libsanitizer/tsan/tsan_platform_linux.cc

   1 //===-- tsan_platform_linux.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 a part of ThreadSanitizer (TSan), a race detector.
   9 //
  10 // Linux- and FreeBSD-specific code.
  11 //===----------------------------------------------------------------------===//
  12
  13
  14 #include "sanitizer_common/sanitizer_platform.h"
  15 #if SANITIZER_LINUX || SANITIZER_FREEBSD
  16
  17 #include "sanitizer_common/sanitizer_common.h"
  18 #include "sanitizer_common/sanitizer_libc.h"
  19 #include "sanitizer_common/sanitizer_posix.h"
  20 #include "sanitizer_common/sanitizer_procmaps.h"
  21 #include "sanitizer_common/sanitizer_stoptheworld.h"
  22 #include "sanitizer_common/sanitizer_stackdepot.h"
  23 #include "tsan_platform.h"
  24 #include "tsan_rtl.h"
  25 #include "tsan_flags.h"
  26
  27 #include <fcntl.h>
  28 #include <pthread.h>
  29 #include <signal.h>
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <stdarg.h>
  34 #include <sys/mman.h>
  35 #include <sys/syscall.h>
  36 #include <sys/socket.h>
  37 #include <sys/time.h>
  38 #include <sys/types.h>
  39 #include <sys/resource.h>
  40 #include <sys/stat.h>
  41 #include <unistd.h>
  42 #include <errno.h>
  43 #include <sched.h>
  44 #include <dlfcn.h>
  45 #if SANITIZER_LINUX
  46 #define __need_res_state
  47 #include <resolv.h>
  48 #endif
  49
  50 #ifdef sa_handler
  51 # undef sa_handler
  52 #endif
  53
  54 #ifdef sa_sigaction
  55 # undef sa_sigaction
  56 #endif
  57
  58 #if SANITIZER_FREEBSD
  59 extern "C" void *__libc_stack_end;
  60 void *__libc_stack_end = 0;
  61 #endif
  62
  63 #if SANITIZER_LINUX && defined(__aarch64__)
  64 void InitializeGuardPtr() __attribute__((visibility("hidden")));
  65 #endif
  66
  67 namespace __tsan {
  68
  69 static uptr g_data_start;
  70 static uptr g_data_end;
  71
  72 enum {
  73   MemTotal  = 0,
  74   MemShadow = 1,
  75   MemMeta   = 2,
  76   MemFile   = 3,
  77   MemMmap   = 4,
  78   MemTrace  = 5,
  79   MemHeap   = 6,
  80   MemOther  = 7,
  81   MemCount  = 8,
  82 };
  83
  84 void FillProfileCallback(uptr p, uptr rss, bool file,
  85                          uptr *mem, uptr stats_size) {
  86   mem[MemTotal] += rss;
  87   if (p >= kShadowBeg && p < kShadowEnd)
  88     mem[MemShadow] += rss;
  89   else if (p >= kMetaShadowBeg && p < kMetaShadowEnd)
  90     mem[MemMeta] += rss;
  91 #ifndef SANITIZER_GO
  92   else if (p >= kHeapMemBeg && p < kHeapMemEnd)
  93     mem[MemHeap] += rss;
  94   else if (p >= kLoAppMemBeg && p < kLoAppMemEnd)
  95     mem[file ? MemFile : MemMmap] += rss;
  96   else if (p >= kHiAppMemBeg && p < kHiAppMemEnd)
  97     mem[file ? MemFile : MemMmap] += rss;
  98 #else
  99   else if (p >= kAppMemBeg && p < kAppMemEnd)
 100     mem[file ? MemFile : MemMmap] += rss;
 101 #endif
 102   else if (p >= kTraceMemBeg && p < kTraceMemEnd)
 103     mem[MemTrace] += rss;
 104   else
 105     mem[MemOther] += rss;
 106 }
 107
 108 void WriteMemoryProfile(char *buf, uptr buf_size, uptr nthread, uptr nlive) {
 109   uptr mem[MemCount] = {};
 110   __sanitizer::GetMemoryProfile(FillProfileCallback, mem, 7);
 111   StackDepotStats *stacks = StackDepotGetStats();
 112   internal_snprintf(buf, buf_size,
 113       "RSS %zd MB: shadow:%zd meta:%zd file:%zd mmap:%zd"
 114       " trace:%zd heap:%zd other:%zd stacks=%zd[%zd] nthr=%zd/%zd\n",
 115       mem[MemTotal] >> 20, mem[MemShadow] >> 20, mem[MemMeta] >> 20,
 116       mem[MemFile] >> 20, mem[MemMmap] >> 20, mem[MemTrace] >> 20,
 117       mem[MemHeap] >> 20, mem[MemOther] >> 20,
 118       stacks->allocated >> 20, stacks->n_uniq_ids,
 119       nlive, nthread);
 120 }
 121
 122 #if SANITIZER_LINUX
 123 void FlushShadowMemoryCallback(
 124     const SuspendedThreadsList &suspended_threads_list,
 125     void *argument) {
 126   FlushUnneededShadowMemory(kShadowBeg, kShadowEnd - kShadowBeg);
 127 }
 128 #endif
 129
 130 void FlushShadowMemory() {
 131 #if SANITIZER_LINUX
 132   StopTheWorld(FlushShadowMemoryCallback, 0);
 133 #endif
 134 }
 135
 136 #ifndef SANITIZER_GO
 137 // Mark shadow for .rodata sections with the special kShadowRodata marker.
 138 // Accesses to .rodata can't race, so this saves time, memory and trace space.
 139 static void MapRodata() {
 140   // First create temp file.
 141   const char *tmpdir = GetEnv("TMPDIR");
 142   if (tmpdir == 0)
 143     tmpdir = GetEnv("TEST_TMPDIR");
 144 #ifdef P_tmpdir
 145   if (tmpdir == 0)
 146     tmpdir = P_tmpdir;
 147 #endif
 148   if (tmpdir == 0)
 149     return;
 150   char name[256];
 151   internal_snprintf(name, sizeof(name), "%s/tsan.rodata.%d",
 152                     tmpdir, (int)internal_getpid());
 153   uptr openrv = internal_open(name, O_RDWR | O_CREAT | O_EXCL, 0600);
 154   if (internal_iserror(openrv))
 155     return;
 156   internal_unlink(name);  // Unlink it now, so that we can reuse the buffer.
 157   fd_t fd = openrv;
 158   // Fill the file with kShadowRodata.
 159   const uptr kMarkerSize = 512 * 1024 / sizeof(u64);
 160   InternalScopedBuffer<u64> marker(kMarkerSize);
 161   // volatile to prevent insertion of memset
 162   for (volatile u64 *p = marker.data(); p < marker.data() + kMarkerSize; p++)
 163     *p = kShadowRodata;
 164   internal_write(fd, marker.data(), marker.size());
 165   // Map the file into memory.
 166   uptr page = internal_mmap(0, GetPageSizeCached(), PROT_READ | PROT_WRITE,
 167                             MAP_PRIVATE | MAP_ANONYMOUS, fd, 0);
 168   if (internal_iserror(page)) {
 169     internal_close(fd);
 170     return;
 171   }
 172   // Map the file into shadow of .rodata sections.
 173   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
 174   uptr start, end, offset, prot;
 175   // Reusing the buffer 'name'.
 176   while (proc_maps.Next(&start, &end, &offset, name, ARRAY_SIZE(name), &prot)) {
 177     if (name[0] != 0 && name[0] != '['
 178         && (prot & MemoryMappingLayout::kProtectionRead)
 179         && (prot & MemoryMappingLayout::kProtectionExecute)
 180         && !(prot & MemoryMappingLayout::kProtectionWrite)
 181         && IsAppMem(start)) {
 182       // Assume it's .rodata
 183       char *shadow_start = (char*)MemToShadow(start);
 184       char *shadow_end = (char*)MemToShadow(end);
 185       for (char *p = shadow_start; p < shadow_end; p += marker.size()) {
 186         internal_mmap(p, Min<uptr>(marker.size(), shadow_end - p),
 187                       PROT_READ, MAP_PRIVATE | MAP_FIXED, fd, 0);
 188       }
 189     }
 190   }
 191   internal_close(fd);
 192 }
 193
 194 void InitializeShadowMemoryPlatform() {
 195   MapRodata();
 196 }
 197
 198 static void InitDataSeg() {
 199   MemoryMappingLayout proc_maps(true);
 200   uptr start, end, offset;
 201   char name[128];
 202 #if SANITIZER_FREEBSD
 203   // On FreeBSD BSS is usually the last block allocated within the
 204   // low range and heap is the last block allocated within the range
 205   // 0x800000000-0x8ffffffff.
 206   while (proc_maps.Next(&start, &end, &offset, name, ARRAY_SIZE(name),
 207                         /*protection*/ 0)) {
 208     DPrintf("%p-%p %p %s\n", start, end, offset, name);
 209     if ((start & 0xffff00000000ULL) == 0 && (end & 0xffff00000000ULL) == 0 &&
 210         name[0] == '\0') {
 211       g_data_start = start;
 212       g_data_end = end;
 213     }
 214   }
 215 #else
 216   bool prev_is_data = false;
 217   while (proc_maps.Next(&start, &end, &offset, name, ARRAY_SIZE(name),
 218                         /*protection*/ 0)) {
 219     DPrintf("%p-%p %p %s\n", start, end, offset, name);
 220     bool is_data = offset != 0 && name[0] != 0;
 221     // BSS may get merged with [heap] in /proc/self/maps. This is not very
 222     // reliable.
 223     bool is_bss = offset == 0 &&
 224       (name[0] == 0 || internal_strcmp(name, "[heap]") == 0) && prev_is_data;
 225     if (g_data_start == 0 && is_data)
 226       g_data_start = start;
 227     if (is_bss)
 228       g_data_end = end;
 229     prev_is_data = is_data;
 230   }
 231 #endif
 232   DPrintf("guessed data_start=%p data_end=%p\n",  g_data_start, g_data_end);
 233   CHECK_LT(g_data_start, g_data_end);
 234   CHECK_GE((uptr)&g_data_start, g_data_start);
 235   CHECK_LT((uptr)&g_data_start, g_data_end);
 236 }
 237
 238 #endif  // #ifndef SANITIZER_GO
 239
 240 void InitializePlatform() {
 241   DisableCoreDumperIfNecessary();
 242
 243   // Go maps shadow memory lazily and works fine with limited address space.
 244   // Unlimited stack is not a problem as well, because the executable
 245   // is not compiled with -pie.
 246   if (kCppMode) {
 247     bool reexec = false;
 248     // TSan doesn't play well with unlimited stack size (as stack
 249     // overlaps with shadow memory). If we detect unlimited stack size,
 250     // we re-exec the program with limited stack size as a best effort.
 251     if (StackSizeIsUnlimited()) {
 252       const uptr kMaxStackSize = 32 * 1024 * 1024;
 253       VReport(1, "Program is run with unlimited stack size, which wouldn't "
 254                  "work with ThreadSanitizer.\n"
 255                  "Re-execing with stack size limited to %zd bytes.\n",
 256               kMaxStackSize);
 257       SetStackSizeLimitInBytes(kMaxStackSize);
 258       reexec = true;
 259     }
 260
 261     if (!AddressSpaceIsUnlimited()) {
 262       Report("WARNING: Program is run with limited virtual address space,"
 263              " which wouldn't work with ThreadSanitizer.\n");
 264       Report("Re-execing with unlimited virtual address space.\n");
 265       SetAddressSpaceUnlimited();
 266       reexec = true;
 267     }
 268 #if SANITIZER_LINUX && defined(__aarch64__)
 269     // Initialize the guard pointer used in {sig}{set,long}jump.
 270     InitializeGuardPtr();
 271 #endif
 272     if (reexec)
 273       ReExec();
 274   }
 275
 276 #ifndef SANITIZER_GO
 277   CheckAndProtect();
 278   InitTlsSize();
 279   InitDataSeg();
 280 #endif
 281 }
 282
 283 bool IsGlobalVar(uptr addr) {
 284   return g_data_start && addr >= g_data_start && addr < g_data_end;
 285 }
 286
 287 #ifndef SANITIZER_GO
 288 // Extract file descriptors passed to glibc internal __res_iclose function.
 289 // This is required to properly "close" the fds, because we do not see internal
 290 // closes within glibc. The code is a pure hack.
 291 int ExtractResolvFDs(void *state, int *fds, int nfd) {
 292 #if SANITIZER_LINUX
 293   int cnt = 0;
 294   __res_state *statp = (__res_state*)state;
 295   for (int i = 0; i < MAXNS && cnt < nfd; i++) {
 296     if (statp->_u._ext.nsaddrs[i] && statp->_u._ext.nssocks[i] != -1)
 297       fds[cnt++] = statp->_u._ext.nssocks[i];
 298   }
 299   return cnt;
 300 #else
 301   return 0;
 302 #endif
 303 }
 304
 305 // Extract file descriptors passed via UNIX domain sockets.
 306 // This is requried to properly handle "open" of these fds.
 307 // see 'man recvmsg' and 'man 3 cmsg'.
 308 int ExtractRecvmsgFDs(void *msgp, int *fds, int nfd) {
 309   int res = 0;
 310   msghdr *msg = (msghdr*)msgp;
 311   struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
 312   for (; cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
 313     if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS)
 314       continue;
 315     int n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(fds[0]);
 316     for (int i = 0; i < n; i++) {
 317       fds[res++] = ((int*)CMSG_DATA(cmsg))[i];
 318       if (res == nfd)
 319         return res;
 320     }
 321   }
 322   return res;
 323 }
 324
 325 // Note: this function runs with async signals enabled,
 326 // so it must not touch any tsan state.
 327 int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
 328     void *abstime), void *c, void *m, void *abstime,
 329     void(*cleanup)(void *arg), void *arg) {
 330   // pthread_cleanup_push/pop are hardcore macros mess.
 331   // We can't intercept nor call them w/o including pthread.h.
 332   int res;
 333   pthread_cleanup_push(cleanup, arg);
 334   res = fn(c, m, abstime);
 335   pthread_cleanup_pop(0);
 336   return res;
 337 }
 338 #endif
 339
 340 #ifndef SANITIZER_GO
 341 void ReplaceSystemMalloc() { }
 342 #endif
 343
 344 }  // namespace __tsan
 345
 346 #endif  // SANITIZER_LINUX || SANITIZER_FREEBSD