compiler-rt/lib/sanitizer_common/sanitizer_posix.cpp

   1 //===-- sanitizer_posix.cpp -----------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file is shared between AddressSanitizer and ThreadSanitizer
  10 // run-time libraries and implements POSIX-specific functions from
  11 // sanitizer_posix.h.
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "sanitizer_platform.h"
  15
  16 #if SANITIZER_POSIX
  17
  18 #include "sanitizer_common.h"
  19 #include "sanitizer_file.h"
  20 #include "sanitizer_flags.h"
  21 #include "sanitizer_libc.h"
  22 #include "sanitizer_posix.h"
  23 #include "sanitizer_procmaps.h"
  24
  25 #include <errno.h>
  26 #include <fcntl.h>
  27 #include <signal.h>
  28 #include <sys/mman.h>
  29
  30 #if SANITIZER_FREEBSD
  31 // The MAP_NORESERVE define has been removed in FreeBSD 11.x, and even before
  32 // that, it was never implemented.  So just define it to zero.
  33 #undef  MAP_NORESERVE
  34 #define MAP_NORESERVE 0
  35 #endif
  36
  37 namespace __sanitizer {
  38
  39 // ------------- sanitizer_common.h
  40 uptr GetMmapGranularity() {
  41   return GetPageSize();
  42 }
  43
  44 bool ErrorIsOOM(error_t err) { return err == ENOMEM; }
  45
  46 void *MmapOrDie(uptr size, const char *mem_type, bool raw_report) {
  47   size = RoundUpTo(size, GetPageSizeCached());
  48   uptr res = MmapNamed(nullptr, size, PROT_READ | PROT_WRITE,
  49                        MAP_PRIVATE | MAP_ANON, mem_type);
  50   int reserrno;
  51   if (UNLIKELY(internal_iserror(res, &reserrno)))
  52     ReportMmapFailureAndDie(size, mem_type, "allocate", reserrno, raw_report);
  53   IncreaseTotalMmap(size);
  54   return (void *)res;
  55 }
  56
  57 void UnmapOrDie(void *addr, uptr size) {
  58   if (!addr || !size) return;
  59   uptr res = internal_munmap(addr, size);
  60   if (UNLIKELY(internal_iserror(res))) {
  61     Report("ERROR: %s failed to deallocate 0x%zx (%zd) bytes at address %p\n",
  62            SanitizerToolName, size, size, addr);
  63     CHECK("unable to unmap" && 0);
  64   }
  65   DecreaseTotalMmap(size);
  66 }
  67
  68 void *MmapOrDieOnFatalError(uptr size, const char *mem_type) {
  69   size = RoundUpTo(size, GetPageSizeCached());
  70   uptr res = MmapNamed(nullptr, size, PROT_READ | PROT_WRITE,
  71                        MAP_PRIVATE | MAP_ANON, mem_type);
  72   int reserrno;
  73   if (UNLIKELY(internal_iserror(res, &reserrno))) {
  74     if (reserrno == ENOMEM)
  75       return nullptr;
  76     ReportMmapFailureAndDie(size, mem_type, "allocate", reserrno);
  77   }
  78   IncreaseTotalMmap(size);
  79   return (void *)res;
  80 }
  81
  82 // We want to map a chunk of address space aligned to 'alignment'.
  83 // We do it by mapping a bit more and then unmapping redundant pieces.
  84 // We probably can do it with fewer syscalls in some OS-dependent way.
  85 void *MmapAlignedOrDieOnFatalError(uptr size, uptr alignment,
  86                                    const char *mem_type) {
  87   CHECK(IsPowerOfTwo(size));
  88   CHECK(IsPowerOfTwo(alignment));
  89   uptr map_size = size + alignment;
  90   // mmap maps entire pages and rounds up map_size needs to be a an integral
  91   // number of pages.
  92   // We need to be aware of this size for calculating end and for unmapping
  93   // fragments before and after the alignment region.
  94   map_size = RoundUpTo(map_size, GetPageSizeCached());
  95   uptr map_res = (uptr)MmapOrDieOnFatalError(map_size, mem_type);
  96   if (UNLIKELY(!map_res))
  97     return nullptr;
  98   uptr res = map_res;
  99   if (!IsAligned(res, alignment)) {
 100     res = (map_res + alignment - 1) & ~(alignment - 1);
 101     UnmapOrDie((void*)map_res, res - map_res);
 102   }
 103   uptr map_end = map_res + map_size;
 104   uptr end = res + size;
 105   end = RoundUpTo(end, GetPageSizeCached());
 106   if (end != map_end) {
 107     CHECK_LT(end, map_end);
 108     UnmapOrDie((void*)end, map_end - end);
 109   }
 110   return (void*)res;
 111 }
 112
 113 void *MmapNoReserveOrDie(uptr size, const char *mem_type) {
 114   size = RoundUpTo(size, GetPageSizeCached());
 115   uptr p = MmapNamed(nullptr, size, PROT_READ | PROT_WRITE,
 116                      MAP_PRIVATE | MAP_ANON | MAP_NORESERVE, mem_type);
 117   int reserrno;
 118   if (UNLIKELY(internal_iserror(p, &reserrno)))
 119     ReportMmapFailureAndDie(size, mem_type, "allocate noreserve", reserrno);
 120   IncreaseTotalMmap(size);
 121   return (void *)p;
 122 }
 123
 124 static void *MmapFixedImpl(uptr fixed_addr, uptr size, bool tolerate_enomem,
 125                            const char *name) {
 126   size = RoundUpTo(size, GetPageSizeCached());
 127   fixed_addr = RoundDownTo(fixed_addr, GetPageSizeCached());
 128   uptr p = MmapNamed((void *)fixed_addr, size, PROT_READ | PROT_WRITE,
 129                      MAP_PRIVATE | MAP_ANON | MAP_FIXED, name);
 130   int reserrno;
 131   if (UNLIKELY(internal_iserror(p, &reserrno))) {
 132     if (tolerate_enomem && reserrno == ENOMEM)
 133       return nullptr;
 134     char mem_type[40];
 135     internal_snprintf(mem_type, sizeof(mem_type), "memory at address 0x%zx",
 136                       fixed_addr);
 137     ReportMmapFailureAndDie(size, mem_type, "allocate", reserrno);
 138   }
 139   IncreaseTotalMmap(size);
 140   return (void *)p;
 141 }
 142
 143 void *MmapFixedOrDie(uptr fixed_addr, uptr size, const char *name) {
 144   return MmapFixedImpl(fixed_addr, size, false /*tolerate_enomem*/, name);
 145 }
 146
 147 void *MmapFixedOrDieOnFatalError(uptr fixed_addr, uptr size, const char *name) {
 148   return MmapFixedImpl(fixed_addr, size, true /*tolerate_enomem*/, name);
 149 }
 150
 151 bool MprotectNoAccess(uptr addr, uptr size) {
 152   return 0 == internal_mprotect((void*)addr, size, PROT_NONE);
 153 }
 154
 155 bool MprotectReadOnly(uptr addr, uptr size) {
 156   return 0 == internal_mprotect((void *)addr, size, PROT_READ);
 157 }
 158
 159 #if !SANITIZER_APPLE
 160 void MprotectMallocZones(void *addr, int prot) {}
 161 #endif
 162
 163 fd_t OpenFile(const char *filename, FileAccessMode mode, error_t *errno_p) {
 164   if (ShouldMockFailureToOpen(filename))
 165     return kInvalidFd;
 166   int flags;
 167   switch (mode) {
 168     case RdOnly: flags = O_RDONLY; break;
 169     case WrOnly: flags = O_WRONLY | O_CREAT | O_TRUNC; break;
 170     case RdWr: flags = O_RDWR | O_CREAT; break;
 171   }
 172   fd_t res = internal_open(filename, flags, 0660);
 173   if (internal_iserror(res, errno_p))
 174     return kInvalidFd;
 175   return ReserveStandardFds(res);
 176 }
 177
 178 void CloseFile(fd_t fd) {
 179   internal_close(fd);
 180 }
 181
 182 bool ReadFromFile(fd_t fd, void *buff, uptr buff_size, uptr *bytes_read,
 183                   error_t *error_p) {
 184   uptr res = internal_read(fd, buff, buff_size);
 185   if (internal_iserror(res, error_p))
 186     return false;
 187   if (bytes_read)
 188     *bytes_read = res;
 189   return true;
 190 }
 191
 192 bool WriteToFile(fd_t fd, const void *buff, uptr buff_size, uptr *bytes_written,
 193                  error_t *error_p) {
 194   uptr res = internal_write(fd, buff, buff_size);
 195   if (internal_iserror(res, error_p))
 196     return false;
 197   if (bytes_written)
 198     *bytes_written = res;
 199   return true;
 200 }
 201
 202 void *MapFileToMemory(const char *file_name, uptr *buff_size) {
 203   fd_t fd = OpenFile(file_name, RdOnly);
 204   CHECK(fd != kInvalidFd);
 205   uptr fsize = internal_filesize(fd);
 206   CHECK_NE(fsize, (uptr)-1);
 207   CHECK_GT(fsize, 0);
 208   *buff_size = RoundUpTo(fsize, GetPageSizeCached());
 209   uptr map = internal_mmap(nullptr, *buff_size, PROT_READ, MAP_PRIVATE, fd, 0);
 210   return internal_iserror(map) ? nullptr : (void *)map;
 211 }
 212
 213 void *MapWritableFileToMemory(void *addr, uptr size, fd_t fd, OFF_T offset) {
 214   uptr flags = MAP_SHARED;
 215   if (addr) flags |= MAP_FIXED;
 216   uptr p = internal_mmap(addr, size, PROT_READ | PROT_WRITE, flags, fd, offset);
 217   int mmap_errno = 0;
 218   if (internal_iserror(p, &mmap_errno)) {
 219     Printf("could not map writable file (%d, %lld, %zu): %zd, errno: %d\n",
 220            fd, (long long)offset, size, p, mmap_errno);
 221     return nullptr;
 222   }
 223   return (void *)p;
 224 }
 225
 226 static inline bool IntervalsAreSeparate(uptr start1, uptr end1,
 227                                         uptr start2, uptr end2) {
 228   CHECK(start1 <= end1);
 229   CHECK(start2 <= end2);
 230   return (end1 < start2) || (end2 < start1);
 231 }
 232
 233 // FIXME: this is thread-unsafe, but should not cause problems most of the time.
 234 // When the shadow is mapped only a single thread usually exists (plus maybe
 235 // several worker threads on Mac, which aren't expected to map big chunks of
 236 // memory).
 237 bool MemoryRangeIsAvailable(uptr range_start, uptr range_end) {
 238   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
 239   if (proc_maps.Error())
 240     return true; // and hope for the best
 241   MemoryMappedSegment segment;
 242   while (proc_maps.Next(&segment)) {
 243     if (segment.start == segment.end) continue;  // Empty range.
 244     CHECK_NE(0, segment.end);
 245     if (!IntervalsAreSeparate(segment.start, segment.end - 1, range_start,
 246                               range_end))
 247       return false;
 248   }
 249   return true;
 250 }
 251
 252 #if !SANITIZER_APPLE
 253 void DumpProcessMap() {
 254   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
 255   const sptr kBufSize = 4095;
 256   char *filename = (char*)MmapOrDie(kBufSize, __func__);
 257   MemoryMappedSegment segment(filename, kBufSize);
 258   Report("Process memory map follows:\n");
 259   while (proc_maps.Next(&segment)) {
 260     Printf("\t%p-%p\t%s\n", (void *)segment.start, (void *)segment.end,
 261            segment.filename);
 262   }
 263   Report("End of process memory map.\n");
 264   UnmapOrDie(filename, kBufSize);
 265 }
 266 #endif
 267
 268 const char *GetPwd() {
 269   return GetEnv("PWD");
 270 }
 271
 272 bool IsPathSeparator(const char c) {
 273   return c == '/';
 274 }
 275
 276 bool IsAbsolutePath(const char *path) {
 277   return path != nullptr && IsPathSeparator(path[0]);
 278 }
 279
 280 void ReportFile::Write(const char *buffer, uptr length) {
 281   SpinMutexLock l(mu);
 282   ReopenIfNecessary();
 283   internal_write(fd, buffer, length);
 284 }
 285
 286 bool GetCodeRangeForFile(const char *module, uptr *start, uptr *end) {
 287   MemoryMappingLayout proc_maps(/*cache_enabled*/false);
 288   InternalMmapVector<char> buff(kMaxPathLength);
 289   MemoryMappedSegment segment(buff.data(), buff.size());
 290   while (proc_maps.Next(&segment)) {
 291     if (segment.IsExecutable() &&
 292         internal_strcmp(module, segment.filename) == 0) {
 293       *start = segment.start;
 294       *end = segment.end;
 295       return true;
 296     }
 297   }
 298   return false;
 299 }
 300
 301 uptr SignalContext::GetAddress() const {
 302   auto si = static_cast<const siginfo_t *>(siginfo);
 303   return (uptr)si->si_addr;
 304 }
 305
 306 bool SignalContext::IsMemoryAccess() const {
 307   auto si = static_cast<const siginfo_t *>(siginfo);
 308   return si->si_signo == SIGSEGV || si->si_signo == SIGBUS;
 309 }
 310
 311 int SignalContext::GetType() const {
 312   return static_cast<const siginfo_t *>(siginfo)->si_signo;
 313 }
 314
 315 const char *SignalContext::Describe() const {
 316   switch (GetType()) {
 317     case SIGFPE:
 318       return "FPE";
 319     case SIGILL:
 320       return "ILL";
 321     case SIGABRT:
 322       return "ABRT";
 323     case SIGSEGV:
 324       return "SEGV";
 325     case SIGBUS:
 326       return "BUS";
 327     case SIGTRAP:
 328       return "TRAP";
 329   }
 330   return "UNKNOWN SIGNAL";
 331 }
 332
 333 fd_t ReserveStandardFds(fd_t fd) {
 334   CHECK_GE(fd, 0);
 335   if (fd > 2)
 336     return fd;
 337   bool used[3];
 338   internal_memset(used, 0, sizeof(used));
 339   while (fd <= 2) {
 340     used[fd] = true;
 341     fd = internal_dup(fd);
 342   }
 343   for (int i = 0; i <= 2; ++i)
 344     if (used[i])
 345       internal_close(i);
 346   return fd;
 347 }
 348
 349 bool ShouldMockFailureToOpen(const char *path) {
 350   return common_flags()->test_only_emulate_no_memorymap &&
 351          internal_strncmp(path, "/proc/", 6) == 0;
 352 }
 353
 354 #if SANITIZER_LINUX && !SANITIZER_ANDROID && !SANITIZER_GO
 355 int GetNamedMappingFd(const char *name, uptr size, int *flags) {
 356   if (!common_flags()->decorate_proc_maps || !name)
 357     return -1;
 358   char shmname[200];
 359   CHECK(internal_strlen(name) < sizeof(shmname) - 10);
 360   internal_snprintf(shmname, sizeof(shmname), "/dev/shm/%zu [%s]",
 361                     internal_getpid(), name);
 362   int o_cloexec = 0;
 363 #if defined(O_CLOEXEC)
 364   o_cloexec = O_CLOEXEC;
 365 #endif
 366   int fd = ReserveStandardFds(
 367       internal_open(shmname, O_RDWR | O_CREAT | O_TRUNC | o_cloexec, S_IRWXU));
 368   CHECK_GE(fd, 0);
 369   int res = internal_ftruncate(fd, size);
 370 #if !defined(O_CLOEXEC)
 371   res = fcntl(fd, F_SETFD, FD_CLOEXEC);
 372   CHECK_EQ(0, res);
 373 #endif
 374   CHECK_EQ(0, res);
 375   res = internal_unlink(shmname);
 376   CHECK_EQ(0, res);
 377   *flags &= ~(MAP_ANON | MAP_ANONYMOUS);
 378   return fd;
 379 }
 380 #else
 381 int GetNamedMappingFd(const char *name, uptr size, int *flags) {
 382   return -1;
 383 }
 384 #endif
 385
 386 #if SANITIZER_ANDROID
 387 #define PR_SET_VMA 0x53564d41
 388 #define PR_SET_VMA_ANON_NAME 0
 389 void DecorateMapping(uptr addr, uptr size, const char *name) {
 390   if (!common_flags()->decorate_proc_maps || !name)
 391     return;
 392   internal_prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, addr, size, (uptr)name);
 393 }
 394 #else
 395 void DecorateMapping(uptr addr, uptr size, const char *name) {
 396 }
 397 #endif
 398
 399 uptr MmapNamed(void *addr, uptr length, int prot, int flags, const char *name) {
 400   int fd = GetNamedMappingFd(name, length, &flags);
 401   uptr res = internal_mmap(addr, length, prot, flags, fd, 0);
 402   if (!internal_iserror(res))
 403     DecorateMapping(res, length, name);
 404   return res;
 405 }
 406
 407
 408 } // namespace __sanitizer
 409
 410 #endif // SANITIZER_POSIX