lib/sanitizer_common/sanitizer_posix.cc

   1 //===-- sanitizer_posix.cc ------------------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file is shared between AddressSanitizer and ThreadSanitizer
  11 // run-time libraries and implements POSIX-specific functions from
  12 // sanitizer_libc.h.
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "sanitizer_platform.h"
  16 #if SANITIZER_POSIX
  17
  18 #include "sanitizer_common.h"
  19 #include "sanitizer_libc.h"
  20 #include "sanitizer_procmaps.h"
  21 #include "sanitizer_stacktrace.h"
  22
  23 #include <sys/mman.h>
  24
  25 namespace __sanitizer {
  26
  27 // ------------- sanitizer_common.h
  28 uptr GetMmapGranularity() {
  29   return GetPageSize();
  30 }
  31
  32 uptr GetMaxVirtualAddress() {
  33 #if SANITIZER_WORDSIZE == 64
  34 # if defined(__powerpc64__)
  35   // On PowerPC64 we have two different address space layouts: 44- and 46-bit.
  36   // We somehow need to figure our which one we are using now and choose
  37   // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
  38   // Note that with 'ulimit -s unlimited' the stack is moved away from the top
  39   // of the address space, so simply checking the stack address is not enough.
  40   return (1ULL << 44) - 1;  // 0x00000fffffffffffUL
  41 # elif defined(__aarch64__)
  42   return (1ULL << 39) - 1;
  43 # else
  44   return (1ULL << 47) - 1;  // 0x00007fffffffffffUL;
  45 # endif
  46 #else  // SANITIZER_WORDSIZE == 32
  47   // FIXME: We can probably lower this on Android?
  48   return (1ULL << 32) - 1;  // 0xffffffff;
  49 #endif  // SANITIZER_WORDSIZE
  50 }
  51
  52 void *MmapOrDie(uptr size, const char *mem_type) {
  53   size = RoundUpTo(size, GetPageSizeCached());
  54   uptr res = internal_mmap(0, size,
  55                             PROT_READ | PROT_WRITE,
  56                             MAP_PRIVATE | MAP_ANON, -1, 0);
  57   int reserrno;
  58   if (internal_iserror(res, &reserrno)) {
  59     static int recursion_count;
  60     if (recursion_count) {
  61       // The Report() and CHECK calls below may call mmap recursively and fail.
  62       // If we went into recursion, just die.
  63       RawWrite("ERROR: Failed to mmap\n");
  64       Die();
  65     }
  66     recursion_count++;
  67     Report("ERROR: %s failed to allocate 0x%zx (%zd) bytes of %s: %d\n",
  68            SanitizerToolName, size, size, mem_type, reserrno);
  69     DumpProcessMap();
  70     CHECK("unable to mmap" && 0);
  71   }
  72   return (void *)res;
  73 }
  74
  75 void UnmapOrDie(void *addr, uptr size) {
  76   if (!addr || !size) return;
  77   uptr res = internal_munmap(addr, size);
  78   if (internal_iserror(res)) {
  79     Report("ERROR: %s failed to deallocate 0x%zx (%zd) bytes at address %p\n",
  80            SanitizerToolName, size, size, addr);
  81     CHECK("unable to unmap" && 0);
  82   }
  83 }
  84
  85 void *MmapNoReserveOrDie(uptr size, const char *mem_type) {
  86   uptr PageSize = GetPageSizeCached();
  87   uptr p = internal_mmap(0,
  88       RoundUpTo(size, PageSize),
  89       PROT_READ | PROT_WRITE,
  90       MAP_PRIVATE | MAP_ANON | MAP_NORESERVE,
  91       -1, 0);
  92   int reserrno;
  93   if (internal_iserror(p, &reserrno)) {
  94     Report("ERROR: "
  95            "%s failed to allocate noreserve 0x%zx (%zd) bytes for '%s' (%d)\n",
  96            SanitizerToolName, size, size, mem_type, reserrno);
  97     CHECK("unable to mmap" && 0);
  98   }
  99   return (void *)p;
 100 }
 101
 102 void *MmapFixedNoReserve(uptr fixed_addr, uptr size) {
 103   uptr PageSize = GetPageSizeCached();
 104   uptr p = internal_mmap((void*)(fixed_addr & ~(PageSize - 1)),
 105       RoundUpTo(size, PageSize),
 106       PROT_READ | PROT_WRITE,
 107       MAP_PRIVATE | MAP_ANON | MAP_FIXED | MAP_NORESERVE,
 108       -1, 0);
 109   int reserrno;
 110   if (internal_iserror(p, &reserrno))
 111     Report("ERROR: "
 112            "%s failed to allocate 0x%zx (%zd) bytes at address %zu (%d)\n",
 113            SanitizerToolName, size, size, fixed_addr, reserrno);
 114   return (void *)p;
 115 }
 116
 117 void *MmapFixedOrDie(uptr fixed_addr, uptr size) {
 118   uptr PageSize = GetPageSizeCached();
 119   uptr p = internal_mmap((void*)(fixed_addr & ~(PageSize - 1)),
 120       RoundUpTo(size, PageSize),
 121       PROT_READ | PROT_WRITE,
 122       MAP_PRIVATE | MAP_ANON | MAP_FIXED,
 123       -1, 0);
 124   int reserrno;
 125   if (internal_iserror(p, &reserrno)) {
 126     Report("ERROR:"
 127            " %s failed to allocate 0x%zx (%zd) bytes at address %zu (%d)\n",
 128            SanitizerToolName, size, size, fixed_addr, reserrno);
 129     CHECK("unable to mmap" && 0);
 130   }
 131   return (void *)p;
 132 }
 133
 134 void *Mprotect(uptr fixed_addr, uptr size) {
 135   return (void *)internal_mmap((void*)fixed_addr, size,
 136                                PROT_NONE,
 137                                MAP_PRIVATE | MAP_ANON | MAP_FIXED |
 138                                MAP_NORESERVE, -1, 0);
 139 }
 140
 141 void *MapFileToMemory(const char *file_name, uptr *buff_size) {
 142   uptr openrv = OpenFile(file_name, false);
 143   CHECK(!internal_iserror(openrv));
 144   fd_t fd = openrv;
 145   uptr fsize = internal_filesize(fd);
 146   CHECK_NE(fsize, (uptr)-1);
 147   CHECK_GT(fsize, 0);
 148   *buff_size = RoundUpTo(fsize, GetPageSizeCached());
 149   uptr map = internal_mmap(0, *buff_size, PROT_READ, MAP_PRIVATE, fd, 0);
 150   return internal_iserror(map) ? 0 : (void *)map;
 151 }
 152
 153
 154 static inline bool IntervalsAreSeparate(uptr start1, uptr end1,
 155                                         uptr start2, uptr end2) {
 156   CHECK(start1 <= end1);
 157   CHECK(start2 <= end2);
 158   return (end1 < start2) || (end2 < start1);
 159 }
 160
 161 // FIXME: this is thread-unsafe, but should not cause problems most of the time.
 162 // When the shadow is mapped only a single thread usually exists (plus maybe
 163 // several worker threads on Mac, which aren't expected to map big chunks of
 164 // memory).
 165 bool MemoryRangeIsAvailable(uptr range_start, uptr range_end) {
 166   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
 167   uptr start, end;
 168   while (proc_maps.Next(&start, &end,
 169                         /*offset*/0, /*filename*/0, /*filename_size*/0,
 170                         /*protection*/0)) {
 171     if (!IntervalsAreSeparate(start, end, range_start, range_end))
 172       return false;
 173   }
 174   return true;
 175 }
 176
 177 void DumpProcessMap() {
 178   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
 179   uptr start, end;
 180   const sptr kBufSize = 4095;
 181   char *filename = (char*)MmapOrDie(kBufSize, __func__);
 182   Report("Process memory map follows:\n");
 183   while (proc_maps.Next(&start, &end, /* file_offset */0,
 184                         filename, kBufSize, /* protection */0)) {
 185     Printf("\t%p-%p\t%s\n", (void*)start, (void*)end, filename);
 186   }
 187   Report("End of process memory map.\n");
 188   UnmapOrDie(filename, kBufSize);
 189 }
 190
 191 const char *GetPwd() {
 192   return GetEnv("PWD");
 193 }
 194
 195 char *FindPathToBinary(const char *name) {
 196   const char *path = GetEnv("PATH");
 197   if (!path)
 198     return 0;
 199   uptr name_len = internal_strlen(name);
 200   InternalScopedBuffer<char> buffer(kMaxPathLength);
 201   const char *beg = path;
 202   while (true) {
 203     const char *end = internal_strchrnul(beg, ':');
 204     uptr prefix_len = end - beg;
 205     if (prefix_len + name_len + 2 <= kMaxPathLength) {
 206       internal_memcpy(buffer.data(), beg, prefix_len);
 207       buffer[prefix_len] = '/';
 208       internal_memcpy(&buffer[prefix_len + 1], name, name_len);
 209       buffer[prefix_len + 1 + name_len] = '\0';
 210       if (FileExists(buffer.data()))
 211         return internal_strdup(buffer.data());
 212     }
 213     if (*end == '\0') break;
 214     beg = end + 1;
 215   }
 216   return 0;
 217 }
 218
 219 void MaybeOpenReportFile() {
 220   if (!log_to_file) return;
 221   uptr pid = internal_getpid();
 222   // If in tracer, use the parent's file.
 223   if (pid == stoptheworld_tracer_pid)
 224     pid = stoptheworld_tracer_ppid;
 225   if (report_fd_pid == pid) return;
 226   InternalScopedBuffer<char> report_path_full(4096);
 227   internal_snprintf(report_path_full.data(), report_path_full.size(),
 228                     "%s.%zu", report_path_prefix, pid);
 229   uptr openrv = OpenFile(report_path_full.data(), true);
 230   if (internal_iserror(openrv)) {
 231     report_fd = kStderrFd;
 232     log_to_file = false;
 233     Report("ERROR: Can't open file: %s\n", report_path_full.data());
 234     Die();
 235   }
 236   if (report_fd != kInvalidFd) {
 237     // We're in the child. Close the parent's log.
 238     internal_close(report_fd);
 239   }
 240   report_fd = openrv;
 241   report_fd_pid = pid;
 242 }
 243
 244 void RawWrite(const char *buffer) {
 245   static const char *kRawWriteError =
 246       "RawWrite can't output requested buffer!\n";
 247   uptr length = (uptr)internal_strlen(buffer);
 248   MaybeOpenReportFile();
 249   if (length != internal_write(report_fd, buffer, length)) {
 250     internal_write(report_fd, kRawWriteError, internal_strlen(kRawWriteError));
 251     Die();
 252   }
 253 }
 254
 255 bool GetCodeRangeForFile(const char *module, uptr *start, uptr *end) {
 256   uptr s, e, off, prot;
 257   InternalScopedString buff(4096);
 258   MemoryMappingLayout proc_maps(/*cache_enabled*/false);
 259   while (proc_maps.Next(&s, &e, &off, buff.data(), buff.size(), &prot)) {
 260     if ((prot & MemoryMappingLayout::kProtectionExecute) != 0
 261         && internal_strcmp(module, buff.data()) == 0) {
 262       *start = s;
 263       *end = e;
 264       return true;
 265     }
 266   }
 267   return false;
 268 }
 269
 270 }  // namespace __sanitizer
 271
 272 #endif  // SANITIZER_POSIX