd);
 252   CHECK_NE(fsize, (uptr)-1);
 253   CHECK_GT(fsize, 0);
 254   *buff_size = RoundUpTo(fsize, GetPageSizeCached());
 255   uptr map = internal_mmap(nullptr, *buff_size, PROT_READ, MAP_PRIVATE, fd, 0);
 256   return internal_iserror(map) ? nullptr : (void *)map;
 257 }
 258
 259 void *MapWritableFileToMemory(void *addr, uptr size, fd_t fd, OFF_T offset) {
 260   uptr flags = MAP_SHARED;
 261   if (addr) flags |= MAP_FIXED;
 262   uptr p = internal_mmap(addr, size, PROT_READ | PROT_WRITE, flags, fd, offset);
 263   int mmap_errno = 0;
 264   if (internal_iserror(p, &mmap_errno)) {
 265     Printf("could not map writable file (%d, %lld, %zu): %zd, errno: %d\n",
 266            fd, (long long)offset, size, p, mmap_errno);
 267     return nullptr;
 268   }
 269   return (void *)p;
 270 }
 271
 272 static inline bool IntervalsAreSeparate(uptr start1, uptr end1,
 273                                         uptr start2, uptr end2) {
 274   CHECK(start1 <= end1);
 275   CHECK(start2 <= end2);
 276   return (end1 < start2) || (end2 < start1);
 277 }
 278
 279 // FIXME: this is thread-unsafe, but should not cause problems most of the time.
 280 // When the shadow is mapped only a single thread usually exists (plus maybe
 281 // several worker threads on Mac, which aren't expected to map big chunks of
 282 // memory).
 283 bool MemoryRangeIsAvailable(uptr range_start, uptr range_end) {
 284   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
 285   uptr start, end;
 286   while (proc_maps.Next(&start, &end,
 287                         /*offset*/nullptr, /*filename*/nullptr,
 288                         /*filename_size*/0, /*protection*/nullptr)) {
 289     if (start == end) continue;  // Empty range.
 290     CHECK_NE(0, end);
 291     if (!IntervalsAreSeparate(start, end - 1, range_start, range_end))
 292       return false;
 293   }
 294   return true;
 295 }
 296
 297 void DumpProcessMap() {
 298   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
 299   uptr start, end;
 300   const sptr kBufSize = 4095;
 301   char *filename = (char*)MmapOrDie(kBufSize, __func__);
 302   Report("Process memory map follows:\n");
 303   while (proc_maps.Next(&start, &end, /* file_offset */nullptr,
 304                         filename, kBufSize, /* protection */nullptr)) {
 305     Printf("\t%p-%p\t%s\n", (void*)start, (void*)end, filename);
 306   }
 307   Report("End of process memory map.\n");
 308   UnmapOrDie(filename, kBufSize);
 309 }
 310
 311 const char *GetPwd() {
 312   return GetEnv("PWD");
 313 }
 314
 315 bool IsPathSeparator(const char c) {
 316   return c == '/';
 317 }
 318
 319 bool IsAbsolutePath(const char *path) {
 320   return path != nullptr && IsPathSeparator(path[0]);
 321 }
 322
 323 void ReportFile::Write(const char *buffer, uptr length) {
 324   SpinMutexLock l(mu);
 325   static const char *kWriteError =
 326       "ReportFile::Write() can't output requested buffer!\n";
 327   ReopenIfNecessary();
 328   if (length != internal_write(fd, buffer, length)) {
 329     internal_write(fd, kWriteError, internal_strlen(kWriteError));
 330     Die();
 331   }
 332 }
 333
 334 bool GetCodeRangeForFile(const char *module, uptr *start, uptr *end) {
 335   uptr s, e, off, prot;
 336   InternalScopedString buff(kMaxPathLength);
 337   MemoryMappingLayout proc_maps(/*cache_enabled*/false);
 338   while (proc_maps.Next(&s, &e, &off, buff.data(), buff.size(), &prot)) {
 339     if ((prot & MemoryMappingLayout::kProtectionExecute) != 0
 340         && internal_strcmp(module, buff.data()) == 0) {
 341       *start = s;
 342       *end = e;
 343       return true;
 344     }
 345   }
 346   return false;
 347 }
 348
 349 SignalContext SignalContext::Create(void *siginfo, void *context) {
 350   auto si = (siginfo_t *)siginfo;
 351   uptr addr = (uptr)si->si_addr;
 352   uptr pc, sp, bp;
 353   GetPcSpBp(context, &pc, &sp, &bp);
 354   WriteFlag write_flag = GetWriteFlag(context);
 355   bool is_memory_access = si->si_signo == SIGSEGV;
 356   return SignalContext(context, addr, pc, sp, bp, is_memory_access, write_flag);
 357 }
 358
 359 } // namespace __sanitizer
 360
 361 #endif // SANITIZER_POSIX